A Comparative Analysis of Air Pollutants and Acute Respiratory Infection Outpatient Visits in Selected Areas of Melaka and Johor

Abstract

Ambient air pollution is an important environmental health concern associated with respiratory morbidity. This study examined the association between major air pollutants and outpatient visits for acute respiratory infection (ARI) in Bukit Rambai, Melaka; Muar, Johor; and Bandar Penawar, Johor, from 2015 to 2018. Hourly concentrations of particulate matter with a diameter of 10 micrometres or less (PM10), ozone (O3), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), and Air Pollutant Index (API) values were obtained from the Department of Environment Malaysia, while daily ARI outpatient data were obtained from selected health clinics representing each study area. As the data were not normally distributed, Spearman rank-order correlation analysis was used to assess the associations. Significant relationships were observed between air quality indicators and ARI outpatient visits across all three locations. In Bukit Rambai, SO2 showed the strongest positive association with ARI outpatient visits (rs = .226), while PM10 was positively associated with ARI visits in Muar (rs = .178) and showed the strongest positive association in Bandar Penawar (rs = .487). Overall, PM10 was the only pollutant that consistently demonstrated a significant positive association with ARI outpatient visits across all three study areas. The findings indicate that the relationship between ambient air pollution and respiratory healthcare utilisation varies according to local environmental and geographical characteristics.