Factors Influencing Particulate Matter 2.5 Levels in Indoor Areas of Rural Houses: A Cross-sectional Study

Abstract

Introduction: Almost 3 billion of the world’s poorest people still rely on solid fuels, with a concomitant increase in indoor Particulate Matter (PM 2.5) concentration resulting in deaths from respiratory diseases. Increased prevalence of respiratory diseases among never smoking young individuals and fairly among women compared to men point towards a causal relationship between chronic smoke inhalation resulting from the burning of biomass fuels. Aim: To assess the quantitative exposure levels of PM 2.5 in a rural setting in South India and determine the association between PM 2.5, type of house, ventilation available and fuel used. Materials and Methods: This community-based crosssectional study was conducted for 3 months from September 2020 to November 2020 in the rural field practice area of Sri Ramachandra Institute of Higher Education and Research, Chennai, Tamil Nadu. The houses were classified into three types Kutcha (roof, walls, and floor made of poor-quality materials), semi pucca (two components made of good quality material and one component is of poor quality), and pucca (roof, walls, and floor made of good quality material) houses according to Census of India 1991. The air quality inside 127 houses was assessed by measuring PM2.5 levels for 24 hours in both kitchen and living rooms. The association between house characteristics, ventilation, type of fuel, and indoor air quality was Studied using student t-test and one-way Analysis Of Variance (ANOVA). Results: Among 323 included residents, 168 were males and 155 females with the mean age 36.99±13.24 years. The difference in average house area and living area between the three types of houses were statistically significant (p-value<0.001). The mean concentrations of PM2.5 were 290.07 µg/m3 and mean differences in PM2.5 levels in living room and kitchen of semi pucca (t=7.32, p-value<0.001) and pucca houses (t=5.47, p-value<0.001) were significant. The association between cross ventilation in kitchen (OR 3.24, p-value=0.042), artificial ventilation (OR 3.23, p=0.026), type of fuel (firewood OR 2.85, p-value=0.042) and PM2.5 levels is significant at 95% CI limits. Conclusion: Indoor air pollution is a silent killer responsible for several respiratory problems. Simple cost-effective measures could reduce indoor PM2.5 levels and thereby indoor air pollution.