Diurnal Concentrations and Variation of Carbon Monoxide in Indoor and Outdoor Air of Residential Homes in Western Sierra Leone

Abstract

It is widely known that more than half of the world’s population use biomass fuels (wood, charcoal, dung) as household energy source, and hence, face significant and diverse range of toxic pollutants. In Sierra Leone, more than 90% of the population relies on biomass fuels. We carried out daytime measurements and observe variation of carbon monoxide (CO) in kitchen and outdoor locations in households that burn wood and charcoal fuels in Western Sierra Leone, during a survey that was conducted in September, 2011. Maximum time average 15 mins, 30 mins, 1 hr and 8 hrs concentrations in indoor and outdoor locations were computed. Mean concentrations decreased in the order, 15 mins to 30 mins to 1 hr and 8 hrs, in the two locations for households that burn wood and charcoal. About 87% and 67% of 8 hrs CO concentrations in kitchens with charcoal and wood stoves were in excess of world health organization (WHO) guideline. Approximately 66% and 63% of 1 hr CO concentrations were not different in the same environments. None of the corresponding outdoor locations had values that are said to be critical to human health. Evidence of greater variation in the maximum time average mean CO concentrations in kitchens with charcoal stoves relative to those using wood was observed. Behavioral patterns in homes burning charcoal coupled with the burning conditions were ascribed to the observed variation. The proportion of the short time and acute CO concentrations in kitchens is a cause for concern for humans from the stand point of improved human health.