Exposure of children to lead and cadmium from a mining area of Brazil

Exploring the Impact of Mining on Community Health and Health Service Delivery: Perceptions of Key Informants Involved in Gold Mining Communities in Burkina Faso

Sub-Saharan Africa is rich in natural resources but also faces widespread poverty. The United Nations' Sustainable Development Goals brought increased attention to resource extraction projects, emphasizing their development potential in extraction regions. While mining companies are required to conduct environmental impact assessments, their effect on the project-affected communities' health mostly lacks systematic management, and their consideration of community perspectives is insufficient. Between March and May 2019, qualitative research was conducted at three industrial gold mines in Burkina Faso. Thirty-six participants, including community leaders, healthcare providers, and mining officials, were interviewed through key informant interviews about their perceptions on the impacts of mining operations on health, health determinants, and health service delivery. Disparities in perceptions were a key focus of the analysis. Mining officials reported mainly positive effects, while healthcare providers and community leaders described enhancing and adverse health impacts without clear trends observed regarding the extent of the impacts on health determinants. The perception of predominantly positive health impacts by mining officials represents a potential risk for insufficient acknowledgement of stakeholders' concerns and mining-related effects on community health in affected populations. Overall, this study enhances comprehension of the complex interplay between mining operations and health, emphasizing the need for comprehensive assessments, stakeholder involvement, and sustainable practices to mitigate negative impacts and promote the well-being of mining communities.

Lead (Pb) and cadmium (Cd) blood levels and potential hematological health risk among inhabitants of the claimed hazardous region around Qaroun Lake in Egypt

BACKGROUND

Lead (Pb) and cadmium (Cd) heavy metals are considered potentially hazardous toxins which cause serious health problems. Many studies reported that the water of Qaroun Lake in Fayoum, Egypt with its fish farms was contaminated with Pb and Cd above permissible levels. However, there is a lack of studies addressing levels of these toxic metals among inhabitants.

OBJECTIVES

We aimed to evaluate blood levels of Pb and Cd and their potential health risk among inhabitants around Qaroun Lake.

MATERIALS AND METHODS

This case-control study estimated Pb and Cd blood levels among 190 individuals from two destinations (near and far away) of Qaroun Lack using an atomic absorption spectrometer after full history taking and routine checkup investigations; Full blood count, serum ferritin, liver enzyme (ALT), and creatinine levels.

RESULTS

There was a significant difference between blood levels of Pb and Cd heavy metals of inhabitants from near and far away Qaroun Lake destinations (p-value < 0.001). The majority of inhabitants around Qaroun Lake had Pb and Cd blood levels above permissible levels (100% and 60% respectively). Critical levels out of them were 12.1% and 30.3% respectively. In comparison to inhabitants faraway Qaroun Lake, three individuals (2.4%) had Cd above the permissible level, while all of them (100%) had Pb level within the permissible level. There were no statistically significant differences between the two sampled populations as regards hemoglobin level, ALT, creatinine, and ferritin serum levels (p-value > 0.05). The difference between studied populations regarding types of anemia was not statistically significant. Subclinical leucopenia was higher in the population near Qaroun Lake when compare to inhabitants far from the lake (13.6% vs. 4.8%, p-value 0.032).

CONCLUSION

Bio-monitoring of populations exposed to Pb and Cd hazardous substances could help in generating an early warning system to reduce the disease burden associated with their toxicity.

Genotoxic Effect of Lead and Cadmium on Workers at Wastewater Plant in Iraq

Heavy metal poisoning is a worldwide problem that is caused by different human industrial activities such as battery and painting manufacturing and occupational exposure of those working at petrol stations. Wastewater is known to contain higher amounts of heavy metals such as lead (Pd) and cadmium (Cd) and might be sources of exposure for workers at the wastewater treatment plant. However, to our best knowledge, no studies were done to evaluate the level of cadmium and lead in blood of workers at wastewater treatment plants and evaluate the subsequent effect of lead and cadmium on delta-aminolevulinic acid dehydratase (δ-ALAD), urinary delta-aminolevulinic acid (Uδ-ALA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) as markers of lead and cadmium toxicity. In this case-control study, 79 workers at the Al-Rustumiya wastewater plant in Baghdad, Iraq, and 40 control subjects were included. The levels of lead and cadmium were measured in blood of the study subjects using the atomic absorption spectroscopy (AAS) method. 8-OHdG was analysed using enzyme-linked immunosorbent assay (ELISA) technique. δ-ALAD and Uδ-ALA were estimated using spectrophotometry-based methods. Our work showed that workers had a significantly higher level of lead and cadmium when compared with the control group (P < 0.05), yet, still within the World Health Organization permissible limit. The level of both metals was positively associated with duration of work at the plant (P < 0.01). The activity of δ-ALAD was inversely associated with the lead level, while both Uδ-ALA and 8-OHdG were positively correlated with the lead level (P < 0.05). These three markers lacked any statistically significant association with the cadmium level (P > 0.05). To sum up, working at the wastewater treatment plant was associated with a higher blood level of lead and cadmium and their possible health hazard. Health and occupational safety authorities are required to set up tighter regulations and protocols to minimize these hazards and ensure a safe working environment.

Impact of mining activities on areas of environmental protection in the southwest of the Amazon: A GIS- and remote sensing-based assessment

The southwest Brazilian Amazon state of Rondônia has a relatively recent non-indigenous occupation, which subsequently develops a variety of human pressures and conflicts of interest presently identified in the region. Given such framework, it is worthwhile to note that there are 57 Conservation Units that must guarantee the biodiversity protection of Amazonia biome. However, due to the need for electricity and the international high demand for minerals, the highlighted scenario has dramatically changed in recent years. Official data from mining processes in the studied area demonstrated the existence of high interest for minerals, especially cassiterite and gold. Mining is indeed an essential activity for the nation mainly due to the generation of jobs and income. On the other hand, it produces several environmental and social impacts that vary accordingly to the peculiarities of the mining and with respect to the type of ore. Therefore, this research work investigated the concentration of mining projects in the state of Rondônia and complementarily evaluated the impact of such activities on areas of environmental protection. Landsat 8 OLI imageries were employed to map the diversity of land covers across the study area and also to evaluate the corresponding impact of mining activities. More than 500 processes have been identified within the Conservation Units. A significant part of the mining areas, covering about 26 km², was observed inside one of the three types of evaluated areas (Integral Protection Sustainable Use Conservation Units and Damping Zone), clearly showing the development of the illegal activity, as defined in terms of the National System of Conservation Units. If deforestation is considered in this analysis, the area increases to about 6110 km², representing more than 5.2% of the Conservation Units. In addition, we proposed the creation of the Mining Pressure Index (MPI), which allows classifying a Conservation Unit by the degree of pressure from mining activities. The proposed index revealed to be very efficient since it predicted high values over Conservation Units where it was expected a greater vulnerability. The index is a promising tool for public policy formulation and management of protected areas, as well as for enforcement action. The results provide a new horizon in terms of the perspective of importance and applicability of geotechnologies in the evaluation of environmental impacts, not restricted to mining activity.

Potentially toxic metal contamination and microbial community analysis in an abandoned Pb and Zn mining waste deposit

Bioindicators have been widely used to assess the contamination of lead/zinc (Pb/Zn) in smelter areas, mining waste disposal areas and in areas containing slags from Pb ore smelting. In this context, the analysis involving microorganisms has gained prominence as a complementary tool in studies aimed at assessing contaminated sites. Therefore, the objective of this study was to assess the contamination of Pb, Zn and cadmium (Cd) in an area where a PbZn smelter operated, using the integration of geochemical and microbial data. The experimental analysis was conducted to characterize the soil collected at three different sites (samples NS, EW and EP). The analysis conducted was physicochemical, metal concentration, metal speciation and analysis of the microbial community through high-throughput sequencing technique. Through the results it was observed that the high concentrations of metals altered the bacterial community present in the soil. Differences were noted between the microbial communities according to the sampling site, especially in sample EP, collected at the margin of the dirt road, which presented higher metal concentrations and microbial diversity. The main phyla detected in the samples were: Proteobacteria, Bacteroidetes and Acidobacteria. Bacteria tolerant to the presence of potentially toxic metals (PTM), such as Rhodoplanes, Kaistobacter, Sphingomonas and Flavisolibacter were identified in the analyzed samples. The phylogenetic groups identified in the study area are similar to those obtained in other studies in metal contaminated areas. The differences between the bacterial communities in each sample indicate that the concentration of PTM may have influenced the microbial community in the soil. Thus, it is noted the importance of the integration of geochemical and microbial data to evaluate the impact of the improper disposal of high PTM concentrated slags in natural soils.

