Global survey of dioxin- and thyroid hormone-like activities in consumer products and toys.

BACKGROUND: Children and consumers are exposed to increasingly complex mixtures of known and as-yet-unknown toxic chemicals from toys and products. However traditional chemical analysis methods only evaluate a small number of chemicals at a time thereby restricting consumer awareness of the full range of potentially harmful chemicals in products. METHODS: We used high-throughput effect-based non-animal methods to investigate exposures to complex chemical mixtures of several kinds of brominated flame retardants (BFRs) for their dioxin- and thyroid hormone-like activities in various kinds of consumer products and toys from 26 different countries, on four continents (Africa, America, Asia and Europe) in combination with chemical analysis of various polybrominated flame retardants (BFRs) and their impurities (such as polyhalogenated PCDD/Fs and PBDD/Fs). RESULTS: We found high levels of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in toys and now, for the first time, also in consumer products that are manufactured from black plastics containing certain brominated flame retardants (BFRs). The presence of PBDD/PBDFs as well as other BFRs in various black plastic materials from additional countries as well as additional kinds of consumer products as confirmed by effect-based in vitro reporter gene DR CALUX and TTR-TRß CALUX assays as well as congener-specific chemical analysis. We compared total Toxicity Equivalent (TEQ) levels of PBDD/F-TEQs analysed by chemical analysis to by CALUX bioassay measured Biological equivalence (BEQ) concentrations (for further info see at ISO 23196, ISO, 2022). In the case of TBBPA, both chemical and TTR-TRß CALUX analysis measure direct the amount of TBBPA. Finally, the daily ingestion of 2,3,7,8-TCDD equivalents from PBDD/Fs-contaminated plastic toys by child mouthing habits have been related to our earlier study (Budin et al., 2020). CONCLUSIONS: Interaction of children with such contaminated plastics may significantly contribute to the daily uptake of dioxin- and thyroid hormone transport disrupting-like compounds. Effect-based bioassays for dioxin- and thyroid hormone-like activities are relevant to pick-out such complex mixtures of known and yet unknown (and therefore not regulated) substances for safer and more sustainable plastics. Low POPs Content Levels and other mechanisms set under the Basel and Stockholm Conventions are set far too high to prevent a significant flow of BFRs and PBDD/Fs into consumer products.

A global-scale assessment of fish mercury concentrations and the identification of biological hotspots.

We present data on a rapid assessment of fish Hg concentrations from 40 different waterbodies in 26 countries that includes data on 451 fish of 92 species. Significant differences in fish Hg concentrations were observed across fish foraging guilds and in general, higher trophic level fish (i.e., piscivores and carnivores) showed the highest mean total Hg (THg) concentrations. However, elevated THg concentrations observed in a lower trophic level, detrivorous species highlights the importance of understanding Hg concentrations across a wide range of trophic levels, and also characterizing site-specific processes that influence methylmercury (MeHg) bioavailability. A linear mixed effects model was used to evaluate the effects of length, trophic level, sampling location, and taxonomy on THg concentrations. A positive, significant relationship between THg in fish and fish size, trophic level, and latitude of the sampling site was observed. A comparison of Hg concentrations across all sites identifies biological mercury hotspots, as well as sites with reduced Hg concentrations relative to our overall sampling population mean Hg concentration. Results from this study highlight the value of rapid assessments on the availability of methylmercury in the environment using fish as bioindicators and the need for expanded biomonitoring efforts in understudied regions of the world. This study also provides insights for the future design and implementation of large-scale Hg biomonitoring efforts intended to evaluate the effectiveness of future Hg reduction strategies instituted by the Minamata Convention on Mercury.

Endocrine Disruptors and Health Effects in Africa: A Call for Action.

