Assessing the impact of cooking fuels on indoor particle matter 2.5 (pm2.5)levels in Sri lankan households

Abstract

Household air pollution resulting from biomass and fossil fuel combustion is a major contributor to indoor PM2.5 concentrations, which is linked to respiratory health issues like chronic bronchitis and asthma. Different types of fuel produce varying amounts of PM2.5, thereby affecting indoor air quality and potential health risks. This study aims to evaluate the relationship between fuel type, PM2.5 levels, and respiratory health outcomes. PM2.5 data were collected continuously over three days from 48 selected households in Kandy, Sri Lanka, using portable samplers. The data were analyzed to compare PM2.5 concentrations across different household fuel types. In addition, the frequency of probable and confirmed cases of chronic bronchitis and asthma was assessed in relation to PM2.5 exposure levels. PM2.5 concentrations were categorized based on standard air quality classifications: Good (≤ 12 μg/m3), Moderate (12.1–35.4 μg/m3), Unhealthy for Sensitive Groups (35.5–55.4 μg/m3), Unhealthy (55.5–150.4 μg/m3), Very Unhealthy (150.5–250.4 μg/m3), and Hazardous (> 250.4 μg/m3). Among the households surveyed, LPG (31) was the most commonly used cooking fuel, followed by firewood (12), while kerosene and electricity were each used by one household. Analysis of PM2.5 concentrations by fuel type showed that kerosene had the highest mean PM2.5 concentrations (57.0 μg/m3.), followed by firewood (n = 12, 34.4 ± 11.7 μg/m3), LPG (n = 31, 31.0 ± 28.4 μg/m3), and electric stoves (n = 1, 21.6 μg/m3). Firewood showed different PM2.5 concentrations depending on the stove type, improved Anagi stoves (n = 1, 46.8 μg/m3), traditional clay stoves (n = 4, 42.1 ± 3.51 μg/m3), traditional stoves (n = 7, 29.9 ± 12.6 μg/m3) Based on standard air quality classifications, 5.4% of observations fell into the 'Good' category, 69.6% were 'Moderate', 14.3% were 'Unhealthy for Sensitive Groups', and 10.7% were classified as 'Unhealthy'. The findings indicate fuel type influences indoor PM2.5 concentrations, with kerosene and biomass linked to the highest exposure. However, this study does not consider household ventilation, which may affect PM2.5 dispersion and exposure. Transitioning to cleaner fuels like LPG and electricity may reduce indoor air pollution and improve respiratory health.