LAUSR

Abstract The first part of the present study addresses meteorological and synoptic factors governing daily maximum 1-hour ozone (O3) concentrations in the city of Augsburg in the months from March to September. In the second part statistical models are applied to assess the association between daily myocardial infarction (MI) frequencies and ozone exposure, under the additional consideration of climatic and synoptic factors. Daily maximum 1-hour ozone concentrations were increased with high air temperatures, low values of specific humidity and high ozone concentrations of the previous day. Besides, four weather types were connected with ozone, the weather type “U”, which describes mainly low-flow conditions, being of particular importance. The daily maximum 1-hour ozone concentrations showed a notable non-linear relationship with MI frequencies in Augsburg. An enhanced MI risk occurred mainly at median to moderately high ozone concentrations. A piecewise linear regression up to the maximum relative risk at approximately the 75%-ozone percentile (116 μg/m3) yielded a significant increase of 3.41% (95% confidence interval: [1.33%, 5.53%]) of the MI frequency per 10 μg/m3 increase in ozone. At higher ozone concentrations a decrease of the MI risk occurred. Three weather types were selected as additional predictors in the statistical models. Most notable was the frequent weather type Anticyclonic (A), which is related to a reduction in MI frequencies.