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Onyena AP, Folorunso OM, Nwanganga N, Udom GJ, Ekhator OC, Frazzoli C, Ruggieri F, Bocca B, Orisakwe OE. Engaging One Health in Heavy Metal Pollution in Some Selected Nigerian Niger Delta Cities. A Systematic Review of Pervasiveness, Bioaccumulation and Subduing Environmental Health Challenges. Biol Trace Elem Res 2024; 202:1356-1389. [PMID: 37518840 DOI: 10.1007/s12011-023-03762-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 07/01/2023] [Indexed: 08/01/2023]
Abstract
The Niger Delta environment is under serious threat due to heavy metal pollution. Many studies have been conducted on the heavy metal contamination in soils, water, seafood and plants in the Niger Delta ecosystem. However, there is a lack of clear understanding of the health consequences for people and strategies for attaining One Health, and a dispersion of information that is accessible. The study focused on investigating the contamination levels, distributions, risks, sources and impacts of heavy metals in selected regions of the Niger Delta. Prior studies revealed that the levels of certain heavy metals, including Cd, Pb, Cu, Cr, Mn, Fe and Ni, in water, sediment, fish and plants in most Niger Delta ecosystems were higher than the acceptable threshold attributed to various anthropogenic stressors. In the reviewed Niger Delta states, ecosystems in Rivers state showed the highest concentrations of heavy metals in most sampled sites. Groundwater quality was recorded at concentrations higher than 0.3 mg/L World Health Organization drinking water guideline. High concentrations of copper (147.915 mg/L) and zinc (10.878 mg/L) were found in Rivers State. The heavy metals concentrations were greater in bottom-dwelling organisms such as bivalves, gastropods and shrimp than in other fishery species. Heavy metal exposure in the region poses risks of communicable and non-communicable diseases. Diverse remediation methods are crucial to reduce contamination levels, but comprehensive strategies and international cooperation are essential to address the health hazards. Actively reducing heavy metals in the environment can achieve One Health objectives and mitigate disease and economic burdens.
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Affiliation(s)
- Amarachi P Onyena
- Department of Marine Environment and Pollution Control, Faculty of Marine Environmental Management, Nigeria Maritime University, Okerenkoko, Delta State, Nigeria
| | - Opeyemi M Folorunso
- African Centre of Excellence for Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt, PMB, Port Harcourt, 5323, Rivers State, Nigeria
| | - Nkem Nwanganga
- Department of Pharmacology, College of Medicine, University of Nigeria, Enugu Campus, Nsukka, Enugu State, Nigeria
| | - Godswill J Udom
- Department of Pharmacology and Toxicology, Federal University Oye-Ekiti, Oye-Ekiti, Nigeria
| | | | - Chiara Frazzoli
- Department of Cardiovascular and Endocrine-Metabolic Diseases and Ageing, Istituto Superiore Di Sanità, Rome, Italy
| | - Flavia Ruggieri
- Department of Environment and Health, Istituto Superiore Di Sanità, Rome, Italy
| | - Beatrice Bocca
- Department of Environment and Health, Istituto Superiore Di Sanità, Rome, Italy
| | - Orish E Orisakwe
- African Centre of Excellence for Public Health and Toxicological Research (ACE-PUTOR), University of Port Harcourt, PMB, Port Harcourt, 5323, Rivers State, Nigeria.
- Provictorie Research Organisation, Rivers State, Port Harcourt, Nigeria.
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Casey EMD, Mojarrabi M, Hannan-Jones MT, Bogard JR. Measuring dietary intake in low-and middle-income countries: a systematic review of the methods and tools for estimating fish and seafood intake. Nutr Rev 2024; 82:453-466. [PMID: 37335872 PMCID: PMC10925904 DOI: 10.1093/nutrit/nuad067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023] Open
Abstract
CONTEXT Fish and seafood consumption makes an important but often under-recognized contribution to dietary patterns and nutrition, particularly in low- and middle-income countries (LMICs). Therefore, valid, and reliable dietary assessment tools (DATs) and methods to measure seafood consumption in resource-poor settings are needed. OBJECTIVE To review the available DATs that have been used to measure fish and seafood consumption in LMICs and to assess their quality. DATA SOURCES A systematic search of the electronic databases Scopus, Embase, and Medline was conducted, identifying 1541 initial articles, of which 122 eligible full-text articles were reviewed. DATA EXTRACTION Data extraction focused on the purpose of dietary assessment, setting, target population group, DAT type, administration mode, type of fish and seafood assessed, specific measure of food intake, use of a portion-size-estimation aid, and details of validity, reliability, and pilot testing of the DATs. DATA ANALYSIS The most common DATs used were food frequency questionnaires (n = 80; 58%), of which 36 (25%) were semi-quantitative. The majority of tools (n = 107; 78%) included measurement of consumption frequency; only 41 studies (30%) measured frequency, quantity, and type of seafood consumed. Only 41 DATs (30%) solely focused on fish or seafood intake. Most DATs were interviewer administered (n = 80; 58%), 23 (16%) mentioned the use of a portion-size-estimation aid, and validity was tested for only 13% of DATs (n = 18). CONCLUSION This systematic review reveals a lack of sufficient detail in the use of standard DATs to fully capture the contribution of fish and seafood to diets in LMICs. Consequently, the need to develop or adapt existing DATs to capture frequency, quantity, and type of fish and seafood intake with consideration of cultural eating practices has been highlighted. This is essential for informing appropriate interventions to leverage the nutritional benefits of seafood consumption in LMICs. SYSTEMATIC REVIEW REGISTRATION PROSPERO registration no. CRD42021253607.
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Affiliation(s)
- Elodie M D Casey
- Queensland University of Technology, School of Exercise and Nutrition Sciences, Brisbane, Queensland, Australia
| | - Misa Mojarrabi
- Queensland University of Technology, School of Exercise and Nutrition Sciences, Brisbane, Queensland, Australia
| | - Mary T Hannan-Jones
- Queensland University of Technology, School of Exercise and Nutrition Sciences, Brisbane, Queensland, Australia
| | - Jessica R Bogard
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Agriculture and Food, Brisbane, Queensland, Australia
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Fish consumption habits of pregnant women in Itaituba, Tapajós River basin, Brazil: risks of mercury contamination as assessed by measuring total mercury in highly consumed piscivore fish species and in hair of pregnant women. ARHIV ZA HIGIJENU RADA I TOKSIKOLOGIJU 2022; 73:131-142. [PMID: 35792767 PMCID: PMC9287832 DOI: 10.2478/aiht-2022-73-3611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 05/01/2022] [Indexed: 11/21/2022]
Abstract
The Tapajós River basin in the Amazon region, Brazil is one of the most active gold mining areas in the world. In this study, we evaluated fish consumption habits and mercury exposure in 110 pregnant women in the city of Itaituba by measuring their total hair mercury concentrations. In addition, we investigated seasonal differences in mercury concentrations in two highly consumed piscivorous fish species, tucunaré (Cichla spp.) and pescada (Plagioscion squamosissimus). Total fish mercury concentrations (THg) during the dry season were 0.62±0.07 mg/kg for Cichla spp. and 0.73±0.08 mg/kg for P. squamosissimus. During the rainy season they were 0.39±0.04 and 0.84±0.08 mg/ kg, respectively. Of our participants 44 % declared that they ate Cichla spp. and 67 % P. squamosissimus. Mean mercury concentration in their hair was 1.6±0.2 mg/kg and was above the US Environmental Protection Agency (US EPA) reference dose of 1 mg/kg in 48 % of them. Mean fish THg concentrations were also above the joint Food and Drug Administration and US EPA safety limit of 0.5 mg/kg for P. squamosissimus during both seasons and for Cichla spp. during the dry season only. These results show that pregnant women should avoid consumption of these piscivorous fish species during pregnancy and call for a regular programme to monitor Hg levels in that area.
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Murphy T, Phan K, Irvine KN, Lean D. The Role of Micronutrients and Toxic Metals in the Management of Epidemics in Cambodia. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:11446. [PMID: 34769963 PMCID: PMC8582812 DOI: 10.3390/ijerph182111446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/11/2021] [Accepted: 10/28/2021] [Indexed: 11/16/2022]
Abstract
The illegal trade of wildlife in SE Asia has been identified as the likely cause of the COVID-19 pandemic. We reviewed 198 papers on the current COVID pandemic in Cambodia, diseases such as avian influenza and Nipah virus, most likely to develop into a new pandemic in Cambodia, and common features of disease that require mitigation. Artisanal goldmining uses pure mercury in the areas where wildlife is smuggled to China. Moreover, 30-40% of Cambodians are zinc deficient. High levels of arsenic in irrigation water (>1000 µg/L) are associated with very low levels of zinc in rice (5 µg/g) and rice is the primary staple food for the region. Brown rice from nine of 15 paddy fields in the arsenic zone of Cambodia had double the new guidelines of 100 µg/kg inorganic arsenic for children's food in the EU and USA. The combination of deficiencies of essential micronutrients like zinc and pervasive presence of arsenic and mercury has the potential to compromise the immunity of many Cambodians. Innovative solutions are suggested to improve micronutrient nutrition. Toxins that suppress the immune system must be better managed to reduce the virulence of pathogens. Cambodia was not likely the source of the COVID-19 but does have problems that could result in a new pandemic.
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Affiliation(s)
- Thomas Murphy
- Faculty of Science and Technology, International University, Phnom Penh 12000, Cambodia;
| | - Kongkea Phan
- Faculty of Science and Technology, International University, Phnom Penh 12000, Cambodia;
| | - Kim Neil Irvine
- Faculty of Architecture & Planning, Rangsit Campus, Thammasat University, Khlong Nueng 12121, Thailand;
| | - David Lean
- Lean Environmental, Apsley, ON K0L1A0, Canada;
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Barenblitt A, Payton A, Lagomasino D, Fatoyinbo L, Asare K, Aidoo K, Pigott H, Som CK, Smeets L, Seidu O, Wood D. The large footprint of small-scale artisanal gold mining in Ghana. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 781:146644. [PMID: 33812105 DOI: 10.1016/j.scitotenv.2021.146644] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/17/2021] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
Gold mining has played a significant role in Ghana's economy for centuries. Regulation of this industry has varied over time and while industrial mining is prevalent in the country, the expansion of artisanal mining, or Galamsey has escalated in recent years. Many of these artisanal mines are not only harmful to human health due to the use of Mercury (Hg) in the amalgamation process, but also leave a significant footprint on terrestrial ecosystems, degrading and destroying forested ecosystems in the region. In this study, the Landsat image archive available through Google Earth Engine was used to quantify the total footprint of vegetation loss due to artisanal gold mines in Ghana from 2005 to 2019 and understand how conversion of forested regions to mining has changed over a decadal period from 2007 to 2017. A combination of machine learning and change detection algorithms were used to calculate different land cover conversions and the timing of conversion annually. Within the study area of southwestern Ghana, our results indicate that approximately 47,000 ha (⨦2218 ha) of vegetation were converted to mining at an average rate of ~2600 ha yr-1. The results indicate that a high percentage (~50%) of this mining occurred between 2014 and 2017. Around 700 ha of this mining occurred within protected areas as mapped by the World Database of Protected Areas. In addition to deforestation, increased artisanal mining activity in recent years has the potential to affect human health, access to drinking water resources and food security. This work expands upon limited research into the spatial footprint of Galamsey in Ghana, complements mapping efforts by local geographers, and will support efforts by the government of Ghana to monitor deforestation caused by artisanal mining.
