There’s a federal assessment program you’ve probably never heard of, yet its results are so powerful that they create policies to limit people’s exposure to cancer-causing and toxic chemicals across the country, from a mobile home park in San Diego to a retired couple’s home in Northwest Michigan to apartments in Minneapolis.
It’s the Integrated Risk Information System or IRIS, a US Environmental Protection Agency (EPA) program that evaluates the health hazards of chemicals. IRIS completes comprehensive assessments of chemicals and develops impartial data on toxicity—critical data that EPA, other federal, state and local agencies rely on to set protections for the levels of chemicals allowed in air or water. In this way, IRIS’ work provides the scientific foundation officials use to ensure that communities have clean air and drinking water.
Take the cancer-causing chemical TCE (trichloroethylene), an industrial solvent used in dry-cleaning and manufacturing products such as electronics, cars, and vacuum cleaners. As shown below, after a comprehensive review of the evidence, the IRIS assessment concluded that TCE can cause cancers of the blood, liver and urinary system, as well as fetal heart defects and toxicity to the immune system.
TCE is a prime culprit contaminating numerous Superfund sites in the U.S., such as an old semiconductor manufacturing site in California and a defunct General Mills plant in Minnesota. But how do state regulators know what levels of TCE in air or drinking water might be dangerous, and the amount of remediation needed?
Often, they consult EPA’s Regional Screening Levels —where levels for TCE are set based on the IRIS assessment. Other actions on TCE include:
- Washington and Massachusetts set clean-up requirements for TCE in homes, soil, groundwater or surface water based on the IRIS assessment.
- California recognized TCE as a chemical known to the state to cause cancer, developmental and male reproductive toxicity, triggering requirements for companies to warn consumers about TCE based on…you guessed it…the IRIS assessment.
- California and Nebraska set indoor air action levels for TCE based on…drum roll please…the IRIS assessment.
- Minnesota released updated drinking water guidance values for TCE, and also requires mitigation measures if indoor air levels exceed health risk thresholds—all based on…one more time…the IRIS assessment.
In other words, IRIS assessments result in concrete actions for creating a cleaner environment and protecting health– actions which are now under threat.
The Senate Appropriations Bill for 2018 proposes deep cuts to EPA’s funding which would slash support for the IRIS program. The bill also proposes an inappropriate move of the IRIS program out of its current location in the Office of Research and Development (ORD), as shown in the diagram below.
The bill’s plan is to place a skeleton of the IRIS program in the Office of Chemical Safety and Pollution Prevention TSCA program, under the direction of former chemical industry lobbyist Nancy Beck.
Such a move is ill-advised, because as stated on EPA’s website: “The placement of the IRIS Program in ORD is intentional. It ensures that IRIS can develop impartial toxicity information independent of its use by EPA’s program and regional offices to set national standards and clean up hazardous sites.” It is critical for IRIS scientists to be able to work free of the influence of parties who will use or be affected by the results of IRIS assessments, such as federal and state regulators or the chemical industry.
In a workshop held last week, a National Academies of Sciences (NAS) committee reviewed recent changes to the IRIS program and process. EPA and IRIS staff presented on their significant work to incorporate the most current scientific principles and methods in their assessments, including:
- Implementing a systematic review process for evidence identification, integration and evaluation
- Development and incorporation of new tools such as semi-automation and machine learning to aid in systematic review
- Appropriate integration of evidence from “New Approach Methods” such as Tox21 and ToxCast which considers both strengths and limitations of these data streams
- Improved peer-review process and collaboration with experts in government and academia
UCSF PRHE also commented to the committee on these improvements. It was clear from the workshop that: the IRIS program has made important advances; it should remain in the non-regulatory Office of Research and Development; and with funding, its chemical hazard assessments can continue to provide a robust scientific foundation for essential public health protections.
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.
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