ORD’s Portfolio of Human Health Science Assessments
EPA’s Office of Research and Development (ORD) plays an important role in helping EPA accomplish its mission to protect human health and the environment. This includes developing high quality human health science assessments that characterize the effects of environmental contaminants on human populations.
ORD’s portfolio approach to human health science assessments leverages new scientific approaches and a fit-for-purpose mindset to meet the diverse needs of decision makers at all levels, from local officials to federal regulatory agencies. By developing a portfolio of human health science assessments, ORD can work with decision makers to identify the assessment product that best meets their needs. This approach emphasizes scoping and problem formulation, early consideration of potential data limitations, and incorporation of a range of scientific approaches.
ORD’s portfolio of human health science assessments includes:
Integrated Science Assessments
Integrated Science Assessments (ISAs) provide a concise review, synthesis, and evaluation of the most policy-relevant science to serve as a scientific foundation for the review of the National Ambient Air Quality Standards. ISAs are scientific documents that characterize the human health and environmental effects from exposure to the criteria air pollutants (ozone and related photochemical oxidants, carbon monoxide, oxides of nitrogen, oxides of sulfur, particulate matter, and lead). All ISAs are vetted through a rigorous peer review process, including review by the EPA Clean Air Scientific Advisory Committee, public meetings and comment periods as announced in the Federal Register for public participation. The process of developing ISAs, including literature review and evaluation, integration of evidence, and characterization of evidence for public health and welfare impacts of criteria air pollutants, is described in the Preamble to the Integrated Science Assessments.
Integrated Risk Information System Assessments
Integrated Risk Information System (IRIS) assessments provide information on the toxicity of chemicals to which the public might be exposed, focusing on human health hazard identification and evaluation of dose-response for those potential hazards, the first two steps in the risk assessment paradigm. IRIS assessments evaluate cancer and/or non-cancer effects from chronic oral ingestion and/or inhalation of environmental contaminants. When feasible, the assessments will derive a less than-lifetime toxicity value (a “subchronic” reference value) for noncancer hazards. IRIS assessments are developed following the EPA guidelines for human health risk assessment, ORD Staff Handbook for Developing IRIS Assessments, and the IRIS Assessment Development Process, which includes independent, external peer review conducted in accordance with the EPA Peer Review Handbook.
Provisional Peer-Reviewed Toxicity Value Assessments
Provisional Peer-Reviewed Toxicity Value (PPRTV) assessments are human health toxicity assessments developed primarily for use in EPA's Superfund Program and include hazard identification and evaluation of dose-response for those potential hazards. PPRTV assessments evaluate cancer and non-cancer effects from chronic and/or subchronic exposures to environmental contaminants found at Superfund sites. PPRTV assessments are developed following EPA guidelines for human health risk assessment and undergo independent, external peer review in accordance with the EPA Peer Review Handbook.
ORD Human Health Toxicity Value (HHTV) Assessments
ORD Human Health Toxicity Value (HHTV) assessments provide toxicity information on environmental contaminants and include hazard identification and evaluation of dose-response for those potential hazards. All aspects of ORD HHTV assessments are flexible—from development process to scope to planned analyses. ORD HHTV assessments evaluate cancer and non-cancer effects from acute, subchronic or chronic exposures to environmental contaminants. Individual ORD HHTV assessments are planned in close coordination with the intended user of the assessment to ensure that the assessment meets the specific need. ORD HHTV assessments are developed following the EPA guidelines for human health risk assessment and undergo independent, external peer review in accordance with the EPA Peer Review Handbook.
EPA Transcriptomics Assessment Product (ETAP)
The EPA Transcriptomic Assessment Product (ETAP) is a human health science assessment for chemicals that lack suitable and sufficient toxicity data that enable evaluation of potential toxicity. To fill the gap, ETAP conducts a short-term in vivo study and transcriptomic measurements to identify a point-of departure and then derive a chronic toxicity value for noncancer effects. Transcriptomics can measure changes in gene activity. Previous studies have demonstrated that doses of chemicals causing disruption of gene activity also cause toxicological responses in traditional chronic toxicity tests. Unlike other human health assessments, ETAP does not provide information on hazard identification because it solely relies on changes in gene activity. ETAP uses a standard, peer-reviewed method for toxicity testing and development of a transcriptomic reference dose. Transcriptomic-based reference values derived from ETAP can be developed in a matter of months, enabling more timely regulatory decision-making.