BACKGROUND: Africa faces a number of unique environmental challenges. Unfortunately, it lacks the infrastructure needed to support the comprehensive environmental studies that could provide the scientific basis to inform environmental policies. There are a number of known sources of endocrine-disrupting chemicals (EDCs) and other hazardous chemicals in Africa. However, a coordinated approach to identify and monitor these contaminants and to develop strategies for public health interventions has not yet been made. OBJECTIVES: This commentary summarizes the scientific evidence presented by experts at the First African Endocrine Disruptors meeting. We describe a "call to action" to utilize the available scientific knowledge to address the impact of EDCs on human and wildlife health in Africa. DISCUSSION: We identify existing knowledge gaps about exposures to EDCs in Africa and describe how well-designed research strategies are needed to address these gaps. A lack of resources for research and a lag in policy implementation slows down intervention strategies and poses a challenge to advancing future health in Africa. CONCLUSION: To address the many challenges posed by EDCs, we argue that Africans should take the lead in prioritization and evaluation of environmental hazards, including EDCs. We recommend the institution of education and training programs for chemical users, adoption of the precautionary principle, establishment of biomonitoring programs, and funding of community-based epidemiology and wildlife research programs led and funded by African institutes and private companies. https://doi.org/10.1289/EHP1774.

Exposure to endocrine-disrupting chemicals in the USA: a population-based disease burden and cost analysis.

BACKGROUND: Endocrine-disrupting chemicals (EDCs) contribute to disease and dysfunction and incur high associated costs (>1% of the gross domestic product [GDP] in the European Union). Exposure to EDCs varies widely between the USA and Europe because of differences in regulations and, therefore, we aimed to quantify disease burdens and related economic costs to allow comparison. METHODS: We used existing models for assessing epidemiological and toxicological studies to reach consensus on probabilities of causation for 15 exposure-response relations between substances and disorders. We used Monte Carlo methods to produce realistic probability ranges for costs across the exposure-response relation, taking into account uncertainties. Estimates were made based on population and costs in the USA in 2010. Costs for the European Union were converted to US$ (€1=$1·33). FINDINGS: The disease costs of EDCs were much higher in the USA than in Europe ($340 billion [2·33% of GDP] vs $217 billion [1·28%]). The difference was driven mainly by intelligence quotient (IQ) points loss and intellectual disability due to polybrominated diphenyl ethers (11 million IQ points lost and 43 000 cases costing $266 billion in the USA vs 873 000 IQ points lost and 3290 cases costing $12·6 billion in the European Union). Accounting for probability of causation, in the European Union, organophosphate pesticides were the largest contributor to costs associated with EDC exposure ($121 billion), whereas in the USA costs due to pesticides were much lower ($42 billion). INTERPRETATION: EDC exposure in the USA contributes to disease and dysfunction, with annual costs taking up more than 2% of the GDP. Differences from the European Union suggest the need for improved screening for chemical disruption to endocrine systems and proactive prevention. FUNDING: Endocrine Society, Ralph S French Charitable Foundation, and Broad Reach Foundation.

Economic implications of mercury exposure in the context of the global mercury treaty: Hair mercury levels and estimated lost economic productivity in selected developing countries.

Several developing countries have limited or no information about exposures near anthropogenic mercury sources and no studies have quantified costs of mercury pollution or economic benefits to mercury pollution prevention in these countries. In this study, we present data on mercury concentrations in human hair from subpopulations in developing countries most likely to benefit from the implementation of the Minamata Convention on Mercury. These data are then used to estimate economic costs of mercury exposure in these communities. Hair samples were collected from sites located in 15 countries. We used a linear dose-response relationship that previously identified a 0.18 IQ point decrement per part per million (ppm) increase in hair mercury, and modeled a base case scenario assuming a reference level of 1 ppm, and a second scenario assuming no reference level. We then estimated the corresponding increases in intellectual disability and lost Disability-Adjusted Life Years (DALY). A total of 236 participants provided hair samples for analysis, with an estimated population at risk of mercury exposure near the 15 sites of 11,302,582. Average mercury levels were in the range of 0.48 ppm-4.60 ppm, and 61% of all participants had hair mercury concentrations greater than 1 ppm, the level that approximately corresponds to the USA EPA reference dose. An additional 1310 cases of intellectual disability attributable to mercury exposure were identified annually (4110 assuming no reference level), resulting in 16,501 lost DALYs (51,809 assuming no reference level). A total of $77.4 million in lost economic productivity was estimated assuming a 1 ppm reference level and $130 million if no reference level was used. We conclude that significant mercury exposures occur in developing and transition country communities near sources named in the Minamata Convention, and our estimates suggest that a large economic burden could be avoided by timely implementation of measures to prevent mercury exposures.

Estimating burden and disease costs of exposure to endocrine-disrupting chemicals in the European union.

