Mass lead intoxication from informal used lead-acid battery recycling in dakar, senegal

Environmental impacts of a stand-alone photovoltaic system in sub-saharan Africa: A case study in Burkina Faso

This study aims to evaluate and compare the environmental impacts of stand-alone photovoltaic (PV) systems with storage installed in Burkina Faso using the life cycle assessment (LCA). SimaPro 9.4 software, Ecoinvent 3.7 database, and the ReCiPe 2018 (H) median method were used to assess the environmental impacts. The functional unit considered is "1 kWh of electricity produced in Burkina Faso by a stand-alone PV system". Four scenarios combining two variables, battery technology (lead-acid and lithium-ion) and end-of-life management (landfill and recycling), were studied to assess 08 environmental indicators. The results show that production and end-of-life management of batteries and PV modules are the main contributors to the environmental impact, with batteries' impact ranging from 73 to 98 % for lead-acid and 50-68 % for lithium-ion batteries. Compared to landfilling, recycling significantly reduces environmental impacts, achieving reductions of 17-77 % for lead-acid batteries (LABs) and 3-99 % for lithium-ion batteries (LIBs). The comparison between scenarios indicates that the LABs PV system with landfilling generates significantly higher scores across all impact categories than LIBs PV scenarios. Specifically, it shows scores over 10 times higher for human carcinogenic toxicity, 5 times higher for human non-carcinogenic toxicity, and 2 times higher for freshwater ecotoxicity. Despite extending battery lifespan, the sensitivity analysis revealed that landfill PV systems remain the most polluting, while in recycled scenarios, this extension brings them closer to the environmental performance of LIBs PV systems. The use of LIBs in photovoltaic systems is more environmentally friendly than that of LABs, regardless of the end-of-life scenario.

Accurate prediction of spatial distribution of soil potentially toxic elements using machine learning and associated key influencing factors identification: A case study in mining and smelting area in southwestern China

Accurate prediction of spatial distribution of potentially toxic elements (PTEs) is crucial for soil pollution prevention and risk control. Achieving accurate prediction of spatial distribution of soil PTEs at a large scale using conventional methods presents significant challenges. In this study, machine learning (ML) models, specially artificial neural network (ANN), random forest (RF), and extreme gradient boosting (XGB), were used to predict spatial distribution of soil PTEs and identify associated key factors in mining and smelting area located in Yunnan Province, China, under the three scenarios: (1) natural + socioeconomic + spatial datasets (NS), (2) NS + irrigation pollution index (IPI) datasets, (3) NS + IPI + deposition (DEPO) datasets. The results highlighted the combination of NS+IPI+DEPO yielded the highest predictive accuracy across ML models. Particularly, XGB exhibited the highest performance for As (R2 =0.7939), Cd (R2 =0.6679), Cu (R2 =0.8519), Pb (R2 =0.8317), and Zn (R2 =0.7669), whereas RF performed the best for Ni (R2 =0.7146). The feature importance and Shapley additive explanation (SHAP) analysis revealed that DEPO and IPI were the pivotal factors influencing the distribution of soil PTEs. Our findings highlighted the important role of DEPO in spatial distribution prediction of soil PTEs, which has often been ignored in previous studies.

Sustainability of new energy vehicles from a battery recycling perspective: A bibliometric analysis

In recent years, new energy vehicles (NEVs) have taken the world by storm. A large number of NEV batteries have been scrapped, and research on NEV battery recycling is important for promoting the sustainable development of NEVs. Battery recycling is an important aspect of the sustainable development of NEVs. In this study, we conducted an in-depth analysis of the current status of research on NEV battery recycling from a new perspective using bibliometric methods and visualization software. This study shows that research targeting the recycling of NEV batteries is growing rapidly, and collaborative networks exist among researchers from different countries, institutions, and fields. The focus of research has shifted from lead-acid batteries to lithium batteries, and the supply chain and circular economy related to NEV battery recycling is an emerging research hotspot. Based on our analysis, we propose that the government should establish policies to improve the recycling networks at the collection stage and provide subsidies to attract consumers. Enterprises should develop low-cobalt and cobalt-free technologies, utilize green solvents, and develop new battery swap modes. The establishment of an information platform is conducive to the further development of collaborative networks.

Spatio-temporal evaluation of metals and metalloids in the water of high Andean livestock micro-watersheds, Amazonas, Peru

Cattle ranching is a fundamental economic activity in northern Peru, where proper management of water resources is crucial. This study, a pioneer in the region, evaluated water quality and its suitability for human consumption, vegetable irrigation, and livestock production. It is also the first study to document the presence of metals and metalloids in vulnerable areas because they are located at the headwaters of river watersheds. The spatiotemporal evaluation of physicochemical parameters, metals, and metalloids was performed in five micro-watersheds (Cabildo, Timbambo, Pomacochas, Atuen, and Ventilla) from water samples collected in the dry season (October 2017) and wet season (March 2018). The parameters were analyzed using microwave plasma atomic emission spectrometry. The results were contrasted with international and Peruvian quality standards related to dairy cow production. The highest values of pH, total dissolved solids, and electrical conductivity were reported during the dry season, and the highest turbidity during the wet season. Of the metals evaluated, arsenic (As) was omnipresent in all the micro-watersheds, followed by lead (Pb). In contrast to World Health Organization regulations, concentrations of As, cadmium (Cd), Pb, and iron represent a risk; according to Peruvian regulations, As and Pb exceed the concentrations established for use in animal drinking water and vegetable irrigation, and according to water guidelines for dairy cattle, concentrations of As, Pb, Cd, and Al exceed the permitted limits. The high concentrations of these metals in the study area are attributable to a synergy between natural factors, such as Andean geology and livestock activity. The data reported will allow for proper water resource management, pollution prevention, and the design and adoption of mitigation measures.

How does formal and informal industry contribute to lead exposure? A narrative review from Vietnam, Uruguay, and Malaysia

INTRODUCTION

Lead industries are one of the major sources of environmental pollution and can affect human through different activities, including industrial processes, metal plating, mining, battery recycling, etc. Although different studies have documented the various sources of lead exposure, studies highlighting different types of industries as sources of environmental contamination are limited. Therefore, this narrative review aims to focus mainly on lead industries as significant sources of environmental and human contamination.

CONTENT

Based on the keywords searched in bibliographic databases we found 44 relevant articles that provided information on lead present in soil, water, and blood or all components among participants living near high-risk areas. We presented three case scenarios to highlight how lead industries have affected the health of citizens in Vietnam, Uruguay, and Malaysia.

SUMMARY AND OUTLOOK

Factories conducting mining, e-waste processing, used lead-acid battery recycling, electronic repair, and toxic waste sites were the primary industries for lead exposure. Our study has shown lead exposure due to industrial activities in Vietnam, Uruguay, Malaysia and calls for attention to the gaps in strategic and epidemiologic efforts to understand sources of environmental exposure to lead fully. Developing strategies and guidelines to regulate industrial activities, finding alternatives to reduce lead toxicity and exposure, and empowering the public through various community awareness programs can play a crucial role in controlling exposure to lead.

Cottage industry as a source of high exposure to lead: A biomonitoring study among people involved in manufacturing cookware from scrap metal

In low-income countries, a widespread but poorly studied type of cottage industry consists of melting scrap metal for making cookware. We assessed the exposure to lead (Pb) among artisanal workers, and their families, involved in manufacturing cookware from scrap metal. In a cross-sectional survey, we compared artisanal cookware manufacturing foundries with carpentry workshops (negative controls) and car battery repair workshops (positive controls), all located in residential areas, in Lubumbashi (DR Congo). We collected surface dust in the workspaces, and blood and urine samples among workers, as well as residents living in the cookware workshops. Trace elements were quantified in the samples by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In surface dust, median Pb concentrations were higher in cookware foundries (347 mg/kg) than in carpentries (234 mg/kg) but lower than in battery repair workshops (22,000 mg/kg). In workers making the cookware (n = 24), geometric mean (GM) Pb blood cencentration was 118 μg/L [interquartile range (IQR) 78.4-204], i.e. nearly twice as high as among carpenters [60.2 μg/L (44.4-84.7), n = 33], and half the concentration of battery repair workers [255 μg/L (197-362), n = 23]. Resident children from the cookware foundries, had higher urinary Pb [6.2 μg/g creatinine (2.3-19.3), n = 6] than adults [2.3 (2.2-2.5), n = 3]. Our investigation confirms the high Pb hazard linked to car battery repair and reveals a high exposure to Pb among artisanal cookware manufacturers and their families, especially children, in residential areas of a city in a low-income country.

