PM10 and asthma medication in schoolchildren.

The authors found that the use of asthma medication among elementary schoolchildren was associated with particulate pollution (particulate matter < 10 microm in aerodynamic diameter [PM10]) in a locale where PM10 consisted primarily of coarse fraction material derived from road sanding and reentrained volcanic ash. School nurses' records in 12 neighborhood schools located close to an ambient air monitoring station were abstracted, and the numbers of oral and inhaled doses of asthma medication given daily over a period of 2.5 yr were calculated.