Trends in neurodevelopmental disability burden due to early life chemical exposure in the USA from 2001 to 2016: A population-based disease burden and cost analysis.

Endocrine disrupting chemicals are known to cause neurodevelopmental toxicity through direct and indirect pathways. In this study we used data from the National Health and Nutrition Examination Surveys, along with known exposure-disease relationships, to quantify the intellectual disability burden attributable to in utero exposure to polybrominated diphenyl ethers (PBDEs), organophosphates, and methylmercury and early life exposure to lead. We also estimated the cost of the IQ points lost and cases of intellectual disability. PBDE exposure was the greatest contributor to intellectual disability burden, resulting in a total of 162 million IQ points lost and over 738,000 cases of intellectual disability. This was followed by lead, organophosphates, and methylmercury. From 2001 to 2016, IQ loss from PBDEs, methylmercury, and lead have decreased or remained stagnant. Organophosphate exposure measurements were only available up to 2008 but did show an increase in organophosphate-attributable IQ loss. Although most of these trends show benefit for children's neurodevelopmental health, they may also point towards the use of potentially harmful substitutions for chemicals that are being phased out.

Disease burden of methylmercury in the German birth cohort 2014.

This study aimed to estimate the disease burden of methylmercury for children born in Germany in the year 2014. Humans are mainly exposed to methylmercury when they eat fish or seafood. Prenatal methylmercury exposure is associated with IQ loss. To quantify this disease burden, we used Monte Carlo simulation to estimate the incidence of mild and severe mental retardation in children born to mothers who consume fish based on empirical data. Subsequently, we calculated the disease burden with the disability-adjusted life years (DALY)-method. DALYs combine mortality and morbidity in one measure and quantify the gap between an ideal situation, where the entire population experiences the standard life expectancy without disease and disability, and the actual situation. Thus, one DALY corresponds to the loss of one year of life in good health. The methylmercury-induced burden of disease for the German birth cohort 2014 was an average of 14,186 DALY (95% CI 12,915-15,440 DALY). A large majority of the DALYs was attributed to morbidity as compared to mortality. Of the total disease burden, 98% were attributed to mild mental retardation, which only leads to morbidity. The remaining disease burden was a result of severe mental retardation with equal proportions of premature death and morbidity.

Human cost burden of exposure to endocrine disrupting chemicals. A critical review.

Recently published papers have alleged that exposures to endocrine disrupting chemicals (EDCs) are causing substantial disease burdens in the EU and US and are consequently costing society hundreds of billions of dollars annually. To date, these cost estimates have not undergone adequate scientific scrutiny, but nevertheless are being used aggressively in advocacy campaigns in an attempt to fundamentally change how chemicals are tested, evaluated and regulated. Consequently, we critically evaluated the underlying methodology and assumptions employed by the chief architects of the disease burden cost estimates. Since the vast majority of their assigned disease burden costs are driven by the assumption that "loss of IQ" and "increased prevalence of intellectual disability" are caused by exposures to organophosphate pesticides (OPPs) and brominated flame retardants (PBDEs), we have taken special care in describing and evaluating the underlying toxicology and epidemiology evidence that was relied upon. Unfortunately, our review uncovered substantial flaws in the approach taken and the conclusions that were drawn. Indeed, the authors of these papers assumed causal relationships between putative exposures to EDCs and selected diseases, i.e., "loss of IQ" and "increased prevalence of intellectual disability", despite not having established them via a thorough evaluation of the strengths and weaknesses of the underlying animal toxicology and human epidemiology evidence. Consequently, the assigned disease burden costs are highly speculative and should not be considered in the weight of evidence approach underlying any serious policy discussions serving to protect the public and regulate chemicals considered as EDCs.

Neurobehavioral deficits, diseases, and associated costs of exposure to endocrine-disrupting chemicals in the European Union.

CONTEXT: Epidemiological studies and animal models demonstrate that endocrine-disrupting chemicals (EDCs) contribute to cognitive deficits and neurodevelopmental disabilities. OBJECTIVE: The objective was to estimate neurodevelopmental disability and associated costs that can be reasonably attributed to EDC exposure in the European Union. DESIGN: An expert panel applied a weight-of-evidence characterization adapted from the Intergovernmental Panel on Climate Change. Exposure-response relationships and reference levels were evaluated for relevant EDCs, and biomarker data were organized from peer-reviewed studies to represent European exposure and approximate burden of disease. Cost estimation as of 2010 utilized lifetime economic productivity estimates, lifetime cost estimates for autism spectrum disorder, and annual costs for attention-deficit hyperactivity disorder. Setting, Patients and Participants, and Intervention: Cost estimation was carried out from a societal perspective, ie, including direct costs (eg, treatment costs) and indirect costs such as productivity loss. RESULTS: The panel identified a 70-100% probability that polybrominated diphenyl ether and organophosphate exposures contribute to IQ loss in the European population. Polybrominated diphenyl ether exposures were associated with 873,000 (sensitivity analysis, 148,000 to 2.02 million) lost IQ points and 3290 (sensitivity analysis, 3290 to 8080) cases of intellectual disability, at costs of €9.59 billion (sensitivity analysis, €1.58 billion to €22.4 billion). Organophosphate exposures were associated with 13.0 million (sensitivity analysis, 4.24 million to 17.1 million) lost IQ points and 59 300 (sensitivity analysis, 16,500 to 84,400) cases of intellectual disability, at costs of €146 billion (sensitivity analysis, €46.8 billion to €194 billion). Autism spectrum disorder causation by multiple EDCs was assigned a 20-39% probability, with 316 (sensitivity analysis, 126-631) attributable cases at a cost of €199 million (sensitivity analysis, €79.7 million to €399 million). Attention-deficit hyperactivity disorder causation by multiple EDCs was assigned a 20-69% probability, with 19 300 to 31 200 attributable cases at a cost of €1.21 billion to €2.86 billion. CONCLUSIONS: EDC exposures in Europe contribute substantially to neurobehavioral deficits and disease, with a high probability of >€150 billion costs/year. These results emphasize the advantages of controlling EDC exposure.

