Municipality of Anchorage

This paper examines the associations between average daily particulate matter less than 10 microns in diameter (PM10) and temperature with daily outpatient visits for respiratory disease including asthma, bronchitis, and upper respiratory illness in Anchorage, Alaska, where there are few industrial sources of air pollution. In Anchorage, PM10 is composed primarily of earth crustal material and volcanic ash. Carbon monoxide is measured only during the winter months. The number of outpatients visits for respiratory diagnoses during the period 1 May 1992 to 1 March 1994 were derived from medical insurance claims for state and municipal employees and their dependents covered by Aetna insurance. The data were filtered to reduce seasonal trends and serial autocorrelation and adjusted for day of the week. The results show that an increase of 10 micrograms/m3 in PM10 resulted in a 3-6% increase in visits for asthma and a 1-3% increase in visits for upper respiratory diseases. Winter CO concentrations were significantly associated with bronchitis and upper respiratory illness, but not with asthma. Winter CO was highly correlated with automobile exhaust emissions. These findings are consistent with the results of previous studies of particulate pollution in other urban areas and provide evidence that the coarse fraction of PM10 may affect the health of working people.ImagesFigure 1. AFigure 1. BFigure 2. AFigure 2. BFigure 3. AFigure 3. BFigure 4. AFigure 4. B

<div class="htmlview paragraph">The Municipality of Anchorage. Alaska has an emissions inspection and maintenance (I/M) program. The program was designed to reduce carbon monoxide (CO). During the first year of operation I/M repairs reduced the fleetwide idle CO emissions by 48.7% and the 2500 RPM CO emissions by 41%.</div> <div class="htmlview paragraph">Since the start up of the program there has been a reduction in ambient CO concentrations and a sharp reduction in the number of days the federal CO standard has been exceeded. Much of this may be due to milder winter temperatures observed since I/M began. To determine if the ambient reduction is due solely to weather, a multiple regression analysis was developed. The analysis shows that the ambient CO reduction achieved in Anchorage can not be attributed solely to weather conditions. A review of data concerning average vehicle miles traveled per day, population changes, and CO control strategies indicates that the main factors causing the non-weather related CO reductions are the federal new car CO standards and the I/M program.</div>