Environmental and take-home lead exposure in children living in the vicinity of a lead battery smelter in Serbia

Blood lead levels (BLLs) have been falling steadily worldwide due to restricted use of lead (Pb) and its compounds. although they remain above preindustrial Pb levels. Elevated BLL can still be found in children living near secondary Pb smelters that represent around 50% of Pb production. There have been no studies on Pb exposure in children living in Serbia ever since the 1980s. The aim of this study was to evaluate the BLLs in children living in two villages in Serbia (Zajača, the location of a secondary lead smelter, and Paskovac, 5 km away), identify the primary determinants of children's BLLs, and investigate the impact of BLLs on children's health symptoms and school achievement. The study was conducted in 2011 on 127 children, aged 1-18 years, whose BLLs were measured using inductively coupled argon plasma mass spectrometry (ICP-MS). The median BLL in children was 12 μg/dl, with a significantly higher value of 17.5 μg/dl in Zajača, compared to 7.6 μg/dl in Paskovac. Only 1 out of 75 and 12 out of 52 children from Zajača and Paskovac, respectively, had BLLs below the CDC recommended 5 μg/dl level. Living near the smelter resulted in 19 times, and having a father who works in the plant 4 times higher odds of elevated BLLs. No significant effects of elevated BLLs health symptoms were seen in this study. BLLs of children living near a battery recycling plant in Serbia, an upper-middle income European country, were in the range and even higher than those of children living in developing countries. For the first time, the contribution of environmental and take-home lead exposure was quantified using mixed-effect modeling, and our results indicate a contribution of 25-40% of the take-home lead exposure to the BLLs of children living in the vicinity of a secondary lead smelter.

Blood lead and cadmium levels in preschool children and associated risk factors in São Paulo, Brazil

In Brazil, there are scarce data on lead (Pb) and cadmium (Cd) contamination, especially for more vulnerable populations such as preschool children. In this paper, we answer two questions: (1) What are the exposure levels of lead and cadmium in preschool children, in Sao Paulo, Brazil? and (2) What are the risk factors associated with this exposure? This cross-sectional study included 50 day care centers (DCCs), totaling 2463 children aged 1-4 years. Venous blood samples were analyzed by ICP-MS. Questionnaires were administered to the parents. Multiple logistic regression models were used to identify associations between blood lead levels (BLLs) and blood cadmium levels (BCLs) and potential risk factors. The geometric mean for BLLs was 2.16 μg/dL (95% CI: 2.10-2.22 μg/dL), and the 97.5th percentile was 13.9 μg/dL (95% CI: 10.0-17.3 μg/dL). For cadmium exposure, the geometric mean for BCLs was 0.48 μg/L (95% CI: 0.47-0.50 μg/L), and the 95th percentile was 2.57 μg/L (95% CI: 2.26-2.75 μg/L). The DCCs' geographic region was associated with high BLLs and BCLs, indicating hot spots for lead and cadmium exposures. In addition, it was found that the higher the vehicles flow, the higher were the BLLs in children. Red lead in household gates was also an important risk factor for lead exposure. Comparing these results with the findings of the Fourth National Report on Human Exposure to Environmental Chemicals by CDC-2013, it was found that in Brazilian preschool children the BLLs are almost three times higher (97.5th percentile) and the BCLs are almost twelve times higher (95th percentile) than those in U.S. children. This information is essential to formulate public health policies.

Metals and arsenic in fish from a Ramsar site under past and present human pressures: Consumption risk factors to the local population

The risk of metals and As in seafood for traditional populations living in a Marine Protected Areas (MPA) is seldom assessed, although the risk of human exposure to contaminants is one of the indicators associated with the socioeconomic goals of MPAs. The current study aimed to estimate the potential risk of some metals (Cd, Pb, and Zn) and arsenic (As) for human health through the ingestion of fish locally harvested in a Ramsar site, the Cananéia-Iguape-Peruíbe Environmental Protected Area (APA-CIP). Previous studies showed environmental impacts in this area due to former mining activities and urbanization. Cathorops spixii, a catfish largely consumed by the local population, was collected along the estuary in three seasons with different rain regimes. Metals and As loads in muscle tissue were quantified and it was estimated (i) the target hazard quotient (THQ) and (ii) the daily intake (EDI) for metals and As, (iii) the cancer risk (CRisk) only for As, and (iv) the number of eligible meals per month. Cd, Pb, and As were found at concentrations above action levels for human consumption. Depending on the level of exposure of the local population, the consumption of C. spixii may pose risk to human health. Highest THQs were estimated for fish collected in sites closer to the main contamination sources in the APA-CIP, i.e. the mouth of Ribeira de Iguape River (P1) and the city of Cananéia (P4, P5, and P6). Arsenic showed high levels of cancer risk, although restricted to the area close to the city. The exposure of the local population to metal and As contaminated seafood cannot be disregarded in environmental studies and management of the APA-CIP.

Environmental Assessment and Blood Lead Levels of Children in Owino Uhuru and Bangladesh Settlements in Kenya

BACKGROUND

Lead exposure is linked to intellectual disability and anemia in children. The United States Centers for Disease Control and Prevention (CDC) recommends biomonitoring of blood lead levels (BLLs) in children with BLL ≥5 μg/dL and chelation therapy for those with BLL ≥45 μg/dL.

OBJECTIVES

This study aimed to determine blood and environmental lead levels and risk factors associated with elevated BLL among children from Owino Uhuru and Bangladesh settlements in Mombasa County, Kenya.

METHODS

The present study is a population-based, cross-sectional study of children aged 12-59 months randomly selected from households in two neighboring settlements, Owino Uhuru, which has a lead smelter, and Bangladesh settlement (no smelter). Structured questionnaires were administered to parents and 1-3 ml venous blood drawn from each child was tested for lead using a LeadCare ® II portable analyzer. Environmental samples collected from half of the sampled households were tested for lead using graphite furnace atomic absorption spectroscopy.

RESULTS

We enrolled 130 children, 65 from each settlement. Fifty-nine (45%) were males and the median age was 39 months (interquartile range (IQR): 30-52 months). BLLs ranged from 1 μg/dL to 31 μg/dL, with 45 (69%) children from Owino Uhuru and 18 (28%) children from Bangladesh settlement with BLLs >5 μg/dL. For Owino Uhuru, the geometric mean BLL in children was 7.4 μg/dL (geometric standard deviation (GSD); 1.9) compared to 3.7 μg/dL (GSD: 1.9) in Bangladesh settlement (p<0.05). The geometric mean lead concentration of soil samples from Owino Uhuru was 146.5 mg/Kg (GSD: 5.2) and 11.5 mg/Kg (GSD: 3.9) (p<0.001) in Bangladesh settlement. Children who resided <200 m from the lead smelter were more likely to have a BLL ≥5 μg/dL than children residing ≥200 m from the lead smelter (adjusted odds ratio (aOR): 33.6 (95% confidence interval (CI): 7.4-153.3). Males were also more likely than females to have a BLL ≥5 μg/dL (39, 62%) compared to a BLL<5 μg/dL [aOR: 2.4 (95% CI: 1.0-5.5)].

CONCLUSIONS

Children in Owino Uhuru had significantly higher BLLs compared with children in Bangladesh settlement. Interventions to diminish continued exposure to lead in the settlement should be undertaken. Continued monitoring of levels in children with detectable levels can evaluate whether interventions to reduce exposure are effective.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

Scientific approval for the study was obtained from the Ministry of Health, lead poisoning technical working group. Since this investigation was considered a public health response of immediate concern, expedited ethical approval was obtained from the Kenya Medical Research Institute and further approval from the Mombasa County Department of Health Services. The investigation was considered a non-research public health response activity by the CDC.

