AIR-POLLUTION AND ASTHMA EMERGENCY ROOM VISITS IN RENO, NEVADA

The association between air pollution and the daily number of emergenc y room (ER) visits for asthma was assessed in Reno, Nevada, for the pe riod 1992-1994. All three hospitals in the region were included. There was a total of 1593 ER visits for asthma during this period of time. The air pollution variables were collected from seven monitoring stati ons, including particulate matter (PM-10), ozone (O-3), and carbon mon oxide (CO). Levels of pollution were moderately elevated (the average concentrations of PM-10, CO, and O-3 were 38.0 mu g/m(3) 4.55 ppm, and 51.0 ppb, respectively). Weighted least-squares (WLS) regression and autoregressive integrated moving average (ARIMA) lime-series analyses were applied and compared. After adjusting for such factors as day of the week, seasonal variation, and weather, both modeling methods showe d that the daily 1-h maximum O-3 concentration was a significant predi ctor of asthma LR visits, although ARIMA increased the magnitude of th e estimated response alter controlling the autocorrelated errors. Tota l asthma visits were found to increase 33.7% (95% Cl; range 6.0-61.5%) for each 100 ppb increase in the O-3 level. No association of the con centration of other measured pollutants with daily asthma ER visits wa s found. The results provide evidence that O-3 pollution concentration s even below the federal standard may have an adverse effect on the re spiratory health of susceptible persons. Further research will be cond ucted, examining the effects of ambient air pollution concentrations o n other respiratory diseases in Reno.