Air pollutants characterization of kitchen microenvironments in southwest Nigeria

Abstract

Developing countries are renowned for poor kitchen air quality, of which documentation on urban domestic kitchen air pollution related to African cooking styles is lacking. This work measured the concentrations of pollutants (CO2, CO, and PM2.5) present in 75 domestic kitchens before, during and after cooking methods of frying, boiling, and stewing. Kitchens utilizing kerosene (39) and liquefied petroleum gas (LPG) (36) stoves randomly selected in an urban area of Southwestern Nigeria were investigated in this study. CO2, PM2.5, and CO concentrations were measured at the breathing zone level from the ground in the middle of the kitchens using relevant instruments. Mean concentrations of CO, CO2, and PM2.5 emitted into the LPG-stove kitchens were 29 ppm, 895 ppm, and 328 μg/m3 while those released from the kerosene-stove kitchens were 31 ppm, 897 ppm, and 345 μg/m3, respectively, during cooking. No significant variance was observed for the CO and CO2 released from the LPG-stove and kerosene-stove kitchens. In all the kitchens, frying (kerosene: CO2 = 1129 ppm, CO = 32.7 ppm, PM2.5 = 380 μg/m3; LPG: CO2 = 903 ppm, CO = 29.0 ppm, PM2.5 = 361 μg/m3) followed by stewing (kerosene: CO2 = 906 ppm, CO = 31.8 ppm, PM2.5 = 341 μg/m3; LPG: CO2 = 895 ppm, CO = 25.20 ppm, PM2.5 = 329 μg/m3) and then boiling (kerosene: CO2 = 897 ppm, CO = 30.4 ppm, PM2.5 = 339 μg/m3; LPG: CO2 = 883 ppm, CO = 23.2 ppm, PM2.5 = 310 μg/m3) were observed to produce the highest concentrations of pollutants. The PM2.5 concentrations in the kitchens significantly exceeded the limit recommended by WHO for indoor air quality. This work revealed the degradation of kitchen air quality via cooking stoves and styles.