‘Worst of worst’ chemicals here to stay – EPA, we need action

When Congress reformed the Toxic Substances Control Act (TSCA) in 2016, it gave EPA a critical job: to protect the public’s health from the ‘worst of the worst’ hazardous chemicals – those that build up in our bodies and persist in the environment, known as persistent, bioaccumulative and toxic chemicals (PBTs). EPA’s recent assessment of five PBT chemicals documents these chemicals in air, water, food, and the bodies of men, women and children across the country. These findings highlight the need for comprehensive EPA action on the many sources of these chemicals to protect families, especially those who are most vulnerable.

TSCA mandates expedited action on the five PBTs shown in the table below, used in everything from industrial processes to the televisions in our living rooms.

Table PBT blog.jpg
Information in table from US EPA, June 2018

Scientists, academics and clinicians commented to EPA that though developmental toxicity is a health hazard for all five PBTs, EPA does not identify the populations most susceptible to these toxic effects: women of childbearing age, pregnant women, infants, and children. The law requires EPA to consider exposure “to a potentially exposed or susceptible subpopulation;” this key consideration is missing from the current assessments. The brains and bodies of fetuses, infants and children are still developing and extremely sensitive to disruption by toxic chemicals during critical windows of susceptibility.

TSCA requires EPA to get rid of exposures to these PBT chemicals (“reduce exposure to the substance to the extent practicable” in the words of the law). To achieve this, EPA must do more than simply ban manufacturing of these chemicals because, as shown in the diagram below, PBTs persist in the environment and move up the food chain—so even if no new chemicals are manufactured, exposures via existing products, and then food and water will continue for decades as people dispose of more and more PBT-containing products to recycling and landfills. For example, researchers estimate that 154 million pounds of DecaBDE will remain within existing in-use products (televisions, furniture, etc) in the U.S. and Canada by 2020—and all these millions of pounds will circulate into the environment and people unless EPA takes action to eliminate this source. This shows the importance of EPA acting comprehensively to address all PBT exposure sources to truly remove people’s exposures to these harmful chemicals.

PBT figure

The PBT assessments demonstrated known exposures to the five PBTs and thus met the law’s requirements for EPA to proceed with rulemaking. However, moving forward, EPA should not use its ‘TSCA systematic review’ method for future systematic reviews due to the problems we detailed in our previous blog. EPA should use an existing empirically based method, such as OHAT or Navigation Guide to inform its PBT rulemaking.

We have already seen the terrible legacy of use of PBT chemicals with DDT. DDT, another very harmful PBT, has been banned for decades yet we are paying the health price of its use. Every pregnant woman still carries the burden of DDT or its metabolite DDE in her body and babies are still being born polluted with this chemical.  It has been linked to liver and adrenal gland toxicity as well as being a probable human carcinogen. Research from just last month shows prenatal exposures to DDT-associated chemicals were associated with an increased risk of autism.  This example shows why we need comprehensive action from EPA now to protect future generations.

About the Author

Veena Singla, PhD is a Senior Scientist in the Healthy People & Thriving Communities program at Natural Resources Defense Council. Prior to that, she was the Associate Director of Science & Policy at PRHE.


DanielleDanielle Fries, MPH, also contributed to this post.  She has a background in environmental health, toxicology, and risk assessment with an MPH from University of Michigan and BS from UC Davis. Danielle was an ORISE fellow with the Contaminants Assessment Branch at the FDA’s Center for Food Safety and Applied Nutrition.