US EPA

EPA is preparing an Integrated Science Assessment (ISA) as part of the review of the primary and secondary National Ambient Air Quality Standards (NAAQS) for Lead (Pb). The ISA will be completed by EPA's Office of Research and Development's Center for Public Health and Environmental Assessment (CPHEA). When final, the ISA is intended to update the previous Pb ISA (EPA/600/R-10/075F), published on June 26, 2013. Interested parties are invited to assist EPA in developing and refining the scientific information base for the review of the Pb NAAQS by submitting research studies and data that have been published, accepted for publication, or presented at a public scientific meeting since January 1, 2011.

EPA has established NAAQS for six criteria pollutants, including for lead (Pb). Periodically, EPA reviews the scientific basis for these standards by preparing an ISA (formerly called an Air Quality Criteria Document). The ISA provides the scientific basis for EPA's decisions, in conjunction with additional technical and policy assessments, on the adequacy of the current NAAQS and the appropriateness of possible alternative standards.

Early steps in this process include announcing the beginning of this periodic NAAQS review and the development of the ISA, and EPA requesting that the public submit scientific literature that they want to bring to the attention of the Agency as it begins this process. The Clean Air Scientific Advisory Committee (CASAC), whose review and advisory functions are mandated by section 109(d)(2) of the Clean Air Act, is charged (among other things) with independent scientific review of the Agency's air quality criteria.

The ISA will build on the scientific assessment from the last review, focusing on assessing the information newly available since that considered in the 2013 ISA. With regard to development of the ISA, the public is encouraged to assist in identifying relevant scientific information for the review by submitting research studies that were not part of the prior review, and have been published or accepted for publication in a peer-reviewed journal. The Agency is interested in obtaining information from new and emerging studies showing effects or no effects from Pb exposure.

For example, the Agency is interested in information about studies of effects of controlled exposure to Pb, including in laboratory animals and in vitro systems; epidemiologic (observational) studies of associations of health outcomes with population exposures to Pb; and studies of ecological effects of Pb exposure. With regard to health effect studies, of particular interest are those studies that address or provide new information on health outcomes for which the scientific evidence presented in the 2013 ISA supported a “causal relationship” or “likely to be causal relationship” with Pb, e.g., cognitive effects in children, cardiovascular effects, and immune system effects; endpoints with less overall evidence and/or notable uncertainties at the time of the 2013 Pb ISA, such as attention deficit hyperactivity disorder, neuro-degenerative effects, and adult obesity; endpoints not previously identified in the 2013 Pb ISA; relationships between Pb exposure concentrations and occurrence of health-related endpoints; health effects associated with blood lead levels below 10 µg/dL and/or with near current exposure concentrations; Pb toxicokinetics and toxicokinetic modeling; information and data useful for assessing biological plausibility for Pb-related health effects; and identification of populations and life stages at increased risk of Pb-related health effects.

For ecological effects of Pb, studies that address or provide new information on terrestrial and aquatic biota are of particular interest including, but not necessarily limited to, effects of Pb on vegetation, soil and aquatic fauna, communities and populations of microorganisms, plants, and animals, as well as research on fate and transport of Pb in environmental media, and exposure-response relationships between Pb in ambient air or other media and ecological endpoints.

Information particular to air-related pathways of human and ecological exposure, including those involving deposition, are also of interest to the Agency. Air-related pathways are those that include air and may also involve media other than air, including indoor and outdoor dust, soil, surface water and sediments, vegetation and biota. Air-related Pb pathways of human exposure include inhalation of ambient air or ingestion of food, water or other materials, including dust and soil, containing Pb that has deposited from ambient air.

EPA also seeks recent information in other areas of Pb research such as human and ecological exposure assessment and exposure assessment methodologies, sources and emissions, chemistry and physics, sampling and analytical methodology, ambient concentrations and size distributions, including environmental media concentration changes in response to changes in Pb deposition, and other effects on public welfare or the environment not listed above.

The Agency also seeks information regarding the design and scope of the review of the air quality criteria and the primary (health-based) and secondary (welfare-based) Pb standards to ensure that it addresses key policy-relevant issues and considers the new science that is relevant to informing our understanding of these issues. Interested parties are invited to assist the EPA by submitting new scientific information that may address key uncertainties identified in the last Pb NAAQS review, which are provided in the Policy Assessment (EPA-452/R-14, May 2014). Other opportunities for submission of new peer-reviewed, published (or in-press) papers will be possible as part of public comment on the draft ISAs that will be reviewed by the CASAC.

To ensure this final statutory requirement is fully met, elsewhere in the July 7, 2020 Federal Register, EPA is issuing a call for information that would facilitate the committee's consideration of these issues.