Exposures to Volatile Organic Compounds (VOCs) among Rural and Urban Households in Southern India in Relation to Primary Cooking Fuels

Abstract

Background: Emissions from cooking fuels that include many health damaging pollutants such as fine particulate matter and a range of polycyclic aromatic hydrocarbons and volatile organic compounds (VOCs) are a major public health concern in low and middle income countries (LMICs). Despite the ubiquity of exposures in India, VOC profiles in rural and urban households are poorly understood. Methods: We report results from cooking period measurements conducted in 112 (56 biomass, 23 kerosene and 34 gas using ) rural and urban households that were part of the larger Tamil Nadu Air Pollution and Health Effects (TAPHE) cohort study in Southern India. Samples were collected on a mixed-bed sorbent (Tenax and Carbopack) tubes. Active air sampling was performed using pre-calibrated constant flow pumps (SKC Inc., PA, USA) set to a flow rate of 0.1 L/min for 100 min. An automated thermal desorption unit connected to GC-MS system was used to quantify 59 VOCs. Pentafluorobenzene, 1,4-difluorobenzene and chlorobenzene-d5 were used as internal standards and percent recovery ranged from 81.7% to 119.9%.Results: Total VOC (TVOC) concentrations in rural homes (4426.8 µg/m3) were significantly higher when compared to urban homes (2010.9 µg/m3). Toluene, styrene, m,p-xylene and benzene were dominant in rural kitchens whereas toluene, m,p-xylene, benzene and isopropyltoluene were dominant in urban kitchens during cooking. Mean TVOC concentrations were the highest in biomass using homes (4617 µg/m3) followed by LPG (2839.7 µg/m3) and kerosene (1639.8 µg/m3) respectively. Benzene levels consistently exceeded the National Ambient Air Quality Guideline value of 5µg/m3 in all rural and urban homes. Winter season, open field burning and industry nearby were associated with significantly higher VOC concentrations.Conclusions: Additional large scale assessments of population exposure to VOCs are needed in LMICs to better characterize health risks associated with solid fuel use.