Bovine lead exposure from informal battery recycling in India

We provide an estimate of annual bovine lead exposure and attributable mortality at informal lead acid battery recycling sites in India. We use Pure Earth's Toxic Sites Identification Program database, the FAO's Gridded Livestock dataset, and a Poisson plume model of lead particle air dispersion to estimate site-level mortality. We calculate that India suffers 2370 excess bovine fatalities each year, resulting in more than USD $2.1 million of economic damage. The distribution of damages by location is highly skewed. While we find most sites (86.3%) induce no mortalities, 6.2% of sites induce minor damage (1 to 5 fatalities), 4.1% induce moderate damage (6 to 20 fatalities), and 3.4% induce severe damage (21 + fatalities). These findings highlight the importance of geospatial data to prioritize mitigation efforts and identify a previously unquantified burden on the rural poor.

Childhood blood lead levels and environmental risk factors in Madagascar

One-third of children globally have blood lead levels (BLLs) exceeding the (former) US CDC reference value of 5 µg/dL; this value may be as high as one-half for children in low- and middle-income countries (LMICs). Lead exposure occurs through a variety of routes (e.g., water, dust, air), and in LMICs specifically, informal economies (e.g., battery recycling) can drive lead exposures due, in part, to absent regulation. Previous work by our team identified a ubiquitous source of lead (Pb), in the form of Pb-containing components used in manually operated pumps, in Toamasina, Madagascar. Characterization of BLLs of children exposed to this drinking water, and identification of additional exposure routes were needed. BLLs were measured for 362 children (aged 6 months to 6 years) in parallel with surveying to assess 14 risk factors related to demographics/socioeconomics, diet, use of pitcher pumps, and parental occupations. BLL data were also compared against a recent meta-review of BLLs for LMICs. Median childhood BLL (7.1 µg/dL) was consistent with those of other Sub-Saharan African LMICs (6.8 µg/dL) and generally higher than LMICs in other continents. Risk factors significantly associated (p < 0.05, univariate logistic regression) with elevated BLL (at ≥ 5 µg/dL) included male gender, living near a railway or major roadway (owing potentially to legacy lead pollution), having lower-cost flooring, daily consumption of foods (beans, vegetables, rice) commonly cooked in recycled aluminum pots (a previously identified lead source for this community), and a maternal occupation (laundry-person) associated with lower socioeconomic status (SES). Findings were similar at the ≥ 10 µg/dL BLL status. Our methods and findings may be appropriate in identifying and reducing lead exposures for children in other urbanizing cities, particularly in Sub-Saharan Africa, where lead exposure routes are complex and varied owing to informal economics and substantial legacy pollution.

Sources of Lead Exposure in West Africa

This commentary is an investigation of sources of lead (Pb) exposure in West Africa. Pb is generally acknowledged as one of the most widespread environmental health hazards in West Africa, and there is heightened concern over adverse health effects at various levels of exposure (at doses once considered safe) in the West African region. A literature review for the possible health implications of Pb exposure on human health showed nervous system dysfunction, anemia, and potential cognitive diseases as the major health issues among children, while adults were found to suffer more from cardiovascular dysfunction, neurological decline, and reproductive diseases. Despite a decline in blood lead levels (BLLs), lead exposure continues to be a major public health concern as no level of Pb exposure can be considered safe. Moreover, lowering BLLs entails identifying various lead sources such as gasoline emissions, leaded paint, canned foods, and beverages, as well as plausible biological pathways of lead exposure and response. However, only countries such as Nigeria and Ghana have extensive research available regarding the different sources of Pb exposure. Further, it is not apparent which country is affected the most by Pb exposure. Therefore, this commentary was aimed to explore different literature sources to describe and list the different sources of Pb exposure in 15 West African countries. The findings indicated water, food, and occupational exposure as the major sources of Pb exposure in the region. People with occupations such as e-waste and Pb acid battery recycling, auto mechanics, fuel attending, welding, electronic repairing, farming/spraying, and mining were found to be at immediate risk. Tobacco, spices and paints constituted additional potential sources of exposure. For residents living near landfills or urban area, the major sources of Pb exposure were soil, air, and dust particles. The review revealed a vast research gap on the sources and implications of Pb exposure. Exposure to Pb could further increase due to uncontrolled traffic, urban growth, inadequate urban planning, and the inadequate enforcement of regulations. Therefore, more extensive research on the changing trends of Pb exposure among West African populations is needed.

Accumulation, environmental risk characteristics and associated driving mechanisms of potential toxicity elements in roadside soils across China

Roadside soils may be affected by potential toxicity elements (TPEs) from vehicles; however, pollution status, ecological and health risks of PTEs in roadside soils were rarely reported on national scale. In this study, a dataset of PTEs in roadside soils was compiled based on the literatures published in 2000-2021, and then pollution level, ecological and health risks of PTEs were evaluated using geochemical accumulation index (I_geo), potential ecological risk index (ER), and human risk assessment coupled with Monte Carlo simulation. Driving factors of PTE accumulation in soils were determined by Geo-detector method. Results indicated that Cd exhibited moderate pollution and considerable ecological risk with the highest I_geo of 1.25 and ER of 100.1, respectively. Vehicle ownership (VP) and precipitation (PP) significantly affected accumulation of PTEs, with q values of 0.209 and 0.191 (P < 0.05), respectively. VP paired with PP enhanced nonlinearly PTE accumulation (q = 0.77). Only 6.89% and 1.54% of non-carcinogenic risks for children and adolescent exceeded the threshold of 1, respectively, whereas 93.11%, 95.67%, 58.80% and 58.14% of carcinogenic risks for senior, adults, adolescent, and children surpassed 1E-06, respectively. The results of this study provided valuable implication for managers to design effective strategies for pollution prevent and risk control.

A microplasma optical emission spectrometry pen for point-of-care diagnosis of child blood lead

Blood lead levels (BLL) of children have attracted considerable attention due to their putative impact on intelligence decline. However, most methods used for the determination of blood lead typically require expensive, bulky, high power and gas consuming instrumentation, limiting their application for a point-of-care diagnosis. Herein we report the development and testing of a portable ballpoint discharge microplasma optical emission spectrometer (BD-OES pen) device having the potential to fill this needed measurement capability. The BD-OES pen utilizes a compact ballpoint-pen format integrating point-discharge microplasma, which permits the determination of child BLL requiring no more than 100 μL blood while providing high specificity, sensitivity and satisfactory limit of detection (0.73 μg L^-1). The handheld BD-OES pen is successfully used to diagnose BLL of 16 asymptomatic children on-site, two of whom had excessive the normal BLL. The pen may aid the on-site and rapid diagnosis of childhood BLL, particularly in low-income areas.

Trends of Blood Lead Levels in US Pregnant Women: The National Health and Nutrition Examination Survey (2001–2018)

Objectives

This study investigates the trends of blood lead levels in US pregnant women based on the National Health and Nutrition Examination Survey from 2001 to 2018.

Methods

A total of 1,230 pregnant women were included in this study. The weighted logistic regression was applied to analyze the association between sociodemographic characteristics with high blood levels. We computed the blood lead levels for each survey period from 2001–2002 to 2017–2018. Moreover, we used the adjusted linear regression model to investigate the time-related change in blood lead level. The odds ratio (OR) with a 95% confidence interval (CI) was calculated accordingly.

Results

The mean blood lead was 0.73 ± 0.03 ug/dL, and high blood lead was observed in 2.53% of individuals. The Mexican Americans were more associated with high blood lead than the non-Hispanic white (OR, 1.072; 95% CI, 1.032-1.112). The mean blood lead level has decreased from 0.97 ug/dL in 2001–2002 to 0.46 ug/dL in 2013–2014. Afterward, a slight increase was observed with the mean blood lead of 0.55 ug/dL in 2015–2016 and 0.53 ug/dL in 2017-2018. In the adjusted linear regression model, each year's increase would lead to a 0.029 ug/dL decrease in blood lead (P < 0.001). However, no significant change was observed in the 2017–2018 cycle compared with 2009–2010 (P = 0.218).

Conclusion

This study summarized the trend of blood lead levels in US pregnant women over 2001–2018. Continued effort is still required to control lead sources better and protect this population from lead exposure.

An infinite life cycle assessment model to re-evaluate resource efficiency and environmental impacts of circular economy systems

Challenges exist in life cycle assessment (LCA) to evaluate resource efficiency and environmental impacts of circular economy systems. Rules attributing recycling benefits/burdens are inconsistent, causing system boundary ambiguity. Besides, LCAs covering one or several life cycles fail to capture the complete resource path, which leads to unfair assessment results for the primary life cycle. This paper develops an infinite life cycle assessment model, which integrates LCA, substance flow analysis, and a state transition matrix into an infinite-life-cycle framework. On this basis, algorithms are formulated to quantify the resource efficiency and attribute environmental impacts following the principle of whole first, then allocation. Our model is demonstrated by a case study of lead-acid batteries. Results show that the resource efficiency of lead in the infinite life cycle assessment model is at least 118.75% higher than that of primary lead derived from the typical finite life cycle models. Measured by the index of environmental toxicity potential, environmental impacts are transferred from the primary product life cycle to recycled product life cycles, with the range fluctuating from 66.26% to 68.12%. Our model enables scholars to make more reasonable assessments for circular economy systems based on traditional LCA adjustment. From the infinite-life-cycle perspective, sustainable production policies should focus on increasing the recycling rate of waste products rather than limiting the exploitation of natural resources.

