Using atmospheric visibility to assess the effects of air pollution on hospital admissions for respiratory diseases

Abstract

Air pollution is a significant hazard to human health. Atmospheric visibility is an aggregative indicator of air pollution and meteorological conditions. Yet, only a few studies have reported the relationship between atmospheric visibility and health risks. This study attempted to utilize atmospheric visibility to assess the effects of air pollution on hospital admissions for respiratory diseases (ICD-9: 460-519). Daily measurements of air pollutants, atmospheric visibility, and Taiwan's National Health Insurance Research Database were obtained for the year 2010 in Taichung. We compared the differences in different locations (coastal and urban areas). A Poisson regression analysis was used to evaluate the relationship between the atmospheric visibility and the respiratory consultation rate, with adjustment for potential confounding factors, including meteorological factors, spatial variances, and types of air pollution. The primary results indicated that air pollution and atmospheric visibility degradation were both more serious in the urban area than in the coastal area. The atmospheric visibilities were divided into Q1 (25th percentile), Q2 (50th percentile), and Q3 (75th percentile); these divisions show the inversely proportional trend between atmospheric visibility range and health risks. It was also observed the similar inversely proportional trend between particulate matter and health risks. Under the hazard periods of atmospheric visibility ≤ 10 km, the relative significant health risks of 1.088 and 1.042 were observed in the coastal area and urban area, respectively. The relative health risks of particulate matters were 1.053 in the coastal area and 1.101 in the urban area during the periods of PM2.5 ≥ 35 µg m-3. This study establishes a new perspective from which to assess the effects of air pollution on hospital admissions for respiratory diseases by utilizing atmospheric visibility. Additionally, it provides a convenient way for the public to understand the relationship between air pollution and its effects on human health.