Rural household energy and implication for indoor BTEX levels in Nigeria

In spite of the fact that household energy and fuels may contribute to indoor air VOC pollution, there is limited information on exposure studies in rural Nigerian homes. By means of a survey conducted in Iheaka and Umuitodo rural communities between 2017 and 2019, we sought to establish the prevalence of various household energy sources in the rural areas, and identify the barriers to uptake of clean technologies and fuels. The indoor (kitchen and living rooms) and ambient concentration levels of BTEX were monitored in 8 randomly selected households for 7 days during the dry season in Umuitodo. The compounds were sampled in the air by placing Tenax tubes axial diffusive samplers (Markes, Llantrisant, UK); at distance of about 1 meter from the cooking spot and a height of 1.5m above ground. Quantification of BTEX was by thermal desorption Gas chromatography /Mass spectrometry (TD-GC/MS). Majority (89%) of the respondents are not aware of renewable energy. Most households use kerosene (85%) and firewood (90%) as the lighting and primary cooking fuels respectively. More than half of the residents reported eye discomfort (65%) and tears/watery eyes (52%) during cooking in the study areas. The mean indoor levels for benzene, toluene, ethylbenzene and xylenes (sum) were respectively 58.8 ±43.5, 29.8±17.6, 4.9±2.3. 20.5±8.9 µg/m3 for kitchen and 15.8 ±33.8, 12.5 ±15.1, 2.4 ±2.3, 16.6 ±13.4 µg/m3 for living room. The I/O ratio with respect to the kitchen were 2-48, 2-22, 2-12 and 2-12 respectively for benzene, toluene, ethylbenzene and xylenes (sum) respectively indicating kitchen indoor BTEX sources in the study area.