Regional Emission Performance Benchmarks for Cookstove Stacking in the Purepecha Region, Mexico

The National Cookstove Program has been launched by the Federal Government of Mexico, attempting to reach one million rural homes by the year 2030. Voluntary ISO emission standards for fine particulate matter (PM2.5) and carbon monoxide (CO) relate emission rates from stoves to indoor air concentrations using a single zone box model (SZM) to derive performance tiers. Region-specific emission benchmarks for cookstove performance that are linked to estimated benefits in reduced indoor air concentrations and resultant health impacts will be important in product selection. Here we compare the SZM to measured indoor PM2.5 and CO concentrations for five stove stacking combinations using controlled cooking tests of typical foods from the Purepecha region of Mexico to derive region-specific benchmarks. The results demonstrate that the SZM systematically overpredicted PM2.5 emissions based on thermal plume effects and ventilation which can be adjusted based on strong relationships (Adjusted r2 = 0.96, p < 0.001) with emission rates and air changes per hour. Adjustment of PM2.5 ISO voluntary standards for systematic bias caused by plume buoyancy and ventilation is important in ensuring that the ISO benchmarks reflect the actual indoor concentrations measured in homes. The ISO benchmarks for CO should be revisited as the indoor concentrations from traditional stoves met the most stringent benchmarks but were in the range of concentrations associated with adverse health impacts in adults and psychosocial impacts in children.