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Affiliation(s)
- Abigail Barenblitt
- Earth System Science Interdisciplinary Center, University of Maryland, College Park, MD, United States; Biospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, United States.
| | - Amanda Payton
- Department of Coastal Studies, East Carolina University, Wanchese, NC, United States
| | - David Lagomasino
- Department of Coastal Studies, East Carolina University, Wanchese, NC, United States
| | - Lola Fatoyinbo
- Biospheric Sciences Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, United States
| | - Kofi Asare
- Ghana Space Science and Technology Institute, Accra, Ghana
| | - Kenneth Aidoo
- Ghana Space Science and Technology Institute, Accra, Ghana
| | | | | | | | | | - Danielle Wood
- Space Enabled Research Group, Massachusetts Institute of Technology, Cambridge, MA, United States
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Cossa H, Scheidegger R, Leuenberger A, Ammann P, Munguambe K, Utzinger J, Macete E, Winkler MS. Health Studies in the Context of Artisanal and Small-Scale Mining: A Scoping Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:1555. [PMID: 33562086 PMCID: PMC7914471 DOI: 10.3390/ijerph18041555] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/25/2021] [Accepted: 02/03/2021] [Indexed: 12/12/2022]
Abstract
Artisanal and small-scale mining (ASM) is an important livelihood activity in many low- and middle-income countries. It is widely acknowledged that there are a myriad of health risk and opportunities associated with ASM. However, little is known with regard to which aspects of health have been studied in ASM settings. We conducted a scoping review of peer-reviewed publications, using readily available electronic databases (i.e., PubMed, Scopus, and Web of Science) from inception to 14 July 2020. Relevant information was synthesized with an emphasis on human and environmental exposures and health effects in a context of ASM. Our search yielded 2764 records. After systematic screening, 176 health studies from 38 countries were retained for final analysis. Most of the studies (n = 155) focused on health in ASM extracting gold. While many of the studies included the collection of environmental and human samples (n = 154), only few (n = 30) investigated infectious diseases. Little attention was given to vulnerable groups, such as women of reproductive age and children. Our scoping review provides a detailed characterisation of health studies in ASM contexts. Future research in ASM settings should address health more comprehensively, including the potential spread of infectious diseases, and effects on mental health and well-being.
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Affiliation(s)
- Hermínio Cossa
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; (A.L.); (P.A.); (J.U.); (M.S.W.)
- University of Basel, P.O. Box, CH-4003 Basel, Switzerland
- Manhiça Health Research Centre, C.P. 1929 Maputo, Mozambique; (K.M.); (E.M.)
| | - Rahel Scheidegger
- Swiss Federal Institute of Technology, P.O. Box, CH-8092 Zurich, Switzerland;
| | - Andrea Leuenberger
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; (A.L.); (P.A.); (J.U.); (M.S.W.)
- University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | - Priska Ammann
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; (A.L.); (P.A.); (J.U.); (M.S.W.)
- University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | - Khátia Munguambe
- Manhiça Health Research Centre, C.P. 1929 Maputo, Mozambique; (K.M.); (E.M.)
- Faculty of Medicine, University Eduardo Mondlane, C.P. 257 Maputo, Mozambique
| | - Jürg Utzinger
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; (A.L.); (P.A.); (J.U.); (M.S.W.)
- University of Basel, P.O. Box, CH-4003 Basel, Switzerland
| | - Eusébio Macete
- Manhiça Health Research Centre, C.P. 1929 Maputo, Mozambique; (K.M.); (E.M.)
- National Directorate of Public Health, Ministry of Health, C.P. 264 Maputo, Mozambique
| | - Mirko S. Winkler
- Swiss Tropical and Public Health Institute, P.O. Box, CH-4002 Basel, Switzerland; (A.L.); (P.A.); (J.U.); (M.S.W.)
- University of Basel, P.O. Box, CH-4003 Basel, Switzerland
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Hair as a Biomarker of Long Term Mercury Exposure in Brazilian Amazon: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018. [PMID: 29534534 PMCID: PMC5877045 DOI: 10.3390/ijerph15030500] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Many studies have assessed mercury (Hg) exposure in the Amazonian population. This article performs a literature search of the studies that used hair as a biomarker of Hg exposure in the Brazilian Amazonian population. The search covered the period from 1996 to 2016 and included articles which matched the following criteria: (1) articles related to Hg exposure into Brazilian Amazon; (2) articles that used hair as a biomarker of Hg exposure; (3) articles that used analytical tools to measure the Hg content on hair and (4) articles that presented arithmetic mean and/or minimum and maximum values of Hg. 36 studies were selected. The findings show that most of the studies were performed along margins of important rivers, such as Negro, Tapajós and Madeira. All the population presented mean levels of Hg on hair above 6 µg g-1 and general population, adults, not determined and men presented levels of Hg on hair above 10 µg g-1. The results show that most of the studies were performed by Brazilian institutions/researchers and the majority was performed in the State of Pará. The present study identified that Amazonian population has long-term been exposed to Hg. In terms of future perspectives, this study suggests the implementation of a strategic plan for environmental health surveillance in the region in order to promote health and benefit Amazonian population.
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Spatial, Temporal, and Dietary Variables Associated with Elevated Mercury Exposure in Peruvian Riverine Communities Upstream and Downstream of Artisanal and Small-Scale Gold Mining. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14121582. [PMID: 29244775 PMCID: PMC5751000 DOI: 10.3390/ijerph14121582] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/12/2017] [Accepted: 12/12/2017] [Indexed: 01/21/2023]
Abstract
Artisanal and small-scale gold mining (ASGM) is a primary contributor to global mercury and its rapid expansion raises concern for human exposure. Non-occupational exposure risks are presumed to be strongly tied to environmental contamination; however, the relationship between environmental and human mercury exposure, how exposure has changed over time, and risk factors beyond fish consumption are not well understood in ASGM settings. In Peruvian riverine communities (n = 12), where ASGM has increased 4–6 fold over the past decade, we provide a large-scale assessment of the connection between environmental and human mercury exposure by comparing total mercury contents in human hair (2-cm segment, n = 231) to locally caught fish tissue, analyzing temporal exposure in women of child bearing age (WCBA, 15–49 years, n = 46) over one year, and evaluating general mercury exposure risks including fish and non-fish dietary items through household surveys and linear mixed models. Calculations of an individual’s oral reference dose using the total mercury content in locally-sourced fish underestimated the observed mercury exposure for individuals in many communities. This discrepancy was particularly evident in communities upstream of ASGM, where mercury levels in river fish, water, and sediment measurements from a previous study were low, yet hair mercury was chronically elevated. Hair from 86% of individuals and 77% of children exceeded a USEPA (U.S. Environmental Protection Agency) provisional level (1.2 µg/g) that could result in child developmental impairment. Chronically elevated mercury exposure was observed in the temporal analysis in WCBA. If the most recent exposure exceeded the USEPA level, there was a 97% probability that the individual exceeded that level 8–10 months of the previous year. Frequent household consumption of some fruits (tomato, banana) and grains (quinoa) was significantly associated with 29–75% reductions in hair mercury. Collectively, these data demonstrate that communities located hundreds of kilometers from ASGM are vulnerable to chronically elevated mercury exposure. Furthermore, unexpected associations with fish mercury contents and non-fish dietary intake highlight the need for more in-depth analyses of exposure regimes to identify the most vulnerable populations and to establish potential interventions.
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Maqbool F, Niaz K, Hassan FI, Khan F, Abdollahi M. Immunotoxicity of mercury: Pathological and toxicological effects. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2017; 35:29-46. [PMID: 28055311 DOI: 10.1080/10590501.2016.1278299] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Mercury (Hg) is toxic and hazardous metal that causes natural disasters in the earth's crust. Exposure to Hg occurs via various routes; like oral (fish), inhalation, dental amalgams, and skin from cosmetics. In this review, we have discussed the sources of Hg and its potential for causing toxicity in humans. In addition, we also review its bio-chemical cycling in the environment; its systemic, immunotoxic, genotoxic/carcinogenic, and teratogenic health effects; and the dietary influences; as well as the important considerations in risk assessment and management of Hg poisoning have been discussed in detail. Many harmful outcomes have been reported, which will provide more awareness.
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Affiliation(s)
- Faheem Maqbool
- a International Campus, Tehran University of Medical Sciences , Tehran , Iran
- b Toxicology and Diseases Group , Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences , Tehran , Iran
| | - Kamal Niaz
- a International Campus, Tehran University of Medical Sciences , Tehran , Iran
- b Toxicology and Diseases Group , Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences , Tehran , Iran
| | - Fatima Ismail Hassan
- a International Campus, Tehran University of Medical Sciences , Tehran , Iran
- b Toxicology and Diseases Group , Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences , Tehran , Iran
| | - Fazlullah Khan
- a International Campus, Tehran University of Medical Sciences , Tehran , Iran
- b Toxicology and Diseases Group , Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences , Tehran , Iran
| | - Mohammad Abdollahi
- a International Campus, Tehran University of Medical Sciences , Tehran , Iran
- b Toxicology and Diseases Group , Pharmaceutical Sciences Research Center, Tehran University of Medical Sciences , Tehran , Iran
- c Department of Toxicology and Pharmacology , Faculty of Pharmacy, Tehran University of Medical Sciences , Tehran , Iran
- d Endocrinology and Metabolism Research Center , Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences , Tehran , Iran
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Sanchez JF, Carnero AM, Rivera E, Rosales LA, Baldeviano GC, Asencios JL, Edgel KA, Vinetz JM, Lescano AG. Unstable Malaria Transmission in the Southern Peruvian Amazon and Its Association with Gold Mining, Madre de Dios, 2001-2012. Am J Trop Med Hyg 2016; 96:304-311. [PMID: 27879461 DOI: 10.4269/ajtmh.16-0030] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Accepted: 09/29/2016] [Indexed: 11/07/2022] Open
Abstract
The reemergence of malaria in the last decade in Madre de Dios, southern Peruvian Amazon basin, was accompanied by ecological, political, and socioeconomic changes related to the proliferation of illegal gold mining. We conducted a secondary analysis of passive malaria surveillance data reported by the health networks in Madre de Dios between 2001 and 2012. We calculated the number of cases of malaria by year, geographic location, intensity of illegal mining activities, and proximity of health facilities to the Peru-Brazil Interoceanic Highway. During 2001-2012, 203,773 febrile cases were identified in Madre de Dios, of which 30,811 (15.1%) were confirmed cases of malaria; all but 10 cases were due to Plasmodium vivax Cases of malaria rose rapidly between 2004 and 2007, reached 4,469 cases in 2005, and then declined after 2010 to pre-2004 levels. Health facilities located in areas of intense illegal gold mining reported 30-fold more cases than those in non-mining areas (ratio = 31.54, 95% confidence interval [CI] = 19.28, 51.60). Finally, health facilities located > 1 km from the Interoceanic Highway reported significantly more cases than health facilities within this distance (ratio = 16.20, 95% CI = 8.25, 31.80). Transmission of malaria in Madre de Dios is unstable, geographically heterogeneous, and strongly associated with illegal gold mining. These findings highlight the importance of spatially oriented interventions to control malaria in Madre de Dios, as well as the need for research on malaria transmission in illegal gold mining camps.
