Research Reports

In Part III of this study, Dr. Belinsky and his associates at the Lovelace Biomedical and Environmental Research Institute examined lung tumors from rats that had inhaled high concentrations of diesel engine exhaust or carbon black particles (see Part I by Dr. Joe Mauderly). The investigators applied molecular biology techniques to measure mutations in selected genes in the DNA from the tumors.

Dr. Beland and his associates at the University of Arkansas School of Medical Sciences developed an assay to measure mutations induced by dinitropyrenes, a class of diesel engine exhaust, in rats. The investigators analyzed the mutations in a selected gene in spleen T lymphocytes from rats treated with 1,6-dinitropyrene under conditions that induced lung tumors at the highest dose tested. They also examined DNA adduct levels in lung and liver tissues and in spleen lymphocytes and white blood cells.

In 1987, the Health Effects Institute entered into a partnership with the National Toxicology Program (NTP) to evaluate the effects of prolonged ozone exposure on F344/N rats. The NTP studies focused on carcinogenicity, while HEI supported eight studies that addressed the biochemical, functional, and structural endpoints and a biostatistical study that developed a sample allocation design and helped to integrate the research findings.

Ozone is a highly reactive gas that is a pervasive air pollutant at ground level. It is a major component of urban smog, forming when emissions from mobile and industrial sources interact with sunlight. In this report, two of studies and in the NTP/HEI Collaborative Ozone Project, were conducted to determine whether prolonged inhalation of ozone produces lasting effects on lung structure, potentially contributing to or aggravating chronic lung disease. Drs. Chang and Pinkerton and their respective colleagues investigated the effects of this prolonged ozone exposure on respiratory tract structure in healthy male and female F344/N rats.