Association between lead source exposure and blood lead levels in some lead manufacturing countries: A systematic review and meta-analysis

Lead is one of the 10 most toxic chemicals of greatest concern for its effects on public health. Predominantly, in undeveloped countries, high blood lead levels (BLLs) persist in the population. To develop intervention strategies that may reduce lead exposure in populations, it is a priority to know the sources of lead pollution. The objective of this critical review and meta-analysis is to assess whether there is an association between different sources of lead exposure and the mean difference in blood lead levels in people exposed. To identify the major lead source exposure, a statistical analysis was performed on selection studies. This investigation reveals the limited information available on the sources of lead in Mexico and other lead producer countries, such as Croatia, Ecuador, Brazil, South Korea, India, Nigeria, Turkey, and China. Meta-analysis could be performed only in battery, smelting mining, and glazed ceramic workers. Battery manufacturing workers have the highest mean difference level of lead in their blood worldwide. Mexico has the second highest mean difference BLL in battery workers in the world. An interesting difference between the mean difference in BLL in mining workers from uncontrolled industry (-39.38) and controlled industry (-5.68) was found. This difference highlighted the success of applying strict control of lead sources and community education to reduce BLL and its potential harmful effects on human health and the environment. Children living near mining sites have the highest mean difference BLL (-11.1). This analysis may aid in assessing the source of lead exposure associated with a range of BLLs in people. Furthermore, this review highlights several social and cultural patterns associated with lead exposure and lead levels in control populations. These results could help to develop international lead regulations and appropriate public health guidelines to protect people around the world.

Investigating the metal contamination status from recycling e-waste sites from Dakar, Senegal

In Senegal, processes employed for recycling e-wastes result in release of so-called heavy metals in the environment. In this study, the metal distribution and concentrations of soils collected from four e-waste recycling areas located in the Dakar area are presented. Measurements are performed using portable X-ray fluorescence and laser-induced breakdown spectroscopy (LIBS) to obtain a complete analysis of the soil, including major and trace elements (i.e., mg/kg). Levels of zinc, copper, manganese, and iron in soils are high but contrasted ranging from 66 mg/kg for Cu in Mbeubeuss landfill to more than 1000 mg/kg for Mn and 10,000 mg/kg for Zn. Lower values are obtained for chromium and lead (Cr = 207 mg/kg and Pb = 181 mg/kg). The most elevated average lead values (i.e., 2935 mg/kg and 1427 mg/kg) are obtained from the e-waste recycling sites located in the urban area of Dakar: Reubeuss and Pikine, respectively. Specific element fingerprints are obtained from each of the studied areas. To evaluate human exposure to the main metals, vegetables grown outside the large e-waste landfill were analyzed. The values obtained for Cr, Cu, Fe, Mn, Sr, and Zn are low, ranging from 0.11 to 9.66 mg/kg for chromium in turnip and iron in beetroots, respectively. The calculated health risk index remains below unit for all vegetables, which means no potential risk of vegetable consumption for human health. The data provided useful information to estimate contaminations and their origin. Therefore, in order to ensure food safety, continuous monitoring of the vegetables grown in the vicinity of recycling areas is needed.

Heavy metals and neurodevelopment of children in low and middle-income countries: A systematic review

BACKGROUND

The presence of harmful environmental exposures, which disproportionately affects low-and-middle income countries (LMICs), contributes to >25% of deaths and diseases worldwide and detrimentally affects child neurodevelopment. Few resources succinctly summarize the existing literature on this topic. Our objective is to systematically review and characterize the evidence regarding the relationship between heavy metals and neurodevelopment of children in LMICs.

METHODS

We conducted a medical librarian-curated search on multiple online databases to identify articles that included individuals <18 years living in a LMIC, quantitatively measured exposure to a heavy metal (either prenatal or postnatal), and used a standardized measurement of neurodevelopment (i.e. cognitive, language, motor, and behavior). Reviews, editorials, or case studies were excluded. Results were analyzed qualitatively, and quality was assessed.

RESULTS

Of the 18,043 screened articles, 298 full-text articles were reviewed, and 100 articles met inclusion criteria. The included studies represented data from 19 LMICs, only one of which was classified as a low-income country. Ninety-four percent of postnatal lead and all postnatal manganese studies showed a negative association with metal exposure and neurodevelopment, which were the strongest relationships among the metals studied. Postnatal exposure of mercury was associated with poor neurodevelopment in only half of studies. Limited data on postnatal arsenic and cadmium suggests an association with worse neurodevelopment. Findings were mixed for prenatal arsenic and lead, although some evidence supports that the neurotoxicity of lead was amplified in the presence of manganese.

CONCLUSIONS AND POTENTIAL IMPACT

We found that lead and manganese appear to consistently have a detrimental effect on the neurodevelopment of children, and more evidence is needed for mercury, arsenic, and cadmium. Better characterization of these effects can motivate and inform prioritization of much needed international policies and programs to reduce heavy metal exposures for young children within LMICs.

The world-wide waste web

Countries globally trade with tons of waste materials every year, some of which are highly hazardous. This trade admits a network representation of the world-wide waste web, with countries as vertices and flows as directed weighted edges. Here we investigate the main properties of this network by tracking 108 categories of wastes interchanged in the period 2001–2019. Although, most of the hazardous waste was traded between developed nations, a disproportionate asymmetry existed in the flow from developed to developing countries. Using a dynamical model, we simulate how waste stress propagates through the network and affects the countries. We identify 28 countries with low Environmental Performance Index that are at high risk of waste congestion. Therefore, they are at threat of improper handling and disposal of hazardous waste. We find evidence of pollution by heavy metals, by volatile organic compounds and/or by persistent organic pollutants, which are used as chemical fingerprints, due to the improper handling of waste in several of these countries.

The 2001–2019 web of international waste trade is investigated, allowing the identification of countries at threat of improper handling and disposal of waste. Chemical tracers are used to identify the environmental impact of waste in these countries.

The Effect of Lead Exposure through Drinking Water on Symptoms of Nervous System Disorders in Communities Around Pasir Sembung Landfill Cianjur, Indonesia, 2020

The nervous system is the system most sensitive to lead (Pb) toxicity, although the poisoning process occurs over a long period of time with a small absorption rate. Lead is a heavy metal that has toxic properties that can contaminate food, drinks, air and water. Lead exposure to the human body can go through various routes, one of which is ingestion. Lead in the environment can come naturally as well as from the results of human activities, one of which is leachate produced from waste that is not managed properly so that the leachate can pollute the environment around the landfill, especially ground water. This study aims to analyze the effect of intake of lead exposure through drinking water on the symptoms of nervous system disorders in the community around Pasir Sembung Landfill, Cianjur, Indonesia on 2020. This study used a cross sectional study design. The research sample consisted of 86 people who live in the ring around the landfill. Data collection was carried out by interview using a questionnaire and water sampling at 20 wells. The results showed that there was an influence between the intake of lead exposure through drinking water on symptoms of nervous system disorders (p value = 0.035; OR = 3.150). Based on these results, it is necessary to take quick steps and proper management efforts from the Cianjur Regency Government and the Pasir Sembung Landfill and related stakeholders in order to reduce the risk of health problems to the people living around the landfill.

Lead concentrations and isotope ratios in blood, breastmilk and feces: contribution of both lactation and soil/dust exposure to infants in a lead mining area, Kabwe, Zambia

Lead (Pb) poses a serious public health concern. Breastmilk may be a possible source of Pb exposure in infants, as Pb can be transferred from the maternal blood to breastmilk. The present study was undertaken to determine the Pb exposure and the contribution of lactation as one of the exposure pathways to infants in a Pb mining area, Kabwe, Zambia. Blood, breastmilk and infants' feces were collected from 418 pairs of infants and mothers. The Pb concentrations, isotope ratios in the samples, and biochemistry in mothers' plasma were analyzed. The overall mean of blood lead levels (BLLs) in infants and mothers were 18.0 and 11.3 μg/dL, respectively. High Pb concentration in breastmilk (range: 0.4-51.9, mean: 5.3 μg/L) above the WHO acceptable level between 2 and 5 μg/L were found and could be one of the sources of Pb exposure in infants. The Pb isotope ratios in infants' feces were the most similar to Pb ratios in the soil samples. The results suggest that infants are also exposed to Pb from the environment. Pb exposure in infants through breastfeeding and soil ingestion could potentially exceed daily intake of Pb which causes neurodevelopmental toxicity. In contrast to the high BLLs in mothers, the plasma biochemical profiles of most analyzed parameters were interestingly within, or close to, the standard reference values. Our data suggest that environmental remediation is urgently needed to reduce the Pb exposure in infants and mothers from the environment in Kabwe in parallel with chelation therapy.