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Affiliation(s)
- Juan F Sanchez
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Andres M Carnero
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Esteban Rivera
- Dirección Regional de Salud de Madre de Dios, Ministerio de Salud del Perú, Puerto Maldonado, Peru
| | - Luis A Rosales
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - G Christian Baldeviano
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Jorge L Asencios
- Dirección Regional de Salud de Madre de Dios, Ministerio de Salud del Perú, Puerto Maldonado, Peru
| | - Kimberly A Edgel
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru
| | - Joseph M Vinetz
- Division of Infectious Diseases, Department of Medicine, University of California San Diego, La Jolla, California
| | - Andres G Lescano
- Department of Parasitology, U.S. Naval Medical Research Unit No. 6 (NAMRU-6), Lima, Peru. .,School of Public Health and Administration, Universidad Peruana Cayetano Heredia, Lima, Peru
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Abstract
CONTEXT Environmental mercury in the Amazon mostly originates from geochemical sources with some from artisanal gold mining (AGM). Geochemical-originated methylmercury (MeHg) reaches the aquatic food chain, ending up in fish. Inorganic Hg used in AGM is responsible for localised environmental contamination and occupational exposure of adults. In addition to this, iatrogenic ethylmercury (EtHg) derived from Thimerosal-containing vaccines (TCVs) exposes immunised infants. OBJECTIVE To understand Hg exposure in the Amazon in relation to environmental fish-MeHg exposure, occupational AGM activities and low-doses of TCV-EtHg. METHODS Medline and Thomson-Reuter Web of Science were searched to retrieve and select papers addressing Hg exposure and human health. RESULTS AND CONCLUSION Environmental-Hg studies addressed health effects associated with birth weight, infant linear growth and neurodevelopment, while, in adults, environmental and occupational studies addressed immune and neurological issues. No widespread clinical toxicity was reported due to fish-MeHg. However, mixed results associated with Hg exposure can be found. Reducing children's exposure to EtHg is possible using Thimerosal-free vaccines, but it is difficult to interfere with fish consumption without consequences to riverine subsistence populations. Policies to diminish Hg exposure should focus on controlling and/or curbing widespread use of Hg (in gold amalgamation) and promotion of Thimerosal-free vaccines for pregnant women and young children.
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Affiliation(s)
- José G Dórea
- a Universidade de Brasília , Brasília , DF , Brasil
| | - Rejane C Marques
- b Universidade Federal do Rio de Janeiro , Rio de Janeiro , RJ, Brasil
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Marques RC, Abreu L, Bernardi JVE, Dórea JG. Traditional living in the Amazon: Extended breastfeeding, fish consumption, mercury exposure and neurodevelopment. Ann Hum Biol 2016; 43:360-70. [DOI: 10.1080/03014460.2016.1189962] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Atlantic Bottlenose Dolphins ( Tursiops truncatus) as A Sentinel for Exposure to Mercury in Humans: Closing the Loop. Vet Sci 2015; 2:407-422. [PMID: 29061950 PMCID: PMC5644643 DOI: 10.3390/vetsci2040407] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 11/03/2015] [Accepted: 11/05/2015] [Indexed: 11/17/2022] Open
Abstract
Mercury (Hg) is a ubiquitous global contaminant with important public health implications. Mercury is released from a variety of anthropogenic, industrial processes, enters the earth's atmosphere and is re-deposited onto the earth's surface in rainfall. Much of this Hg enters the oceans which cover the majority of the earth's surface. In the marine environment, inorganic Hg is converted to the most toxic form of the element, methylmercury, and biomagnified through the trophic levels of the food web. The bottlenose dolphin (Tursiops truncatus) is the apex predator in many estuarine and coastal ecosystems. Due to their long life span and trophic position, bottlenose dolphins bioaccumulate high concentrations of contaminants including Hg, thus making them an important sentinel species for ecosystem and public health. Bottlenose dolphins in Florida bioaccumulate high concentrations of Hg in their blood, skin and internal organs. The concentrations of Hg in blood and skin of bottlenose dolphins of the Indian River Lagoon, FL (IRL) are among the highest reported world-wide. In previous studies, we demonstrated associations between concentrations of total Hg in the blood and skin of IRL dolphins and markers of endocrine, renal, hepatic, hematologic and immune system dysfunction. The predominant manifestation of exposure to mercury in humans is neurotoxicity. During the 1950s and 1960s, residents of Minamata bay, Japan were exposed to high concentrations of methyl mercury as the result of ingestion of fish and shellfish that had become contaminated in this infamous environmental disaster. Affected adults had severe motor and sensory abnormalities often leading to death. Methyl mercury crosses the placenta during pregnancy. Children exposed in utero were born with multiple congenital anomalies and also suffered from neurologic disorders. Significantly, local cats that consumed Hg contaminated fish developed severe signs of neurotoxicity which led to their subsequent description as the "dancing cats of Minamata bay". Unfortunately, the cause of these strange manifestations in cats was not recognized in time to prevent hundreds of additional cases from occurring. More recent studies have shown that exposure to mercury as a result of seafood consumption during pregnancy may result in multiple cognitive and neurodevelopmental effects in children. The levels of mercury found in bottlenose dolphins and the health effects we identified alerted us to the possibility of an important public health hazard. The IRL occupies 40 percent of the east coast of Florida and is bordered by counties with approximately 2.5 million human inhabitants. Therefore, we hypothesized that local inhabitants in communities bordering the IRL could be at risk of exposure to Hg from the consumption of fish and shellfish. We measured hair Hg in 135 local residents and found a mean concentration of 1.53 µg/g which was higher than that from previous studies of sport fishermen and coastal residents in other states. Over 50% of participants had a hair Hg concentration which exceeded the U.S. EPA exposure guideline. Hair Hg concentration was directly related to the frequency of seafood consumption and to the proportion of fish and shellfish obtained from local recreational sources. This study clearly exemplifies the importance of an animal sentinel in identifying a public health hazard and is virtually unique in "closing the loop" between animal and human health.
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Basu N, Clarke E, Green A, Calys-Tagoe B, Chan L, Dzodzomenyo M, Fobil J, Long RN, Neitzel RL, Obiri S, Odei E, Ovadje L, Quansah R, Rajaee M, Wilson ML. Integrated assessment of artisanal and small-scale gold mining in Ghana--part 1: human health review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2015; 12:5143-76. [PMID: 25985314 PMCID: PMC4454960 DOI: 10.3390/ijerph120505143] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 04/27/2015] [Accepted: 05/08/2015] [Indexed: 12/28/2022]
Abstract
This report is one of three synthesis documents produced via an integrated assessment (IA) that aims to increase understanding of artisanal and small-scale gold mining (ASGM) in Ghana. Given the complexities surrounding ASGM, an IA framework was utilized to analyze economic, social, health, and environmental data, and co-develop evidence-based responses with pertinent stakeholders. The current analysis focuses on the health of ASGM miners and community members, and synthesizes extant data from the literature as well as co-authors' recent findings regarding the causes, status, trends, and consequences of ASGM in Ghana. The results provide evidence from across multiple Ghanaian ASGM sites that document relatively high exposures to mercury and other heavy metals, occupational injuries and noise exposure. The work also reviews limited data on psychosocial health, nutrition, cardiovascular and respiratory health, sexual health, and water and sanitation. Taken together, the findings provide a thorough overview of human health issues in Ghanaian ASGM communities. Though more research is needed to further elucidate the relationships between ASGM and health outcomes, the existing research on plausible health consequences of ASGM should guide policies and actions to better address the unique challenges of ASGM in Ghana and potentially elsewhere.
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Affiliation(s)
- Niladri Basu
- Faculty of Agricultural and Environmental Sciences, McGill University, CINE Building Macdonald Campus of McGill University, 21,111 Lakeshore Rd., Ste. Anne de Bellevue, QC H9X 3V9, Canada.
| | | | - Allyson Green
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
| | | | - Laurie Chan
- Faculty of Science, Department of Biology, University of Ottawa, ON K1N 6N5, Canada.
| | - Mawuli Dzodzomenyo
- Department of Biological, Environmental, and Occupational Health Sciences, School of Public Health, University of Ghana, Legon Boundary, Accra, Ghana.
| | - Julius Fobil
- Department of Biological, Environmental, and Occupational Health Sciences, School of Public Health, University of Ghana, Legon Boundary, Accra, Ghana.
| | - Rachel N Long
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
| | - Richard L Neitzel
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
| | - Samuel Obiri
- Council for Scientific and Industrial Research-Water Research Institute, Accra, Ghana.
| | | | - Lauretta Ovadje
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
| | - Reginald Quansah
- Department of Biological, Environmental, and Occupational Health Sciences, School of Public Health, University of Ghana, Legon Boundary, Accra, Ghana.
- Noguchi Institute for Medical Research, College of Health Sciences, University of Ghana, Legon Boundary, Accra, Ghana.
| | - Mozhgon Rajaee
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
| | - Mark L Wilson
- Department of Epidemiology, Department of Ecology and Evolutionary Biology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
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Sánchez Rodríguez LH, Flórez-Vargas O, Rodríguez-Villamizar LA, Vargas Fiallo Y, Stashenko EE, Ramírez G. Lack of autoantibody induction by mercury exposure in artisanal gold mining settings in Colombia: Findings and a review of the epidemiology literature. J Immunotoxicol 2014; 12:368-75. [DOI: 10.3109/1547691x.2014.986591] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Valle D, Lima JMT. Large-scale drivers of malaria and priority areas for prevention and control in the Brazilian Amazon region using a novel multi-pathogen geospatial model. Malar J 2014; 13:443. [PMID: 25412882 PMCID: PMC4247612 DOI: 10.1186/1475-2875-13-443] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 11/15/2014] [Indexed: 12/03/2022] Open
Abstract
Background Most of the malaria burden in the Americas is concentrated in the Brazilian Amazon but a detailed spatial characterization of malaria risk has yet to be undertaken. Methods Utilizing 2004-2008 malaria incidence data collected from six Brazilian Amazon states, large-scale spatial patterns of malaria risk were characterized with a novel Bayesian multi-pathogen geospatial model. Data included 2.4 million malaria cases spread across 3.6 million sq km. Remotely sensed variables (deforestation rate, forest cover, rainfall, dry season length, and proximity to large water bodies), socio-economic variables (rural population size, income, and literacy rate, mortality rate for children age under five, and migration patterns), and GIS variables (proximity to roads, hydro-electric dams and gold mining operations) were incorporated as covariates. Results Borrowing information across pathogens allowed for better spatial predictions of malaria caused by Plasmodium falciparum, as evidenced by a ten-fold cross-validation. Malaria incidence for both Plasmodium vivax and P. falciparum tended to be higher in areas with greater forest cover. Proximity to gold mining operations was another important risk factor, corroborated by a positive association between migration rates and malaria incidence. Finally, areas with a longer dry season and areas with higher average rural income tended to have higher malaria risk. Risk maps reveal striking spatial heterogeneity in malaria risk across the region, yet these mean disease risk surface maps can be misleading if uncertainty is ignored. By combining mean spatial predictions with their associated uncertainty, several sites were consistently classified as hotspots, suggesting their importance as priority areas for malaria prevention and control. Conclusion This article provides several contributions. From a methodological perspective, the benefits of jointly modelling multiple pathogens for spatial predictions were illustrated. In addition, maps of mean disease risk were contrasted with that of statistically significant disease clusters, highlighting the critical importance of uncertainty in determining disease hotspots. From an epidemiological perspective, forest cover and proximity to gold mining operations were important large-scale drivers of disease risk in the region. Finally, the hotspot in Western Acre was identified as the area that should receive highest priority from the Brazilian national malaria prevention and control programme. Electronic supplementary material The online version of this article (doi:10.1186/1475-2875-13-443) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Denis Valle
- School of Forest Resources and Conservation, University of Florida, 408 McCarty Hall C, PO Box 110339, Gainesville, FL, USA.
