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 or = 34 micro g/m(3). A significant 18.1% increase (RR: 1.181, 95% CI: 1.010-1.381) in the rate of quick-relief medication prescriptions occurred during days with PM(10) of 34-60 micro g/m(3), and a 28.8% increase (RR: 1.288, 95% CI: 1.026-1.619) occurred during days with PM(10) > or = 61 micro g/m(3). Similar results for outpatient asthma visits and quick-relief medication occurred in weekly models. There were no significant associations with PM(2.5) in either daily or weekly models. These subtle but statistically significant associations suggest that non-industrial, geologic sources of PM(10) may have measurable health effects at levels below current national standards.