Study Flags Hidden Toxins Trapped In Your Kitchen

New Delhi: The air inside your kitchen can often be as polluted and at times even more foul than the air outside, according to a study conducted by researchers from Delhi Technological University (DTU) and IIT-Delhi.The study led by Dr Rajeev Kumar Mishra and research scholar Monika Sharma from DTU’s advanced air and acoustics research laboratory, along with Prof Mukesh Khare of IIT-Delhi, examined indoor air quality in households in north Delhi’s GTB Nagar by monitoring kitchens and bedrooms of four income groups — urban poor, low-income, middle-income and high-income — across winter, summer and monsoon.Kitchens emerged as the most polluted space in nearly every household category, regardless of the income level. Average PM2.5 concentrations in kitchens ranged between 60 and 100 micrograms per cubic metre (µg/m3), while PM10 levels ranged from 115 to 145 µg/m3, significantly above safe limits recommended by global health agencies.During winter, PM10 concentrations peaked at nearly 250 µg/m3 in kitchens and 200 µg/m3 in bedrooms. “A poorly ventilated kitchen was found to have higher concentrations of PM10 (247 µg/m3), PM2.5 (200 µg/m3) and PM1 (153 µg/m3). PM1 contributed around 40% to 85% of PM10, according to the study.The study, which was published in Particulate Science and Technology, a journal, found that indoor pollution was strongly linked to daily household chores. “Cooking, especially breakfast and dinner, caused sharp spikes in particulate matter levels. Poor ventilation, attached kitchens, long cooking time and lack of exhaust systems further worsened the indoor air quality. Even in affluent homes with modern infrastructure, indoor pollution remained high because of activities, such as burning of incense, dusting and inadequate ventilation during winters,” Mishra said.The study offers a stark snapshot of Delhi’s housing inequality. In urban poor and low-income households, cramped layouts and the absence of separate kitchens meant pollution spread rapidly throughout such houses. Many of them lack windows or exhaust systems, trapping smoke and fine particles indoors for hours.Researchers noted that PM1 — extremely fine particles capable of penetrating deep into the lungs — formed a large proportion of indoor pollution, contributing nearly 70% to 80% of PM10 in several houses.Women, children and elderly residents were identified as the most vulnerable to such pollution because they spend considerable time indoors. ‘Exposure modelling’ conducted by the researchers showed that PM2.5 particles were being heavily deposited in lower lungs, increasing long-term risks of respiratory and cardiovascular diseases. Adults showed the highest exposure because of higher breathing rates, while children faced elevated risks due to developing lungs.Pressing for policy interventions, including the need for indoor air quality guidelines, improved ventilation standards in houses, public awareness campaigns and affordable mitigation measures for low-income communities, Mishra points out that Delhi’s air pollution debate has been focusing overwhelmingly on outdoor emissions while neglecting indoor environments where many people spend nearly 90% of their time.