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EPA Science Matters Newsletter: IRIS Improves: EPA Advances Signature Chemical Health Assessment Program

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Published October 2014

National Academy of Sciences report applauds Agency actions to enhance program.

On May 5, 2014, the National Research Council of the National Academy of Sciences released a report commending EPA actions to advance the Agency’s Integrated Risk Information System (IRIS) program, which provides information on the potential health effects of environmental contaminants.

The National Academy of Sciences spent two years reviewing IRIS. Its report, Review of EPA’s Integrated Risk Information System (IRIS) Process, highlights how far the program has advanced since 2011, when Agency researchers embraced a commitment to making improvements, particularly in the areas of transparency, accessibility, and scientific integrity. “Overall,” the committee that issued the report wrote, “the changes that EPA has proposed and implemented to various degrees constitute substantial improvements in the IRIS process.”

Since it was started in 1985, the IRIS program has served as a key resource for health officials, environmental agencies, private companies, and others needing accurate, easy-to-access, and relevant information about the health risks of chemicals that might be encountered in air, water, and soil.

In the years since, the program has reviewed hundreds of chemicals, from acenapthene to zineb. The IRIS database includes health effects information on high-profile chemicals such as dioxin, trichloroethylene, benzene, and many others. The list includes chemicals likely to be found in a wide range of exposure scenarios, from tobacco smoke and tailpipe emissions to chemicals in drinking water.

Over the past few years, EPA scientists and managers have been working to make significant advancements while they increase the capacity to assess more chemicals every year.

“We are enhancing the process to improve the science and increase public engagement,” says EPA’s Vincent Cogliano, acting director of IRIS. “In the past we would work on the assessment and then present it to the public. Now, there will be two or three opportunities to see what we are doing and comment before a draft is sent to peer review. We hope that through this early public engagement we will identify key issues, so they are debated early in the process.”

The New IRIS Process

Before beginning to develop a chemical health assessment, IRIS program officials will now meet with representatives of various EPA program offices. They represent people who rely on IRIS findings to make decisions about emissions, permits, and other regulatory programs to protect public health and are a prime example of the kind of IRIS users that need to be involved early in the process, explains Cogliano.

Next, a public meeting is held to outline strategies for conducting an assessment and to invite open discussion about key issues that will be addressed in the assessment and available and ongoing research that pertains to these issues. A public release of preliminary assessment materials follows, providing outside parties with a transparent view of the strategy the IRIS program is using to search the scientific literature, as well as the results of that literature search. Tables, too, are included to present clear summaries of the critical scientific literature that EPA researchers will use to develop the assessment.

Relevant, Impactful Science

“These chemicals often have hundreds or thousands of studies,” Cogliano says. “We do our literature search, then we document the evidence and come up with draft conclusions. Then, it goes through a comment and review process that can take more than a year.”

State health officials consult IRIS when they are trying to decide how to manage toxic cleanups or issue permits to industrial users. The improved process is making it easier for these and other stakeholders, including public advocacy groups, industry officials, public health experts, and residents who live or work near contaminated areas, to have input into the IRIS chemical assessment process.

Gary Ginsberg, state toxicologist at the Connecticut Department of Health, says he uses IRIS almost every day. “Right now, I’m doing a trichloroethlylene risk assessment. The IRIS file from 2011 is instrumental both for cancer and non-cancer. It’s become institutionalized as the go-to place, the first place of reference for toxicology data,” he explains.

Improvements to the IRIS site’s graphic design and its presentation of IRIS assessments and the wealth of science they contain will help Ginsberg and other users find the information they seek. The new, streamlined document structure includes:

  • a preamble describing how EPA applies guidance, methods, and criteria to develop assessments;
  • an executive summary highlighting major assessment conclusions;
  • a detailed literature search strategy and the study evaluation process used; and
  • distinct sections on hazard identification and dose-response analysis.

Cogliano expects that a new Science Advisory Board committee will get updated IRIS assessments to review more frequently as relevant science emerges. He also anticipates that the number of chemicals added to the IRIS database each year will increase significantly.  

The improved process has gone a long way to enhance stakeholder engagement, increase transparency, and improve the scientific integrity of the IRIS program.  All of these advances factored into the improvements noted in the National Academy of Sciences report. Yet, Agency scientists are not done. They are already making plans to convene a workshop later this year to address some of the recommendations the report committee made to further strengthen the program.

EPA remains committed to continuing to build on their progress, ensuring that IRIS continues to have impact by supporting decisions designed to keep our communities healthy and our environment clean.