Researchers at the Indian Institute of Technology (IIT) Mandi, in collaboration with Institut National de Recherche et de Sécurité (INRS), France, and the National Physical Laboratory (CSIR-NPL), India, have conducted a comprehensive study on the detrimental effects of indoor air pollution resulting from traditional cooking practices in rural kitchens across three Northeast (NE) Indian states. 

In a series of three papers, a research team from IIT Mandi comprising of Bijay Sharma, PhD scholar, and Dr Sayantan Sarkar, Assistant Professor, School of Civil & Environmental Engineering, and his collaborators analysed the extent and consequences of harmful emissions produced during indoor cooking using firewood and mixed biomass.

Despite advancements, more than 50% of the rural population in Northeastern India (Assam, Arunachal Pradesh, and Meghalaya) continues to use traditional solid fuels such as firewood and mixed biomass for cooking, leading to the release of significant pollutants into the kitchen air. 

The research aimed to gauge the severity and disease burden associated with the use of biomass cooking fuel compared to LPG-based cooking.

The researchers measured size-resolved concentrations of aerosols, that is, particles suspended in the air, and toxic trace metals and carcinogenic organic substances bound with it, during cooking with firewood, mixed biomass, and Liquefied Petroleum Gas (LPG). They modelled the deposition patterns of these particles and associated chemicals in various sections of the human respiratory system. The resulting inhalation exposure to these chemicals during cooking was then calculated.

Utilising this data, the researchers estimated the health impact (disease burden) on the rural NE Indian population, focusing on respiratory diseases.

The study revealed that exposure to harmful aerosols in firewood/biomass-using kitchens was 2-19 times higher than in LPG-using kitchens, with respiratory deposition ranging from 29% to 79% of the total aerosol concentration. The fraction of the population using firewood and mixed biomass faced 2-57 times higher disease burdens than LPG users.

Furthermore, the research found that the potential for oxidative stress, which leads to damaged cells, proteins, and DNA, was likely to be four to five times higher among people using biomass in kitchens than those using LPG. This stress is driven by the inhalation of metals and organic chemicals produced during indoor cooking using biomass fuel.