Comparison of knowledge of occupational hazards of lead exposure and blood lead estimation among roadside and organized panel beaters in Enugu metropolis, Nigeria

INTRODUCTION

occupational practices continuously exposes workers to hazards of lead. This study aimed to compare the knowledge of occupational hazards associated with lead exposure, and blood lead estimation among roadside and organized panel beaters in Enugu metropolis, Nigeria.

METHODS

this was a cross-sectional study. Multistage sampling method was used to select 428 panel beaters in Enugu metropolis. Samples were analyzed using Atomic Absorption Spectrometer at 283.3 wavelengths. Data were entered and analyzed using Statistical Package for Social Science 20. Comparative analysis were done using chi - square, T-test, Mann-Whitney U-test, Kruskal-Wallis test, logistic regression and level of significance was set at 5%.

RESULTS

the majority of respondents on both roadside (59.8%) and organized (73.4%) sectors had poor knowledge of hazards of lead exposure. The difference was significant using χ² (P<0.05). The median blood lead levels were 3.0µg|dl and 16.0µg|dl for roadside and organized panel beaters respectively. The difference was significant with Mann-Whitney U test (P<0.001). The prevalence of elevated blood lead at 10µg|dl were 36.9% (roadside sector) and 64.5% (organized sector). The duration of working hours (OR = 4.34, CI = 1.729 - 10.338) was found to be the predictor of elevated blood lead levels.

CONCLUSION

there were general poor knowledge of hazards of lead exposure and high prevalence of elevated lead levels which were more among organized panel beaters. Advocacy on standard organizational structures that support improved occupational health practices is needed and routine outreach by research institutions for health education and safety training.

Prevalence of lead toxicity in adolescents in Kuwait

Background

Elevated blood lead level (EBLL) is a public health problem in both developing and industrialized countries. Being a petrochemical-based economy, lead (Pb) levels are expected to be high in Kuwait, but systematic data on population exposure are lacking. This study aimed at determining the prevalence of EBLL in adolescents in Kuwait.

Methods

Adolescents (N = 1385; age range 11–16 years) were cross-sectionally selected from public middle schools from all Governorates of Kuwait, utilizing multistage cluster random sampling. Pb in whole blood was analyzed by inductively coupled plasma mass spectrometry. Distribution of blood Pb levels (BLL) among Governorates and sexes were compared by non-parametric tests and the prevalence of EBLL (defined as BLL above the CDC reference level of ≥5 μg/dL) was estimated by χ² test. Binary logistic regression was used for assessing the association between EBLL and Governorate.

Results

Median (IQR) BLL was 5.1(3.6–7.1) μg/dL [4.9 (3.8–6.5) μg/dL in males and 5.4 (3.3–7.6) μg/dL in females; p = 0.001]. In the overall sample, 51% had BLL ≥5 μg/dL; 13% had ≥10 μg/dL and 3% > 20 μg/dL. Prevalence of EBLL was 47% in males and 56% in females (p < 0.001). EBLLs were clustered in Al-Asima, Al-Ahmadi (in both sexes); Al-Jahra (in males) and Mubarak Al-Kabeer (in females) Governorates.

Conclusions

EBLL is a significant public health problem in adolescents in Kuwait. Urgent public health intervention is required in areas with EBLL, and the sources of exposure need to be identified for prevention.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11210-z.

Health and Economic Consequences of Lead Exposure Associated with Products and Services Provided by the Informal Economy

In low- and middle-income countries (LMICs), the presence of an informal economy can lead to human exposure to toxic metals such as lead (Pb). This paper demonstrates the local health and economic benefits of modifying practices within the informal economic sector in Madagascar. Specifically, leaded components in 504 locally manufactured household water pumps were replaced with unleaded components. Prior to the intervention, 32% of the household systems exhibited lead concentrations above the World Health Organization (WHO) provisional drinking water guideline of 10 μg/L, but after the intervention, fewer than 3% of the systems were in exceedance. The reduction of lead concentration is modeled to reduce the fraction of children with elevated BLLs (>5 μg/dL) from 34 to 13%. The reduction in BLLs is estimated to provide an average economic benefit of US$11 800 per child based on predicted increases in lifetime productivity. This corresponds to a total benefit of US$8.7 million for the 730 children aged 1-5 associated with the pumps, representing a return on investment of greater than 1000-to-1. Results demonstrate how the formation of partnerships between public, private, and civil society entities, as suggested by UN Sustainable Development Goal 17, can realize important local economic and health benefits in LMICs.

Neurodevelopment and exposure to neurotoxic metal(loid)s in environments polluted by mining, metal scrapping and smelters, and e-waste recycling in low and middle-income countries

This review covers a wide body of literature to gain an understanding of the impacts of informal activities related to metal extraction (primary mining and recycling) on early life exposure to neurotoxicants and on neurodevelopment. In primary mining, gold extraction with Hg amalgamation is the main environmental cause of Hg pollution in most artisanal small-scale gold mining (ASGM) activities around the world. Nevertheless, in Sub-Saharan Africa (SSA), Pb disrupted from gold-related ores, mining, and artisanal cookware production are an important neurotoxicant that seriously contaminates the affected population, with devastating effects on children. In e-waste recycling settings, the range of neurotoxic substances that contaminate mothers and children is wider than in primary mining environments. Thus, Hg and Pb are major pre- and postnatal neurotoxicants affecting children in the informal metal extraction activities and SSA countries show the highest record of human contamination and of neurotoxic effects on children. There are additional sources of neurotoxic contamination from mining and metal processing activities (cyanide tailing in South America and SSA) and/or co-exposure to Hg-containing products such as cosmetics (soaps and Hg-based skin lightning creams in Africa) and pediatric Thimerosal-containing vaccines (TCVs, that breaks down to ethyl-mercury) in current use in middle and low income countries. However, the action of these neurotoxicants (per se or in combination) on children needs more attention and research. Studies show a negative association between biomarkers of all environmental metal(loid)s (As, Cd, Hg, Mn, and Pb) studied and neurodevelopment in young children. Sadly, in many unregulated activities, child labor is widely employed, thus presenting an additional occupational exposure. Children living in polluted environments related to metal processing are disproportionately exposed to a wide range of co-occurring neurotoxic substances. The review showed compelling evidence from highly representative parts of the world (Africa, Asia, and Latin America) that the studied neurotoxic substances negatively affected areas of the brain associated with language, memory and executive function, as well as psychosocial behavior. Protecting the environment and children from unregulated and highly polluting metal extraction and processing are inextricably intertwined and deserve urgent attention.

Design and simulation of a secondary resource recycling system: A case study of lead-acid batteries

The recycling of secondary resources is complicated as consumers, recyclers and governments are all involved in this process. In developing countries, compared to legal recyclers, illegal recyclers not only have cost advantages but also create serious pollution. Inappropriate management policies may cause disorder in the recycling market or inefficient fiscal management. This paper takes China's lead-acid batteries (LABs) from 2000 to 2015 as an example to construct a model of a secondary resource recovery system based on heterogeneous groups and analyzes the environmental and economic impacts of used LAB recycling. By simulating the implementation of different tax cuts, subsidies and regulatory policies by the government in each year, we observe the overall environmental impact of the recycling industry. This study finds that when the total amount of government expenditures is limited, the optimal policy combination emphasizes tax reduction and subsidy policies during the growth period of the recycling industry and uses more funds for supervision in the mature period. Under the balance of fiscal revenues and expenditures, the optimal policy combination can reduce the number of illegal recycling companies and waste lead emissions from the recycling market by 97.9% and 45.8%, respectively. Compared to research conducted using mathematical models and system dynamics models, this result is more in line with the actual situation, and the content is more intuitive. The government needs to adopt different policy combinations in different periods according to the state of the recycling market so that the recycling of secondary resources can achieve the optimal effect.

