Validity of annoyance scores for estimation of long term air pollution exposure in epidemiologic studies - The Swiss Study on Air Pollution and Lung Diseases in Adults (SAPALDIA)

In air pollution epidemiology, estimates of long term exposure are often ba sed on measurements made at one fixed site monitor per area. This may lead to exposure misclassification. The present paper validates a questionnaire- based indicator of ambient air pollution levels and its applicability to as sess their within-area variability. Within the framework of the SAPALDIA (S wiss Study on Air Pollution and Lung Diseases in Adults) cross-sectional st udy (1991), 9,651 participants reported their level of annoyance caused by air pollution on an 11-point scale. This subjective measure was compared wi th annual mean concentrations of particulate matter less than 10 mu m in di ameter (PM10) and nitrogen dioxide. The impact of individual factors on rep orted scores was evaluated, Nitrogen dioxide concentrations at home outdoor s (measured in 1993), smoking, workplace dust exposure, and respiratory sym ptoms were found to be predictors of individual annoyance scores. Regressio n of population mean annoyance scores against annual mean PM10 and nitrogen dioxide concentrations (measured in 1993 and 1991, respectively) across ar eas showed a linear relation and strong correlations (r> 0.85). Analysis wi thin areas yielded consistent results. The observed associations between su bjective and objective air pollution exposure estimates suggest that popula tion mean scores, but not individual scores, may serve as a simple tool for grading air quality within areas. Reported annoyance due to air pollution should be considered an indicator for a complex environmental condition and thus might be used for evaluating the implementation of environmental poli cies.