CONTEXT: Rapidly increasing evidence has documented that endocrine-disrupting chemicals (EDCs) contribute substantially to disease and disability. OBJECTIVE: The objective was to quantify a range of health and economic costs that can be reasonably attributed to EDC exposures in the European Union (EU). DESIGN: A Steering Committee of scientists adapted the Intergovernmental Panel on Climate Change weight-of-evidence characterization for probability of causation based upon levels of available epidemiological and toxicological evidence for one or more chemicals contributing to disease by an endocrine disruptor mechanism. To evaluate the epidemiological evidence, the Steering Committee adapted the World Health Organization Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group criteria, whereas the Steering Committee adapted definitions recently promulgated by the Danish Environmental Protection Agency for evaluating laboratory and animal evidence of endocrine disruption. Expert panels used the Delphi method to make decisions on the strength of the data. RESULTS: Expert panels achieved consensus at least for probable (>20%) EDC causation for IQ loss and associated intellectual disability, autism, attention-deficit hyperactivity disorder, childhood obesity, adult obesity, adult diabetes, cryptorchidism, male infertility, and mortality associated with reduced testosterone. Accounting for probability of causation and using the midpoint of each range for probability of causation, Monte Carlo simulations produced a median cost of €157 billion (or $209 billion, corresponding to 1.23% of EU gross domestic product) annually across 1000 simulations. Notably, using the lowest end of the probability range for each relationship in the Monte Carlo simulations produced a median range of €109 billion that differed modestly from base case probability inputs. CONCLUSIONS: EDC exposures in the EU are likely to contribute substantially to disease and dysfunction across the life course with costs in the hundreds of billions of Euros per year. These estimates represent only those EDCs with the highest probability of causation; a broader analysis would have produced greater estimates of burden of disease and costs.

Assessment of mercury exposure among small-scale gold miners using mercury stable isotopes.

Total mercury (Hg) concentrations in hair and urine are often used as biomarkers of exposure to fish-derived methylmercury (MeHg) and gaseous elemental Hg, respectively. We used Hg stable isotopes to assess the validity of these biomarkers among small-scale gold mining populations in Ghana and Indonesia. Urine from Ghanaian miners displayed similar Δ(199)Hg values to Hg derived from ore deposits (mean urine Δ(199)Hg=0.01‰, n=6). This suggests that urine total Hg concentrations accurately reflect exposure to inorganic Hg among this population. Hair samples from Ghanaian miners displayed low positive Δ(199)Hg values (0.23-0.55‰, n=6) and low percentages of total Hg as MeHg (7.6-29%, n=7). These data suggest that the majority of the Hg in these miners' hair samples is exogenously adsorbed inorganic Hg and not fish-derived MeHg. Hair samples from Indonesian gold miners who eat fish daily displayed a wider range of positive Δ(199)Hg values (0.21-1.32‰, n=5) and percentages of total Hg as MeHg (32-72%, n=4). This suggests that total Hg in the hair samples from Indonesian gold miners is likely a mixture of ingested fish MeHg and exogenously adsorbed inorganic Hg. Based on data from both populations, we suggest that total Hg concentrations in hair samples from small-scale gold miners likely overestimate exposure to MeHg from fish consumption.

How developing nations can protect children from hazardous chemical exposures while sustaining economic growth.

Increasing worldwide use of chemicals, including heavy metals used in industry and pesticides used in agriculture, may produce increases in chronic diseases in children unless steps are taken to manage the production, use, trade, and disposal of chemicals. In 2020 the developing world will account for 33 percent of global chemical demand and 31 percent of production, compared with 23 percent and 21 percent, respectively, in 1995. We describe present and potential costs of environmental exposures and discuss policy options to protect future generations of children in a sustainable development context. Specifically, we describe the principles of sound chemicals management, as follows: precaution, or the use of cost-effective measures to prevent potentially hazardous exposures before scientific understanding is complete; the right to know, or informing the public--especially vulnerable groups--in a timely fashion about the safe use of chemicals and any releases of chemicals into the environment; pollution prevention, or preventing the use of hazardous chemicals and the production of pollutants, rather than focusing on managing wastes; internalization of environmental and health costs, or ensuring that the consequences of exposures are reflected in the price of chemicals through such approaches as "polluter pays"; and use of best available scientific information in making decisions such as what chemicals to allow into the market. We recommend that industrializing nations in particular employ these principles to prevent disease among their populations while at the same time minimizing the risk to their own economic development.