Healthy women's PEF variations with ambient summer concentrations of PM10,PM2.5, SO42-, H+, and O-3

The relationship between ambient air pollution and daily change in peak exp iratory flow (PEF) was studied in a sample of 473 nonsmoking women (age 19 to 43 yr) in Virginia over summers 1995-1996. Daily 24-h averages of partic ulate matter (PM2.5 and PM10), fine particulate sulfate (SO42-) and strong acid (H+), hourly ozone (O-3), and select meteorologic variables (e.g., tem perature) were collected at a regional outdoor monitoring site. Subjects to ok PEF measurements twice daily for a 2-wk period using a standard MiniWrig ht peak flow meter. Concurrent measures for summer periods of 24-h PM2.5 (m u g/m(3)) ranged from 3.5 to 59.7; H+ (nmol/m(3)) from 0 to 250; maximal da ily 8-h average O-3 (ppb) from 17.0 to 87.6. Morning PEF decrements were si gnificantly associated with H+ and PM2.5. An increase of 50 eta mol/m(3) of H+ and 10 mu g/m(3) of PM2.5 related to decreases of 0.89 (95% CI = 0.21 t o 1.57) and 0.73 (95% CI = 0.07 to 1.38) L/min in morning PEF, respectively . Ozone was the only exposure related to evening PEF with 5-d cumulative la g exposure showing the greatest effect; 7.65 L/min (95% CI = 2.25 to 13.0) decrease per 30 ppb O-3 increase. Separate physiologic effects were observe d for summer ambient concentrations of two different pollutants (PEF decrem ents related to PM2.5, in morning and O-3 in evening) at concentrations bel ow the new U.S. EPA 24-h ambient air quality standard for PM2.5, and 8-h st andard for O-3.