COMPETING INTERESTS

The authors declare no competing financial interests.

Cardiovascular-Related Outcomes in U.S. Adults Exposed to Lead

Cardiovascular-related clinical markers were evaluated in this cross-sectional study of United States adults (aged ≥ 20) exposed to lead via the National Health and Nutrition Examination Survey 2007-2008 and the 2009-2010 datasets. In four quartiles of exposure-0-2 μg/dL, 2-5 μg/dL, 5-10 μg/dL, and 10 μg/dL and over, clinical and anthropometric markers were evaluated-to examine how the markers manifested in the quartiles. Associations were determined via linear regression. Finally, clinical makers, and how they manifested between exposed and less-exposed occupations, were explored in addition to how duration of exposure altered these clinical markers. In regression analysis, Diastolic Blood Pressure (DBP) and high-density lipoprotein (HDL) cholesterol, were significantly associated with blood lead level (BLL). In the occupational analysis, Systolic Blood Pressure (SBP), DBP, C-reactive protein (CRP), triglycerides, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, showed differences between populations in the exposed and less-exposed occupations. Regarding Agriculture, Forestry & Fishing, the duration of exposure altered SBP, CRP, and LDL cholesterol. With mining, the duration of exposure altered SBP, DBP, triglycerides, and HDL cholesterol, whereas in construction, the duration in occupation altered SBP, triglycerides, and CRP. In conclusion, lead exposure has a profound effect on the cardiovascular system, with potentially adverse outcomes existing at all exposure levels.

A Systematic Review of Children's Environmental Health in Brazil

In the region of the Americas, approximately 100,000 children under the age of 5 years die each year due to environmental hazards. Brazil, due to its large size and wide range of environmental challenges, presents numerous hazards to children's health. The aim of this study was to systematically review the scientific literature that describes children's exposures to environmental pollutants in Brazil and their effects on Brazilian children's health. A systematic review of the scientific literature was performed without language restrictions and time of publication (years). The literature search was conducted in the following key resources: PubMed (MEDLINE), Scopus and Web of Science with the MeSH Terms: Environmental exposure AND Brazil (filters: Human, Child [birth to 18 years] and Affiliation Author). The Virtual Health Library was also employed to access the databases Scielo and Lilacs. The search strategy was [DeCS Terms]: Child OR adolescent AND Environmental exposure AND Brazil. Health effects in children associated with exposure to environmental pollutants in Brazil were reported in 74 studies, during the period between 1995 and 2015. The most frequently cited effect was hospital admission for respiratory causes including wheezing, asthma, and pneumonia among children living in areas with high concentrations of air pollutants. A broad spectrum of other health effects possibly linked to pollutants also was found such as prematurity, low birth weight, congenital abnormality (cryptorchidism, hypospadia, micropenis), poor performance in tests of psychomotor and mental development, and behavioral problems. Exposure to pesticides in utero and postnatally was associated with a high risk for leukemia in children <2 years old. These results show that there is a need in Brazil for stricter monitoring of pollutant emissions and for health surveillance programs especially among vulnerable populations such as pregnant women and young children.

Trace element levels in blood and associated factors in adults living in the metropolitan area of São Paulo, Brazil

This study evaluated blood arsenic (As), cadmium (Cd), lead (Pb), mercury (Hg), copper (Cu) and manganese (Mn) levels in a group of residents (n=374) in the metropolitan area of São Paulo (MASP) and investigated the association between trace element levels in blood and sociodemographic and lifestyle factors. Trace elements were measured in specimens by inductively coupled plasma mass spectrometry (ICP-MS). Geometric means were 3.6μg/L, 0.13μg/L, 23.9μg/L, 1.4μg/L, 999μg/L, and 12.5μg/L for As, Cd, Pb, Hg, Cu, and Mn, respectively. As, Pb and Hg levels were associated with education level. Men presented higher blood lead levels (PbB) and lower blood copper levels (CuB) than women. Fish consumption was primarily related to increased blood Hg levels (HgB). Smokers exhibited 1.8 times more blood cadmium levels (CdB) than non-smokers. Only 4% of the study samples exceeded the Pb reference values for the MASP population, and 12% had Hg levels higher than the German HBM-I value (5μg/L for adults).The study group showed slightly higher exposure to As, Hg and Mn and lower Cd than those of European and North American studies.

What are the blood lead levels of children living in Latin America and the Caribbean?

INTRODUCTION

Information on the prevalence of lead exposure is essential to formulate efficient public health policies. Developed countries have implemented successful public policies for the prevention and control of lead poisoning. In the United States, Canada, Japan and the European Union, for instance, periodically repeated prevalence studies show that blood lead levels (BLLs) in children have decreased overall. Although BLL of Latino children in the U.S. have also dropped in recent years, the geometric mean remains higher than that of white children. Little is known about lead exposure in children in Latin America and the Caribbean (LAC). In this review, we responded to two questions: What is currently known about lead sources and levels in children in LAC? Are there public policies to prevent children's exposure to lead in LAC?

METHOD

We conducted a literature review covering the period from January 2000 to March 2014 in the PubMed and Lilacs databases to obtain English, Portuguese and Spanish language studies reporting the prevalence of BLLs in children aged 0-18years living in LAC countries. No specific analytical method was selected, and given the scarcity of data, the study was highly inclusive.

RESULTS

Fifty-six papers were selected from 16 different LAC countries. The children's BLLs found in this review are high (≥10μg/dL) compared to BLLs for the same age group in the U. S. However, most studies reported an association with some type of "lead hot spot", in which children can be exposed to lead levels similar to those of occupational settings. Only Peru and Mexico reported BLLs in children from population-based studies.

CONCLUSIONS

Most BLLs prevalence studies carried out in LAC were in areas with known emission sources. The percentage of children at risk of lead poisoning in LAC is unknown, and probably underestimated. Thus, there is an urgent need to establish public health policies to quantify and prevent lead poisoning, specifically by prioritizing the identification and control of "hot spots".

Medical geology in the framework of the sustainable development goals

Exposure to geogenic contaminants (GCs) such as metal(loid)s, radioactive metals and isotopes as well as transuraniums occurring naturally in geogenic sources (rocks, minerals) can negatively impact on environmental and human health. The GCs are released into the environment by natural biogeochemical processes within the near-surface environments and/or by anthropogenic activities such as mining and hydrocarbon exploitation as well as exploitation of geothermal resources. They can contaminate soil, water, air and biota and subsequently enter the food chain with often serious health impacts which are mostly underestimated and poorly recognized. Global population explosion and economic growth and the associated increase in demand for water, energy, food, and mineral resources result in accelerated release of GCs globally. The emerging science of "medical geology" assesses the complex relationships between geo-environmental factors and their impacts on humans and environments and is related to the majority of the 17 Sustainable Development Goals in the 2030 Agenda of the United Nations for Sustainable Development. In this paper, we identify multiple lines of evidence for the role of GCs in the incidence of diseases with as yet unknown etiology (causation). Integrated medical geology promises a more holistic understanding of the occurrence, mobility, bioavailability, bio-accessibility, exposure and transfer mechanisms of GCs to the food-chain and humans, and the related ecotoxicological impacts and health effects. Scientific evidence based on this approach will support adaptive solutions for prevention, preparedness and response regarding human and environmental health impacts originating from exposure to GCs.

