Toxic Substances Control Act (TSCA) Implementation: How the Amended Law Has Failed to Protect Vulnerable Populations from Toxic Chemicals in the United States

Abstract

Exposures to industrial chemicals are widespread and can increase the risk of adverse health effects such as cancer, developmental disorders, respiratory effects, diabetes, and reproductive problems. The amended Toxic Substances Control Act (amended TSCA) requires the U.S. Environmental Protection Agency (EPA) to evaluate risks of chemicals in commerce, account for risk to potentially exposed and susceptible populations, and mitigate risks for chemicals determined to pose an unreasonable risk to human health and the environment. This analysis compares EPA’s first 10 chemical risk evaluations under amended TSCA to best scientific practices for conducting risk assessments. We find EPA’s risk evaluations underestimated human health risks of chemical exposures by excluding conditions of use and exposure pathways; not considering aggregate exposure and cumulative risk; not identifying all potentially exposed or susceptible subpopulations, and not quantifying differences in risk for susceptible groups; not addressing data gaps; and using flawed systematic review approaches to identify and evaluate the relevant evidence. We present specific recommendations for improving the implementation of amended TSCA using the best available science to ensure equitable, socially just safeguards to public health. Failing to remedy these shortcomings will result in continued systematic underestimation of risk for all chemicals evaluated under amended TSCA.

Rebuttal to Correspondence: “Toxic Substances Control Act (TSCA) Implementation: How the Amended Law Has Failed to Protect Vulnerable Populations from Toxic Chemicals in the United States”

“…First, Tweedale incorrectly states we “regard RA [risk assessment] as a holistic process. In fact, it is a sequential process.” There is no clear basis for his assertion regarding our views, and in fact in Supporting Information Figure 3 of our paper, we detail the sequential steps of the systematic review process as a step in the risk evaluation process . Second, with regard to EPA’s failure to document how it evaluated records found by its literature search, he incorrectly states we “accept this situation; they note only that U.S. EPA found most published toxicity findings for each chemical.” Nowhere in our analysis do we say we accept the exclusion of studies without justification or that we believe “U.S.…”

“…We appreciate the correspondence from Anthony Tweedale on our recent policy analysis on the amended Toxic Substances Control Act (TSCA) . Our analysis focused on how the U.S. Environmental Protection Agency (EPA)’s risk evaluations underestimated human health risks of chemical exposures by excluding conditions of use and exposure pathways, not considering aggregate exposure and cumulative risk, not identifying all potentially exposed or susceptible subpopulations and not quantifying differences in risk for susceptible groups, not addressing data gaps, and using a flawed systematic review approach to identify and evaluate relevant evidence.…”

“…This lack of transparency in decision making around the evidence base threatens the validity of EPA’s conclusions for each risk evaluation under TSCA and ultimately may have underestimated risk to vulnerable populations. As we stated in our analysis, “while it is scientifically appropriate for EPA to revisit several aspects of the first 10 evaluations, the advantages of making corrections or improvements to the risk evaluations must be balanced against the disadvantages of further delays in issuing risk management rules to address unreasonable risk, which would result in continued harmful exposures.”…”

The development and function of the brain barriers – an overlooked consideration for chemical toxicity

“…While having economic and consumer benefit, these chemicals are used ubiquitously in communities and associated with air pollution, electronic waste, flame retardants, plastics, and pesticides ( Diamanti-Kandarakis et al, 2009 ; Gore et al, 2014 ; O'Shaughnessy et al, 2021 ). Although there are at least tens of thousands of manufactured compounds currently in the chemical universe, very few have undergone toxicological evaluation ( Judson et al, 2009 ; Rayasam et al, 2022 ) and even fewer have undergone developmental neurotoxicity testing. Grandjean and Landrigan (2006) published a systematic review identifying over 100 industrial chemicals known to be neurotoxic to humans, five of which could be classified as developmental neurotoxicants (arsenic, lead, methylmercury, polychlorinated biphenyls, and toluene).…”

The Importance of Governance Efficiency in Environmental Policy Research in Energy Shortage Period

“…The governance efficiency of fiscal investment in these industries is an extremely important research issue. The assessment studies at each policy stage can serve as a foundation for the implementation of a broader environmental governance plan in the future [11] . The government's policy package should not only address environmental issues, but also improve employment structure and equity.…”