Real-Time Assessment of Black Carbon Pollution in Indian Households Due to Traditional and Improved Biomass Cookstoves
Use of improved (biomass) cookstoves (ICs) has been widely proposed as a Black
Carbon (BC) mitigation measure with significant climate and health benefits. ICs encompass a
range of technologies, including natural draft (ND) stoves, which feature structural modifications
to enhance air flow, and forced draft (FD) stoves, which additionally employ an external fan to
force air into the combustion chamber. We present here, under Project Surya, the first real-time in
situ Black Carbon (BC) concentration measurements from five commercial ICs and a traditional
(mud) cookstove for comparison. These experiments reveal four significant findings about the
tested stoves. First, FD stoves emerge as the superior IC technology, reducing plume zone BC
concentration by a factor of 4 (compared to 1.5 for ND). Indoor cooking-time BC concentrations,
which varied from 50 to 1000 μg m−3 for the traditional mud cookstove, were reduced to 5−100
μg m−3 by the top-performing FD stove. Second, BC reductions from IC models in the same
technology category vary significantly: for example, some ND models occasionally emit more BC
than a traditional cookstove. Within the ND class, only microgasification stoves were effective in
reducing BC. Third, BC concentration varies significantly for repeated cooking cycles with same stove (standard deviation up to
50% of mean concentration) even in a standardized setup, highlighting inherent uncertainties in cookstove performance. Fourth,
use of mixed fuel (reflective of local practices) increases plume zone BC concentration (compared to hardwood) by a factor of 2
to 3 across ICs.