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Motts JA, Shirley DL, Silbergeld EK, Nyland JF. Novel biomarkers of mercury-induced autoimmune dysfunction: a cross-sectional study in Amazonian Brazil. ENVIRONMENTAL RESEARCH 2014; 132:12-8. [PMID: 24742722 PMCID: PMC4060520 DOI: 10.1016/j.envres.2014.03.024] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 01/30/2014] [Accepted: 03/18/2014] [Indexed: 05/23/2023]
Abstract
Mercury is a ubiquitous environmental contaminant, causing both neurotoxicity and immunotoxicity. Given its ability to amalgamate gold, mercury is frequently used in small-scale artisanal gold mining. We have previously reported that elevated serum titers of antinuclear autoantibodies (ANA) are associated with mercury exposures of miners in gold mining. The goal of this project was to identify novel serum biomarkers of mercury-induced immunotoxicity and autoimmune dysregulation. We conducted an analysis of serum samples from a cross-sectional epidemiological study on miners working in Amazonian Brazil. In proteomic screening analyses, samples were stratified based on mercury concentrations and ANA titer and a subset of serum samples (N=12) were profiled using Immune Response Biomarker Profiling ProtoArray protein microarray for elevated autoantibodies. Of the up-regulated autoantibodies in the mercury-exposed cohort, potential target autoantibodies were selected based on relevance to pro-inflammatory and macrophage activation pathways. ELISAs were developed to test the entire sample cohort (N=371) for serum titers to the highest of these autoantibodies (anti-glutathione S-transferase alpha, GSTA1) identified in the high mercury/high ANA group. We found positive associations between elevated mercury exposure and up-regulated serum titers of 3760 autoantibodies as identified by ProtoArray. Autoantibodies identified as potential novel biomarkers of mercury-induced immunotoxicity include antibodies to the following proteins: GSTA1, tumor necrosis factor ligand superfamily member 13, linker for activation of T cells, signal peptide peptidase like 2B, stimulated by retinoic acid 13, and interferon induced transmembrane protein. ELISA analyses confirmed that mercury-exposed gold miners had significantly higher serum titers of anti-GSTA1 autoantibody [unadjusted odds ratio=89.6; 95% confidence interval: 27.2, 294.6] compared to emerald miners (referent population). Mercury exposure was associated with increased titers of several autoantibodies in serum including anti-GSTA1. These proteins play a wide variety of roles, including as antioxidants, in the regulation of pro- and anti-inflammatory cytokines, as well as danger and oxidative stress signaling. Dysregulation of these proteins and pathways is believed to play a role in autoimmune diseases such as rheumatoid arthritis, Sjögren׳s syndrome, and multiple sclerosis. Taken together, these results suggest that mercury exposure can induce complex autoimmune dysfunction and the immunotoxic effects of this dysfunction may be measured by serum titers to autoantibodies such as anti-GSTA1.
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Affiliation(s)
- Jonathan A Motts
- Department of Biology, University of South Carolina, Columbia, SC 29209, USA
| | - Devon L Shirley
- Department of Pathology, Microbiology & Immunology, University of South Carolina, School of Medicine, Columbia, SC, USA
| | - Ellen K Silbergeld
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Jennifer F Nyland
- Department of Pathology, Microbiology & Immunology, University of South Carolina, School of Medicine, Columbia, SC, USA.
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Sheehan MC, Burke TA, Navas-Acien A, Breysse PN, McGready J, Fox MA. Global methylmercury exposure from seafood consumption and risk of developmental neurotoxicity: a systematic review. Bull World Health Organ 2014; 92:254-269F. [PMID: 24700993 PMCID: PMC3967569 DOI: 10.2471/blt.12.116152] [Citation(s) in RCA: 169] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 10/15/2013] [Accepted: 11/12/2013] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To examine biomarkers of methylmercury (MeHg) intake in women and infants from seafood-consuming populations globally and characterize the comparative risk of fetal developmental neurotoxicity. METHODS A search was conducted of the published literature reporting total mercury (Hg) in hair and blood in women and infants. These biomarkers are validated proxy measures of MeHg, a neurotoxin found primarily in seafood. Average and high-end biomarkers were extracted, stratified by seafood consumption context, and pooled by category. Medians for average and high-end pooled distributions were compared with the reference level established by a joint expert committee of the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). FINDINGS Selection criteria were met by 164 studies of women and infants from 43 countries. Pooled average biomarkers suggest an intake of MeHg several times over the FAO/WHO reference in fish-consuming riparians living near small-scale gold mining and well over the reference in consumers of marine mammals in Arctic regions. In coastal regions of south-eastern Asia, the western Pacific and the Mediterranean, average biomarkers approach the reference. Although the two former groups have a higher risk of neurotoxicity than the latter, coastal regions are home to the largest number at risk. High-end biomarkers across all categories indicate MeHg intake is in excess of the reference value. CONCLUSION There is a need for policies to reduce Hg exposure among women and infants and for surveillance in high-risk populations, the majority of which live in low-and middle-income countries.
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Affiliation(s)
- Mary C Sheehan
- Risk Sciences and Public Policy Institute, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, United States of America (USA)
| | - Thomas A Burke
- Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - Ana Navas-Acien
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - Patrick N Breysse
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - John McGready
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - Mary A Fox
- Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
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Li Y, Zhang B, Yang L, Li H. Blood mercury concentration among residents of a historic mercury mine and possible effects on renal function: a cross-sectional study in southwestern China. ENVIRONMENTAL MONITORING AND ASSESSMENT 2013; 185:3049-3055. [PMID: 22791021 DOI: 10.1007/s10661-012-2772-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 06/28/2012] [Indexed: 06/01/2023]
Abstract
This cross-sectional study aimed to investigate blood mercury (B-Hg) concentration of residents living in the vicinity of Chatian mercury mine (CMM) in southwestern China and to assess the possible effects on renal function. It evaluates the effects of gender and age (children, <18 years; adults, 18-60 years; elderly, >60 years) on the B-Hg and serum creatinine (SCR) and serum urea nitrogen (SUN) levels. In the CMM, elevated levels were found for B-Hg, SCR, and SUN with mean values at 6.09 μg/L, 74.21 μmol/L, and 13.26 mmol/L, which were significantly higher than those in the control area, respectively. Moreover, the coefficients between paired results for B-Hg and SCR and SUN levels were positive at statistical significance (B-Hg vs. SCR, r = 0.45, p < 0.01; B-Hg vs. SUN, r = 0.20, p < 0.05). The aforementioned results revealed that mercury exposure can cause human renal function impairment. B-Hg, SCR, and SUN can also be useful biomarkers to assess the extent of mercury exposure among residents in areas with extensive mining activities. Furthermore, data analysis revealed that there was a tendency for higher B-Hg, SCR, and SUN levels in females than in males, and the levels of B-Hg, SCR, and SUN increased among the older residents. We conclude that females and the elderly in the mining area were more susceptible to mercury exposure, and therefore, they deserve further research.
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Affiliation(s)
- Yonghua Li
- Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A Datun Road, Chaoyang District, Beijing 100101, China.
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Hong YS, Kim YM, Lee KE. Methylmercury exposure and health effects. J Prev Med Public Health 2012; 45:353-63. [PMID: 23230465 PMCID: PMC3514465 DOI: 10.3961/jpmph.2012.45.6.353] [Citation(s) in RCA: 222] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 10/17/2012] [Indexed: 12/31/2022] Open
Abstract
Methylmercury is a hazardous substance that is of interest with regard to environmental health, as inorganic mercury circulating in the general environment is dissolved into freshwater and seawater, condensed through the food chain, ingested by humans, and consequently affects human health. Recently, there has been much interest and discussion regarding the toxicity of methylmercury, the correlation with fish and shellfish intake, and methods of long-term management of the human health effects of methylmercury. What effects chronic exposure to a low concentration of methylmercury has on human health remains controversial. Although the possibility of methylmercury poisoning the heart and blood vessel system, the reproductive system, and the immune system is continuously raised and discussed, and the carcinogenicity of methylmercury is also under discussion, a clear conclusion regarding the human health effects according to exposure level has not yet been drawn. The Joint FAO/WHO Expert Committee on Food Additives proposed to prepare additional fish and shellfish intake recommendations for consumers based on the quantified evaluation of the hazardousness of methylmercury contained in fish and shellfish, methylmercury management in the Korea has not yet caught up with this international trend. Currently, the methylmercury exposure level of Koreans is known to be very high. The starting point of methylmercury exposure management is inorganic mercury in the general environment, but food intake through methylation is the main exposure source. Along with efforts to reduce mercury in the general environment, food intake management should be undertaken to reduce the human exposure to methylmercury in Korea.
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Affiliation(s)
- Young-Seoub Hong
- Department of Preventive Medicine, Dong-A University College of Medicine, Busan, Korea
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Karagas MR, Choi AL, Oken E, Horvat M, Schoeny R, Kamai E, Cowell W, Grandjean P, Korrick S. Evidence on the human health effects of low-level methylmercury exposure. ENVIRONMENTAL HEALTH PERSPECTIVES 2012; 120:799-806. [PMID: 22275730 PMCID: PMC3385440 DOI: 10.1289/ehp.1104494] [Citation(s) in RCA: 448] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 01/24/2012] [Indexed: 05/17/2023]
Abstract
BACKGROUND Methylmercury (MeHg) is a known neuro-toxicant. Emerging evidence indicates it may have adverse effects on the neuro-logic and other body systems at common low levels of exposure. Impacts of MeHg exposure could vary by individual susceptibility or be confounded by beneficial nutrients in fish containing MeHg. Despite its global relevance, synthesis of the available literature on low-level MeHg exposure has been limited. OBJECTIVES We undertook a synthesis of the current knowledge on the human health effects of low-level MeHg exposure to provide a basis for future research efforts, risk assessment, and exposure remediation policies worldwide. DATA SOURCES AND EXTRACTION We reviewed the published literature for original human epidemiologic research articles that reported a direct biomarker of mercury exposure. To focus on high-quality studies and those specifically on low mercury exposure, we excluded case series, as well as studies of populations with unusually high fish consumption (e.g., the Seychelles), marine mammal consumption (e.g., the Faroe Islands, circumpolar, and other indigenous populations), or consumption of highly contaminated fish (e.g., gold-mining regions in the Amazon). DATA SYNTHESIS Recent evidence raises the possibility of effects of low-level MeHg exposure on fetal growth among susceptible subgroups and on infant growth in the first 2 years of life. Low-level effects of MeHg on neuro-logic outcomes may differ by age, sex, and timing of exposure. No clear pattern has been observed for cardio-vascular disease (CVD) risk across populations or for specific CVD end points. For the few studies evaluating immunologic effects associated with MeHg, results have been inconsistent. CONCLUSIONS Studies targeted at identifying potential mechanisms of low-level MeHg effects and characterizing individual susceptibility, sexual dimorphism, and non-linearity in dose response would help guide future prevention, policy, and regulatory efforts surrounding MeHg exposure.
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Affiliation(s)
- Margaret R Karagas
- Section of Biostatistics and Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.
