Air Toxics

This report describes a study by Dr. Thomas Cahill and colleagues to create and evaluate a new method to measure acrolein and other volatile carbonyls present at low concentrations in ambient air. Acrolein is an important aldehyde that is very difficult to measure accurately, so developing better methods for measuring levels and exposure is critical to better risk assessment for the chemical. The investigators developed a sampler that traps acrolein using sodium bisulfite in an aqueous medium.

This report describes a study to evaluate genotoxic effects of exposure to 1,3-butadiene and its metabolites. 1,3-Butadiene is classified as a human carcinogen via inhalation, but risk assessment is complicated due to differences in metabolism between mice and rats and between males and females. Dr. Walker and colleagues studied mutagenicity in rats and mice of both genders, with a focus on evaluating stereoisomers of 1,3-butadiene metabolites and low exposure concentrations.

A Special Report of the Institute's Air Toxics Review Panel. Special Report 16 summarizes the health effects of exposure to the 21 mobile-source air toxics (MSATs) defined by the 2001 EPA mobile-source rulemaking and critically analyzes the literature for a subset of seven MSATs (acetaldehyde, acrolein, benzene, 1,3-butadiene, formaldehyde, naphthalene, and polycyclic organic matter). The report also assesses and summarizes research gaps and unresolved questions, as understood in the context of the current regulatory agenda. The report focuses on MSATs for which mobile sources are a sizable source of human exposure and for which existing data suggest that health effects might be observed at concentrations approaching those found in ambient air. For each MSAT, the following questions are addressed: (1) To what extent are mobile sources a significant source of exposure to this MSAT? (2) Does this MSAT affect human health? (3) Does this MSAT affect human health at environmental conditions?

This study by Dr. Elizabeth Delzell and colleagues is the first major update of the most extensive human study to date of potential carcinogenic effects of 1,3-butadiene (BD). The earlier study investigated mortality among the largest occupational group exposed to BD: 18,000 men employed in the styrene-butadiene rubber (SBR) industry between 1944 and 1991. In the current study, these workers were followed for an additional 7 years and the effects of exposure to other compounds were evaluated.