Metal mining and birth defects: a case-control study in Lubumbashi, Democratic Republic of the Congo

Industrial air pollution and newborn hearing screening failure

Hearing loss in newborns is a prevalent issue that can hinder the growth of language skills and cognitive development. Given that hearing loss often co-occurs with other adverse birth outcomes and the recognized role of metals in causing such outcomes, it is conceivable that metals may also serve as a risk factor of hearing loss. This study examined the associations between maternal residential exposure to thirteen PM2.5-bound metals and failure in Newborn Hearing Screening (NHS) in offspring in New Mexico from 2008 to 2017 to ascertain possible implications of these environmental exposures. This retrospective cohort study included 141,406 births (7670 births in disease group and 133,736 births in non-diseased group) in New Mexico during 2008-2017. Thirteen PM2.5-bound metals released from the U.S. Environmental Protection Agency (EPA) Toxic Release Inventory (TRI) facilities were investigated potentially as risk factors. The RSEI model estimated maternal residential exposure to PM2.5-bound metals during pregnancy, and spatial log-binomial regressions, adjusted for confounders, calculated adjusted relative risks (aRRs) for the association with NHS failure. Findings indicated that maternal residential exposure to PM2.5-bound metals - including antimony, barium, beryllium, chromium, cobalt, manganese, mercury, vanadium, and zinc - during pregnancy were positively associated with NHS failure in offspring, showing aRRs ranging from 1.07 to 2.18. A significant trend was observed when exposures were categorized as zero, low, medium, and high of these metals. Our findings indicate that maternal exposure to these PM2.5-bound metals may adversely affect newborn hearing, underscoring air pollution as a modifiable risk factor for improving hearing health outcomes.

Maternal exposure to ambient ozone and fetal congenital heart defects: a national multicenter study in China

BACKGROUND

Ambient O3 has demonstrated an aggravated increasing trend in the context of global warming. The available evidence of maternal exposure to ambient O3 on fetal congenital heart defects (CHD) is still limited, especially in high polluted areas.

OBJECTIVE

To examine associations of maternal exposure to ambient O3 during early pregnancy with fetal CHDs.

METHODS

We conducted a national multicenter study in 1313 hospitals from 26 provinces in China and collected a total of 27,817 participants at high risk of CHD from 2013 to 2021. Exposure to ambient O3 during the embryonic period, preconception, the first trimester and periconception was assessed by extracting daily concentrations from a validated grid dataset at each subject's residential district. CHDs were diagnosed based on fetal echocardiography.

RESULTS

Each 10 µg/m3 increase of exposure to ambient O3 during the embryonic period was approximately linearly associated with a 12.7% (odds ratio [OR]: 1.127, 95% confidence interval [CI]: 1.098, 1.155) increase in odds of pooled CHD (p < 0.001). The associations remain robust after adjusting for ambient PM2.5 and NO2 exposure. The odds of different types of CHD in association with ambient O3 exposure varied greatly. We observed significant association of ambient O3 exposure with ventricular septal defect (VSD), tetralogy of Fallot (TOF); pulmonary stenosis (PS), pulmonary atresia (PA), transposition of great arteries (TGA) and persistent left superior vena cava (PLSVC), with TOF demonstrating the strongest estimates (OR: 1.194, 95% CI:1.107, 1.288). The estimates for preconception, the first trimester and periconception demonstrate consistent findings with the main analyses, indicating stronger associations of ambient O3 exposure during the periconception period.

IMPACT

Our study provides evidence that higher ambient O3 during early pregnancy was significantly associated with increased odds of fetal CHD. Our findings suggest that pregnant women, clinical practitioners, and policy makers need to pay more attention to the exposure to higher ambient O3 during early pregnancy to reduce the risk of developing CHD and to improve outcomes across the life span.

Surgical long-term outcomes of Hirschsprung Disease in the Democratic Republic of Congo: a case series of 31 patients in a resource-limited setting

BACKGROUND

Hirschsprung disease (HD) contributes significantly to the burden of disease related to conditions amenable to pediatric surgery within the Democratic Republic of Congo (DRC). However, it has received less clinical attention due to limited resources. We aimed at assessing the long-term follow-up outcomes following an innovate resection approach in South Kivu, eastern DRC.

METHODS

In this case series, the authors elucidate the admissions for HD spanning from 2016 to 2021 at a Pediatric Surgical Center in the DRC. All patients underwent surgical management. Due to the absence of an extemporaneous biopsy, the resection margin was defined by a formula developed by the authors: 5 cm for patients under 5 years, 5 cm plus 1 cm per age from 6-10 years, and 5 cm plus 0.5 cm per age above 10 years. Post-operative mortality and complication rates were equally computed. Descriptive statistics were calculated for continuous variables. Discharge-to-Follow-up data were visualized using time-to-event curves.

RESULTS

Thirty-one patients aged 195 (interquartile range: 18-669) days were included in this study. Thirteen (58.93%) were from mining areas. The patients were surgically managed and follow-up for a year. 6.45% died in the 30-day post-operative period and 19.35% were lost to follow-up. The complaints were recorded from the fourth month following the surgery with most of the patients complained about fecal soiling (58.06%). The overall complaint rate was 80% (95%CI:56.20%-90.69%). The overall rate of incontinence was different compared to those with fecal soiling (p = 0.04). Although lacking statistical significance, the length of stay (LoS) post-surgery predicting an 9% increased incidence of complaints during the follow-up period (adjusted Hazard Ratio: 1.09, 95% CI:0.97-1.23).