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Zolnikov TR. Limitations in small artisanal gold mining addressed by educational components paired with alternative mining methods. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 419:1-6. [PMID: 22297251 DOI: 10.1016/j.scitotenv.2012.01.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 01/06/2012] [Accepted: 01/07/2012] [Indexed: 05/04/2023]
Abstract
Current solutions continue to be inadequate in addressing the longstanding, worldwide problem of mercury emissions from small artisanal gold mining. Mercury, an inexpensive and easily accessible heavy metal, is used in the process of extracting gold from ore. Mercury emissions disperse, affecting human populations by causing adverse health effects and environmental and social ramifications. Many developing nations have sizable gold ore deposits, making small artisanal gold mining a major source of employment in the world. Poverty drives vulnerable, rural populations into gold mining because of social and economic instabilities. Educational programs responding to this environmental hazard have been implemented in the past, but have had low positive results due to lack of governmental support and little economic incentive. Educational and enforced intervention programs must be developed in conjunction with governmental agencies in order to successfully eliminate this ongoing problem. Industry leaders offered hopeful suggestions, but revealed limitations when trying to develop encompassing solutions to halt mercury emissions. This research highlights potential options that have been attempted in the past and suggests alternative solutions to improve upon these methods. Some methods include buyer impact recognition, risk assessment proposals exposing a cost-benefit analysis and toxicokinetic modeling, public health awareness campaigns, and the education of miners, healthcare workers, and locals within hazardous areas of mercury exposure. These methods, paired with the implementation of alternative mining techniques, propose a substantial reduction of mercury emissions.
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Affiliation(s)
- Tara R Zolnikov
- Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115, USA.
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Nyland JF, Fillion M, Barbosa F, Shirley DL, Chine C, Lemire M, Mergler D, Silbergeld EK. Biomarkers of methylmercury exposure immunotoxicity among fish consumers in Amazonian Brazil. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:1733-8. [PMID: 21868305 PMCID: PMC3261989 DOI: 10.1289/ehp.1103741] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 08/25/2011] [Indexed: 05/03/2023]
Abstract
BACKGROUND Mercury (Hg) is a ubiquitous environmental contaminant with neurodevelopmental and immune system effects. An informative biomarker of Hg-induced immunotoxicity could aid studies on the potential contribution to immune-related health effects. OBJECTIVES Our objectives were to test the hypothesis that methylmercury (MeHg) exposures affect levels of serum biomarkers and to examine interactions between Hg and selenium (Se) in terms of these responses. METHODS This cross-sectional epidemiological study assessed adults living along the Tapajós River, a system long affected by MeHg. We measured antinuclear (ANA) and antinucleolar (ANoA) autoantibody levels and eight cytokines in serum samples (n = 232). Total Hg (including MeHg) and Se were measured in blood, plasma, hair, and urine. RESULTS The median (range) total Hg concentrations were 14.1 μg/g (1.1-62.4), 53.5 μg/L (4.3-288.9), 8.8 μg/L (0.2-40), and 3.0 μg/L (0.2-16.1) for hair, blood, plasma, and urine, respectively. Elevated titers of ANA (but not ANoA) were positively associated with MeHg exposure (log-transformed, for blood and plasma), unadjusted [odds ratio (OR) = 2.6; 95% confidence interval (CI): 1.1, 6.2] and adjusted for sex and age (OR = 2.9; 95% CI: 1.1, 7.5). Proinflammatory [interleukin (IL)-6 and interferon (IFN)-γ], anti-inflammatory (IL-4), and IL-17 cytokine levels were increased with MeHg exposure; however, in the subset of the population with elevated ANA, proinflammatory IL-1β, IL-6, IFN-γ, and tumor necrosis factor (TNF)-α and anti-inflammatory (IL-4) cytokine levels were decreased with MeHg exposure. Although Se status was associated with MeHg level (correlation coefficient = 0.86; 95% CI: 0.29, 1.43), Se status was not associated with any changes in ANA and did not modify associations between Hg and ANA titers. CONCLUSIONS MeHg exposure was associated with an increased ANA and changes in serum cytokine profile. Moreover, alterations in serum cytokine profiles differed based on ANA response, suggesting a specific phenotype of MeHg susceptibility. Further research on the potential health implications of these observed immunological changes is warranted.
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Affiliation(s)
- Jennifer F Nyland
- Department of Pathology, Microbiology, and Immunology, School of Medicine, University of South Carolina, Columbia, South Carolina 29209, USA.
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Nyland JF, Wang SB, Shirley DL, Santos EO, Ventura AM, de Souza JM, Silbergeld EK. Fetal and maternal immune responses to methylmercury exposure: a cross-sectional study. ENVIRONMENTAL RESEARCH 2011; 111:584-9. [PMID: 21396635 PMCID: PMC3081921 DOI: 10.1016/j.envres.2011.02.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 02/16/2011] [Accepted: 02/17/2011] [Indexed: 05/19/2023]
Abstract
Methylmercury (MeHg) is a ubiquitous environmental contaminant with known neurodevelopmental effects. In humans, prenatal exposures primarily occur through maternal consumption of contaminated fish. In this study, we evaluated the association between prenatal exposure to MeHg and titers of total immunoglobulins (Ig) and specific autoantibodies in both mothers and fetuses by analyzing maternal and cord blood serum samples. We examined multiple immunoglobulin isotypes to determine if these biomarkers could inform as to fetal or maternal responses since IgG but not IgM can cross the placenta. Finally, we evaluated serum cytokine levels to further characterize the immune response to mercury exposure. The study was conducted using a subset of serum samples (N=61 pairs) collected from individuals enrolled in a population surveillance of MeHg exposures in the Brazilian Amazon during 2000/2001. Serum titers of antinuclear and antinucleolar autoantibodies were measured by indirect immunofluorescence. Serum immunoglobulins were measured by enzyme-linked immunosorbent assay (ELISA) and BioPlex multiplex assay. Serum cytokines were measured by BioPlex multiplex assay. In this population, the geometric mean mercury level was within the 95th percentile for US populations of women of childbearing age but the upper level of the range was significantly higher. Fetal blood mercury levels were higher (1.35 times) than those in their mothers, but highly correlated (correlation coefficient [r]=0.71; 95% CI: 0.54, 0.89). Total IgG (r=0.40; 95% CI: 0.19, 0.62) and antinuclear autoantibody (odds ratio [OR]=1.05; 95% CI: 1.02, 1.08) levels in paired maternal and fetal samples were also associated; in contrast, other immunoglobulin (IgM, IgE, and IgA) levels were not associated between pairs. Total IgG levels were significantly correlated with both maternal (r=0.60; 95% CI: 0.25, 0.96) and cord blood mercury levels (r=0.61; 95% CI: 0.25, 0.97), but individual isotypes were not. Serum cytokines, interleukin-1β (r=0.37; 95% CI: 0.01, 0.73), interleukin-6 (r=0.34; 95% CI: 0.03, 0.65), and tumor necrosis factor-α (r=0.24; 95% CI: 0.015, 0.47), were positively correlated between maternal and fetal samples. Antinuclear and antinucleolar autoantibody titer and serum cytokine levels, in either maternal or cord blood, were not significantly associated with either maternal or cord blood mercury levels. These data provide further evidence that there are likely IgG biomarkers of mercury-induced immunotoxicity in this population since IgG levels were elevated with increased, and associated with, mercury exposure. However, unlike previous data from adult males and non-pregnant females, we found no evidence that antinuclear and antinucleolar autoantibody titer is a reliable biomarker of mercury immunotoxicity in this population.
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Affiliation(s)
- Jennifer F Nyland
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205 USA
- Department of Pathology, Microbiology & Immunology, University of South Carolina School of Medicine, 6439 Garner’s Ferry Road, Columbia, SC, 29209 USA
- Corresponding author/current address: University of South Carolina School of Medicine, 6439 Garner’s Ferry Road, Building 1, Room B10, Columbia, SC 29209 USA, 1- (803) 216-3416 – phone, 1- (803) 733-1515 – fax,
| | - Susie B Wang
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205 USA
| | - Devon L Shirley
- Department of Pathology, Microbiology & Immunology, University of South Carolina School of Medicine, 6439 Garner’s Ferry Road, Columbia, SC, 29209 USA
| | - Elisabeth O Santos
- Institue Evandro Chagas, Fundaçao Nacional da Saúde, Belem do Pará-66090, Brazil
| | - Ana Maria Ventura
- Institue Evandro Chagas, Fundaçao Nacional da Saúde, Belem do Pará-66090, Brazil
| | - Jose M de Souza
- Institue Evandro Chagas, Fundaçao Nacional da Saúde, Belem do Pará-66090, Brazil
| | - Ellen K Silbergeld
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205 USA
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Swenson JJ, Carter CE, Domec JC, Delgado CI. Gold mining in the Peruvian Amazon: global prices, deforestation, and mercury imports. PLoS One 2011; 6:e18875. [PMID: 21526143 PMCID: PMC3079740 DOI: 10.1371/journal.pone.0018875] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2010] [Accepted: 03/22/2011] [Indexed: 11/30/2022] Open
Abstract
Many factors such as poverty, ineffective institutions and environmental regulations may prevent developing countries from managing how natural resources are extracted to meet a strong market demand. Extraction for some resources has reached such proportions that evidence is measurable from space. We present recent evidence of the global demand for a single commodity and the ecosystem destruction resulting from commodity extraction, recorded by satellites for one of the most biodiverse areas of the world. We find that since 2003, recent mining deforestation in Madre de Dios, Peru is increasing nonlinearly alongside a constant annual rate of increase in international gold price (∼18%/yr). We detect that the new pattern of mining deforestation (1915 ha/year, 2006–2009) is outpacing that of nearby settlement deforestation. We show that gold price is linked with exponential increases in Peruvian national mercury imports over time (R2 = 0.93, p = 0.04, 2003–2009). Given the past rates of increase we predict that mercury imports may more than double for 2011 (∼500 t/year). Virtually all of Peru's mercury imports are used in artisanal gold mining. Much of the mining increase is unregulated/artisanal in nature, lacking environmental impact analysis or miner education. As a result, large quantities of mercury are being released into the atmosphere, sediments and waterways. Other developing countries endowed with gold deposits are likely experiencing similar environmental destruction in response to recent record high gold prices. The increasing availability of satellite imagery ought to evoke further studies linking economic variables with land use and cover changes on the ground.
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Affiliation(s)
- Jennifer J Swenson
- Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America.
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Berzas Nevado JJ, Rodríguez Martín-Doimeadios RC, Guzmán Bernardo FJ, Jiménez Moreno M, Herculano AM, do Nascimento JLM, Crespo-López ME. Mercury in the Tapajós River basin, Brazilian Amazon: a review. ENVIRONMENT INTERNATIONAL 2010; 36:593-608. [PMID: 20483161 DOI: 10.1016/j.envint.2010.03.011] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2009] [Revised: 02/24/2010] [Accepted: 03/29/2010] [Indexed: 05/23/2023]
Abstract
This paper presents a review about mercury contamination and human exposure in the Tapajós River basin (Brazil), one of the major tributaries of the Amazon impacted by traditional gold mining from the mid 1980s. The most recent review in this region was published more than ten years ago and since then many articles about environment and especially human populations have revealed new aspects of mercury toxicology. Additionally, new biomarkers of mercury exposure and toxicity have been studied in these populations. However, there are still many open, about both mercury's biogeochemical cycle and mercury health risks. Further environmental and human risk research directions are proposed.