Arbuscular mycorrhizal fungi-assisted phytoremediation of a lead-contaminated site

Knowledge of the behavior of plant species associated with arbuscular mycorrhizal fungi (AMF) and the ability of such plants to grow on metal-contaminated soils is important to phytoremediation. Here, we evaluate the occurrence and diversity of AMF and plant species as well as their interactions in soil contaminated with lead (Pb) from the recycling of automotive batteries. The experimental area was divided into three locations: a non-contaminated native area, a coarse rejects deposition area, and an area receiving particulate material from the chimneys during the Pb melting process. Thirty-nine AMF species from six families and 10 genera were identified. The Acaulospora and Glomus genera exhibited the highest occurrences both in the bulk (10 and 6) and in the rhizosphere soils (9 and 6). All of the herbaceous species presented mycorrhizal colonization. The highest Pb concentrations (mgkg^-1) in roots and shoots, respectively, were observed in Vetiveria zizanoides (15,433 and 934), Pteris vitata (9343 and 865), Pteridim aquilinun (1433 and 733), and Ricinus communis (1106 and 625). The diversity of AMF seems to be related to the area heterogeneity; the structure communities of AMF are correlated with the soil Pb concentration. We found that plant diversity was significantly correlated with AMF diversity (r=0.645; P>0.05) in areas with high Pb soil concentrations. A better understanding of AMF communities in the presence of Pb stress may shed light on the interactions between fungi and metals taking place in contaminated sites. Such knowledge can aid in developing soil phytoremediation techniques such as phytostabilization.

Soil contamination assessment for Pb, Zn and Cd in a slag disposal area using the integration of geochemical and microbiological data

Improper disposal of mining waste is still considered a global problem, and further details on the contamination by potentially toxic metals are required for a proper assessment. In this context, it is important to have a combined view of the chemical and biological changes in the mining dump area. Thus, the objective of this study was to evaluate the Pb, Zn and Cd contamination in a slag disposal area using the integration of geochemical and microbiological data. Analyses of soil organic matter (SOM), pH, Eh, pseudo-total concentration of metals, sequential extraction and microbial community by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were conducted. Metal availability was evaluated based on the geoaccumulation index (I _geo), ecological risk ([Formula: see text]), Risk Assessment Code (RAC) and experimental data, and different reference values were tested to assist in the interpretation of the indices. The soil pH was slightly acidic to neutral, the Eh values indicated oxidized conditions and the average SOM content varied from 12.10 to 53.60 g kg^-1. The average pseudo-total concentrations of metals were in the order of Zn > Pb > Cd. Pb and Zn were mainly bound to the residual fraction and Fe-Mn oxides, and a significant proportion of Cd was bound to the exchangeable and carbonate fractions. The topsoil (0-20 cm) is highly contaminated (I _geo) with Cd and has a very high potential ecological risk ([Formula: see text]). Higher bacterial diversity was mainly associated with higher metal concentrations. It is concluded that the integration of geochemical and microbiological data can provide an appropriate evaluation of mining waste-contaminated areas.

Lead and cadmium exposure in children living around a coal-mining area in Yatağan, Turkey

The study was designed to determine asymptomatic lead poisoning prevalence and cadmium exposure of preschool children living in a coal-mining area in Yatağan, Mugla, Turkey. The research was conducted between May and June 2002. The study included 236 children (53.4% female and 46.6% male) who were identified among the healthy children between the ages of 6 months and 6 years, using a systematic sampling method, from the records of the local medical centre of Yatağan. Assessments of the levels of blood lead and cadmium were performed by an atomic absorption spectrophotometer, in the Department of Biophysics, Cerrahpaşa Medical Faculty. The mean age of females and males were 49±18 and 43±19 months, respectively. The mean blood lead level was 33.8±15.6 μg/dL in females and 38.8±16.0 μg/dL in males. The mean blood lead level of the males was significantly higher than the females ( P<0.05). Correlation analysis showed a statistically significant negative correlation between blood lead level and age in both sex groups ( r=-0.367, P< 0.001). The blood lead level was found to be > 10 μg/dL in 95.7% and > 20 μg/dL in 87.6% of all children. The mean blood cadmium level of all children was 1.31±0.72 mg/dL. The blood cadmium level was found to be >0.5 μg/dL, which is considered to be toxic, in 85% of all children. The difference in blood cadmium levels between sexes was not significant. A statistically significant negative correlation was found between blood cadmium level and age of all children ( r=-0.382, P<0.001). Although it is not possible to understand from this study what proportion of the biological lead and cadmium burden results from mining waste and what proportion comes from other sources, such as paint and gasoline residue deposited in soil and air, these results do indicate that asymptomatic lead poisoning and cadmium exposure are significant problems in children living in the Yatağan area. In conclusion, environmental lead measurements (house dust, soil, drinking water and air) must be performed, the results must be compared with the normal limits, and precautions must be taken if necessary in the Yatağan area. Future public health research efforts should focus on reducing the excessive levels of lead and cadmium in the environment.

Determination of contamination levels of Pb, Cd, Cu, Ni, and Mn caused by former lead mining gallery

In the present study, levels of metal contamination caused by former lead mining area were figured out. For this purpose, Pb, Cd, Cu, Ni, and Mn were determined not only in sediment samples taken from different places of the mining area but also in some plants taken around the mining place. In the digestion of plant samples, dry ashing procedure was applied. Flame atomic absorption spectrophotometer (FAAS) was used in the determination of analytes of interest. All the parameters in digestion and detection procedures were optimized to obtain efficient digestion and high sensitivities for analytes. Standard addition and direct calibration methods were applied to find whether there was any matrix interference to affect the determination of analytes. Mn concentration was found to be the highest for each sample analyzed. Lead concentration was found to be between 41 and 249 mg/kg in soil/sediment samples and between 2.2 and 1003 mg/kg in plant samples. The highest contamination levels for all of the analytes with the exception of Cd were found in current sediment sample.

Environmental and Occupational Lead Exposure Among Children in Cairo, Egypt: A Community-Based Cross-Sectional Study

The aim of this study was to assess childhood lead exposure in a representative sample of Cairo, and to investigate the possible risk factors and sources of exposure. This cross-sectional study was conducted from November 2014 through April 2015. The target population was children aged 6 to 18 years, recruited into 4 groups, garbage city, moderate-living standard area, urban and suburban schools, and workshops in the city of Cairo. Blood lead levels (BLLs) and hemoglobin (Hb) concentrations were measured. Also, potential local environmental sources were assessed for hazardous lead contamination. Analysis on 400 participants has been carried out. A total of 113 children had BLLs in the range 10 to 20 μg/dL. Smoking fathers, housing conditions, playing outdoors, and exposure to lead in residential areas were significantly correlated with high BLLs. The mean values of hemoglobin were inversely correlated with BLLs. Children involved in pottery workshops had the highest BLLs and the lowest Hb values with a mean of (43.3 μg/dL and 8.6 g/dL, respectively). The mean value of environmental lead in workshop areas exceeded the recommended levels. Also, those values measured in dust and paint samples of garbage city were significantly high. Moreover, the mean lead levels in the soil samples were significantly higher in urban schools (P = 0.03) than the suburban ones. Childhood lead poisoning accounts for a substantial burden in Egypt, which could be preventable. Development of national prevention programs including universal screening program should be designed to reduce incidence of lead toxicity among children.

An optical biosensor from green fluorescent Escherichia coli for the evaluation of single and combined heavy metal toxicities

A fluorescence-based fiber optic toxicity biosensor based on genetically modified Escherichia coli (E. coli) with green fluorescent protein (GFP) was developed for the evaluation of the toxicity of several hazardous heavy metal ions. The toxic metals include Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(III). The optimum fluorescence excitation and emission wavelengths of the optical biosensor were 400 ± 2 nm and 485 ± 2 nm, respectively. Based on the toxicity observed under optimal conditions, the detection limits of Cu(II), Cd(II), Pb(II), Zn(II), Cr(VI), Co(II), Ni(II), Ag(I) and Fe(III) that can be detected using the toxicity biosensor were at 0.04, 0.32, 0.46, 2.80, 100, 250, 400, 720 and 2600 μg/L, respectively. The repeatability and reproducibility of the proposed biosensor were 3.5%–4.8% RSD (relative standard deviation) and 3.6%–5.1% RSD (n = 8), respectively. The biosensor response was stable for at least five weeks, and demonstrated higher sensitivity towards metal toxicity evaluation when compared to a conventional Microtox assay.

