Environmental Justice Implications of Biomass Fuel Combustion: Assessing Indoor Air Quality and Health Equity in Rural Indian Households

Exposure to household air pollutants has become a major environmental health issue in developing countries. This study aimed to explore the impact of indoor air pollution and its toxicological hazards, especially focusing on cooking practices in rural households. We conducted real-time monitoring of ambient particulate matter (PM2.5) and carbon monoxide (CO) levels in 61 rural kitchens and surveyed 516 households in West Bengal, India. The observed average concentrations of CO, PM2.5, relative humidity, and temperature in five different kitchen types were 11.50 ppm, 780.64 µg/m³, 56.43%, and 26.14 °C, respectively. The highest CO and PM2.5 levels were recorded in indoor kitchens (AQI: 413; PM2.5: 882.8 µg/m³), followed by outdoor kitchens (AQI: 257; PM2.5: 362.6 µg/m³). PM2.5 and AQI levels varied by fuel type, with the highest concentrations found in kitchens using cow dung cakes, followed by firewood, and then LPG. We developed an exposure index to assess the exposure of cooks, non-cooks, and children under five. The average exposure index values were 2.7 times higher for households using firewood and other traditional cooking fuels compared to those using LPG. This indicates that individuals using firewood and similar fuels are at a significantly higher risk than those using LPG. Further, the hazard quotient was calculated using indoor PM2.5 concentrations, intake concentration, and toxicological risk assessment, showing higher health risks for users of firewood and cow dung cakes compared to LPG users. However, the study emphasizes the urgent need to transition to cleaner cooking fuels and advocates for expanding access to these alternatives to reduce the health risks associated with traditional cooking methods. It also highlights the implications of these efforts for achieving the UN Sustainable Development Goals on affordable and clean energy (SDG 7) and climate action (SDG 13).