title: Air pollution and daily hospital admissions in metropolitan Los Angeles.
abstract: We used daily time-series analysis to evaluate associations between ambient carbon monoxide, nitrogen dioxide, particulate matter [less than and equal to] 10 microm in aerodynamic diameter (PM(10)), or ozone concentrations, and hospital admissions for cardiopulmonary illnesses in metropolitan Los Angeles 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. NO(2), and, to a lesser extent, PM(10) tracked CO and showed similar associations with cardiovascular disease, but O(3) 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 and Asians), and in persons older than 65 years of age. Pulmonary disease admissions associated more with NO(2) and PM(10) than with CO. Pulmonary effects were generally smaller than cardiovascular effects and were more sensitive to the choice of model. We conclude that in Los Angeles, atmospheric stagnation with high primary (CO/NO(2)/PM(10)) pollution, most common in autumn/winter, increases the risk of hospitalization for cardiopulmonary illness. Summer photochemical pollution (high O(3)) apparently presents less risk.
authors.affiliation: Rancho Los Amigos National Rehabilitation Center, Downey, California 90242, USA. linn@hsc.usc.edu
authors.forename: W S
authors.initials: WS
authors.lastname: Linn
authors.forename: Y
authors.initials: Y
authors.lastname: Szlachcic
authors.forename: H
authors.initials: H
authors.lastname: Gong
authors.forename: P L
authors.initials: PL
authors.lastname: Kinney
authors.forename: K T
authors.initials: KT
authors.lastname: Berhane
mesh_terms: D000328:Adult; D000368:Aged; D000393:Air Pollutants / Q000009:adverse effects / Q000032:analysis; D000397:Air Pollution / Q000009:adverse effects* / Q000706:statistics & numerical data; D002248:Carbon Monoxide / Q000009:adverse effects / Q000032:analysis; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology; D004782:Environmental Health; D005260:Female; D006801:Humans; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009585:Nitrogen Dioxide / Q000009:adverse effects / Q000032:analysis; D010126:Ozone / Q000009:adverse effects / Q000032:analysis; D010343:Patient Admission / Q000706:statistics & numerical data; D012621:Seasons; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D010126:Ozone; D002248:Carbon Monoxide; D009585:Nitrogen Dioxide