Altered functional activations of prefrontal brain areas during emotional processing of fear in Inuit adolescents exposed to environmental contaminants

Exposure to mercury, lead and polychlorinated biphenyls (PCBs) have been associated with emotional dysregulation, but their neuronal correlates have yet to be examined. Inuit from Nunavik (Northern Quebec, Canada) face internalizing problems and are among the most exposed individuals to these environmental contaminants in the world. The aim of this study was to examine the link between pre- and postnatal exposure to these contaminants and brain fear-circuitry in Inuit adolescents. Facial expression stimuli were presented to participants (mean age = 18.3 years) in a magnetic resonance imaging (MRI) scanner. Fear conditioning and extinction tasks included neutral faces as the conditioned threat and safety cues and a fearful face paired with a shrieking scream as the unconditioned stimulus. Functional MRI data were gathered at the conditioning phase (n = 71) and at the extinction phase (n = 62). Mercury, lead and PCB 153 concentrations were measured in blood samples at birth (cord blood) and at the time of the adolescent testing to estimate pre- and postnatal exposure, respectively. For each time point, exposures were categorized in tertiles (low, moderate and high exposed groups). Mixed analyses of variance were conducted for each contaminant of interest controlling for sex, age, socioeconomic status, drug/alcohol use, food insecurity and contaminant co-exposure. Results revealed greater differential activation during the conditioning phase in the right orbitofrontal cortex in participants with moderate and high concentrations of cord blood PCB 153 compared to those in the low exposure group. During the extinction phase, the high prenatal mercury exposed group showed a lower differential activation in the right and left anterior cingulate cortex compared to those in the low-exposed group; whereas there was a higher differential activation in right dorsolateral prefrontal cortex in the high postnatal lead exposed group compared to the moderate- and low-exposed groups. Our study is the first to show alterations in the prefrontal brain areas in fear conditioning and extinction tasks in relation to environmental contaminant exposures. The observed brain correlates may advance our understanding of the emotional problems associated with environmental chemical toxicity.

Child lead exposure near abandoned lead acid battery recycling sites in a residential community in Bangladesh: Risk factors and the impact of soil remediation on blood lead levels

Lead is a potent neurotoxin that is particularly detrimental to children's cognitive development. Batteries account for at least 80% of global lead use and unsafe battery recycling is a major contributor to childhood lead poisoning. Our objectives were to assess the intensity and nature of child lead exposure at abandoned, informal used lead acid battery (ULAB) recycling sites in Kathgora, Savar, Bangladesh, as well as to assess the feasibility and effectiveness of a soil remediation effort to reduce exposure. ULAB recycling operations were abandoned in 2016 due to complaints from residents, but the lead contamination remained in the soil after operations ceased. We measured soil and blood lead levels (BLLs) among 69 children living within 200 m of the ULAB recycling site once before, and twice after (7 and 14 months after), a multi-part remediation intervention involving soil capping, household cleaning, and awareness-raising activities. Due to attrition, the sample size of children decreased from 69 to 47 children at the 7-month post-intervention assessment and further to 25 children at 14 months. We conducted non-parametric tests to assess changes in soil lead levels and BLLs. We conducted baseline surveys, as well as semi-structured interviews and observations with residents throughout the study period to characterize exposure behaviors and the community perceptions. We conducted bivariate and multivariate regression analyses of exposure characteristics to determine the strongest predictors of baseline child BLLs. Prior to remediation, median soil lead concentrations were 1400 mg/kg, with a maximum of 119,000 mg/kg and dropped to a median of 55 mg/kg after remediation (p < 0.0001). Among the 47 children with both baseline and post-intervention time 1 measurements, BLLs dropped from a median of 21.3 μg/dL to 17.0 μg/dL at 7 months (p < 0.0001). Among the 25 children with all three measurements, BLLs dropped from a median of 22.6 μg/dL to 14.8 μg/dL after 14 months (p < 0.0001). At baseline, distance from a child's residence to the nearest abandoned ULAB site was the strongest predictor of BLLs and baseline BLLs were 31% higher for children living within 50 m from the sites compared to those living further away (n = 69, p = 0.028). Women and children spent time in the contaminated site daily and relied on it for their livelihoods and for recreation. Overall, this study highlights the intensity of lead exposure associated with the ULAB recycling industry. Additionally, we document the feasibility and effectiveness of a multi-part remediation intervention at a contaminated site embedded within a residential community; substantially reducing child BLLs and soil lead concentrations.

Effectiveness of Mass Media Campaigns to Improve Handwashing-Related Behavior, Knowledge, and Practices in Rural Bangladesh

Water, sanitation, and handwashing interventions that use intensive interpersonal communication improve targeted behaviors, but are expensive at scale. Mass media is an alternative that could reach more people at lower cost but has rarely been rigorously evaluated. We assessed the effectiveness of a mass media campaign in improving handwashing knowledge and practices in rural Bangladesh. We conducted a cross-sectional assessment before the campaign among 8,947 households and again after 4 months of the campaign among 8,400 different households in the same areas. Trained enumerators conducted spot checks of water, sanitation, and hygiene facilities, and recorded reported knowledge and practices. We compared these outcomes after versus before the campaign using generalized linear models with robust standard errors. After the media campaign, caregivers were more likely to recall ≥ 3 messages regarding handwashing (prevalence ratio [PR] = 1.44, 1.34-1.55), sanitation (PR = 1.45, 1.35-1.55), and safe water (PR = 1.17, 1.08-1.26). After the campaign, the prevalence of using soap and water during handwashing demonstrations was higher among caregivers (PR = 1.15, 1.12-1.19) and children (PR = 1.31, 1.22-1.41). Hands were more commonly observed to be visibly clean among caregivers (PR = 1.14, 1.07-1.20) and children (PR = 1.13, 1.05-1.21). Soap and water was more commonly observed in handwashing stations near latrines (PR = 1.12, 1.06-1.19) and in cooking/eating places (PR = 1.09, 1.01-1.18). Our findings indicate improved handwashing knowledge and behaviors following a mass media campaign. This promising approach can be deployed to improve water, sanitation, and hygiene practices at scale and should be evaluated in other contexts.

An Investigation of the Wild Rat Crown Incisor as an Indicator of Lead (Pb) Exposure Using Inductively Couple Plasma Mass Spectrometry (ICP-MS) and Laser Ablation ICP-MS

Lead (Pb) is a metal toxicant of great public health concern. The present study investigated the applicability of the rat incisor in Pb exposure screening. The levels of lead in teeth (Pb-T) in the crown and root of incisors in laboratory Pb-exposed Sprague Dawley rats were quantified using inductively coupled plasma mass spectrometry (ICP-MS). The crown accumulated much Pb-T than the root of the Sprague Dawley rat incisor. The levels of lead in blood (Pb-B) were positively correlated with the Pb-T in the crown and root incisors of the Sprague Dawley rats. As an application of the Pb-T crown results in experimental rats, we subsequently analyzed the Pb-T in the crown incisors of Pb-exposed wild rats (Rattus rattus) sampled from residential sites within varying distances from an abandoned lead-zinc mine. The Pb-T accumulation in the crown of incisors of R. rattus rats decreased with increased distance away from the Pb-Zn mine. Furthermore, the Pb-T was strongly correlated (r = 0.85) with the Pb levels in the blood. Laser ablation ICP-MS Pb-T mappings revealed a homogenous distribution of Pb in the incisor with an increased intensity of Pb-T localized in the tip of the incisor crown bearing an enamel surface in both Sprague Dawley and R. rattus rats. These findings suggest that Pb-T in the crown incisor may be reflective of the rat's environmental habitat, thus a possible indicator of Pb exposure.

Drinking water pollutants may affect the immune system: concerns regarding COVID-19 health effects

The current coronavirus pandemic is leading to significant impacts on the planet, changing our way of life. Although the COVID-19 virus mechanisms of action and pathogenesis are still under extensive research, immune system effects are evident, leading, in many cases, to respiratory distress. Although apparent pollution reduction has been noticed by the population, environmental and human health impacts due to the increased use of plastic waste and disinfectants is concerning. One of the main routes of human exposure to pollutants is through drinking water. Thus, this point of view discusses some major contaminants in drinking water known to be immunotoxic, exploring sources and drinking water routes and emphasizing the known mechanisms of action that could likely compromise the effective immune response of humans, particularly raising concerns regarding people exposed to the COVID-19 virus. Based on a literature review, metals, plastic components, plasticizers, and per- and polyfluoroalkyl substances may display the potential to exacerbate COVID-19 respiratory symptoms, although epidemiological studies are still required to confirm the synergistic effects between these pollutants and the virus.

Investigation of the Use of Low Temperature Geothermal Organic Rankine Cycle Engine in an Autonomous Polygeneration Microgrid

Low-enthalpy geothermal resources (<150 °C) can be used for electricity generation and are widespread around the world, occurring at shallow depths. At the same time, in many parts of the world, there are existing low-enthalpy geothermal wells that are used for a multitude of applications such as for buildings’ heating and agriculture-related applications. The dominant technology to convert low-grade heat (<150 °C) to electricity is the Organic Rankine Cycle (ORC). The autonomous polygeneration microgrid (APM) concept aims to holistically meet in a sustainable way the needs of an off-grid community in terms of electrical loads, space heating and cooling, potable water production through desalination, and the use of hydrogen as fuel for transportation, in the most cost-effective manner possible. Photovoltaics (PVs) and wind turbines have been investigated extensively, since PVs can be installed practically anywhere in the world and wind turbines in areas with sufficient wind potential. The aim of this paper is to investigate techno-economically the potential of utilizing low-enthalpy geothermal resources in small-scale APMs through an ORC engine to fully satisfy the needs of small settlements. In order to accomplish this task with confidence, a case study for the Greek island of Milos has been developed and a typical settlement has been considered. It is worth mentioning that experimental results from a realized low-power (<10 kWe) ORC engine manufactured to operate at temperatures up to 140 °C are used to add reliability in the calculations. In order to meet the needs of the people, four different APMs based on PVs, wind turbines, and geothermal ORC of different but appropriate configurations were designed and sized through optimization. The optimization process was based on particle swarm optimization (PSO). The comparative examination of the results shows that the use of a low-power, low-temperature ORC engine in an APM is technically feasible; more cost effective than the configurations based on PVs, wind turbines, or combination of both; and has increased environmental sustainability.

