Nitrogen Oxides

This report describes the quality assurance and quality control program developed for the previously reported epidemiologic study of nitrogen dioxide (NO₂) and respiratory illness in children (Health Effects Institute Research Report 58, Parts I and II). The specific aims of the program were to make certain that data were sufficiently accurate, complete, verifiable, and retrievable.

This publications contains two reports by Drs. Jonathan M. Samet, John D. Spengler, and colleagues, who conducted a prospective investigation of 1,205 healthy infants living in homes with gas or electric stoves in Albuquerque, NM. Nitrogen dioxide exposures were carefully estimated from repeated measurements in multiple locations in the subjects' homes throughout the entire 18-month observation period. Respiratory illnesses were monitored prospectively using a surveillance system based on daily parental diaries of respiratory signs and symptoms. Parental reports of illness episodes were validated in a subset of the population by comparison with clinical diagnoses and microbiological testing. Potential confounding factors that influence respiratory infections were reduced by selecting subjects whose parents did not smoke or intend to use day-care services outside the home.

The human health effects that result from breathing air pollutants depend on the amount of pollutant inhaled from the air (exposure dose) and the amount of inhaled material that stays in the respiratory tract (retained dose). Because the retained dose of a pollutant may damage the respiratory tract and cause disease, it is a key factor for determining appropriate government regulations for air pollutants. Drs.

This report describes a study by Dr. Johnson and colleagues to test the hypothesis that inhaled oxidants can cause lung damage by inactivating the proteinase inhibitors that normally protect the lung from proteolysis. In the first set of experiments, the functional activity of rat alpha-1-proteinase inhibitor (á1-PI) was measured in rat lung lavage fluid from rats exposed acutely or chronically to varying concentrations of NO₂, diesel exhaust, O₃, and O₃ in conjunction with CO₂.