June 29, 2023
US EPA Proposes New or Strengthened Causal Relationships Between Lead Exposure and Health Effects in Its Updated “Integrated Science Assessment for Lead”
In its recently released draft update to the “Integrative Science Assessment for Lead,” US EPA proposed that scientific evidence now suggests lead exposure causes kidney effects and mortality, among other health effects.
In early 2022, US EPA announced plans to release an update to its “Integrated Science Assessment (ISA) for Lead (Pb),” and recently released the first draft. This updated draft ISA for Pb is part of a broader review of the National Ambient Air Quality Standards (NAAQS) for Pb. In the draft ISA, US EPA concluded that recent scientific evidence supports new, strengthened, or weakened causal relationships between Pb exposure and certain health effects. US EPA evaluates the overall strength of evidence for potential causal relationships between Pb and health effects using a five-level hierarchy, spanning “causal” to “not likely to be a causal relationship.”
A summary of the proposed changes in causal relationships outlined in the draft ISA for Pb, along with those published in the last ISA, is presented in the table below.
In addition, US EPA has released the third volume of its Integrated Review Plan (IRP Volume 3) for the NAAQS for Pb. In the IRP Volume 3, US EPA reaffirmed its conclusion that cognitive effects in children (specifically, intelligence quotient [IQ] decrement) remain to be the most sensitive endpoint on which the primary NAAQS for Pb should be based, as well as any potential changes in the primary standard.
Following review and feedback from the US EPA’s Clean Air Scientific Advisory Committee on June 13-14, 2023, the draft ISA for Pb will be revised; it is anticipated to be released in its final form in spring 2024.
If you have any questions about the updated draft ISA for Pb, the IRP Volume 3, or their implications, please visit our website or contact:
Steven Boomhower, Ph.D.
Senior Toxicologist
sboomhower@gradientcorp.com
Denali Boon, Ph.D., M.P.H.
Senior Epidemiologist
dboon@gradientcorp.com
Topics: Lead, Air Quality, Integrated Science Assessment (ISA), National Ambient Air Quality Standards (NAAQS)