Insights into the anthropogenic load and occupational health risk of heavy metals in floor dust of selected workplaces in an industrial city of Iran

The levels of Cd, Cr, Cu, Fe, Mn, Pb and Zn were determined in floor dusts from mechanical (MRWs) and battery repairing workshops (BRWs) in Yazd, Iran. The study aimed to evaluate the anthropogenic contribution to the presence of heavy metals (HMs), the possible sources and the related risks that could arise from occupational exposure in the studied workplace microenvironments. Among the analyzed heavy metals, Cu, Pb and Zn exhibited enhanced concentrations in the floor dusts. The EF calculations showed an extremely severe enrichment of HMs, especially for Cd, Cu and Pb, while floor dusts were characterized as "extremely polluted" with regards to those metals. In any case, both EF and I_geo values were significantly higher in the BRWs. These results were also supported by NIPI and PLI values, while contour maps of PLI values in both MRWs and BRWs outlined workshops in N-NE part of Yazd as more impacted compared to other spatial locations. Principal component analysis (PCA) and Pearson's correlation outscored workshops activities as the principal sources of heavy metals. The health risk assessment suggested considerable non-carcinogenic risks regarding Pb in the BRWs which exhibited HQ_ing (mean 2.91) and HI (mean 3.03) values higher than safe level. Regarding carcinogenic risks, CR values for both Cd and Cr were below the safe level (1.0 × 10^-6). The occupational exposure to Pb was evaluated through the predicted BLL values, where with averages of 3.33 μg/dl and 21.4 μg/dl for MRWs and BRWs workers, respectively, indicated a severe Pb exposure for BRWs workers.

Securing of an Industrial Soil Using Turfgrass Assisted by Biostimulants and Compost Amendment

This work aimed to study the effects of compost (applied at two rates) and two commercial microbial biostimulants on the mobility and bioavailability of potentially toxic elements (PTEs) in an industrial soil phytostabilized by Dactylis glomerata L. or a mixed stand of grasses (Lolium perenne L., Poa pratensis L. and Festuca arundinacea Shreb.). The soil showed very high pseudototal and bioavailable concentrations of cadmium (Cd) and lead (Pb), due to improper lead-acid batteries storage. Compost amendment in combination with the two biostimulants produced the best outcomes in terms of plant growth and nutrient uptake. The same mix of beneficial microbes improved soil biological fertility enhancing soil nitrogen fixing and ammonia oxidizing bacteria, while reduced the pore water and NH4NO3 extractable concentrations of Cd and at lower extent of Pb in soil. Accordingly, the lower mobility and bioavailability of Cd in soil determined a lower uptake and accumulation of Cd in shoots of different grass species. Our results suggest that a green cap with turfgrass assisted by biostimulants and compost amendment in PTE-contaminated industrial sites could be a reliable and effective practice to protect and restore soil biological fertility and to reduce the risk of PTE dispersion in the surrounding environment.

Child defecation and feces management practices in rural Bangladesh: Associations with fecal contamination, observed hand cleanliness and child diarrhea

Child open defecation is common in low-income countries and can lead to fecal exposure in the domestic environment. We assessed associations between child feces management practices vs. measures of contamination and child diarrhea among households with children <5 years in rural Bangladesh. We visited 360 households quarterly and recorded caregiver-reported diarrhea prevalence, and defecation and feces disposal practices for children <5 years. We examined caregiver and child hands for visible dirt and enumerated E. coli in child and caregiver hand rinse and stored drinking water samples. Safe child defecation (in latrine/potty) and safe feces disposal (in latrine) was reported by 21% and 23% of households, respectively. Controlling for potential confounders, households reporting unsafe child defecation had higher E. coli prevalence on child hands (prevalence ratio [PR] = 1.12, 1.04-1.20) and in stored water (PR = 1.12,1.03-1.21). Similarly, households reporting unsafe feces disposal had higher E. coli prevalence on child hands (PR = 1.11, 1.02-1.21) and in stored water (PR = 1.10, 1.03-1.18). Effects on E. coli levels were similar. Children in households with unsafe defecation and feces disposal had higher diarrhea prevalence but the associations were not statistically significant. Our findings suggest that unsafe child feces management may present a source of fecal exposure for young children.

Pollution characteristics and chronic health risk assessment of metals and metalloids in ambient PM2.5 in Licheng District, Jinan, China

PM_2.5 samples were collected at the Wangsheren primary school site in Licheng District of Jinan, China, during 2016. Eleven metals and metalloids including Al, As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sb and Se in PM_2.5 were measured by inductively coupled plasma-mass spectroscopy. The annual average mass concentration of PM_2.5 was found to be 88.7 μg m^-3. The highest PM_2.5 concentrations were obtained during the heating seasons of winter and spring. The concentrations of metals and metalloids in PM_2.5 were in a descending order of Al, Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg and Be. The enrichment factors showed that Pb, Mn, As, Se, Cr, Sb, Ni, Cd, Hg originated from anthropogenic sources. Factor analysis indicated that the main sources of the metals were coal combustion dust, soil dust, metallurgical industry, brake abrasion of vehicles and other mixed sources. Coal combustion dust was the primary source of metal pollution in PM_2.5. Non-carcinogenic risks associated with exposure through the respiratory system were between 6.30 × 10^-4 and 7.62 × 10^-1, which were lower than the safe limit (1). The carcinogenic risks of Cr, As and Cd were 3.17 × 10^-5, 1.52 × 10^-5, 2.22 × 10^-6, respectively, which were higher than the precautionary criterion (10^-6/year). This study indicates that the air pollution of PM_2.5 is of public health concern in Licheng District of Jinan, particularly related to potential carcinogenic metals of As, Cr and Cd. Intervention action is needed to reduce the emission sources of these elements, especially coal combustion in winter heating season.

Risk factors associated with developing anxiety in Inuit adolescents from Nunavik

This study aimed to examine the relation between anxiety among the at-risk population of Inuit adolescents and diverse developmental risk factors including exposure to environmental chemicals, a subject of concern in Nunavik. Anxiety was assessed in 89 Inuit participants (mean age = 18.4 years; range = 16.2-21.9) with the Screen for Child Anxiety Related Emotional Disorders (SCARED) and the State-Trait Anxiety Inventory (STAI). Potential risk factors for anxiety were documented at birth, 11 years of age and 18 years of age, including blood levels of chemicals (mercury, lead, PCBs) and nutrients, as well as age, sex, estimated IQ, drug and alcohol use, bullying, exposure to domestic violence, food insecurity, crowding and socio-economic status. Results showed that participants scored high on both measures of anxiety, particularly the SCARED, for which the mean score was above the clinical threshold. Multiple regression results show that significant risk predictors obtained from the SCARED scores were female sex (β = 0.32), higher current blood mercury concentration (β = 0.26), food insecurity (β = 0.26) and bullying experiences in the last year (β = 0.21). The significant predictors for the STAI trait anxiety were food insecurity (β = 0.25) and lower estimated IQ (β = -0.31), whereas food insecurity (β = 0.21), lower blood levels of vitamin E (β = -0.25) and higher cord blood mercury concentrations (β = 0.25) were found for STAI situational anxiety. Further regression analyses suggested that the adolescent-related variables were the most important risk factors. Our findings show that Inuit adolescents are at risk for anxiety via multiple contributing factors, particularly current exposure to mercury, food insecurity and female sex.

