EPA’s new Human Health Risk Assessment (HHRA) framework a step in the right direction

The Environmental Protection Agency (EPA) is offering new guidance for risk analysts who conduct important human health assessments on behalf of the Agency.

If you’ll recall, last December, George Mason University conducted a survey of toxicology experts and found widespread agreement on a need for the government to establish clearer policies and better methodology for chemical risk and hazard assessments.

We believe this framework is a step in the right direction. For one, it is consistent with many of the best practices which, for several years, ACC and the National Academy of Sciences have been recommending to the Agency in order to improve the quality and timeliness of its chemical risk assessments.

Although the document doesn’t speak directly to assessments under specific programs like EPA’s Integrated Risk Information System (IRIS), it’s clear that these programs could benefit from the framework’s guidance. (More on that below.)

What the guidance document offers

Below is a breakdown of some of the elements ACC was pleased to find in EPA’s framework:

  • The important role of planning, scoping and problem formulation. Before an assessment begins, analysts should determine the exact problem it is designed to address – whether the assessment is “fit for purpose” – in order to inform a specific type of risk management decision.
  • The quality of the data matters. Decisions should be supported by data that is high quality and relevant to the assessment at hand. Data and information should be evaluated against several factors: soundness, applicability and utility, clarity and completeness, uncertainty and variability, and the extent of evaluation and review (EPA also stated this in 2003).
  • Transparency and communication are important. The document specifically states, “All steps, key assumptions, limitations and decisions, as well as associated rationales, should be presented clearly.” Risk managers and stakeholders should understand what the results actually mean, and that is done through appropriate and accurate communication.
  • Risk assessments need to rely on meaningful human health endpoints. They should provide expected or central estimates of risk, and they should provide a broad range of risk estimates (important for analyzing economic benefits).
  • The importance of seeking public and stakeholder input during the assessment process. This is especially important at the planning stage to justify the time and precious resources that would need to be spent. The document also notes that external peer review should continue to play a key role in informing assessments.
  • Accurate risk characterization in the final assessment stages. EPA’s 2000 Risk Characterization Handbook similarly calls for Transparency, Clarity, Consistency and Reasonableness in all completed risk assessments.

What about IRIS?

Again, while the framework doesn’t speak directly to IRIS assessments, if the EPA intends to use IRIS assessments to inform important regulatory decisions, it is imperative the Agency seriously consider incorporating some of the framework’s process improvements into IRIS.

EPA has made some changes to IRIS, but the program could be made stronger by improving the problem formulation, planning and scoping phase, and by developing documents that provide expected or central estimates of risk, not just conservative values.

Furthermore, hazard identification and dose response must be improved to provide plausible and realistic estimates of when adverse effects are likely. Assessments must also provide information to inform human variability as well as uncertainty.

Overall, we believe EPA’s new HHRA framework represents an important step forward in improving the design and conduct of chemical assessments, and we are committed to working with EPA and other stakeholders to ensure assessments are the highest quality possible.

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