CONCLUSION

HD cause avertable morbidity in South Kivu. These data suggest that the long-term outcome in HD can be mitigated through appropriate surgical management during the operative and intervention aimed at optimizing the LoS.

Effect of 'Galamsey' on Human Fertility: A Systematic Review

Background and Aims

In Ghana, the term 'galamsey' refers to illicit small-scale gold mining. It is a primary factor in water pollution, land degradation and other environmental harm. It has also been connected to health risks like displacement and mercury poisoning. The rates of infertility among humans are rising, according to a recent study. While there are several theories explaining the rise in infertility rates, environmental contaminants may be a significant contributing role in this phenomenon. Fertility in both men and women can be impacted by a variety of environmental factors. The possible impacts of environmental contaminants on reproduction are especially concerning. We systematically reviewed the published literature on the effects of chemicals used in 'galamsey' on reproductive function.

Methods

A comprehensive search of major databases including Medical and Allied Healthcare databases was systematically searched to identify studies published within the last period of 2010-2022. The modern SPIDER template for eligibility criteria was adopted as a guide in study selection after a literature search. Two reviewers independently screened studies for eligibility, extracted data, and assessed study quality.

Results

Out of the 500 database, 20 documents were processed for their eligibility while 15 were included in the current study. The findings revealed that there is an association between the use of metals and reduced fertility in both males and females. 'Galamsey' exposure was also linked to decreased sperm count, motility and morphology in males as well as hormonal imbalance and increased chances of miscarriage and still birth among conceived mothers and females. Children born in these areas may have various forms of defects and malformations.

Conclusion

This systematic review provides evidence that illegal mining activities have a deleterious effect on human fertility. These findings highlight the need for environmental and health reforms to address future public health threats.

Late modern war and the geos: The ecological 'beforemaths' of advanced military technologies

This article develops the idea that late modern war's relationship with the geos (the ground and the life it sustains) is doubly destructive. While part of this is recognized in a recent focus on slow violence and ecological aftermaths, there is little consideration of the 'beforemath', or the sites of extraction that make advanced military technologies possible. Drawing attention to mining in the Democratic Republic of the Congo (DRC), the article connects military technologies to arms manufacturers and their use of extracted minerals (e.g. cobalt, tantalum, copper, uranium). Shared patterns of environmental and public health effects across parts of Iraq, Gaza and the DRC indicate the doubly destructive nature of late modern war's relationship with the geos: toxic materials threaten life after war as the deposits of bombardment and before war as mineral commodities at the beginning of arms supply chains. The article explicates how a perspective from the beforemath radically refigures the ways we think about war and spatiality, temporality, and the range of bodies affected in ways that promise a fuller understanding of the violence distributed by practices of late modern war.

Recycling potential of cobalt metal from end-of-life new energy passenger vehicles in China

The growing demand for new energy vehicles (NEVs) has resulted in a corresponding increase in demand for cobalt as a critical material. It is crucial to estimate the cobalt resource recycling potential of China's NEV industry to ensure a balance between the supply and demand for cobalt metal minerals. This article is based on using the historical data of the new energy passenger vehicle (NEPV) sales volume from 2013 to 2022 to estimate the NEPV sales volume from 2023 to 2035. On this basis, the Weibull distribution was used to analyse the different sales scenarios (low sales and high sales) of NEPVs in China, and the recycling potential of cobalt metal in NEPVs was evaluated under three battery life scenarios (8, 10 and 12 years) from 2023 to 2035. Based on the above scenarios, in 2035, the greatest recycling potential of cobalt is predicted to be 166.9 kilotonnes, with economic values of CNY 49.01-94.60 billion. Moreover, the extent to which the recycling potential of cobalt can cover the market demand for NEPVs was analysed. Our analysis concluded that recycling cobalt as a secondary supply has emerged as a necessary solution to supplement the primary supply, which can make a significant contribution to alleviating the pressure of the supply and demand.

Prevalence and risk of occurrence of visible birth defects in mining areas in South Kivu: A hospital-based cross-sectional study

BACKGROUND

Possible contamination related to mining activities might contribute with other risk factors in increasing the burden of birth defects (BDs) in many developing countries including the Democratic Republic of Congo. The subsequent prevalence is frequently underestimated. Implementation of focused public health interventions is hindered by the paucity of comprehensive data. We assessed the potential impact of mining on the prevalence and occurrence of visible BDs in neonates in South Kivu (SK).

METHODS

A hospital-based cross-sectional study was conducted among 65,474 newborns registered in 7 hospitals in SK from 2016-2021. Hospitals were categorized based on mining activities in their respective catchment areas. Living in a mining zone was the exposure, whereas the outcome was visible BDs. Prevalence was estimated per 100,000 live births, and risk of occurrence with odds ratio (OR) and their 95% confidence interval.

RESULTS

261 neonates with visible BDs were recorded accounting for a prevalence of 399 cases per 100,000 live births. The prevalence ranges between 217 and 1365 cases per 100,000 live births. An increased risk was found in mining zones(OR=2.07; 95%CI=1.59-2.68), Mubumbano(OR=1.72, 95%CI=1.22-2.43), and Mwenga(OR=3.89, 95%CI=2.73-5.54), whereas a reduced risk was reported in non-mining zones(OR=0.48, 95%CI=0.37-0.62) in Katana (OR=0.49, 95%CI=0.33-0.73). Musculoskeletal(28.74%) and central nervous systems(19.92%) were the most common BDs. A significant difference in prevalence for BDs involving the face, GI system and abdominal wall, musculoskeletal, central nervous and genitourinary systems between mining and non-mining zones was found(p<0.001).

