December 12th, 2017
We used daily time–series analysis to evaluate associations between ambient carbon monoxide, nitrogen dioxide, particulate matter ?10 µm in aerodynamic diameter (PM10), or ozone concen-trations, and hospital admissions for cardiopulmonary illnesses in metropolitan LosAngeles during 1992–1995. We performed Poisson regressions for the entire patient population and for subgroups defined by season, region, or personal characteristics, allowing for effects of temporal variation, weather, and autocorrelation. CO showed the most consistently significant (p< 0.05) relationships to cardiovascular admissions.A wintertime 25th–75th percentile increase in CO (1.1–2.2 ppm) predicted an increase of 4% in cardiovascular admissions. NO2, and, to a lesser extent, PM10 tracked CO and showed similar associations with cardiovascular disease, but O3 was negatively or nonsignificantly associated. No significant demographic differences were found, although increased cardiovascular effects were suggested in diabetics, in whites and blacks (relative to Hispanics andAsians), and in persons older than 65 years of age. Pulmonary disease admissions associated more with NO2and PM10than with CO. Pulmonary effects were generally smaller than cardiovascular effects and were more sensitive to the choice of model. We conclude that in LosAngeles, atmospheric stagnation with high primary (CO/NO2/PM10) pollution, most common in autumn/winter, increases the risk of hospitalization for cardiopulmonary illness. Summer photochemical pollution (high O3) apparently presents less risk. Key words: air pollutants, carbonmonoxide, epidemiology, LosAngeles, morbidity, nitrogen dioxide, ozone, particulate matter. Environ Health Perspect 108:427–434 (2000).[Online 27 March 2000]http://ehpnet1.niehs.nih.gov/docs/2000/108p427-434linn/abstract.html Reproduced with permission from Environmental Health Perspectives