Health effects due to short and long-term air pollution exposure: Evidence from survey of residents living in rural and urban regions near Kolkata.

This study aimed to explore the exposure of PM2.5 on upper and lower respiratory symptoms in urban and rural regions near Kolkata. A total of 1155 people comprised of all ages were surveyed. We conducted multivariate regression model to examine the association between air pollution and health outcomes in overall population, and subgroup stratified by socio-demographic factors, age, and gender and lifestyle behavior. We found strong association of long-term exposure in rural (R2 = 0.89, p < 0.01) and urban (R2 = 0.894, p < 0.01) population and for short-term, the model could predict significantly with an accuracy of 0.8 for rural and 0.74 for urban regions. For every 10 µg/m3 increment of PM2.5, highest long and short-term associations in rural was found in asthma (1.98, CI: 1.24-2.73) and cough (1.47, CI: 1.21-1.73) compared to wheeze (1.45, CI: 1-1.9) and cough (1.54, CI: 1.47-1.61) in urban. For subgroup analysis, the effect of PM2.5 exposure was more in male (1.93, CI: 1.85-2) than female (1.59, CI: 1.47-1.71). Risk was developed in people with low (1.78, CI: 1.57-1.99) and middle (1.53, CI: 1.41-1.65) income category than high SEC in rural region, whereas people with high (1.82, CI: 1.6-2.02) and middle (1.5, CI: 1.45-1.55) SEC suffered more risk than low in urban regions. In both regions, aged (1.49, CI: 1.44-1.55) and adults (1.32, CI: 1.25-1.4) were more prone to health risk than young (1.23, CI: 1.21-1.25) population. Household emission is a strong source of indoor air pollution in rural regions.

Emission source-types and duration of outdoor exposure are important factors for association between pollution and health outcomes. Along with these types of cooking fuel use, kitchen location, smoking status and presence of chimney proved to be strong determining parameters for health burden development.