CONCLUSION

There is an excessive risk for visible BDs in areas with hazardous mining activities in SK region.​​ More complex studies are needed to define the possible causal relationship. Moreover, findings generated herein should be corroborated by other research design, periodically monitored by public health authorities, and used to inform initiatives promoting enhanced environmental health, access to pediatric surgical care, and public health campaigns aimed at decreasing risk of BDs.

Occupational, environmental, and toxicological health risks of mining metals for lithium-ion batteries: a narrative review of the Pubmed database

BACKGROUND

The global market for lithium-ion batteries (LIBs) is growing exponentially, resulting in an increase in mining activities for the metals needed for manufacturing LIBs. Cobalt, lithium, manganese, and nickel are four of the metals most used in the construction of LIBs, and each has known toxicological risks associated with exposure. Mining for these metals poses potential human health risks via occupational and environmental exposures; however, there is a paucity of data surrounding the risks of increasing mining activity. The objective of this review was to characterize these risks.

METHODS

We conducted a review of the literature via a systematic search of the PubMed database on the health effects of mining for cobalt, lithium, manganese, and nickel. We included articles that (1) reported original research, (2) reported outcomes directly related to human health, (3) assessed exposure to mining for cobalt, lithium, manganese, or nickel, and (4) had an available English translation. We excluded all other articles. Our search identified 183 relevant articles.

RESULTS

Toxicological hazards were reported in 110 studies. Exposure to cobalt and nickel mining were most associated with respiratory toxicity, while exposure to manganese mining was most associated with neurologic toxicity. Notably, no articles were identified that assessed lithium toxicity associated with mining exposure. Traumatic hazards were reported in six studies. Three articles reported infectious disease hazards, while six studies reported effects on mental health. Several studies reported increased health risks in children compared to adults.

CONCLUSIONS

The results of this review suggest that occupational and environmental exposure to mining metals used in LIBs presents significant risks to human health that result in both acute and chronic toxicities. Further research is needed to better characterize these risks, particularly regarding lithium mining.

The synthesis strategies of covalent organic frameworks and advances in their application for adsorption of heavy metal and radionuclide

Covalent organic frameworks (COFs) are a novel type of porous materials, with unique properties, such as large specific surface areas, high porosity, pronounced crystallinity, tunable pore sizes, and easy functionalization, and thus have received considerable attention in recent years. COFs play an essential role in the catalytic degradation, adsorption, and separation of heavy metals, radionuclides. In recent years, considering several outstanding characteristics of COFs, including their good thermal/chemical stability, high crystallinity, and remarkable adsorption capacity, they have been widely used in the removal of various environment pollutants. This review primarily discusses the synthesis strategies of COFs along with their diverse synthesis methods, and provides a comprehensive summary and analysis of recent research advances in the use of COFs for removing heavy metal ions and radionuclides from water bodies. Additionally, the adsorption mechanism of COFs with regard to metal ions was determined by analyzing the structural characteristics of COFs. Finally, the future research directions on COFs adsorb rare earth element was discussed.

Prenatal Parental Exposure to Metals and Birth Defects: A Prospective Birth Cohort Study

While maternal exposure to high metal levels during pregnancy is an established risk factor for birth defects, the role of paternal exposure remains largely unknown. We aimed to assess the associations of prenatal paternal and maternal metal exposure and parental coexposure with birth defects in singletons. This study conducted within the Jiangsu Birth Cohort recruited couples in early pregnancy. We measured their urinary concentrations for 25 metals. A total of 1675 parent-offspring trios were included. The prevalence of any birth defects among infants by one year of age was 7.82%. Paternal-specific gravity-corrected urinary concentrations of titanium, vanadium, chromium, manganese, cobalt, nickel, copper, and selenium and maternal vanadium, chromium, nickel, copper, selenium, and antimony were associated with a 21-91% increased risk of birth defects after adjusting for covariates. These effects persisted after mutual adjustment for the spouse's exposure. Notably, when assessing the parental mixture effect by Bayesian kernel machine regression, paternal and maternal chromium exposure ranked the highest in relative importance. Parental coexposure to metal mixture showed a pronounced joint effect on the risk of overall birth defects, as well as for some specific subtypes. Our findings suggested a couple-based prevention strategy for metal exposure to reduce birth defects in offspring.

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.

Hypoxaemia and risk of asphyxia during underground work in artisanal cobalt mines

BACKGROUND

More than half the cobalt needed for vehicle electrification originates from the southern part of the Democratic Republic of the Congo (DRC), with a substantial part being extracted by artisanal miners.

AIMS

To investigate oxygen saturation during underground work among cobalt artisanal miners.

METHODS

In a field survey, we measured oxygen saturation (SpO2) and heart rate by pulse oximetry in 86 miners from two underground mines and 24 miners from a surface mine at four different time points: before descent into the mine (T1), at 50 minutes in the mine (T2), upon leaving the shaft (T3), and 10 minutes after having left the mine (T4).

RESULTS

Miners working underground (-36 to -112 meters) were somewhat older (34.8 ± 6.7 years) than those working in the surface mine (32.0 ± 6.5 years), and they worked more hours daily (12.6 ± 1.2 hours) than controls (9.0 ± 0.0 hours). All participants had SpO2 >95% at T1 and T4. At T2, SpO2 dropped below 93% and 80% in 35% and 10% underground miners, respectively; SpO2 was still <93% at T3 in 13%. SpO2 remained stable among surface miners. Later, we showed that underground ambient oxygen levels decreased well below 21% in several pits.

