Cooking as a source of indoor air pollution in rural areas of Tanzania

Abstract

This study was concerned with the assessment of the contribution of cooking fuelwood, charcoal and kerosene to indoor air pollution in households in Msangani, Chahua and Kazimzumbwi villages in the Coast Region, Tanzania. It has also assessed the performance of Single Compartment Model in predicting indoor pollution levels under Tanzania conditions. The methods used in this study were household survey, measurements, and observation. The pollutants measured were Carbon monoxide (CO), Sulphur dioxide (SO2) and Nitrogen oxides (NOX) using a combustion analyzer CA-6200-CALc manufacured by RAECO of USA, and Suspended Particulate Matter (SPM) using a filter and vacuum pump. It was observed that 97.3% of the 112 families surveyed utilized simple “three stones” fires for cooking. Other observed cooking facilities in the study areas were charcoal stoves and kerosene stoves. The overall pattern shows that the population in the three villages spent about 76.8% of their time indoors. The hourly indoor average SPM levels during cooking period ranged from 13571 mg/m3 to 305798 mg/m3. Compared with SPM levels recorded in similar studies, these values were much higher, and may contribute to health problems observed in the study areas. The CO concentrations before cooking, for households that use fuel wood, exceeded the WHO hourly standard of 30 mg/m3 in 69.4 % of the surveyed households, while the concentrations for those households using charcoal and kerosene were zero. The overall average CO concentrations in mg/m3 at all households during cooking were 325 ± 211 and 148 ± 44 when fuelwood and charcoal biomass were used respectively. The measured values of CO were above the recommended WHO guidelines with an hourly objective value of 30 mg/m3. A Single Compartment Model provided a satisfactory approximation of the measured CO concentrations with an average ratio of measured/modelled CO concentration at 1.1± 0.3. The study recommends improvement to the ventilation system including the provision of an adequate number of windows and installation of chimneys for removal of combustion pollutants from indoor environment. © 2009 International Formulae Group. All rights reserved. Key words : Biomass; cooking; fuelwood; indoor air pollution.