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Affiliation(s)
- J J Berzas Nevado
- Department of Analytical Chemistry and Food Technology, Faculty of Chemistry, University of Castilla-La Mancha, Ciudad Real, Spain
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Feingold BJ, Vegosen L, Davis M, Leibler J, Peterson A, Silbergeld EK. A niche for infectious disease in environmental health: rethinking the toxicological paradigm. ENVIRONMENTAL HEALTH PERSPECTIVES 2010; 118:1165-72. [PMID: 20385515 PMCID: PMC2920090 DOI: 10.1289/ehp.0901866] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 04/12/2010] [Indexed: 05/21/2023]
Abstract
OBJECTIVE In this review we highlight the need to expand the scope of environmental health research, which now focuses largely on the study of toxicants, to incorporate infectious agents. We provide evidence that environmental health research would be strengthened through finding common ground with the tools and approaches of infectious disease research. DATA SOURCES AND EXTRACTION We conducted a literature review for examples of interactions between toxic agents and infectious diseases, as well as the role of these interactions as risk factors in classic "environmental" diseases. We investigated existing funding sources and research mandates in the United States from the National Science Foundation and the National Institutes of Health, particularly the National Institute of Environmental Health Sciences. DATA SYNTHESIS We adapted the toxicological paradigm to guide reintegration of infectious disease into environmental health research and to identify common ground between these two fields as well as opportunities for improving public health through interdisciplinary research. CONCLUSIONS Environmental health encompasses complex disease processes, many of which involve interactions among multiple risk factors, including toxicant exposures, pathogens, and susceptibility. Funding and program mandates for environmental health studies should be expanded to include pathogens in order to capture the true scope of these overlapping risks, thus creating more effective research investments with greater relevance to the complexity of real-world exposures and multifactorial health outcomes. We propose a new model that integrates the toxicology and infectious disease paradigms to facilitate improved collaboration and communication by providing a framework for interdisciplinary research. Pathogens should be part of environmental health research planning and funding allocation, as well as applications such as surveillance and policy development.
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Affiliation(s)
- Beth J Feingold
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
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Gardner RM, Nyland JF, Silva IA, Ventura AM, Souza JMD, Silbergeld EK. Mercury exposure, serum antinuclear/antinucleolar antibodies, and serum cytokine levels in mining populations in Amazonian Brazil: a cross-sectional study. ENVIRONMENTAL RESEARCH 2010; 110:345-54. [PMID: 20176347 PMCID: PMC2873228 DOI: 10.1016/j.envres.2010.02.001] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 01/29/2010] [Accepted: 02/02/2010] [Indexed: 05/19/2023]
Abstract
Mercury is an immunotoxic substance that has been shown to induce autoimmune disease in rodent models, characterized by lymphoproliferation, overproduction of immunoglobulin (IgG and IgE), and high circulating levels of auto-antibodies directed at antigens located in the nucleus (antinuclear auto-antibodies, or ANA) or the nucleolus (antinucleolar auto-antibodies, or ANoA). We have reported elevated levels of ANA and ANoA in human populations exposed to mercury in artisanal gold mining, though other confounding variables that may also modulate ANA/ANoA levels were not well controlled. The goal of this study is to specifically test whether occupational and environmental conditions (other than mercury exposure) that are associated with artisanal gold mining affect the prevalence of markers of autoimmune dysfunction. We measured ANA, ANoA, and cytokine concentrations in serum and compared results from mercury-exposed artisanal gold miners to those from diamond and emerald miners working under similar conditions and with similar socio-economic status and risks of infectious disease. Mercury-exposed gold miners had higher prevalence of detectable ANA and ANoA and higher titers of ANA and ANoA as compared to diamond and emerald miners with no occupational mercury exposure. Also, mercury-exposed gold miners with detectable ANA or ANoA in serum had significantly higher concentrations of pro-inflammatory cytokines IL-1beta, TNF-alpha, and IFN-gamma in serum as compared to the diamond and emerald miners. This study provides further evidence that mercury exposure may lead to autoimmune dysfunction and systemic inflammation in affected populations.
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Affiliation(s)
- Renee M. Gardner
- Johns Hopkins Bloomberg School of Public Health, Department of Environmental Health Sciences, Baltimore, MD 21205
| | - Jennifer F. Nyland
- Johns Hopkins Bloomberg School of Public Health, Department of Environmental Health Sciences, Baltimore, MD 21205
- University of South Carolina School of Medicine, Department of Pathology, Microbiology & Immunology, Columbia, SC 29209
| | - Ines A. Silva
- Johns Hopkins Bloomberg School of Public Health, Department of Environmental Health Sciences, Baltimore, MD 21205
| | - Ana Maria Ventura
- Institute Evandro Chagas (IEC), Fundaçao Nacional da Saúde, Belem do Pará-66090, Brazil
| | - Jose Maria de Souza
- Institute Evandro Chagas (IEC), Fundaçao Nacional da Saúde, Belem do Pará-66090, Brazil
| | - Ellen K. Silbergeld
- Johns Hopkins Bloomberg School of Public Health, Department of Environmental Health Sciences, Baltimore, MD 21205
- Corresponding Author: Ellen K. Silbergeld, Johns Hopkins Bloomberg School of Public Health, Environmental Health Sciences, 615 N. Wolfe St., Room E6644, Baltimore, MD, 21205, Phone: (410) 955-8678, Fax: (443) 287-6414,
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Barbieri FL, Gardon J. Hair mercury levels in Amazonian populations: spatial distribution and trends. Int J Health Geogr 2009; 8:71. [PMID: 20025776 PMCID: PMC2816200 DOI: 10.1186/1476-072x-8-71] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Accepted: 12/21/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Mercury is present in the Amazonian aquatic environments from both natural and anthropogenic sources. As a consequence, many riverside populations are exposed to methylmercury, a highly toxic organic form of mercury, because of their intense fish consumption. Many studies have analysed this exposure from different approaches since the early nineties. This review aims to systematize the information in spatial distribution, comparing hair mercury levels by studied population and Amazonian river basin, looking for exposure trends. METHODS The reviewed papers were selected from scientific databases and online libraries. We included studies with a direct measure of hair mercury concentrations in a sample size larger than 10 people, without considering the objectives, approach of the study or mercury speciation. The results are presented in tables and maps by river basin, displaying hair mercury levels and specifying the studied population and health impact, if any. RESULTS The majority of the studies have been carried out in communities from the central Amazonian regions, particularly on the Tapajós River basin. The results seem quite variable; hair mercury means range from 1.1 to 34.2 microg/g. Most studies did not show any significant difference in hair mercury levels by gender or age. Overall, authors emphasized fish consumption frequency as the main risk factor of exposure. The most studied adverse health effect is by far the neurological performance, especially motricity. However, it is not possible to conclude on the relation between hair mercury levels and health impact in the Amazonian situation because of the relatively small number of studies. CONCLUSIONS Hair mercury levels in the Amazonian regions seem to be very heterogenic, depending on several factors. There is no obvious spatial trend and there are many areas that have never been studied. Taking into account the low mercury levels currently handled as acceptable, the majority of the Amazonian populations can be considered exposed to methylmercury contamination. The situation for many of these traditional communities is very complex because of their high dependence on fish nutrients. It remains difficult to conclude on the Public Health implication of mercury exposure in this context.
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Holmes P, James KAF, Levy LS. Is low-level environmental mercury exposure of concern to human health? THE SCIENCE OF THE TOTAL ENVIRONMENT 2009; 408:171-82. [PMID: 19850321 DOI: 10.1016/j.scitotenv.2009.09.043] [Citation(s) in RCA: 231] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2009] [Revised: 09/17/2009] [Accepted: 09/24/2009] [Indexed: 05/24/2023]
Abstract
Mercury has long been recognised as toxic, principally in relation to its effects on humans following acute or prolonged high-level occupational exposures and, in the latter half of the last century, from a number of environmental incidents. Recognised target organs are the kidneys, central nervous system and thyroid glands. Recently concern has grown about the potential risks to the human population from current background environmental levels, leading bodies such as the World Health Organisation to call for the reduction or, wherever possible, elimination of the use of mercury. This review considers the strength of the epidemiological evidence on the effects of prolonged low-level exposure to the various forms of mercury. The limited research base suggests that several of the potential targets of long-term environmental exposure to mercury are similar to those occurring from occupational exposure including the renal, cardiovascular and immune systems. However, the evidence also suggests that, particularly in the case of organic mercury compounds, the most sensitive endpoint is central nervous system toxicity, especially in relation to exposure during the in utero period and childhood. It also appears that those human populations which have traditionally consumed diets high in seafoods are at greatest risk. While the extent of risk to the general population that may arise from existing environmental exposure levels appears limited, this conclusion is based on an incomplete dataset and therefore the general consensus view that exposure to mercury in its various forms should be minimised where practical, appears to be justified. A number of potential areas of further research are suggested as being pre-requisite to the development of a more rigorous risk assessment.
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Affiliation(s)
- P Holmes
- Institute of Environment and Health, Cranfield Health, First Floor Building 63, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK.
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Li P, Feng X, Qiu G, Shang L, Li G. Human hair mercury levels in the Wanshan mercury mining area, Guizhou Province, China. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2009; 31:683-691. [PMID: 19160059 DOI: 10.1007/s10653-008-9246-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2007] [Accepted: 12/29/2008] [Indexed: 05/27/2023]
Abstract
The total mercury (T-Hg) and methyl mercury (Me-Hg) concentrations in the hair were measured to evaluate mercury (Hg) exposure for the residents in Da-shui-xi Village (DSX) and Xia-chang-xi Village (XCX) in the Wanshan Hg mining area, Guizhou Province, Southwestern China. The mean concentrations in the hair of DSX residents were 5.5 ± 2.7 μg/g and 1.9 ± 0.9 μg/g for T-Hg and Me-Hg, respectively. The concentrations in the hair of XCX residents were 3.3 ± 1.4 μg/g and 1.2 ± 0.5 μg/g for T-Hg and Me-Hg, respectively. Hair Me-Hg concentrations were significantly correlated to T-Hg (r = 0.42, P < 0.01) in the two sites; on average, hair Me-Hg concentration accounted for 40 and 44% of T-Hg for DSX and XCX residents, respectively. Age has no obvious correlation with hair Hg and the hair Hg levels showed a significant gender difference, with higher T-Hg and Me-Hg concentrations in the hair from males than females. The rice collected from the two sites showed high levels of T-Hg and Me-Hg concentration. The results indicated a certain Hg exposure for the residents in DSX and XCX in the Wanshan Hg mining area.
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Affiliation(s)
- Ping Li
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China
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Gardner RM, Nyland JF, Evans SL, Wang SB, Doyle KM, Crainiceanu CM, Silbergeld EK. Mercury induces an unopposed inflammatory response in human peripheral blood mononuclear cells in vitro. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:1932-8. [PMID: 20049214 PMCID: PMC2799469 DOI: 10.1289/ehp.0900855] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 08/19/2009] [Indexed: 05/03/2023]
Abstract
BACKGROUND The human immune response to mercury is not well characterized despite the body of evidence that suggests that Hg can modulate immune responses, including the induction of autoimmune disease in some mouse models. Dysregulation of cytokine signaling appears to play an important role in the etiology of Hg-induced autoimmunity in animal models. OBJECTIVES In this study, we systematically investigated the human immune response to Hg in vitro in terms of cytokine release. METHODS Human peripheral blood mononuclear cells (PBMCs) were isolated from 20 volunteers who donated blood six separate times. PBMCs were cultured with lipopolysaccharide and concentrations of mercuric chloride (HgCl(2)) up to 200 nM. Seven cytokines representing important pathways in physiologic and pathologic immune responses were measured in supernatants. We used multilevel models to account for the intrinsic clustering in the cytokine data due to experimental design. RESULTS We found a consistent increase in the release of the proinflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha, and concurrent decrease in release of the antiinflammatory cytokines interleukin 1-receptor antagonist (IL-1Ra) and IL-10 in human PBMCs treated with subcytotoxic concentrations of HgCl(2). IL-4, IL-17, and interferon-gamma increased in a concentration-response manner. These results were replicated in a second, independently recruited population of 20 different volunteers. CONCLUSIONS Low concentrations of HgCl(2) affect immune function in human cells by dysregulation of cytokine signaling pathways, with the potential to influence diverse health outcomes such as susceptibility to infectious disease or risk of autoimmunity.
