Air pollution and acute respiratory morbidity: an observational study of multiple pollutants.

Recently there have been several attempts to estimate the health and economic effects of one or more airborne pollutants using the Health Interview Survey (HIS), a large cross-sectional database collected by the National Center for Health Statistics. The ultimate implications of these studies are unclear, however, since they frequently include different pollutants and health outcomes in the regression analysis. This paper attempts to determine the separate health consequences of two air pollutants common to the urban environment, ozone and particulate matter, using six separate years of the HIS. The results, using a fixed effects model that controls for intercity differences, indicate an association between smaller size particles (fine particulate) and both minor restrictions in activity and respiratory conditions severe enough to result in work loss and bed disability in adults. Ozone, on the other hand, appears to be associated only with the more minor restrictions. However, the measurement error associated with estimating exposure to ozone may limit the usefulness of the HIS which relies on a 2-week recall of health status. The results are compared with other studies using the HIS and related studies involving acute respiratory symptoms.