CONCLUSIONS

Pulse oximetry revealed relevant hypoxaemia during underground work in a substantial proportion of artisanal miners. Such hypoxaemia without evidence of underlying cardiovascular disease is indicative of low ambient oxygen, due to insufficient mine ventilation. This may cause deaths from asphyxia. The hazards of low ambient oxygen in artisanal mines must be prevented by appropriate technical measures ensuring the supply of sufficient fresh air.

Effect of soil organic matter-mediated electron transfer on heavy metal remediation: Current status and perspectives

Soil contamination by heavy metals poses major risks to human health and the environment. Given the current status of heavy metal pollution, many remediation techniques have been tested at laboratory and contaminated sites. The effects of soil organic matter-mediated electron transfer on heavy metal remediation have not been adequately studied, and the key mechanisms underlying this process have not yet been elucidated. In this review, microbial extracellular electron transfer pathways, organic matter electron transfer for heavy metal reduction, and the factors affecting these processes were discussed to enhance our understanding of heavy metal pollution. It was found that microbial extracellular electrons delivered by electron shuttles have the longest distance among the three electron transfer pathways, and the application of exogenous electron shuttles lays the foundation for efficient and persistent remediation of heavy metals. The organic matter-mediated electron transfer process, wherein organic matter acts as an electron shuttle, promotes the conversion of high valence state metal ions, such as Cr(VI), Hg(II), and U(VI), into less toxic and morphologically stable forms, which inhibits their mobility and bioavailability. Soil type, organic matter structural and content, heavy metal concentrations, and environmental factors (e.g., pH, redox potential, oxygen conditions, and temperature) all influence organic matter-mediated electron transfer processes and bioremediation of heavy metals. Organic matter can more effectively mediate electron transfer for heavy metal remediation under anaerobic conditions, as well as when the heavy metal content is low and the redox potential is suitable under fluvo-aquic/paddy soil conditions. Organic matter with high aromaticity, quinone groups, and phenol groups has a stronger electron transfer ability. This review provides new insights into the control and management of soil contamination and heavy metal remediation technologies.

Heavy metals and trace elements in maternal blood and prevalence of congenital limb abnormalities among newborns: the Japan Environment and Children's Study

BACKGROUND

Heavy metals such as lead (Pb) and cadmium (Cd) have been associated with adverse pregnancy and developmental outcomes, including congenital abnormalities. This study investigated the association between exposure to heavy metals and trace elements during fetal life and congenital limb abnormalities in infants.

METHODS

This study is based on a prospective ongoing nationwide birth cohort from the Japan Environment and Children's Study (JECS). The concentrations of Cd, Pb, mercury (Hg), selenium (Se), and manganese (Mn) were measured in maternal blood collected during the mid-late trimesters. Inclusion criteria were available from questionnaires filled in during pregnancy, including information about congenital limb abnormalities at birth or at one month. To examine the associations with limb anomalies and individual chemicals, logistic regression models were applied following log-transformation or division into quartiles of Cd, Pb, Hg, Se, and Mn concentrations. To assess the associations with the heavy metals and trace elements mixture, quantile g-computation was employed. All models were adjusted for age, maternal smoking history, maternal alcohol intake, history of smoking, and infant sex.

RESULTS

Data from 90,163 participants were included in the analysis, of whom 369 had congenital limb abnormalities in any of the collected information, and 89,794 had none. Among the 369 cases of congenital limb abnormalities, there were 185 and 142 cases of polydactyly and syndactyly, respectively. The median concentrations of Pb, Cd, Hg, Se, and Mn were 5.85, 0.66, 3.64, 168, and 15.3 ng/g, respectively. There were no associations between maternal blood concentrations of Pb [adjusted odd ratio = 0.83; 95% confidence interval = 0.61, 1.11], Cd [0.87; 0.68, 1.10], Hg [0.88; 0.73, 1.07], Se [1.07; 0.44, 2.59], and Mn [0.91; 0.64, 1.30] with congenital limb abnormalities. No significant association was observed between the mixture of heavy metals and trace elements [0.85; 0.72, 1.02] and any congenital limb abnormalities. Moreover, there was no association with all polydactylies and all syndactylies, or any type of abnormality as a subdivision.

CONCLUSION

At the maternal exposure levels of Cd, Pb, Hg, Se, and Mn assessed in the present study, no association was identified with the risk of developing congenital limb abnormalities in children.

EFSA Panel on Contaminants in the Food Chain (CONTAM), Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hogstrand C, Hoogenboom L(R, Leblanc J, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Vleminckx C, Wallace H, Barregård L, Benford D, Broberg K, Dogliotti E, Fletcher T, Rylander L, Abrahantes JC, Gómez Ruiz JÁ, Steinkellner H, Tauriainen T, Schwerdtle T. Update of the risk assessment of inorganic arsenic in food

The European Commission asked EFSA to update its 2009 risk assessment on arsenic in food carrying out a hazard assessment of inorganic arsenic (iAs) and using the revised exposure assessment issued by EFSA in 2021. Epidemiological studies show that the chronic intake of iAs via diet and/or drinking water is associated with increased risk of several adverse outcomes including cancers of the skin, bladder and lung. The CONTAM Panel used the benchmark dose lower confidence limit based on a benchmark response (BMR) of 5% (relative increase of the background incidence after adjustment for confounders, BMDL05) of 0.06 μg iAs/kg bw per day obtained from a study on skin cancer as a Reference Point (RP). Inorganic As is a genotoxic carcinogen with additional epigenetic effects and the CONTAM Panel applied a margin of exposure (MOE) approach for the risk characterisation. In adults, the MOEs are low (range between 2 and 0.4 for mean consumers and between 0.9 and 0.2 at the 95th percentile exposure, respectively) and as such raise a health concern despite the uncertainties.