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Affiliation(s)
- Renee M. Gardner
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Jennifer F. Nyland
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Sean L. Evans
- Department of Molecular Microbiology and Immunology and
| | - Susie B. Wang
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Kathleen M. Doyle
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Ciprian M. Crainiceanu
- Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Ellen K. Silbergeld
- Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Address correspondence to E.K. Silbergeld, Johns Hopkins Bloomberg School of Public Health, Environmental Health Sciences, 615 N. Wolfe St., Room E6644, Baltimore, MD 21205 USA. Telephone: (410) 955-8678. Fax: (443) 287-6414. E-mail:
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Barbieri FL, Cournil A, Gardon J. Mercury exposure in a high fish eating Bolivian Amazonian population with intense small-scale gold-mining activities. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2009; 19:267-277. [PMID: 20183195 DOI: 10.1080/09603120802559342] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Methylmercury exposure in Amazonian communities through fish consumption has been widely documented in Brazil. There is still a lack of data in other Amazonian countries, which is why we conducted this study in the Bolivian Amazon basin. Simple random sampling was used from a small village located in the lower Beni River, where there is intense gold mining and high fish consumption. All participants were interviewed and hair samples were taken to measure total mercury concentrations. The hair mercury geometric mean in the general population was 3.02 microg/g (CI: 2.69-3.37; range: 0.42-15.65). Age and gender were not directly associated with mercury levels. Fish consumption showed a positive relation and so did occupation, especially small-scale gold mining. Hair mercury levels were lower than those found in Brazilian studies, but still higher than in non-exposed populations. It is necessary to assess mercury exposure in the Amazonian regions where data is still lacking, using a standardized indicator.
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Passos CJS, Mergler D. Human mercury exposure and adverse health effects in the Amazon: a review. CAD SAUDE PUBLICA 2009; 24 Suppl 4:s503-20. [PMID: 18797727 DOI: 10.1590/s0102-311x2008001600004] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2008] [Accepted: 04/29/2008] [Indexed: 11/22/2022] Open
Abstract
This paper examines issues of human mercury (Hg) exposure and adverse health effects throughout the Amazon region. An extensive review was conducted using bibliographic indexes as well as secondary sources. There are several sources of Hg (mining, deforestation, reservoirs), and exposure takes place through inhalation or from fish consumption. There is a wide range of exposure, with mean hair-Hg levels above 15 microg/g in several Amazonian communities, placing them among the highest reported levels in the world today. Dietary Hg intake has been estimated in the vicinity of 1-2 microg/kg/day, considerably higher than the USEPA RfD of 0.1 microg/kg/day or the World Health Organization recommendation of 0.23 microg/kg/day. Neurobehavioral deficits and, in some cases, clinical signs have been reported both for adults and children in relation to Hg exposure in several Amazonian countries. There is also some evidence of cytogenetic damage, immune alterations, and cardiovascular toxicity. Since fish provide a highly nutritious food source, there is an urgent need to find realistic and feasible solutions that will reduce exposure and toxic risk, while maintaining healthy traditional dietary habits and preserving this unique biodiversity.
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Affiliation(s)
- Carlos J S Passos
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brasil.
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Ilbäck NG, Frisk P, Friman G. Effects of xenobiotics and nutrients on host resistance studied in experimental human infections adapted to rodents. J Pharmacol Toxicol Methods 2008; 58:179-88. [DOI: 10.1016/j.vascn.2008.05.132] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2008] [Accepted: 05/12/2008] [Indexed: 01/05/2023]
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Lead poisoning associated with malaria in children of urban areas of Nigeria. Int J Hyg Environ Health 2008; 211:591-605. [PMID: 18599348 DOI: 10.1016/j.ijheh.2008.05.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 05/06/2008] [Accepted: 05/07/2008] [Indexed: 12/24/2022]
Abstract
The principal objectives of this study are to (a) investigate the prevalence of elevated blood lead levels (EBLLs) in children of three major cities of Nigeria with different levels of industrial pollution; (b) identify the environmental, social and behavioral risk factors for the EBLLs in the children; and (c) explore the association between malaria (endemic in the study areas) and EBLLs in the pediatric population. The study involved 653 children aged 2-9 years (average, 3.7 years). The mean blood lead level (BLL) for the children was 8.9+/-4.8microg/dL, the median value was 7.8microg/dL, and the range was 1-52microg/dL. About 25% of the children had BLL greater than 10microg/dL. There were important differences in BLLs across the three cities, with the average value in Ibadan (9.9+/-5.2microg/dL) and Nnewi (8.3+/-3.5microg/dL) being higher than that in Port Harcourt (4.7+/-2.2micro/dL). Significant positive associations were found between BLL and a child's town of residence (p<0.001), age of the child (p=0.004), length of time the child played outside (p<0.001), presence of pets in a child's home (p=0.023), but negatively with educational level of caregiver (p<0.001). This study is one of the first to find a significant negative association between BLL and malaria in a pediatric population, and this association remained significant after controlling for confounding diseases and symptoms. The shared environmental and socio-demographic risks factors for lead exposure and Plasmodium (most common malaria parasites) infection in urban areas of Nigeria are discussed along with possible ways that lead exposure may influence the host response to infection with malarial parasites.
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Hacon S, Barrocas PRG, Vasconcellos ACSD, Barcellos C, Wasserman JC, Campos RC, Ribeiro C, Azevedo-Carloni FB. An overview of mercury contamination research in the Amazon basin with an emphasis on Brazil. CAD SAUDE PUBLICA 2008; 24:1479-92. [DOI: 10.1590/s0102-311x2008000700003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 07/03/2007] [Indexed: 11/22/2022] Open
Abstract
This article provides an overview of research on mercury contamination in the Amazon Basin and its evolution from 1990 to 2005. The assessment was based on an extensive and systematic review using bibliographic databases available online and a review of projects by research groups. Brazilian research groups were identified using the database of the Brazilian National Research Council (CNPq). A geographic information system was used to determine the location of the studies. Different aspects of mercury contamination were evaluated (environmental studies, impacts on human health, technological improvements). For 1990-2005, a total of 455 publications were identified. The main advances and remaining gaps in relation to environmental issues and human health were identified and discussed. Although the scientific output varied considerably over the period, there was a general increase in the total number of publications per year from the early 1990s (fewer than 20) until 2005 (more than 30), considering the articles published in indexed journals.
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Bose-O'Reilly S, Lettmeier B, Gothe RM, Beinhoff C, Siebert U, Drasch G. Mercury as a serious health hazard for children in gold mining areas. ENVIRONMENTAL RESEARCH 2008; 107:89-97. [PMID: 18321481 DOI: 10.1016/j.envres.2008.01.009] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 11/08/2007] [Accepted: 01/15/2008] [Indexed: 05/26/2023]
Abstract
In many developing countries, mercury is used to extract gold from ore in small-scale mining areas. Exposure through mercury in these small-scale mining communities is a serious health hazard, especially to the children living and working there. Many children begin working with immediate contact to mercury from the very early age of seven. In Indonesia and Zimbabwe, 166 children were clinically examined for mercury. The mercury concentration in the blood, urine, and hair was analyzed. Compared to the control groups, the exposed children showed typical symptoms of mercury intoxication, such as ataxia. The children working with mercury had high levels of this substance in the various biomonitors. The exposure derives mainly from the liquid mercury used to bind gold, forming an amalgam. The amalgam is heated and the smelting amalgam releases mercury vapor plus the wanted gold. Mercury vapor in contrast to liquid mercury is highly toxic. This elemental, vaporized mercury is the main form of exposure. Since in over 50 countries children live in small-scale gold mining areas and are exposed in a similar way to mercury, immediate action is needed to reduce this severe chemical health hazard for children. Child labor with hazardous substances such as mercury must be stopped.
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Affiliation(s)
- Stephan Bose-O'Reilly
- Institute of Public Health, Medical Decision Making and Health Technology Assessment, UMIT-University for Health Sciences, Medical Informatics and Technology, Eduard Wallnoefer-Zentrum I, A-6060 Hall i.T., Austria.
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Umbangtalad S, Parkpian P, Visvanathan C, Delaune RD, Jugsujinda A. Assessment of Hg contamination and exposure to miners and schoolchildren at a small-scale gold mining and recovery operation in Thailand. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2007; 42:2071-9. [PMID: 18074277 DOI: 10.1080/10934520701626985] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Gold extracted by Hg-amalgamation process, which can cause both health and environmental problems, is widespread in South East Asia including Myanmar, Laos, Cambodia, and Thailand. Small-scale gold mining operations have been carried out since the year 2000 in Phanom Pha District, Phichit Province, Thailand. Since no data is available for evaluating Hg exposure, an investigation of mercury (Hg) contamination and exposure assessment was carried out at this mine site. Environmental monitoring illustrated the total Hg in water was as high as 4 microg/l while Hg in sediment ranged between 102 to 325 microg/kg dry weight. Both Hg deposition from the air (1.28 microg/100 cm(2)/day) and concentration in surface soil (20,960 microg/kg dry weight) were elevated in the area of amalgamation. The potential of Hg exposure to miners as well as to schoolchildren was assessed. The concentrations of Hg in urine of 79 miners who were directly (group I) or indirectly (group II) involved in the gold recovery operation were 32.02 and 20.04 microg/g creatinine, respectively, which did not exceed regulatory limits (35 microg/g creatinine). Hair Hg levels in both groups (group I and group II) also were not significantly higher than the non-exposed group. In terms of risk factors, gender and nature of food preparation and consumption were the two significant variables influencing the concentration of Hg in urine of miners (P < 0.05). A hazard quotient (HQ) was estimated based on the inorganic Hg exposure of individual miners. The HQ values of group I were in a range 16 to 218 times higher than the safety level set as 1. By comparison the group II HQ index was very low (0.03-0.39). The miners in group I who worked and ate food from this area experienced potentially high exposure to Hg associated with the mining process. In a second Hg exposure assessment, a group of 59 schoolchildren who attended an elementary school near the gold mine site was evaluated for Hg exposure. A slightly higher Hg urine concentration was detected in group I and group II (involved and not involved in gold recovery) at average levels of 15.82 and 9.95 microg/g creatinine, respectively. The average Hg values for both groups were below the established levels indicating no risk from Hg intake. Average Hg hair level in all schoolchildren (0.93 microg/g) was not significantly higher than reference group. There were two variables (gender and personal hygiene) which affected the concentration of Hg in urine of schoolchildren (P < 0.05). The result (HQ) also suggested that schoolchildren were not at risk (< 1). Schoolchildren involved in gold mining activities showed some indirect exposure to Hg from the adults working in mining area.