Blood Lead Levels in Andean Infants and Young Children in Ecuador: An International Comparison

Lead (Pb) exposure in infants and children remains an international health concern. Blood lead (PbB) levels of a cohort of 130 Ecuadorian infants and young children aged 0.33 to 5.8 yr were compared to values reported for similar age groups in Africa, Asia, Europe, Latin America, and the United States. The mean PbB level for the total group of 130 Ecuadorian infants and young children in this study was 29.4 μg/dl (SD: 24.3; range: 3.0-128.2; median: 21.7; geometric mean: 20.7 μg/dl). The mean PbB level for the 0-2 yr age group (infants) was 33.6 μg/dl (SD: 28.9; median: 22.0; range: 3.9-119.7; geometric mean: 23.6 μg/dl), while the average PbB level for the 3-5 yr age group (young children) was 27.9 μg/dl (SD: 22.5: median: 22; range: 3-128.2; geometric mean: 19.8 μg/dl). The difference between the mean PbB levels for the infants and young children was not statistically significant. The average PbB level of 32.6 μg/dl for males was not statistically different from the mean PbB level of 26.3 μg/dl for females. The PbB levels observed in Ecuadorian infants and young children in this investigation were elevated above the World Health Organization (WHO) level of concern of 10 μg/dl and Centers for Disease Control and Prevention (CDC) current reference value of 5 μg/dl. Values were comparable to concentrations found in Pakistan, where occupational use of Pb is prevalent. These findings further indicate that infants and young children exposed to Pb from Pb glazing of ceramics in Andean Ecuadorian villages exhibit greater potential metal-mediated poisoning than children of similar ages in Asia, Europe, other Latin American countries, and the United States.

Multiple exposure and effects assessment of heavy metals in the population near mining area in South China

The objective of this study was to investigate the levels of Cd, Pb, Cu and Zn in the environment and several important food sources grown and consumed in the vicinity of Dabaoshan mine in Southern China, and evaluate potential health risks among local residents. The Cd, Pb, Cu and Zn concentrations of arable soils and well water near the mines exceeded the quality standard values. The concentrations of Cd and Pb in some food crops (rice grain, vegetable and soybean) samples were significantly higher than the maximum permissible level. The Cd and Pb concentrations in half of the chicken and fish meat samples were higher than the national standard. The residents living near Dabaoshan mine had higher Cd and Pb levels in hair than those of a non-exposed population. The intake of rice was identified as a major contributor to the estimated daily intake of these metals by the residents. The hazard index values for adults and children were 10.25 and 11.11, respectively, with most of the estimated risks coming from the intake of home-grown rice and vegetables. This study highlights the importance of multiple pathways in studying health risk assessment of heavy metal exposure in China.

Biomarkers of lead exposure among a population under environmental stress

This study aimed to evaluate the relationship between blood lead and serum creatinine and blood lead and serum urea nitrogen levels as biomarkers of lead exposure from subjects living in a historic polymetallic mining area in China. Elevated levels were found for blood lead, serum creatinine, and serum urea nitrogen in the mining area with mean values at 245.65 μg/l, 74.16 μmol/l, and 12.79 mmol/l, which were significantly higher than those in the control area, respectively. Moreover, the coefficients between paired results for blood lead and serum creatinine and blood lead and serum urea nitrogen were positively statistically significant (serum creatinine vs. blood lead, r = 0.35, p < 0.05; serum urea nitrogen vs. blood lead, r = 0.48, p < 0.05). With respect to the effects of sex and age on the blood lead, serum creatinine, and serum urea nitrogen levels, data analysis revealed there was a tendency for higher blood lead, serum creatinine, and serum urea nitrogen levels in females than in males, and the levels of blood lead, serum creatinine, and serum urea nitrogen increased among older residents. We conclude that females and the older population in the mining area are more susceptible to lead exposure. Blood lead, serum creatinine, and serum urea nitrogen can be useful biomarkers of lead exposure among populations under environmental stress.

Manioc flour consumption as a risk factor for lead poisoning in the Brazilian Amazon

Recent studies reported elevated blood lead (Pb) levels in riparian populations of the Amazon. For this reason, the aim of the present study was to assess the risk to riparians in the Brazilian Amazon to Pb exposure due to the intake of contaminated manioc flour. Lead levels were determined in whole blood (n = 74) and in manioc flour samples (n = 30) in three different communities. Mean blood Pb levels were 16.8 μg/dl, with individuals living in Açaituba presenting the highest mean blood Pb level (22.4 μg/dl), followed by Nova Canaã (17.3 μg/dl) and Santa Cruz (9.8 μg/dl). The minimum blood Pb level found was 0.83 μg/dl and the maximum was 44.3 μg/dl. The estimated daily intake (EDI) was calculated and compared to the benchmark dose lower confidence limit (BMDL) for neurotoxicity. Mean Pb in manioc flour was 0.34 μg/g while EDI was 79 μg/d, corresponding to 260% of the BMDL (varying from 168 to 308%). This finding is of great importance since this high EDI may exert adverse effects on the nervous system of this population. Manioc flour intake may thus present considerable risk of Pb exposure in this region. Risk management strategies and further studies on adverse effects in this population are needed.

Relative contribution of potential modes of surface dust lead contamination in the homes of boatyard caulkers

OBJECTIVES

The aim of this study was to quantify the relative contributions to surface lead contamination of boat-caulkers' houses of three contamination modes, namely "take-home" lead from the caulker, "natural" spatial dispersal from boatyard to household and "redistribution" of accumulated lead-laden dust within the house.

METHODS

Boat-caulkers' houses situated in areas surrounding boat repair yards were recruited. Caulkers' houses that were located close together were divided into location-matched pairs, within which one was randomly assigned to be given a cleaning and designated a CL house, and the other was to be left uncleaned and designated a NCL house. Geographically isolated caulker's houses were randomly assigned to one of the two categories. The nearest non-boatyard worker's house (NB) was additionally recruited for each set. The surface lead loading rate (SLLR), defined as the mass of lead deposited in dust per unit area of surface per unit time, was measured over a period of 3 mo in all houses, and the data were modeled using linear mixed effects regression.

RESULTS

Adjusted values of SLLR differed only slightly between CL and NCL houses (0.96 to 1.02 times) but were between 1.65 and 2.03 times higher in CL and NCL houses than in NB houses depending on proximity to the boatyard and between 2.12 and 2.61 times higher in houses within one km of a boatyard than in more distant houses depending on category of house.

CONCLUSIONS

Newly deposited dust lead likely resulted from the take-home and spatial dispersion modes. The contribution of redistribution is very small.

Lead exposure assessment from study near a lead-acid battery factory in China

The production of lead-acid battery in China covered about one-third of the world total output and there are more than 2000 lead-acid battery factories. They may cause the major environment lead pollution. Blood lead levels of several hundreds of residents were over 100 μg/L due to the waste discharges from a lead-acid battery factory in Heyuan, Guangdong province. This study aimed to find out the environmental lead sources, the human lead exposure pathways, and the amplitudes from a lead-acid battery factory. The study results showed that lead levels in soil, dust, tree leaves and human blood declined with the distances increased from the production site. Twenty nine of 32 participants had blood lead levels of over 100 μg/L with an exceptional high value of 639 μg/L for one child. This result suggested that the lead-acid battery production from this factory has caused the elevated lead levels in its neighboring environment and residents. Dust intake was the dominant exposure pathway for humans (over 90%). The lead levels found in adult and toddler (6.19 and 50.1 μg/kg/d, respectively) in the polluted area were far higher than the provisional tolerable weekly intake (PTWI) of 25 μg/kg body weight (translated into 3.5 μg/kg/d), which was established by the joint FAO/WHO Expert Committee. Blood lead levels within the family members were strongly correlated with the house dust lead levels. Our results in this study suggested that further studies in this area should be performed to assess human exposure and relevant human health risks from living close to lead-acid battery factories.