Chronic exposure to heavy metals from informal e-waste recycling plants and children's attention, executive function and academic performance

E-waste contains valuable metals that require appropriate waste management plans. However, rudimentary e-waste processing methods are a source of heavy metals environmental pollution. This study has characterised concentrations of heavy metals in soil (n = 10), water (n = 10) and hair (n = 44) of children in areas surrounding Jakarta (Indonesia), where e-waste is being or has been conducted in the past, and in a reference unexposed site. Chronic exposure to Mn, Pb, Hg, As and Cd and its associations with attention and executive function, characterised with the Trail Making Test (TMT), along with academic performance scores was conducted using multivariate regression analysis. Models were adjusted for age, gender, parental education, environmental tobacco smoke and residential traffic. Lead (3653 ± 3355 mg/kg), cadmium (3.4 ± 0.9 mg/kg) and mercury (15.2 ± 28.5 mg/kg) concentrations from soil and manganese concentrations in water (1.43 ± 0.64 mg/L) in the exposed sites were higher than current regulations. Heavy metal concentrations in hair of children living near e-waste facilities was higher than for children living in non-exposed areas (Pb: 0.155 ± 0.187 vs 0.0729 ± 0.08 mg/g; Mn: 0.130 ± 0.212 vs 0.018 ± 0.045 mg/g; Hg: 0.008 ± 0.0042 vs 0.002 ± 0.0011 mg/g) suggesting chronic exposure to heavy metals. Manganese exposure was associated with worse cognitive performance in the domains of attention (TMT-A score: 66 s, 95% CI 0.09, 132), executive function (TMT-B score: 105 s, 95% CI 11.5, 198) and social sciences (-29%, 95% CI -54, -4.7) (per unit of Mn in hair mg/g). These results suggest that informal e-waste activities contribute to local heavy metal soil contamination, and could be an important source of metal exposure to children living in the vicinity of these facilities with putative impacts on their cognitive performance. E-waste management regulation and remediation programmes should be implemented to reduce environmental pollution and associated health effects.

Environmental exposure to lead and hematological parameters in Afro-Brazilian children living near artisanal glazed pottery workshops

This study aimed to evaluate the exposure to environmental lead (Pb) of children from a traditional community of African descent in Brazil and the effects on hematological parameters. Children (n = 75) aged 5.5-13 years from the exposed areas classified as low (LEx) and moderately (MEx) exposed were compared with children (n = 75) of a control group (CG). Dust Pb loading rates (RtPbs) at children's homes were measured. Peripheral venous blood samples were collected to assess Pb biomarkers of exposure and effects. All Pb determinations were performed by graphite furnace atomic absorption spectrometry. The median (IQR) of RtPb, PbB level, and ALA-D activity were 65 (25-137) μgPb/m²/30 days, 1.0 (0.1-2.8) μg/dL, and 71 (55-86) U/L, respectively. Spearman correlation evidenced the relationship of PbB with RtPb (rho = 0.368, P < 0.001) and ALA-D activity (rho = -0.587; P ˂ 0.001). After adjusting for exposure degree and child's age, a decline of 7.4 U/L in ALA-D activity was associated with a 10-fold increase in PbB. The prevalence ratio of elevated PbB (>5 μg/dL) in LEx and MEx areas were 1.5 and 3.7, respectively. Indoor dust exposure, living near pottery workshops and the secondary exposure were the main determinants of elevated PbB levels, which were associated with hematological effects.

Metal(loid) bioaccessibility and children's health risk assessment of soil and indoor dust from rural and urban school and residential areas

This study focused on the oral bioaccessibility and children health risks of metal(loid)s (As, Cd, Cr, Cu, Ni, Pb and Zn) in soil/indoor dust of school and households from Lanzhou, China. The simple bioaccessibility extraction test method was applied to assess bioaccessibility, and children's health risk was assessed via statistical modeling (hazard quotients, hazard index and incremental lifetime carcinogenic risk). Metal(loid) content and bioaccessibility in indoor dust samples were significantly higher than those in corresponding soil samples (p < 0.05). The order for mean values of bioaccessibility of the elements in soil was as follows: Cd (57.1%) > Zn (44.6%) > Pb (39.9%) > Cu (33.2%) > Ni (12.4%) > Cr (5.3%) > As (4.4%), while for indoor dust, the order was: As (73.0%) > Cd (68.4%) > Pb (63.3%) > Zn (60.4%) > Cu (36.5%) > Ni (25.2%) > Cr (13.6%). The Pearson correlation coefficient showed that metal(loid) bioaccessibility was in general significantly negatively correlated to the Al, Fe and Mn contents. Neither noncarcinogenic nor carcinogenic risks exceeded the tolerance interval for 3-5- and 6-9-year-old children for all elements. They both were mostly attributed to As considering metal(loid)s types and to school indoor dust considering sources. Therefore, maintaining interior sanitation would be an effective measure to reduce the potential health effects of indoor dust on children.

Probabilistic estimates of prenatal lead exposure at 195 toxic hotspots in low- and middle-income countries

BACKGROUND

Prior estimates of pediatric lead-related disease burden in low- and middle-income countries (LMICs) used population estimates of maternal blood lead levels (BLLs). This approach may underestimate fetal BLLs by not considering potentially high prenatal lead exposure from toxic hotspots. OBJECTIVES: We developed a probabilistic approach to using the Adult Lead Methodology (ALM) to estimate fetal BLLs from prenatal exposure to lead-contaminated soil at hotspots in the Toxic Site Identification Program (TSIP).

METHODS

We created distributions for each ALM parameter using published literature and extracted soil lead measurements from the TSIP database. Each iteration of the probabilistic ALM randomly selected values from the input distributions to generate a site-specific fetal BLL estimate. For each site, we ran 5000 model iterations, producing a site-specific fetal BLL distribution.

RESULTS

195 TSIP sites, in 33 LMICs, met our study inclusion criteria; an estimated 820,000 women of childbearing age are at risk for lead exposure at these sites. The predicted geometric means (GM) for site-specific fetal BLLs ranged from 3.3 μg/dL to 534 μg/dL, and 98% of sites had estimated GM fetal BLLs >5 μg/dL, the current reference level of the United States Centers for Disease Control and Prevention (CDC), while 11 sites had estimated GM fetal BLLs above the CDC chelation threshold of 45 μg/dL.

DISCUSSION

The TSIP soil lead data and this probabilistic approach to the ALM show that pregnant women living near TSIP sites may have BLLs that put their fetus at risk for neurologic damage and other sequelae, underscoring the need for interventions to reduce lead exposure at toxic hotspots.

Blood Lead Levels in Children Living Near an Informal Lead Battery Recycling Workshop in Patna, Bihar

BACKGROUND

Lead can cause significant biological and neurologic damage, even at small concentrations, and young children are at higher risk. Informal recycling of lead batteries and lead-based workshops/industries have increased the burden of lead toxicity in developing countries, including India. Many informal recycling lead battery workshops have been established by the local people of Patna, Bihar as self-employment opportunities. However, most of the residents are not aware of the risk factors associated with lead poisoning.

OBJECTIVES

The present pilot study aimed to assess blood lead levels (BLLs) and hemoglobin levels among children aged between 3 to 12 years in the settlement of Karmalichak near Patna, India.

MATERIALS AND METHODS

Children residing near the informal lead battery manufacturing unit were selected for BLL assessment. A total of 41 children were enrolled in the questionnairebased survey.

RESULTS

All the children in the present study had detectable lead concentrations in their blood. Only 9% of the studied children had a BLL ≤5 μg/dl, while 91% children had a BLL above >5 μg/dl.

CONCLUSIONS

The present study carried out in children of Karmalichak region of Patna, India was an attempt to better understand the problem of lead toxicity, describe the epidemiology of its adverse effects, identify sources and routes of exposure, illustrate the clinical effects and develop strategies of prevention so that remedial measures may be taken by government agencies and regulatory bodies. In view of the high lead levels in children in the study area, attempts are being made to develop strategies for future prevention by relocating the informal battery recycling workshops from the area. Moreover, parents have been advised to increase nutritional supplementation of children by providing calcium-, iron- and zinc-rich foods, including milk and vegetables.

PARTICIPANT CONSENT

Obtained.

ETHICAL APPROVAL

The study was approved by the ethical committee of Era's Lucknow Medical College & Hospital, Era University, Lucknow (India).

COMPETING INTERESTS

The authors declare no competing financial interests.

Recycling of scrap metal into artisanal cookware in the informal sector: A public health threat from multi metal exposure in South Africa

Recycling of scrap metal into artisanal cookware is widespread in poorly resourced countries. The aim of the study was to determine the risk of metal exposure from the use of artisanal cookware available in South Africa. Twenty cookware samples were purchased from local manufacturers and informal traders across South Africa. Aluminum and silicon concentrations were determined using XRF and the total content of 18 elements (Ag, As, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, V and Zn) were evaluated using ICPMS. Leaching of metals from cut pieces of cookware over a 2-h period of boiling in a 3% acetic acid solution was repeated 3 times and revealed multi-metal migration that was compared to EU maximum permissible levels. The mean Al migration of 509 mg L^-1 was over 100 times the EU maximum permissible level allowed for cookware. Lead was detected in all samples with 11 (55%), 12 (60%) and 9 (45%) of samples being over the maximum EU permissible level (10 μg Pb L^-1) for 1st, 2nd and 3rd migrations respectively. The mean As migration concentrations in the first leaching event ranged from 0.23 to 24.1 μg L^-1 with four pots (20%) over the maximum EU permissible limit for As (2 μg L^-1). Notably, all four pots were well below the maximum EU permissible As limit by the 3rd migration. Cadmium and mercury were detected in each pot across all three migrations however the levels were relatively low. Transmission electron microscopy revealed dramatic changes in surface structure after leaching of cookware.

