Continued firewood use after decades of access to low-cost LPG

Abstract

PDS 64: Health impact assessment and environmental justice, Johan Friso Foyer, Floor 1, August 26, 2019, 1:30 PM - 3:00 PM Background: Household air pollution, one of the world’s largest environmental health hazards, is a modifiable risk factor amenable to intervention through cleaner cooking. Over the last 40 years, large direct consumer subsidies for LPG have facilitated the national transition of Ecuador’s population from cooking with biomass and kerosene to cooking with LPG. Now, more than 90% of households cook primarily with LPG. Methods: We administered 808 surveys to primary household cooks in eight rural and peri-urban communities across four provinces in the coastal and Andean regions of Ecuador to identify current fuel use patterns, fuel costs and accessibility, and motivations for observed patterns. A sub-sample of 160 primary cooks across four communities received 48-hour time-resolved PM2.5 exposure monitoring, with a 20% subset receiving a co-located gravimetric filter PM2.5 monitor. All stoves were monitored using temperature loggers. Results: Over 99% of households reported daily LPG use and most more than once a day. Households reported more than 20 years of historic LPG use and unconstrained access to cylinders. Nevertheless, 40% of households reported using firewood as a cooking fuel, nearly always as a secondary alternative to LPG (20% peri-urban; 52% rural), and 60% of rural firewood users reported at least weekly use. Mean 48-hour PM2.5 exposure was estimated to be 35 µg/m3 and 20% of estimates were above the WHO Interim-I guideline of 35 µg/m3. Conclusions: By leveraging the unique conditions of Ecuador, we offer novel assessments of cooking fuel use patterns and personal exposure to PM2.5 in the context of decades of low cost, accessible clean cooking fuels in a middle-income country. Our data suggest that cessation of traditional biomass use is a separate behavioral transition from the adoption of clean fuels, potentially limiting the health benefits of adoption-focused clean cooking efforts.