Direct Environmental Lead Detection by Photoluminescent Perovskite Formation with Nanogram Sensitivity

Although the global ban on leaded gasoline has markedly reduced lead poisoning, many other environmental sources of lead exposure, such as paint, pipes, mines, and recycling sites remain. Existing methods to identify these sources are either costly or unreliable. We report here a new, sensitive, and inexpensive lead detection method that relies on the formation of a perovskite semiconductor. The method only requires spraying the material of interest with methylammonium bromide and observing whether photoluminesence occurs under UV light to indicate the presence of lead. The method detects as little as 1.0 ng/mm2 of lead by the naked eye and 50 pg/mm2 using a digital photo camera. We exposed more than 50 different materials to our reagent and found no false negatives or false positives. The method readily detects lead in soil, paint, glazing, cables, glass, plastics, and dust and could be widely used for testing the environment and preventing lead poisoning.

Characterization of the internal working-life exposome using minimally and non-invasive sampling methods - a narrative review

During recent years, we are moving away from the 'one exposure, one disease'-approach in occupational settings and towards a more comprehensive approach, taking into account the totality of exposures during a life course by using an exposome approach. Taking an exposome approach however is accompanied by many challenges, one of which, for example, relates to the collection of biological samples. Methods used for sample collection in occupational exposome studies should ideally be minimally invasive, while at the same time sensitive, and enable meaningful repeated sampling in a large population and over a longer time period. This might be hampered in specific situations e.g., people working in remote areas, during pandemics or with flexible work hours. In these situations, using self-sampling techniques might offer a solution. Therefore, our aim was to identify existing self-sampling techniques and to evaluate the applicability of these techniques in an occupational exposome context by conducting a literature review. We here present an overview of current self-sampling methodologies used to characterize the internal exposome. In addition, the use of different biological matrices was evaluated and subdivided based on their level of invasiveness and applicability in an occupational exposome context. In conclusion, this review and the overview of self-sampling techniques presented herein can serve as a guide in the design of future (occupational) exposome studies while circumventing sample collection challenges associated with exposome studies.

Transplacental transfer of cobalt: Evidence from a study of mothers and their neonates in the African Copperbelt

BACKGROUND

Transfer of the trace metal cobalt (Co) from mother to foetus has not been documented in populations with high environmental exposure to Co, as is the case in the African Copperbelt mining region. We analysed data obtained from 246 mother-infant pairs included (at delivery) in a previously published case-control study on birth defects, done in Lubumbashi (Democratic Republic of Congo) between March 1, 2013, and Feb 28, 2015.

METHODS

Co was measured by Inductively Coupled Plasma Mass Spectrometry in maternal blood, maternal urine, umbilical cord blood and placental tissue, as available.

RESULTS

The Co concentrations [geometric mean (GM) with interquartile range (IQR)] in maternal blood (GM 1.77 µg/L, IQR 1.07-2.93) and urine (GM 7.42 µg/g creatinine, IQR 4.41-11.0) were highly correlated (Spearman r = 0.71, n = 166; p < 0.001) and considerably higher than reference values determined for general populations elsewhere in the world. The concentrations of Co in umbilical cord blood (GM 2.41 µg/L) were higher (Wilcoxon test, p < 0.001) than in maternal blood (GM 1.37 µg/L), with a correlation between both values (Spearman r = 0.34; n = 127, p < 0.001). Co concentrations in placental tissue (geometric mean 0.02 µg/g wet weight) correlated with concentrations in maternal blood (Spearman r = 0.50, n = 86, p < 0.001) and in neonatal blood (Spearman r = 0.23, n = 83, p = 0.039).

CONCLUSION

This first study of maternal and neonatal Co concentrations in the African Copperbelt provides strong evidence of a high transfer of Co from mother to foetus.

“They polluted our cropfields and our rivers, they killed us”: Farmers’ complaints about mining pollution in the Katangese Copperbelt

The adverse impacts of mining industries on human health, local biodiversity, and food security are well-documented in the Katangese Copperbelt. However, farmers' perceptions of pollution and their struggles to obtain compensation for the externalities of mining industries are little addressed in scientific and public debates. Drawing on interviews with smallholder farmers, local civil society archives, oral histories, and analysis of satellite images, this article presents a case of farmers of Mulungwishi Valley whose fields and waterways were polluted by mining effluents. While 25% of respondent farmers argued that they had noticed pollution from the beginning of the 2000s, testimonies from civil society, customary authorities, and farmers concurred that the phenomenon has increased since 2010. Particularly between 2013 and 2014, the death of fish in the Mulungwishi River, the coloration of the water, the spread of mining effluents across the valley, and crop failure raised concerns and despair among farmers. Remarkable changes in land cover and use were noticeable. Since a joint impact assessment in 2014 by la Générale des Carrières et des Mines' (Gécamines) experts and farmers, civil society unsuccessfully continued a struggle to obtain compensation for about 2570 farmers affected by pollution. Despite an absolute silence of the polluter, 88% of these farmers insisted on the depollution of the valley and were willing to accept, if it was offered, financial compensation of $US 2820 per farmer. The decade-long persistence of farmers in asserting these requests debunks the view of farmers as passive or not concerned about environmental pollution. This article will be helpful for stakeholders (victims and polluters) to find common ground when resolving this environmental issue that has resulted in socio-economic difficulties beyond the valley.