Age-related changes to environmental exposure: variation in the frequency that young children place hands and objects in their mouths

Children are exposed to environmental contaminants through direct ingestion of water, food, soil, and feces, and through indirect ingestion owing to mouthing hands and objects. We quantified ingestion among 30 rural Bangladeshi children < 4 years old, recording every item touched or mouthed during 6-hour video observations that occurred annually for 3 years. We calculated the frequency and duration of mouthing and the prevalence of mouth contacts with soil and feces. We compared the mouthing frequency distributions to those from US children to evaluate the appropriateness of applying the US data to the Bangladeshi context. Median hand-mouthing frequency was 43-72 times/h and object-mouthing frequency 17-34 times/h among the five age groups assessed. For half of the observations, > 75% of all hand mouthing was associated with eating. The frequency of indoor hand mouthing not related to eating was similar to the frequency of all indoor hand mouthing among children in the United States. Object-mouthing frequency was higher among Bangladeshi children compared with US children. There was low intra-child correlation of mouthing frequencies over our longitudinal visits. Our results suggest that children's hand- and object-mouthing vary by geography and culture and that future exposure assessments can be cross-sectional if the goal is to estimate population-level distributions of mouthing frequencies. Of all observations, a child consumed soil in 23% and feces in 1%.

Effects of soil particle size on metal bioaccessibility and health risk assessment

Oral ingestion is the main exposure pathway through which humans ingest trace metals in the soil, particularly for children. Metals in different soil particle size fractions may vary in terms of concentration and properties. Urban school/kindergarten soil samples were collected from three cities: Lanzhou in northwest China, Wuhan in central China, and Shenzhen in southeast China. Soil samples were classified according to particle size (<63 μm, 63-150 μm, 150-250 μm, and 250-2000 μm) to estimate the effects of soil particle size on the total content and bioaccessibility of metals (Cd, Cr, Cu, Ni, Pb, and Zn). Based on the results, we assessed whether the standard size <150 μm (containing < 63 μm and 63-150 μm), recommended by the Technical Review Workgroup (TRW) of the Environmental Protection Agency (EPA), and <250 μm (containing < 63 μm, 63-150 μm, and 150-250) recommended by the Bioaccessibility Research Group of Europe (BARGE), are suitable where the largest proportion adhering to hands is the finest soil (<63 μm). The results showed that different metals exhibited different relationships between soil particle size and content and between soil particle size and bioaccessibility. Pb and Zn generally exhibited the greatest bioaccessibility in the coarsest particle sizes (250-2000 μm); whereas the highest Ni bioaccessibility occurred in the finest sizes (<63 μm); the bioaccessibility of other metals did not exhibit any obvious relationships with particle size. When assessing health risks using bioaccessible metal content in the recommended soil particle size ranges (<150 μm and <250 μm) and in finer particles (<63 μm), the results for noncarcinogenic risks to children exhibited no obvious difference, while the actual carcinogenic risks may be underestimated with the use of soil particle size ranges < 150 μm and <250 μm. Therefore, when choosing an optimal particle size fraction to evaluate the health risk of oral soil ingestion, we recommend the use of the bioaccessible metal content in <63 μm soil fraction.

Circular economy and environmental health in low- and middle-income countries

Background

The circular economy framework for human production and consumption is an alternative to the traditional, linear concept of ‘take, make, and dispose’. Circular economy (CE) principles comprise of ‘design out waste and pollution’, ‘retain products and materials in use’, and ‘regenerate natural systems’. This commentary considers the risks and opportunities of the CE for low- and middle-income countries (LMICs) in the context of the Sustainable Development Goals (SDGs), acknowledging that LMICs must identify their own opportunities, while recognising the potential positive and negative environmental health impacts.

Main body

The implementation of the CE in LMICs is mostly undertaken informally, driven by poverty and unemployment. Activities being employed towards extracting value from waste in LMICs are imposing environmental health risks including exposure to hazardous and toxic working environments, emissions and materials, and infectious diseases. The CE has the potential to aid towards the achievement of the SDGs, in particular SDG 12 (Responsible Consumption and Production) and SDG 11 (Sustainable Cities and Communities). However, since SDG 3 (Good Health and Well-Being) is critical in the pursuit of all SDGs, the negative implications of the CE should be well understood and addressed. We call on policy makers, industry, the health sector, and health-determining sectors to address these issues by defining mechanisms to protect vulnerable populations from the negative health impacts that may arise in LMICs as these countries domesticate the CE.

Conclusion

Striving towards a better understanding of risks should not undermine support for the CE, which requires the full agency of the public and policy communities to realise the potential to accelerate LMICs towards sustainable production and consumption, with positive synergies for several SDGs.

Trace elements in rice grain and agricultural soils: assessment of health risk of inhabitants near a former secondary lead smelter in Khulna, Bangladesh

Ingestion of food grain grown in metal-contaminated soils may cause serious effects on human health. This study assessed the concentrations of Pb, As, Cd and Zn in agricultural soils and in rice grains near a former secondary lead smelter in Khulna, Bangladesh. It analyzed 29 samples of surface soil and rice grain collected around 500 m of the smelter. Contamination factor (C_f), pollution load index and total hazard quotient (THQ) were calculated to determine ecological and human health risks. Cd was not detected in any of the samples. For the soil samples, medians of the concentrations of Pb, As and Zn were 109, 6.2 and 514 mg/kg, respectively. For the rice grain samples, medians of the concentrations of Pb, As and Zn were 4, 1.4 and 25 mg/kg fw, respectively. Medians of the concentrations of Pb and As in rice grain were higher compared to their maximum allowable limit (0.2 mg/kg), which indicate potential health risks to inhabitants near the Pb smelter. The mean values of C_f for Pb, As, and Zn were, respectively, 11.6, 2.1 and 7.4. For Pb, around 41% of the samples had C_f > 6 indicating very strong contamination. THQ values for Pb and As were greater than 1.0, which evinces the health hazards of these trace elements. Measures should be taken to prevent trace elements exposure from Pb smelter in the study area.

Probabilistic Human Health Risk Assessment of Heavy Metal Intake via Vegetable Consumption around Pb/Zn Smelters in Southwest China

Vegetable contamination in mining and smelting areas has resulted in high dietary intakes of heavy metals, which pose potential health risks to local residents. In this study, paired soil-vegetable samples were collected around Pb/Zn smelters in Southwest China. Probabilistic risks to local residents via vegetable consumption were evaluated with a Monte Carlo simulation. The mean concentrations of As, Cd, Cu, Pb, and Zn in the soils were 116.76, 3.59, 158.56, 196.96, and 236.74 mg/kg, respectively. About 38.18%, 58.49%, and 52.83% of the vegetable samples exceeded the maximum allowable concentrations for As, Cd, and Pb, respectively. The daily dietary intake of As, Cd, and Pb exceeded the provisional tolerable daily intakes for local residents, with children showing the highest intake via vegetable consumption. The percentages of the target hazard quotients of As, Cd, and Pb for local residents exceeding the safe value of one were about 95%, 50%, and 25%, respectively. The 95th percentiles of the hazard index for children, adolescents, and adults were 15.71, 11.15, and 9.34, respectively, indicating significant risks to local residents, especially children. These results highlight a need to develop effective strategies to reduce heavy metal contamination and exposure to protect human health.

Health risks to metals in multimedia via ingestion pathway for children in a typical urban area of China

With the rapid development of the industrialization and urbanization, the urban environment was heavily contaminated by metals. Therefore, studies on health risk assessment of exposure to metals for urban population is necessary and urgent, especially for children, who are more susceptible to environmental pollution due to their undeveloped immune system. Moreover, ingestion has been proved to be the most important pathway of human metals exposure. Therefore, typical metals, including Lead(Pb), Cadmium(Cd), Arsenic(As), Chromium(Cr), and Manganese(Mn), were analyzed in duplicated diet, drinking water, and soil in this study. The integrated risks of oral exposure to these metals for the local children were then evaluated on a field sampling and measured child-specific exposure factors basis. Results showed that the studied urban environments were polluted by metals to a certain degree. Food ingestion was the largest, which accounted for 66.7%-98.4%. Furthermore, soil ingestion was also a non-negligible exposure route, which accounted for 29.7% for Pb. The combined oral non-carcinogenic and carcinogenic risks all exceeding the corresponding maximum acceptable levels. The non-carcinogenic risk was mainly attributed to the food ingestion of As and Cr, and the soil ingestion of As, while, the carcinogenic risk was mainly attributed to the food ingestion of As and Cr, and the soil ingestion of Cr. This study emphasizes attentions should be paid to children in urban areas due to the potential adverse health risk associated with metals via oral exposure pathway.