Assessing household level exposure reductions associated with use of improved biomass cook-stoves in India: Results from field assessments for Project Surya

摘要

Background:Cleaner cook-stoves are considered to be an important class of interventions for reducing emissions and exposures resulting from household use of solid fuels with accompanying benefits for health and climate for populations of developing countries. Few field based evaluations have however been performed to assess their efficacy. AinrThis pilot arm of Project Surya (aimed at demonstrating health and climate relevant improvements accompanying stove and fuel interventions ) focused on measuring exposure reductions for select market models of improved biomass cook stoves in 2 Indian states. Methods: The study was designed as a controlled field experiment with paired measurements of 24-hour kitchen concentrations of PM2.5 and CO being performed before and after installing the improved biomass cook stoves. 6 commercial models were selected to cover stove technologies that used free/ forced convection and/or fuel processing respectively. Results:The median 24-hr kitchen concentrations of PM 2.5 were 300 μg/m3 [inter-quartile range 533 μg/m3] and 161 μg/m3 [inter-quartile range 261μg/m3] while using traditional and improved cook stoves respectively. Corresponding, median 24-hr kitchen concentrations of CO were 5.88 ppm[IQR 8.7 ppm] and 3.4ppm [IQR 5.69ppm] while using traditional and improved cook stoves respectively. Both free and forced convection models showed significant reductions in household concentrations as compared to traditional cook-stoves (ranging between 43- 67%) for both PM 2.5 and CO, with the forced convection stoves achieving the highest reductions. Conclusions: Although some models showed promise, stoves would need to be benchmarked against WHO Air Quality Guidelines to be labeled as improved as compared to traditional open fires. This is further complicated by perhaps limited use of the "improved stove" and the stove "staying improved" over time to achieve desired health benefits for exposed members of the household.