Maternal Exposure to PM2.5 and the Risk of Congenital Heart Defects in 1.4 Million Births: A Nationwide Surveillance-Based Study

BACKGROUND

Evidence remains limited about the association of maternal exposure to ambient fine particulate matter (airborne particles with an aerodynamic diameter ≤2.5 µm [PM2.5]) with fetal congenital heart defects (CHDs) in highly polluted regions, and few studies have focused on preconception exposure.

METHODS

Using a nationwide surveillance-based case-control design in China, we examined the association between maternal exposure to PM2.5 during periconception (defined as 3 months before conception until 3 months into pregnancy) and risk of CHD in offspring. The study included 1 434 998 births involving 7335 CHDs from 2014 through 2017 on the basis of the National Population-Based Birth Defects Surveillance System, covering 30 provinces, municipalities, or municipal districts in China. We assigned maternal PM2.5 exposure during the periconception period to each participant using satellite-based PM2.5 concentrations at 1-km spatial resolution. Multilevel logistic regression models were used to calculate the multivariable-adjusted odds ratio and 95% CI for CHDs in offspring associated with maternal PM2.5 exposure, and the exposure-response association was investigated using restricted cubic spline analysis. Subgroup or sensitivity analyses were conducted to identify factors that may modify the association.

RESULTS

The average maternal exposure to PM2.5 levels across all participants was 56.51 μg/m3 (range, 10.95 to 182.13 μg/m3). For each 10 μg/m³ increase in maternal PM2.5 exposure, the risk of CHDs in offspring was increased by 2% (odds ratio, 1.02 [95% CI, 1.00 to 1.05]), and septal defect was the most influenced subtype (odds ratio, 1.04 [95% CI, 1.01 to 1.08]). The effect of PM2.5 on CHD risk was more pronounced during the preconception period. Mothers <35 years of age, those living in northern China, and those living in low-income areas were more susceptible to PM2.5 exposure than their counterparts (all P<0.05). PM2.5 exposure showed a linear association with total CHDs or specific CHD types.

CONCLUSIONS

High maternal PM2.5 exposure, especially during the preconception period, increases risk of certain types of CHD in offspring. These findings are useful for CHD prevention and highlight the public health benefits of improving air quality in China and other highly polluted regions.

Reducing disease and death from Artisanal and Small-Scale Mining (ASM) - the urgent need for responsible mining in the context of growing global demand for minerals and metals for climate change mitigation

Artisanal and small-scale mining (ASM) takes place under extreme conditions with a lack of occupational health and safety. As the demand for metals is increasing due in part to their extensive use in 'green technologies' for climate change mitigation, the negative environmental and occupational consequences of mining practices are disproportionately felt in low- and middle-income countries. The Collegium Ramazzini statement on ASM presents updated information on its neglected health hazards that include multiple toxic hazards, most notably mercury, lead, cyanide, arsenic, cadmium, and cobalt, as well as physical hazards, most notably airborne dust and noise, and the high risk of infectious diseases. These hazards affect both miners and mining communities as working and living spaces are rarely separated. The impact on children and women is often severe, including hazardous exposures during the child-bearing age and pregnancies, and the risk of child labor. We suggest strategies for the mitigation of these hazards and classify those according to primordial, primary, secondary, and tertiary prevention. Further, we identify knowledge gaps and issue recommendations for international, national, and local governments, metal purchasers, and employers are given. With this statement, the Collegium Ramazzini calls for the extension of efforts to minimize all hazards that confront ASM miners and their families.

Maternal proximity to mountain-top removal mining and birth defects in Appalachian Kentucky, 1997-2003

Extraction of coal through mountaintop removal mining (MTR) alters many dimensions of the landscape. Explosive blasts, exposed rock, and coal washing have the potential to pollute air and water. Previous research suggests that infants born to mothers living in areas with MTR have a higher prevalence of birth defects. In this cross-sectional study, we further examine the relationship between MTR activity and several types of birth defects. Maternal exposure to MTR was assessed using remote sensing data from Skytruth, which captures MTR activity in the Central Appalachian region of the United States. Active MTR area was quantified within a five-kilometer buffer surrounding geocoded maternal address captured on birth records for live births to Appalachian Kentucky mothers between 1997 and 2003 (N = 95,581). We assigned high, medium, and low exposure based on the tertile of total MTR area within 5-km, and births with no MTR within this buffer were assigned zero exposure. The presence or absence of a birth defect grouped into six major organ systems was identified using birth records alone. Finally, we applied conditional multiple imputation for variables with missing values before conducting separate multivariable log-binomial regression models for each birth defect group. Prevalence ratio (PR) estimates were adjusted for individual level covariates from birth records. The prevalence of gastro-intestinal defects was significantly higher in birth records with high and low active MTR exposure compared to records with no exposure. (High exposure: PR = 1.99, 95% CI = 1.14-3.47; low exposure PR = 1.88, 95% CI = 1.06-3.31). This study supports some of the existing findings of previous ecological studies. Research addressing the relationship between gastro-intestinal birth defects and MTR coal mining is warranted but should carefully consider temporal dimensions of exposure.

