CHRONIC DISEASE-ASSOCIATED WITH LONG-TERM CONCENTRATIONS OF NITROGEN-DIOXIDE

A prospective epidemiologic cohort study of 6,000 residentially stable and non-smoking Seventh-day Adventists (SDA) in California was conduc ted to evaluate long-term cumulative levels of ambient nitrogen dioxid e (NO2) in association with several chronic diseases. These diseases i ncluded respiratory symptoms, cancer, myocardial infarction (Ml), and all natural cause mortality. Cumulative ambient concentrations of NO2 were estimated for each study subject using monthly interpolations fro m fixed site monitoring stations and applying these estimates to the m onthly residence and work place zip code histories of study participan ts. In addition, a personal NO2 exposure study on a randomly selected sample of 650 people in southern California was conducted to predict t otal personal NO2 exposure using household and lifestyle characteristi cs and ambient NO2 concentrations. It was found that good predictabili ty could be obtained (correlation coefficient between predicted and ob served values = 0.79) from a model predicting personal NO2. The result ing regression equations from the personal NO2 exposure study were app lied to the epidemiologic study cohort to adjust ambient concentration s Of NO2. No statistically significant associations were found between either the adjusted or unadjusted mean concentration estimates of NO2 and the development of new cases of respiratory symptoms or change in respiratory symptom severity. Also, no statistically significant asso ciations were found between long-term ambient concentrations Of NO2 an d incidence of cancer, Ml, or all natural-cause mortality. However, th e last three outcomes were based on a larger population that could not be adjusted for indoor concentrations.