Research Reports

One major component of urban smog is ozone, a highly reactive gas that forms when emissions from mobile and industrial sources react chemically in the presence of sunlight.  One concern is that prolonged ozone exposure could cause noncancerous lung diseases such as fibrosis and emphysema. The NTP's bioassay project presented a unique opportunity for a collaboration between the HEI and the NTP.

In two separate studies, Drs. Koenig and Utell examined the effects of exposing healthy subjects and subjects with asthma to combined oxidant and acid pollutants. Each team of investigators conducted studies in which human volunteers received either combined or sequential exposures to oxidant gases and acid aerosols and standard pulmonary function tests were performed and symptoms were recorded. Dr. Koenig and colleagues exposed 28 adolescents with asthma to varying concentrations of ozone, nitrogen dioxide, and sulfuric acid. Dr. Utell and colleagues examined the effects of sequential exposures to sulfuric acid and ozone on pulmonary function in 30 subjects with asthma and 30 healthy subjects between the ages of 18 and 45. 

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. Prolonged ozone exposure may injure respiratory tissue, leading to the development or exacerbation of chronic lung diseases such as fibrosis or emphysema. An excess of connective tissue can lead to fibrosis and changes in connective tissue are believed to be an underlying cause of emphysema. Dr.

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. The study of the effects of long-term ozone exposure on lung complex carbohydrates, described in this report, was one of eight laboratory studies supported by the NTP/HEI collaborative agreement. In addition to studying lung and nasal structure and function, investigators studied other constituents of lung connective tissue. Dr.