Airborne particulate matter from primarily geologic, non-industrial sources at levels below National Ambient Air Quality Standards is associated with outpatient visits for asthma and quick-relief medication prescriptions among children less than 20 years old enrolled in Medicaid in Anchorage, Alaska

In Anchorage., Alaska, particulates with aerodynamic diameter <= 10 pin (PM to) arise primarily from natural, geologic sources, and particulates with aerodynamic diameter <= 2.5 mu m (PM2.5) arise primarily from automobile emissions. The current study used a population-based time-series analysis design to evaluate the effects of daily and weekly PM10 and PM2.5 on respiratory health outcomes among children < 20 years of age residing in Anchorage enrolled in Medicaid. All generated estimating equations models were adjusted 3 for season, year, weekends, temperature, wind speed, and precipitation. Relative to the days with PM10 mass concentration <= 13 mu g/m, a significant 9.3% increase (RR: 1.093, 95% Cl: 1.004-1.191) in the rate of outpatient visits for asthma occurred during days with PM10 of 20-33 mu g/m(3). No further dose-response occurred for days with PM10 >= 34 mu g/m(3). A significant 18.1 % increase (RR: 1. 181, 95% Cl: 1.010-1.381) in the rate of quick-relief medication prescriptions occurred during days with PM 10 of 34-60 mu g/m, and a 28.8% increase (RR: 1.288, 95%) CI: 1.026-1.619) occurred during days with PM10 >= 61 mu g/m(3). Similar results for outpatient asthma visits and quick-relief medication occurred in weekly models. There were no significant associations with PM2.5 in either daily or weekly models. These subtle but statistically significant associations suggest that non-industrial, geologic sources of PM10 may have measurable health effects at levels below current national standards. (c) 2006 Elsevier Inc. All rights reserved.