ABSTRACT

Fuelwood is a common energy source for cooking and the smoke from it exposes users to great health risks and indoor air pollution. Most households still use traditional 3-stones stove. The study assessed pollutants under traditional and improved modern cooking methods using different woody species as fuel in the rural households of Abia and Akwa Ibom States. It also determined the dominant fuelwood species used through markets and household surveys. Two local government areas (LGAs) in each State were randomly selected. The study was conducted in Umuariaga and Okweukwu communities in Ikwuano LGA, Ohuhu and Umukabia communities in Umuahia North LGA of Abia State, Nkwa and Use Ndon communities in Ibiono Ibom LGA, Ikpe Ikot Ntuen and Ekpeyong Ufum communities in Essien Udim LGA of Akwa Ibom State. Questionnaire administration, field experimentation and laboratory trials were used for the investigations. The study also characterized indoor air quality when different species of fuelwood and different stove types were used in both States. In addition, indoor gas emissions were compared between traditional cooking stoves and 3 improved stoves namely: Econofire, Dadinkowa and EnviroFit. Dactyladenia barteri is the most common fuelwood species with 80% prevalence followed by Barteria nigritiana (68.5%) and Anthonotha macrophylla (68.0%) across the two States. The levels of indoor air pollutants nitrogen dioxide (NO₂), sulphur dioxide (SO₂), carbon monoxide (CO), carbon dioxide (CO₂), particulate matter (PM_2.5 and PM₁₀) emitted by the 3 dominant species were assessed using measures of spread. Dactyladenia barteri emitted significantly higher concentrations of NO₂, SO₂, PM_2.5 and PM₁₀ than Anthonotha macrophylla and Barteria nigritiana when measured either in the household or laboratory. This suggests that D. barteri is the most harmful of the wood species and also their values were above recommended WHO and National Ambient Air Standards. The highest concentrations of CO and CO₂ levels were from woods of A. macrophylla and B. nigritiana respectively. A. macrophylla emitted the lowest concentrations of SO₂ and CO while B. nigritiana produced lowest concentrations of PM_2.5 and PM₁₀ from all the types of stove used in the household and the laboratory. The results suggest that D. barteri fuelwood poses greater threat to human health as it generates more indoor air pollutants. Econofire was the most efficient cook stove because it produces the shortest mean duration for boiling 5 litres of water both in the households and laboratory with 1873.3 seconds and 1663.3 seconds respectively. Dadinkowa produced the second shortest duration for boiling water with 2290 seconds at the household level. Traditional tripod stove produced the longest duration for boiling water in the household and laboratory trials with 2732.5 seconds and 2193.3 seconds respectively. Households should be encouraged to switch to Econofire Improved Cookstove and choose A. macrophylla fuelwood to minimize risk of indoor air pollution and achieve efficiency of cooking.