Ozone & Oxidants

Dr. John Balmes and colleagues of the University of California, San Francisco, and Dr. Mark Frampton and associates of the University of Rochester characterized ozone-induced responses in two different study populations: normal and asthmatic men and women in the Balmes study (Part I), and male and female nonsmokers and smokers in the Frampton study (Part II). The investigators addressed three issues: (1) Is an individual's reactivity to inhaled methacholine related to changes in lung function after exposure to ozone? (2) What is the relation between ozone-induced airway inflammation and changes in lung function? and (3) Do the changes in lung function and markers of inflammation in response to ozone exposure differ between normal people and people with asthma?

Dr. Loomis and colleagues at the University of North Carolina and Dr. Víctor Borja-Aburto of the Instituto Nacional de Salud Pública in Cuernavaca, Mexico, collected mortality, air quality, and weather data from records and monitoring stations in Mexico City from 1990 through 1992. Using statistical techniques, the investigators evaluated the association between mortality and ambient levels of ozone, sulfur dioxide, and total suspended particles, both individually and in a model that included all three pollutants.

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.