Air Toxics

Dr. Albertini and colleges organized a group of researchers from the United States, Czech Republic, The Netherlands, and the United Kingdom to determine whether biomarkers in the blood and urine of workers exposed to butadiene in occupational settings correlated with their personal exposure. Samples were collected from male workers employed either in a plant that used butadiene and styrene to produce rubber polymer in Prague. They also collected blood and urine from male administrative workers at the plant who had no direct occupational exposure to butadiene and served as control subjects.

Drs Turteltaub and Mani at Lawrence Livermore National Laboratory investigated benzene metabolism in rodents over a large dose range that encompassed concentrations close to those of human ambient exposure. Understanding benzene metabolism at low exposure levels is critical to benzene assessment to determine the shape of the dose-response curve at low concentrations.The investigators administered radioactive benzene to mice and rats and subsequently analyzed bone marrow, liver, urine, and plasma from these animals.

This report describes two studies that measured emissions in roadway tunnels. Dr. Alan Gertler and colleagues at the Desert Research Institute studied particulate matter emissions in the Tuscarora Mountain Tunnel located on the Pennsylvania Turnpike. Dr Daniel Grosjean and colleague at DGA, Inc studied carbonyl emissions in the Tuscarora Mountain Tunnel and in the Caldecott Tunnel in California. The unique environment in tunnel studies allows the investigators to measure emission rates averaged over many vehicles, to determine the physical and chemical character of emissions under ambient conditions, and in some instances to compare current emissions with past emissions at the same location. Both groups of investigators also measured emissions at times when the proportions of gasoline engine vehicles and diesel engine vehicles differed, allowing them to estimate the differences between emissions from the two sources.

Dr. Eastmond and colleagures at the University of California, Riverside investigated whether chromosomal changes could be used as biomarkers of benzene exposure in mice and humans. The first part of the study involved detecting chromosomal alterations in cells using a modification of a molecular cytogenetic technique known as fluorescence in situ hybridization (FISH). Eastmond and colleagues evaluated the frequency of such chromosomal aberrations in the erythrocytes (red blood cells) from the bone marrow of mice exposed to various doses of benzene and for different exposure durations.

In an effort to improve air quality and decrease dependence on petroleum, alternative fuels such as methanol have been considered to substitute for gasoline or diesel fuel. Methanol is also a candidate to provide the hydrogen for fuel cells. Before people are exposed to increased concentrations of methanol, the potential health effects of such exposures require study. Dr. Burbacher and colleagues of the University of Washington studied the effects of long-term exposure to methanol vapors on metabolism and reproduction in adult female monkeys (Macaca fascicularis) and developmental effects in their offspring, who were exposed prenatally to methanol. 

Dr. Arey and colleagues of the University of California, Riverside, examined the genotoxic potential of two PAHs (naphthalene and phenanthrene) that are common air pollutants, and a subset of their atmospheric transformation products. The investigators evaluated the genotoxicity of these compounds using a variety of human cell lines with a range of metabolic capabilities. They examined the ability of these compounds to produce small-scale (damage to genes) and large-scale (damage to chromosomes) genetic damage.