Experiências brasileiras e o debate sobre comunicação e governança do risco em áreas contaminadas por chumbo

No artigo são apresentados dois estudos de caso sobre contaminação por chumbo no Brasil. As situações estudadas referem-se a Santo Amaro da Purificação, nordeste, e Adrianópolis, sul, onde comunidades convivem com a contaminação ambiental e a exposição humana ao chumbo em decorrência das atividades industriais e de mineração desenvolvidas durantes décadas, por uma mesma empresa, de forma inconsistente com os padrões ambientais e de mineração, com pouco controle dos impactos ambientais e à saúde humana advindos. Os principais objetivos da investigação realizada foram analisar as estratégias de comunicação de risco adotadas junto às comunidades locais e avaliar o engajamento delas no processo de gerenciamento do risco. A metodologia aplicada incluiu análise de notícias jornalísticas e entrevistas realizadas com diferentes atores sociais, como moradores, jornalistas, pesquisadores e autoridades. Os resultados indicaram a necessidade de promover o envolvimento público no debate e no processo decisório. Os resultados validaram também a hipótese de que os modelos associativos (representados por associações de moradores, por exemplo) são importantes na promoção e no estímulo da participação pública no gerenciamento do risco.

Toxic and essential elements in blood from delivering women in selected areas of São Paulo State, Brazil

This study was designed to evaluate the degree of environmental contamination and possible exposure of pregnant women to toxic elements in seven selected areas of São Paulo State, Brazil. The overall median concentration of Mo in maternal blood was 0.53 μg L⁻¹, highly significant differences found between sites (p < 0.0001). Cd was found to be low overall - 0.09 μg L⁻¹ (0.01-0.58 μg L⁻¹) - with mothers from the Coastal and Rural 1 sites having the highest levels (p < 0.016).Median Hg concentration was 0.60 μg L⁻¹ (0.06 μg L⁻¹-4.35 μg L⁻¹); median Pb level was 16.2 μg L⁻¹ (3.5-57.7 μg L⁻¹) and no differences between sites were observed for both metals. Median Mn level was 16.7 μg L⁻¹ (7.0-39.7 μg L⁻¹), being highest in Urban 2 site (p < 0.016). Concentrations of maternal Co were found to range between 0.06 μg L⁻¹ and 1.1 μg L⁻¹ (median 0.25 μg L⁻¹) and As level was 0.60 μg L⁻¹ (0.10-3.8 μg L⁻¹) overall, with no statistical significance between sites for Co and As. Median Se concentrations were found to be 64 μg L⁻¹ (36-233 μg L⁻¹), with the highest median levels found in Urban 3 site; site differences were statistically significant (p < 0.0001). Correlation for each element (between paired maternal and cord blood) was measured only in Rural site 1; significant correlation was shown for Hg, Pb, Mn and Co (p < 0.05). These findings may be interpreted as indicating low environmental contamination in São Paulo State, Brazil. These findings could also indicate that pregnant women have little or no contact with pollutants, possibly due to awareness campaigns carried out by public health practitioners.

Whole blood, serum, and saliva lead concentrations in 6- to 8-year-old children

With increasing evidence of adverse health effects of lower lead levels (below 10microg/dL in whole blood), studies on novel internal dose biomarkers are needed. This study aimed at: (1) assessing the lead exposure by measuring this element in whole blood (Pb-blood), serum (Pb-serum), and 3 different types of saliva: whole (Pb-whole-saliva), submandibular/sublingual (Pb-sub-saliva) and parotid saliva (Pb-parotid-saliva); (2) correlating Pb-blood with Pb-serum; and (3) relating Pb-blood and Pb-serum with the lead found in the different salivas. The study population included 444 children aged 6 to 8 years attending 4 government schools in the district of Campos Eliseos, in Ribeirao Preto, Sao Paulo State, Brazil. Whole blood, serum, parotid, submandibular/sublingual ("sub-saliva"), and whole saliva were collected in trace element-free tubes. Lead concentrations were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Median Pb-blood and Pb-serum were 2.1microg/dL and 0.4microg/L, respectively. Ten percent of the children had Pb-blood between 4.0 and 9.4microg/dL. Boys showed higher Pb-blood than girls (2.3 vs. 2.0microg/dL, p<0.0003). Lead concentrations in whole, sub, and parotid saliva were 1.7, 1.4, and 1.3microg/L, respectively. No significant correlations were found between Pb-blood and Pb-serum, between Pb-blood and lead in the 3 different salivas, or between Pb-serum and Pb-whole-saliva or Pb-sub-saliva. However, there was a weak statistically significant correlation between Pb-serum and Pb-parotid-saliva. In conclusion, the mean Pb-blood concentration was 2.4microg/dL, with 10% of the children exhibiting Pb-blood between 4.0 and 9.4microg/dL. Boys presented higher Pb-blood. Results suggest that Pb-blood has no correlation with Pb-serum or lead in the 3 different salivas collected here. A weak but statistically significant correlation between Pb-serum and Pb-parotid-saliva was found. Our results also point to the need for carrying out more studies on sources of exposure and lead levels in children in Brazil.

Elevated blood lead levels in a riverside population in the Brazilian Amazon

Lead (Pb) is recognized as one of the most toxic metals. Sources of Pb exposure have been widely documented in North America, and the removal of Pb additives from gasoline was reflected in a dramatic lowering of blood Pb concentration. In Latin America, the removal of Pb from gasoline resulted in decreased exposure, but Pb levels in many areas remain high due to occupational and environmental sources of exposure. While many of the Pb sources have been identified (mining, industries, battery recycling, lead-based paint, ceramics), new ones occasionally crop up. Here we report on blood Pb (B-Pb) levels in remote riverside communities of the Brazilian Amazon. Blood Pb (B-Pb) levels were determined in 448 persons from 12 villages of the Lower Tapajós River Basin, Pará, Brazil. Socio-demographic and dietary information, as well as occupational, residential and medical history was collected using an interview-administered questionnaire. B-Pb, measured by ICP-MS, showed elevated concentrations. Mean B-Pb was 13.1 microg/dL +/- 8.5, median B-Pb was 11.2 microg/dL and ranged from 0.59 to 48.3 microg/dL. Men had higher B-Pb compared to women (median: 15.3 microg/dL vs 7.9 microg/dL respectively). B-Pb increased with age for women, while it decreased for men. For both genders, B-Pb decreased with education. There were significant differences between villages. Exploratory analyses, using linear partition models, showed that for men B-Pb was lower among those who were involved in cattle-raising, and higher among those who hunted, farmed and fished. The distribution profile of B-Pb directed us towards artisanal transformation of manioc to flour (farinha), which requires heating in a large metal pan, with stirring primarily done by young men. In the village with the highest B-Pb, analysis of Pb concentrations (dry weight) of manioc (prior to transformation) and farinha (following transformation) from 6 houses showed a tenfold increase in Pb concentration (mean: 0.017 +/- 0.016 to 0.19 +/- 0.10 microg/g). This was confirmed in one of these villages where we sampled manioc paste (just before roasting) and the roasted farinha (0.05 microg/g vs 0.20 microg/g). While there may be other sources (ammunition, sinkers for fishing nets), the high concentrations in farinha, a dietary staple, assuredly makes an important contribution. Further action needs to reduce Pb sources in this region.

Lead contamination, the media and risk communication: a case study from the Ribeira Valley, Brazil

This paper discusses the importance of risk communication in studies of public health issues, and analyses the roles of scientists and the media in communicating scientific data, and their influence on risk perception. The findings are based on a case study from Adrianópolis in the Ribeira Valley (Brazil), conducted between 2005 and 2006, where residents were exposed to lead contamination that originated from a smelter and a sulphide mine. This study had two goals: (1) to understand the impact of information regarding lead contamination on the daily lives of the local inhabitants; (2) to understand and analyse the consequences of an absence of a strategy for risk communication by the researchers involved in the study. Besides drawing attention to the need for studies concerning passive environmental issues, the Adrianópolis case study showed that there was a lack of adequate planning for dissemination of information to local inhabitants that seriously undermined the relationships between researchers, the community and the media, and this caused damage to the various stakeholders.