Landscape Analysis of Cobalt Mining Activities from 2009 to 2021 Using Very High Resolution Satellite Data (Democratic Republic of the Congo)

The cobalt mining sector is well positioned to be a key contributor in determining the success of the Democratic Republic of the Congo (DRC) in meeting the Sustainable Development Goals (SDGs) by 2030. Despite the important contribution to the DRC’s economy, the rapid expansion of mining operations has resulted in major social, health, and environmental impacts. The objective of this study was to quantitatively assess the cumulative impact of mining activities on the landscape of a prominent cobalt mining area in the DRC. To achieve this, an object-based method, employing a support vector machine (SVM) classifier, was used to map land cover across the city of Kolwezi and the surrounding mining areas, where long-term mining activity has dramatically altered the landscape. The research used very high resolution (VHR) satellite imagery (2009, 2014, 2019, 2021) to map the spatial distribution of land cover and land cover change, as well as analyse the spatial relationship between land cover classes and visually identified mine features, from 2009 to 2021. Results from the object-based SVM land cover classification produced an overall accuracy of 85.2–90.4% across the time series. Between 2009 and 2021, land cover change accounted to: rooftops increasing by 147.2% (+7.7 km2); impervious surface increasing by 104.7% (+3.35 km2); bare land increasing by 85.4% (+33.81 km2); exposed rock increasing by 56.2% (+27.46 km2); trees decreasing by 4.5% (−0.34 km2); shrub decreasing by 38.4% (−26.04 km2); grass and cultivated land decreasing by 27.1% (−45.65 km2); and water decreasing by 34.6% (−3.28 km2). The co-location of key land cover classes and visually identified mine features exposed areas of potential environmental pollution, with 91.6% of identified water situated within a 1 km radius of a mine feature, and vulnerable populations, with 71.6% of built-up areas (rooftop and impervious surface class combined) situated within a 1 km radius of a mine feature. Assessing land cover patterns over time and the interplay between mine features and the landscape structure allowed the study to amplify the findings of localised on-the-ground research, presenting an alternative viewpoint to quantify the true scale and impact of cobalt mining in the DRC. Filling geospatial data gaps and examining the present and past trends in cobalt mining is critical for informing and managing the sustainable growth and development of the DRC’s mining sector.

Evaluation of heavy metal contamination in copper mine tailing soils of Kitwe and Mufulira, Zambia, for reclamation prospects

Understanding the level of heavy metal contamination coupled with the assessment of environmental and human risks associated with mine waste dumpsites is an important step to initiating efficient measures for mine wasteland restoration, stabilization, and bioremediation. In the present study, concentration of the heavy metals; Copper (Cu), Cobalt (Co), Iron (Fe), Lead (Pb), Manganese (Mn), and Zinc (Zn) in soil from mine waste dumpsites around Kitwe (Sites: TD25 and TD26) and Mufulira (Site: TD10), Zambia, was assessed to determine the level of contamination, ecological risks, and progress made in reclamation. The mine waste dumpsites in the two towns are located in the vicinity of residential areas. Therefore, there is need to provide information for optimization of protocols for post-mining landscape in Zambia and elsewhere to limit soil, river, and groundwater contamination and to accelerate the restoration process . Mean values for soil pH, electrical conductivity, and organic matter varied between 5.9-8.4, 2534.8-538.6 μS/cm, and 0.90-2.75%, respectively. The mean concentrations of heavy metals of TD25, TD26, and TD10 decreased in order of Fe > Cu > Co > Mn > Pb > Zn across all sites. However, the order of overall degree of heavy metal contamination computed using control soil as a baseline in TD25, TD26, and TD10 was Cu > Co > Fe > Pb > Mn > Zn. The pollution load index was 0.355 at TD25, 0.329 at TD26, and 0.189 at TD10, indicating high soil pollution at TD25 and TD26. The Potential Ecological Risk Index for all heavy metals tested at TD25, TD26, and TD10 showed low ecological risk in the vicinity of the studied dumpsites. Furthermore, the present study also showed that the polluted soils around smelter sites and mine waste dumpsites are susceptible to dispersion by wind and water. Additionally, results from TD10 revealed that the initiated remediation of the tailings dam was somewhat successful. Finally, this study provided an updated status regarding the accumulation of heavy metals in mine waste dumpsites of Kitwe and Mufulira, Zambia and baseline information necessary to enhance post-mining landscape reclamation.

Parental metal exposures as potential risk factors for spina bifida in Bangladesh

BACKGROUND

Neural tube defects are a pressing public health concern despite advances in prevention from folic acid-based strategies. Numerous chemicals, in particular arsenic, have been associated with neural tube defects in animal models and could influence risk in humans.

OBJECTIVES

We investigated the relationship between parental exposure to arsenic and 17 metals and risk of neural tube defects (myelomeningocele and meningocele) in a case control study in Bangladesh.

METHODS

Exposure assessment included analysis of maternal and paternal toenail samples using inductively coupled plasma mass spectrometry (ICP-MS). A total of 278 participants (155 cases and 123 controls) with data collected from 2016 to 2020 were included in the analysis.

RESULTS

In the paternal models, a one-unit increase in the natural logarithm of paternal toenail arsenic was associated with a 74% (odds ratio: 1.74, 95% confidence interval: 1.26-2.42) greater odds of having a child with spina bifida, after adjusting for relevant covariates. Additionally, paternal exposure to aluminum, cobalt, chromium, iron, selenium, and vanadium was associated with increased odds of having a child with spina bifida in the adjusted models. In the maternal models, a one-unit increase in the natural logarithm of maternal toenail selenium and zinc levels was related to a 382% greater (odds ratio: 4.82, 95% confidence interval: 1.32-17.60) and 89% lower (odds ratio: 0.11, 95% confidence interval: 0.03-0.42) odds of having a child with spina bifida in the adjusted models, respectively. Results did not suggest an interaction between parental toenail metals and maternal serum folate.