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Affiliation(s)
- S Umbangtalad
- Environmental Engineering and Management Program, School of Environment Resources and Development, Asian Institute of Technology, Pathumthani, Thailand
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Abstract
During recent years there have been several incidents in which symptoms of disease have been linked to consumption of food contaminated by chemical substances (e.g., 2,3,7,8-tetrachlorodibenzo-p-dioxin, TCDD). Furthermore, outbreaks of infections in food-producing animals have attracted major attention regarding the safety of consumers, e.g., Bovine Spongiform Encephalitis (BSE) and influenza in chicken. As shown for several xenobiotics in an increasing number of experimental studies, even low-dose xenobiotic exposure may impair immune function over time, as well as microorganism virulence, resulting in more severe infectious diseases and associated complications. Moreover, during ongoing infection, xenobiotic uptake and distribution are often changed resulting in increased toxic insult to the host. The interactions among infectious agents, nutrients, and xenobiotics have thus become a developing concern and new avenue of research in food toxicology as well as in food-borne diseases. From a health perspective, in the risk assessment of xenobiotics in our food and environment, synergistic effects among microorganisms, nutrients, and xenobiotics will have to be considered. Otherwise, such effects may gradually change the disease panorama in society.
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Wickre JB, Folt CL, Sturup S, Karagas MR. Environmental exposure and fingernail analysis of arsenic and mercury in children and adults in a Nicaraguan gold mining community. ACTA ACUST UNITED AC 2005; 59:400-9. [PMID: 16268116 DOI: 10.3200/aeoh.59.8.400-409] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Gold mining can release contaminants, including mercury, into the environment, and may increase exposure to naturally occurring elements such as arsenic. The authors investigated environmental and human tissue concentrations of arsenic and mercury in the gold mining town of Siuna, Nicaragua. The study involved 49 randomly selected households in Siuna, from whom a questionnaire along with environmental and fingernail samples were collected. Environmental samples indicated that mercury concentrations in drinking water, although generally low, were higher near the mine site. Arsenic concentrations were elevated in water and soil samples, but their distribution was unrelated to the mining site. Mercury concentrations in fingernail samples were correlated with residential proximity to the mine, drinking water concentrations, occupation, and, among children, with soil concentrations. Fingernail arsenic concentrations correlated with drinking water concentrations among adults who consumed higher levels, and with soil concentrations among children. Fingernail analysis helped to identify differential exposure pathways in children and adults. Mercury and arsenic uptake via soil exposure in children warrants further consideration.
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Affiliation(s)
- Joel B Wickre
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, USA
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Cunha EM, Oliveira MJR, Ferreira PG, Aguas AP. Mercury intake by inflammatory phagocytes: in vivo cytology of mouse macrophages and neutrophils by X-ray elemental microanalysis coupled with scanning electron microscopy. Hum Exp Toxicol 2005; 23:447-53. [PMID: 15497820 DOI: 10.1191/0960327104ht472oa] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Phagocytes remove and store mercury (Hg) that enters the body. Macrophages and granulocytes respond in opposite ways to Hg: macrophages loose cell viability, and neutrophils become protected from apoptosis. We have investigated the cytology of early intake of Hg by macrophages and neutrophils after a short period (2-4 min) of in vivo exposure to HgCl2. The two types of phagocytes were attracted either to a subcutaneous air pouch or to the peritoneal cavity of BALB/c mice by in situ BSA injection. BSA caused, 72 hours later, inflammatory exudates where neutrophils (air-pouch cavity) or macrophages (peritoneal cavity) were the predominant cell type. A lethal dose of HgCl2 (25 mg) was then injected in the two inflammatory cavities. The mice died 2-4 min later and the cell exudates were harvested and studied by scanning electron microscopy coupled with X-ray elemental microanalysis (SEM-XRM). More than half of the phagocytes showed ingested Hg; a higher percentage of macrophages (around 70%) than neutrophils (around 50%) were positive for the metal. Intracellular particles of Hg were spheroid and presented a small diameter (less than 20 nm). They could be seen in large numbers inside phagocytes (up to 20-30 Hg dots per cell); they were scattered throughout the cytoplasm of the cells. The ability of phagocytes to ingest Hg increased as the BSA-induced inflammation progressed. We conclude that (i) Hg is quickly ingested as small particles by phagocytes; (ii) endocytosis of Hg increases with the degree of activation of phagocytes; and (iii) phagocytes internalize Hg by pinocytosis.
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Affiliation(s)
- Elisabete M Cunha
- Department of Anatomy, ICBAS (Abel Salazar Institute for Biomedical Sciences), University of Porto, 4099-003 Porto, Portugal.
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Dórea JG, de Souza JR, Rodrigues P, Ferrari I, Barbosa AC. Hair mercury (signature of fish consumption) and cardiovascular risk in Munduruku and Kayabi Indians of Amazonia. ENVIRONMENTAL RESEARCH 2005; 97:209-219. [PMID: 15533337 DOI: 10.1016/j.envres.2004.04.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Revised: 04/09/2004] [Accepted: 04/12/2004] [Indexed: 05/24/2023]
Abstract
Fish is an important natural resource in the diet of inhabitants of the Amazon rain forest and a marker of its consumption (hair Hg) was used to compare selected cardiovascular risk parameters between tribes of Eastern Amazonia. Three Munduruku (Terra Preta, Kaburua, Cururu) villages and one Kayabi village at the banks of head rivers (Tapajos, Tropas, Kabitutu, Cururu, Curuzinho, Teles Pires) of the Tapajos Basin were studied in relation to fish Hg concentrations, mercury in hair (fish consumption) and erythrocytes, body mass index (height/weight, kg/cm2), and blood pressure. The mean fish Hg concentrations were higher in predatory (578.6 ng/g) than in nonpredatory species (52.8 ng/g). Overall only 26% of fish Hg concentrations were above 500 ng/g, and only 11% were above 1000 ng/g. There was no systematic trend in fish Hg concentrations from rivers with a history of gold-mining activities. The biomarker of fish consumption (hair Hg) was significantly associated with erythrocyte-Hg (r=0.5181; P=0.0001) and was significantly higher in Kayabi (12.7 microg/g) than in the Munduruku (3.4 microg/g). Biomarker-assessed fish consumption rate was higher in the Kayabi (110 g/day) than in the Munduruku villages (30 g/day). Although no significant differences in body mass index (BMI) were observed between tribes, there was a trend of lower increase in blood pressure with age among the higher fish consumers (Kayabi). Summary clinical evaluation did not detect neurologic complaints compatible with Hg intoxication (paraparesis, numbness, tremor, balancing failure), but endemic tropical diseases such as clinical history of malaria showed a high prevalence (55.4%). Fish is an abundant natural resource, important in the Indian diet, that has been historically consumed without perceived problems and can easily be traced through hair Hg. The exposure to freshwater fish monomethyl mercury is less of an issue than endemic infectious diseases such as malaria and lack of basic medical services.
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Affiliation(s)
- José G Dórea
- Faculdade de Ciências da Saúde, Universidade de Brasília, C.P. 04322, 70919-970 Brasília, DF, Brazil.
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Silva IA, Nyland JF, Gorman A, Perisse A, Ventura AM, Santos ECO, de Souza JM, Burek CL, Rose NR, Silbergeld EK. Mercury exposure, malaria, and serum antinuclear/antinucleolar antibodies in Amazon populations in Brazil: a cross-sectional study. Environ Health 2004; 3:11. [PMID: 15522122 PMCID: PMC538267 DOI: 10.1186/1476-069x-3-11] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2004] [Accepted: 11/02/2004] [Indexed: 05/19/2023]
Abstract
BACKGROUND Mercury is an immunotoxic metal that induces autoimmune disease in rodents. Highly susceptible mouse strains such as SJL/N, A.SW, B10.S (H-2s) develop multiple autoimmune manifestations after exposure to inorganic mercury, including lymphoproliferation, elevated levels of autoantibodies, overproduction of IgG and IgE, and circulating immune complexes in kidney and vasculature. A few studies have examined relationships between mercury exposures and adverse immunological reactions in humans, but there is little evidence of mercury-associated autoimmunity in humans. METHODS To test the immunotoxic effects of mercury in humans, we studied communities in Amazonian Brazil with well-characterized exposures to mercury. Information was collected on diet, mercury exposures, demographic data, and medical history. Antinuclear and antinucleolar autoantibodies (ANA and ANoA) were measured by indirect immunofluorescence. Anti-fibrillarin autoantibodies (AFA) were measured by immunoblotting. RESULTS In a gold mining site, there was a high prevalence of ANA and ANoA: 40.8% with detectable ANoA at > or =1:10 serum dilution, and 54.1% with detectable ANA (of which 15% had also detectable ANoA). In a riverine town, where the population is exposed to methylmercury by fish consumption, both prevalence and levels of autoantibodies were lower: 18% with detectable ANoA and 10.7% with detectable ANA. In a reference site with lower mercury exposures, both prevalence and levels of autoantibodies were much lower: only 2.0% detectable ANoA, and only 7.1% with detectable ANA. In the gold mining population, we also examined serum for AFA in those subjects with detectable ANoA (> or =1:10). There was no evidence for mercury induction of this autoantibody. CONCLUSIONS This is the first study to report immunologic changes, indicative of autoimmune dysfunction in persons exposed to mercury, which may also reflect interactions with infectious disease and other factors.
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Affiliation(s)
- Ines A Silva
- The Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe Street, Room E6642, Baltimore, Maryland, 21201 USA
| | - Jennifer F Nyland
- The Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe Street, Room E6642, Baltimore, Maryland, 21201 USA
| | - Andrew Gorman
- Department of Epidemiology, University of Maryland Medical School, Baltimore, Maryland, USA
| | - Andre Perisse
- Department of Epidemiology, University of Maryland Medical School, Baltimore, Maryland, USA
| | - Ana Maria Ventura
- Institute Evandro Chagas (IEC), Fundaçao Nacional da Saúde, Belem do Pará-66090, Brazil
| | - Elizabeth CO Santos
- Institute Evandro Chagas (IEC), Fundaçao Nacional da Saúde, Belem do Pará-66090, Brazil
| | - Jose M de Souza
- Institute Evandro Chagas (IEC), Fundaçao Nacional da Saúde, Belem do Pará-66090, Brazil
| | - CL Burek
- The Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe Street, Room E6642, Baltimore, Maryland, 21201 USA
| | - Noel R Rose
- The Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe Street, Room E6642, Baltimore, Maryland, 21201 USA
| | - Ellen K Silbergeld
- The Johns Hopkins University Bloomberg School of Public Health, 615 N. Wolfe Street, Room E6642, Baltimore, Maryland, 21201 USA
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Dórea JG. Cassava cyanogens and fish mercury are high but safely consumed in the diet of native Amazonians. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2004; 57:248-256. [PMID: 15041248 DOI: 10.1016/j.ecoenv.2003.12.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2003] [Revised: 11/17/2003] [Accepted: 12/08/2003] [Indexed: 05/24/2023]
Abstract
The two most important staple foods (cassava and fish) in the diet of native Amazonians contain neurotoxins (linamarin and monomethyl mercury, MMHg). These same neurotoxins are public health issues in other parts of the world. Factors such as chemistry, environment, and human ecology determine the endemism of neuropathies caused by consumption of cassava (Manihot esculenta Crantz) and fish. Linamarin is a natural component of cassava tubers that can be destroyed before consumption by proper processing. Furthermore, small amounts of the toxin absorbed by people consuming cassava can be effectively metabolized if the diet contains adequate protein-containing sulfur amino acids. Naturally occurring Hg in the waters of the Amazonian rain forest is methylated to MMHg by microorganisms and bioconcentrated in the aquatic food chain. There is no effective method for MMHg removal from fish. Despite high concentrations of naturally occurring neurotoxins in cassava (linamarin) and fish (MMHg), daily consumption of these foods in large amounts over the course of a lifetime poses no health hazards for Amazonians.
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Affiliation(s)
- José G Dórea
- Faculdade de Ciĉncias da Saúde, Universidade de Brasília, Brasília, Brazil.
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