Bioaccessible lead in soils, slag, and mine wastes from an abandoned mining district in Brazil

We determined the amount of bioaccessible lead in samples of contaminated soils and in mining and refining wastes collected in the surroundings of a former smelter in a rural area in southeastern Brazil. Previous studies showed that some resident children and adults had blood Pb levels above recommended limits, but the contamination route was not established. The incidental ingestion of contaminated soils and dusts is considered to be a major route of lead uptake by humans. Bioavailability of heavy metals like Pb depends on solubility during digestion. We used in vitro tests that simulate human gastrointestinal (GI) media to measure the amount of soluble Pb under such conditions. Pb in soil and solid waste samples ranged from 0.03 to 4.1% and 1.2 to 15%, respectively. On average, 70% of the lead content was soluble in three different simulated gastric solutions (pH 1.5 and 1.7). For the same samples, lead solubility decreased to 2-22% when the pH was raised to pH 7 to approximate conditions found in the small intestine. These results indicate that if soils and dusts of the area are ingested, most of the lead will dissolve in the stomach, and part of it will remain soluble in the duodenum, i.e., would be potentially available for absorption. These findings may explain the high blood Pb levels previously reported.

Use of human nails as bio-indicators of heavy metals environmental exposure among school age children in Kenya

Metal pollution and its health effects present a challenge currently facing the developing countries. Metal poisoning is usually difficult and expensive to assess or screen in these countries due to limited resources, which means that policies, guidelines, regulations and institutional managements are limited. Hair and nail as biopsy materials were suggested as more attractive biomarkers in assessing heavy metals environmental exposure. This paper deals with quantitative determination of lead (Pb), cadmium (Cd), calcium (Ca), zinc (Zn), and iron (Fe) in fingernails of children (n=200) in urban and rural areas using atomic absorption spectrometry. Factors that were suspected to influence the accumulation of Pb and Cd in children were obtained through a questionnaire. The mean levels of heavy metals in children in urban areas were found to be higher (27.5+/-1.8 microg/g Pb and 0.73+/-0.08 microg/g Cd) than in rural areas (19.7+/-0.9 microg/g Pb and 0.44+/-0.06 microg/g Cd). The difference was significant (P<0.05; DF=168, t-test). Other factors that were found to have significant influence were socio-economic background, health conditions, dietary habits and environmental risk exposure. The results also showed that the school location has more influence on the heavy metals level than the area of residence. The children in a school near the highway were found to have a mean of 34.4+/-3.5 microg/g Pb as compared to those who lived near the highway (31.6+/-2.8 microg/g Pb), however the difference was not significant (P>0.05), suggesting a common source of contaminants in the areas. The correlation results also indicated that a high level of Pb in the nail influenced negatively Zn and Fe but not Ca levels (R=-0.256 Zn; -0.188 Fe) while high levels of Cd had a negative relationship with Fe only (R=-0.241). The association of toxic metals in the nails of children with environmental exposure, and nutritional status implies that policies and actions to reduce heavy metal levels must be implemented and reinforced to address the health issues affecting children and by extension the general public in this country.

Enzymatic inhibition and morphological changes in Hoplias malabaricus from dietary exposure to lead(II) or methylmercury

Neotropical fish traíra (Hoplias malabaricus) were used to investigate the effects of dietary doses of metals through individual exposures to either inorganic lead(II) or methylmercury, respectively, 21 microg Pb2+g(-1) w.w. and 75 ng H(3)C-Hg+g(-1) w.w., every 5 days, for 70 days (14 doses). The erythrocyte delta-aminolevulinic acid dehydratase (ALAd) activity was inhibited after 14 doses of Pb2+ and H(3)C-Hg+. The muscle cholinesterase (ChE) activity was inhibited after 14 doses of H(3)C-Hg+. Damage in cytoskeleton and nuclei were observed after exposure to inorganic lead. Individuals exposed to H(3)C-Hg+ showed the presence of atypical granules and vesicles, cytoplasm disorganization, and mitochondria damages in hepatocytes also after 14 doses. The present results demonstrate that erythrocyte ALAd and muscle ChE activities can be used as long-term biomarkers of sublethal, subchronic, and trophic exposures to Pb2+, and H(3)C-Hg+ in fish. Also the morphological aspects described in the present work confirm the toxicity of both studied metals.

Arsenic occurrence in Brazil and human exposure

Environmental exposure to arsenic (As) in terms of public health is receiving increasing attention worldwide following cases of mass contamination in different parts of the world. However, there is a scarcity of data available on As geochemistry in Brazilian territory, despite the known occurrence of As in some of the more severely polluted areas of Brazil. The purpose of this paper is to discuss existing data on As distribution in Brazil based on recent investigations in three contaminated areas as well as results from the literature. To date, integrated studies on environmental and anthropogenic sources of As contamination have been carried out only in three areas in Brazil: (1) the Southeastern region, known as the Iron Quadrangle, where As was released into the drainage systems, soils and atmosphere as a result of gold mining; (2) the Ribeira Valley, where As occurs in Pb-Zn mine wastes and naturally in As-rich rocks and soils; (3) the Amazon region, including the Santana area, where As is associated with manganese ores mined over the last 50 years. Toxicological studies revealed that the populations were not exposed to elevated levels of As, with the As concentrations in surface water in these areas rarely exceeding 10 microg/L. Deep weathering of bedrocks along with formation of Fe/Al-enriched soils and sediments function as a chemical barrier that prevents the release of As into the water. In addition, the tropical climate results in high rates of precipitation in the northern and southeastern regions and, hence, the As contents of drinking water is diluted. Severe cases of human As exposure related to non-point pollution sources have not been reported in Brazil. However, increasing awareness of the adverse health effects of As will eventually lead to a more complete picture of the distribution of As in Brazil.

Lead exposure in an urban community: investigation of risk factors and assessment of the impact of lead abatement measures

INTRODUCTION

A battery recycling plant located in an urbanized area contaminated the environment with lead oxides. The Secretary of Environment of the State of São Paulo demanded an evaluation of lead exposure among the population in the vicinity of the plant.

OBJECTIVES

To assess the lead exposure of children, to propose control measures and evaluate the impact of these measures.

METHODS

Cross-sectional study of all children<13 years old in a radius of 1km from the plant responsible for the contamination. Blood lead levels (BLL) were determined for each child and questionnaires were applied to their parents. Mean BLL were compared before and after control measures were implemented. Logistic regression identified risk factors of lead exposure.

RESULTS

Of the 850 investigated children, 311 presented BLL above the action limit established by the World Health Organization. Overall, the median BLL was 7.3 micro g/dL and it varied according to age of children (higher among 1-5 years old) and distance of the residence from the plant. Risk factors identified for BLL>10 micro g/dL were: to live in unpaved areas, parent working in the plant, distance from the plant, to play on the ground, pica, and to drink locally produced milk. After control measures were implemented (closing the plant, soil removal, dust vacuum-cleaning in the households, etc.), a reduction of 46% in BLL was observed considering the 241 re-evaluated children with levels >10 micro g/dL.

CONCLUSIONS

This study showed that combined abatement measures were effective in reducing BLL in children living close to a contaminating source. These results informed the decision-making process regarding management of contaminated areas in Brazil.

Health impact of living near an abandoned mine--case study: Jales mines

The activities of mining exploitation in Campo de Jales were performed in an uncontrolled way and gave rise to serious environmental contamination: rubbish depositories have been accumulated with no treatment or maintenance. An investigation developed around Jales Mine showed the existence of some chemical impact originated from the waste produced during mining activities. Some "black spots" for a wide suite of heavy metals were determined in stream sediments and alluvium drained from Jales tailings, which could constitute hazard factors for the area and potential danger for public health. The main objective of this study is to know the effects on health caused by this environmental contamination. It is a case-control study, where two populations--from Campo de Jales and Vilar de Maçada--were compared. They both have very similar living conditions, and were inquired about health issues and screening for lead and cadmium exposure. The results point out to higher prevalence of irritating symptomatology in the mucous of the eyes and respiratory system as well as higher lead and cadmium exposure in the Campo de Jales population.

Occupational and environmental human lead exposure in Brazil

The purpose of this paper is to present a review of data on assessment of exposure and adverse effects due to environmental and occupational lead exposure in Brazil. Epidemiological investigations on children lead exposure around industrial and mining areas have shown that lead contamination is an actual source of concern. Lead in gasoline has been phasing out since the 1980s, and it is now completely discontinued. The last lead mining and lead refining plant was closed in 1995, leaving residual environmental lead contamination which has recently been investigated using a multidisciplinary approach. Moreover, there are hundreds of small battery recycling plants and secondary smelting facilities all over the country, which produce focal urban areas of lead contamination. Current regulatory limits for workplace lead exposure have shown to be inadequate as safety limits according to a few studies carried out lately.