DISCUSSION

Parental toenail levels of numerous metals were associated with increased risk of spina bifida in Bangladeshi infants. Paternal arsenic exposure was positively associated with neural tube defects in children and is of particular concern given the widespread arsenic poisoning of groundwater resources in Bangladesh and the lack of nutritional interventions aimed to mitigate paternal arsenic exposure. The findings add to the growing body of literature of the impact of metals, especially paternal environmental factors, on child health.

Effects of Cd2+ and Pb2+ on enantioselective degradation behavior of α-cypermethrin in soils and their combined effect on activities of soil enzymes

Heavy metals may coexist with pesticides in farmland through wastewater irrigation, application of pesticides and chemical fertilizers, or unappropriated waste disposal. Heavy metals are toxic to soil microorganism, which may influence the environmental behavior of pesticides subsequently. In this study, the influence of Cd²⁺ and Pb²⁺ on the degradation of α-cypermethrin and its metabolites, 3-phenoxphenoxybenzoic acid (3-PBA) and 3-(2',2'-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (DCCA), were investigated through soil incubation experiment. It was found heavy metals like Cd²⁺ and Pb²⁺ will inhibit the degradation of α-cypermethrin, especially at high concentrations. Pb²⁺ has a stronger inhibitory effect on the degradation of α-cypermethrin than Cd²⁺ in the same concentration. With the presence of 10 mg/kg Pb²⁺, the half-life of α-cypermethrin increased from 41.1 to 99.9 days, even the half-life was 129.3 days with 50 mg/kg of Pb²⁺. Besides, heavy metals influenced the chiral selective degradation of α-cypermethrin. The enantiomer fraction was near 0.5 when 10 mg/kg of heavy metals existed. Furthermore, the adverse effects of heavy metals on soil urease, catalase, and sucrase activity were assayed. In tested concentrations (10 and 50 mg kg^-1), the heavy metals result in strong inhibition of the activity of the enzymes present on soil, jeopardizing the biodegradation by the microbiome and which may inhibit the degradation of α-cypermethrin.

Nano-remediation of toxic heavy metal contamination: Hexavalent chromium [Cr(VI)]

The inexorable industrialization and modern agricultural practices to meet the needs of the increasing population have polluted the environment with toxic heavy metals such as Cr(VI), Cu²⁺, Cd²⁺, Pb^2+, and Zn²⁺. Among the hazardous heavy metal(loid)s contamination in agricultural soil, water, and air, hexavalent chromium [Cr(VI)] is the most virulent carcinogen. The metallurgic industries, tanneries, paint manufacturing, petroleum refineries are among various such human activities that discharge Cr(VI) into the environment. Various methods have been employed to reduce the concentration of Cr(VI) contamination with nano and bioremediation being the recent advancement to achieve recovery at low cost and higher efficiency. Bioremediation is the process of using biological sources such as plant extracts, microorganisms, and algae to reduce the heavy metals while the nano-remediation uses nanoparticles to adsorb heavy metals. In this review, we discuss the various activities that liberate Cr(VI). We then discuss the various conventional, nano-remediation, and bioremediation methods to keep Cr(VI) concentration in check and further discuss their efficiencies. We also discuss the mechanism of nano-remediation techniques for better insight into the process.

Temporal variation characteristics and source apportionment of metal elements in PM2.5 in urban Beijing during 2018-2019

To explore high-resolution temporal variation characteristics of atmospheric metal elements concentration and more accurate pollution sources apportionment, online monitoring of metal elements in PM_2.5 with 1-h time resolution was conducted in Beijing from August 22, 2018 to August 21, 2019. Concentration of 18 elements varied between detection limit (ranging from 0.1 to 100 ng/m³) and nearly 25 μg/m³. Si, Fe, Ca, K and Al represented major elements and accounted for 93.47% of total concentration during the study period. Compared with previous studies, airborne metal pollution in Beijing has improved significantly which thanks to strict comprehensive control measures under the Clean Air Action Plan since 2013. Almost all elements present higher concentrations on weekdays than weekends, while concentrations of elements associated with dust sources during holidays are higher than those in working days after the morning peak, and there is almost no concentration difference in the evening peak period. Soil and dust, vehicle non-exhaust emissions, biomass, industrial processes and fuel combustion were apportioned as main sources of atmospheric metal pollution, accounting for 63.6%, 18.4%, 16.8%, 1.0% and 0.18%, respectively. Furthermore, main occurrence season of metal pollution is judged by characteristic radar chart of varied metal elements proposed for the first time in this study, for example, fuel combustion type pollution mainly occurs in winter and spring. Results of 72-h backward trajectory analysis of air masses showed that, except for local emissions, atmospheric metal pollution in Beijing is also affected by regional transport from Inner Mongolia, Hebei, the Bohai Sea and Heilongjiang.

Agnathia otocephaly: A case from the Katanga Copperbelt

BACKGROUND

Agnathia otocephaly is a rare craniofacial malformation complex characterised by absent/hypoplastic mandible, abnormally positioned ears meeting at level of neck. Besides mutations in two genes, PRRX1 and OTX2, a teratogenic cause has been suggested. A higher risk of congenital malformations has been associated with paternal work in mining in the Democratic Republic of the Congo's part of the Copperbelt.

CASE

We studied a female neonate with a clinical diagnosis of agnathia otocephaly, stillborn in Lubumbashi in 2019. The child's father had been working as an artisanal mineworker at the time of conception.

RESULTS

Genetic analysis did not reveal a causal mutation. The concentrations of cobalt, arsenic cadmium, and uranium in cord blood of the infant were much higher than those of normal neonates from a previous study.

CONCLUSION

In the absence of identified genetic causes, we hypothesize this case of agnathia otocephaly was related to an exogenous cause, possibly the father's mining-related job.