Cost of developmental delay from prenatal exposure to airborne polycyclic aromatic hydrocarbons.

Early life exposure to ambient polycyclic aromatic hydrocarbons (PAHs) can result in developmental delay. The negative health effects of PAHs have been well-documented but the cost of developmental delay due to PAH exposure has not been studied. The Columbia Center for Children's Environmental Health previously has reported the significant effect of prenatal exposure to ambient PAHs on delayed mental development at three years, using the Bayley Scales in a cohort of low-income women and children in New York City (NYC). Here we have used the cohort results to estimate the annual costs of preschool special education services for low-income NYC children with developmental delay due to PAH exposure using the Environmentally Attributable Fraction method. The estimated cost of PAH-exposure-related services is over $13.7 million per year for Medicaid births in NYC. This high cost supports policies to reduce level of PAHs in NYC air.

Applying cost analyses to drive policy that protects children: mercury as a case study.

Exposure in prenatal life to methylmercury (MeHg) has become the topic of intense debate in the United States after the Environmental Protection Agency (EPA) announced a proposal in 2004 to reverse strict controls on emissions of mercury from coal-fired power plants that had been in effect for the preceding 15 years. This proposal failed to incorporate any consideration of the health impacts on children that would result from increased mercury emissions. We assessed the impact on children's health of industrial mercury emissions and found that between 316,588 and 637,233 babies are born with mercury-related losses of cognitive function ranging from 0.2 to 5.13 points. We calculated that decreased economic productivity resulting from diminished intelligence over a lifetime results in an aggregate economic cost in each annual birth cohort of $8.7 billion annually (range: $0.7-$13.9 billion, 2000 dollars). $1.3 billion (range: $51 million-$2.0 billion) of this cost is attributable to mercury emitted from American coal-fired power plants. Downward shifts in intellectual quotient (IQ) are also associated with 1566 (range: 115-2675) excess cases of mental retardation (MR defined as IQ < 70) annually. This number accounts for 3.2% (range: 0.2-5.4%) of MR cases in the United States. If the lifetime excess cost of a case of MR (excluding individual productivity losses) is $1,248,648 in 2000 dollars, then the cost of these excess cases of MR is $2.0 billion annually (range: $143 million-$3.3 billion). Preliminary data suggest that more stringent mercury policy options would prevent thousands of cases of MR and billions of dollars over the next 25 years.

Mental retardation and prenatal methylmercury toxicity.

BACKGROUND: Methylmercury (MeHg) is a developmental neurotoxicant; exposure results principally from consumption of seafood contaminated by mercury (Hg). In this analysis, the burden of mental retardation (MR) associated with methylmercury exposure in the 2000 U.S. birth cohort is estimated, and the portion of this burden attributable to mercury (Hg) emissions from coal-fired power plants is identified. METHODS: The aggregate loss in cognition associated with MeHg exposure in the 2000 U.S. birth cohort was estimated using two previously published dose-response models that relate increases in cord blood Hg concentrations with decrements in IQ. MeHg exposure was assumed not to be correlated with native cognitive ability. Previously published estimates were used to estimate economic costs of MR caused by MeHg. RESULTS: Downward shifts in IQ resulting from prenatal exposure to MeHg of anthropogenic origin are associated with 1,566 excess cases of MR annually (range: 376-14,293). This represents 3.2% of MR cases in the US (range: 0.8%-29.2%). The MR costs associated with decreases in IQ in these children amount to $2.0 billion/year (range: $0.5-17.9 billion). Hg from American power plants accounts for 231 of the excess MR cases/year (range: 28-2,109), or 0.5% (range: 0.06%-4.3%) of all MR. These cases cost $289 million (range: $35 million-2.6 billion). CONCLUSIONS: Toxic injury to the fetal brain caused by Hg emitted from coal-fired power plants exacts a significant human and economic toll on American children.

Cost effectiveness of lead screening.

Lead-screening programs may reduce childhood disabilities, but at what cost? Through a review of the literature, we performed a cost-effectiveness analysis in which the costs, savings, and health benefits of two lead-screening strategies--employing either a free erythrocyte protoporphyrin assay or blood lead measurement--were compared with each other and with a strategy of no screening in a population of three-year-old children. When the prevalence of lead poisoning among the children screened is 7 per cent or more, we estimate that free erythrocyte protoporphyrin screening averts morbidity and results in net savings: It is both better and cheaper than no screening. At prevalences below 7 per cent, the net positive costs from screening and early treatment must be weighed against the noneconomic benefits of improved quality of life and considered in relation to other investments that could be made to benefit society. At all prevalence rates, free erythrocyte protoporphyrin screening is more cost effective than blood lead screening.

Prospective economic evaluation of lead poisoning prevention programs.

This paper illustrates an economic methodology for the prospective evaluation of individual lead poisoning screening and prevention programs. A method is presented for prospectively estimating the prevalence and expected health consequences of lead poisoning in an urban population. The economic costs of these consequences are calculated and cost-benefit analysis is used to complete the evaluation. A case study is developed to illustrate the potential utility of the model as a framework for the prospective evaluation of programs under funding consideration.