Health survey among people living near an abandoned mine. A case study: Jales mine, Portugal

Campo de Jales is a village surrounding the abandoned Jales mine. The area is heavily contaminated with heavy metals and dusts from large tailings piles as result of centuries of mining operations. The aim of this study is to investigate potential health threats associated with site contamination. The population studied comprised two groups: people living in Campo de Jales (n = 229) and a control group - people living in Vilar de Macada (n = 234). Lead and cadmium exposure and symptoms survey were carried out. The results showed a significant higher levels of blood lead and cadmium between the Campo de Jales residents (lead: 9.5 microgr/dl versus 7.7 microgr/dl; cadmium: 0.84 microgr/dl versus 0,65 microgr/dl) as well as to a higher prevalence of respiratory and irritation symptoms and great concern about his own health.

IN CONCLUSION

community is the scene of long-term health problems resulting from the site environmental contamination.

Anthropometric, environmental, and dietary predictors of elevated blood cadmium levels in Ukrainian children: Ukraine ELSPAC group

No comprehensive data on sources or risk factors of cadmium exposure in Ukrainian children are available. In this we measured the blood levels of cadmium among 80 Ukrainian children and evaluated sources of exposure. A nested case-control study from a prospective cohort of Ukrainian 3-year-old children was conducted. We evaluated predictors of elevated blood cadmium using a multivariable logistic regression model. The model included socioeconomic data, parent occupation, environmental tobacco smoke, hygiene, body-mass index, and diet. Dietary habits were evaluated using the 1992 Block-NCI-HHHQ Dietary Food Frequency survey. Elevated cadmium was defined as blood levels in the upper quartile (0.25 microg/L). The mean age for all 80 children was 36.6 months. Geometric mean cadmium level was 0.21 microg/L (range = 0.11-0.42 microg/L; SD = 0.05). Blood cadmium levels were higher among children taking zinc supplements (0.25 vs 0.21 microg/L; P = 0.032), children who ate sausage more than once per week (0.23 vs 0.20; P = 0.007) and children whose fathers worked in a by-product coking industry (0.25 vs 0.21; P = 0.056). In the multivariable model, predictors of elevated blood cadmium levels included zinc supplementation (adjusted OR = 14.16; P < 0.01), father working in a by-product coking industry (adjusted OR = 8.50; P = 0.03), and low body mass index (<14.5; adjusted OR = 5.67; P = 0.03). This is the first study to indicate a strong association between elevated blood cadmium levels and zinc supplementation in young children. Whole-blood cadmium levels observed in this group of Ukrainian children appear to be similar to those reported in other Eastern European countries.

Lead, hemoglobin, zinc protoporphyrin and ferritin concentrations in children

OBJECTIVE

To assess the relationship of blood lead and hemoglobin, zinc protoporphyrin, and ferritin concentrations in children.

METHODS

A cross-sectional study was carried out in 136 anemic and non-anemic children from two rural villages near a lead smelter in Adrianópolis, Southern Brazil, from July to September 2001. Hemoglobin electrophoresis was performed to exclude children with hemoglobin variants and thalassemia syndromes associated with anemia. Lead was determined by atomic absorption spectrophotometry; hemoglobin by automated cell counting; zinc protoporphyrin by hematofluorometry; ferritin by chemiluminescence. Student's t-test, Mann-Whitney test, and the c(2) test were used to assess the significance of the differences between the variables investigated in anemic and non-anemic children. Stepwise multivariate linear regression analysis was performed using two models for anemic and non-anemic children respectively.

RESULTS

Lead was negatively associated to hemoglobin (p<0.017) in the first model, and in the second model lead was positively associated to zinc protoporphyrin (p<0.004) after controlling for ferritin, age, sex, and per capita income. There was an inverse association between hemoglobin and blood lead in anemic children. It was not possible to confirm if anemic children had iron deficiency anemia or subclinical infection, considering that the majority (90.4%) had normal ferritin.

CONCLUSIONS

The study detected a relationship between anemia and elevated blood lead concentrations. Further epidemiological studies are necessary to investigate the impact of iron nutritional interventions as an attempt to decrease blood lead in children.

Predictors of elevated blood lead levels among 3-year-old Ukrainian children: a nested case-control study

OBJECTIVES

Lead is common in the general population. However, data are lacking for the Ukraine and many other countries from the former Soviet Union (FSU). In this study we evaluate the level of blood lead among 212 Ukrainian children and determine predictors of elevated lead levels. We also describe the health effects associated with elevated blood lead.

METHODS

A nested case-control study from a prospective cohort of Ukrainian 3-year-old children was conducted in March 1998. Blood assays were analyzed for lead by labs at the Centers for Disease Control and using portable examination kits. We evaluated predictors of elevated blood lead (blood levels in the upper quartile >4.65 microg/dL) using a multivariable logistic regression model. The model included socioeconomic status, parent occupation, environmental tobacco smoke, hygiene, diet, and health status.

RESULTS

The geometric mean lead level was 3.15 microg/dL (range, 0.7--22.7). In our adjusted model, we observed a strong association between lead levels in the upper quartile and children whose fathers worked manual labor jobs in industries associated with lead exposures [adjusted odds ratio (OR)=2.25; P=0.025] and mothers who smoke indoors (adjusted OR=2.87; P=0.047). Daily hygiene and dietary habits were not associated with elevated lead levels. No increased risks of overall morbidity or lead-associated illness were observed (anemia, dental caries, renal disease, cardiovascular diseases, and musculoskeletal complaints).

CONCLUSION

This is the first study to describe lead levels and associated variables among Ukrainian children in the peer-reviewed literature. Elevated lead levels in these children were associated with paternal occupation and mothers smoking indoors. At age 3 no adverse health effects were observed. More data are needed to determine the level of heavy metal contamination in children from the Ukraine and many other former Soviet nation-states.

Environmental contamination and human exposure to lead in Brazil

Adverse effects caused by environmental lead pollution are well recognized. Being a widespread agent in the environment and a major harmful element to organic systems, mostly to children, lead has been investigated all over the world, aiming to improve measures regarding its control. The purpose of this chapter is to present a review of the situation of production, uses, assessment of exposure, and adverse effects from environmental lead contamination in Brazil. It also presents aspects of Brazilian legislation setting up maximum permissible levels of lead in several environmental compartments such as surface and drinking water, soils, sediment, urban air, and also in commercially sold food, vegetables, fish, and meat, in an effort to control industrial emissions. Epidemiological investigations on children's lead exposure around industrial and mining areas are revised, showing that many situations where lead contamination is potentially present still need to be addressed by governmental agencies. In Brazil, lead was withdrawn from gasoline by the end of the 1980s, and the last lead mining and primary smelting plant was closed in 1995, leaving residual environmental lead contamination, which has recently been investigated using a multidisciplinary approach. Nevertheless, there are hundreds of small secondary battery recycling plants all over the country, running smelting facilities that produce local urban areas of lead contamination.

A study of pediatric blood lead levels in a lead mining area in South Africa

This study aimed to determine the blood lead distributions among young children in the lead mining town of Aggeneys in South Africa's Northern Cape Province, and in the comparison community of Pella, about 40 Km away. A further objective of the study was to explore factors associated with elevated blood lead levels. Children aged between 6 and 10 years (average age, 8 years) were studied, 86 from Aggeneys and 68 from Pella. The results showed that blood lead levels among the children of Aggeneys averaged around 16 microg/dL, while in Pella the mean blood lead level equaled 13 microg/dL. Overall, children with raised blood lead levels performed less well at school relative to other children. Within Aggeneys, fathers of "high" lead children tended to shower at work rather than at home, which may have been insufficient to prevent lead from being transported into the home. In conclusion, more stringent environmental control measures are needed, as well as stricter personal hygiene measures, to prevent childhood lead exposure in the mining community.