Household fuel type, ventilation and chimney characteristics and self-reported health outcomes in selected counties of Kenya

Household air pollution (HAP) from cooking fuels remains a significant public health concern in Kenya. The combined effects of fuel type, ventilation quality, and chimney characteristics on health outcomes are not well understood. To assess the associations between household fuel use, ventilation, chimney characteristics, and self-reported health outcomes among Kenyan households. A cross-sectional survey was conducted across nine selected counties in Kenya during October-November 2024. A total of 384 households were sampled using stratified and purposive sampling approaches. Households were categorized into eight groups based on cooking fuel type (clean vs. unclean), ventilation quality (good vs. poor), and chimney presence, with households purposively recruited; this exposure-stratified design was intended to enable comparison across household categories rather than to estimate population-representative symptom prevalence. Self-reported health outcomes were collected via KoboCollect. Chi-square tests and Fisher’s exact tests assessed associations between household categories and health symptoms. Significant associations were found between household categories and multiple health outcomes. Households with poor ventilation, no chimney, and unclean fuel (PV + NC+UF) reported the highest prevalence of headaches (58.3%) and substantial rates of respiratory symptoms. Good ventilation with no chimney and unclean fuel (GV + NC+UF) showed elevated eye irritation (53.8%) and dizziness (44.2%). Clean fuel use substantially reduced symptom prevalence even in suboptimal conditions for example, eye irritation decreased from 53.8% in GV + NC+UF to 17.6% in GV + NC+CF (67% relative reduction). Chimney presence was associated with lower rates of household member wheezing (6.3% vs. 15.6%, p =.005) and dizziness (18.1% vs. 31.1%, p =.004). Traditional chimneys showed markedly worse outcomes than modern chimneys, with higher rates of nighttime coughing (47.8% vs. 11.7%, p <.001), morning coughing (21.7% vs. 5.8%, p =.010), and headaches attributed to stove smoke (57.1% vs. 15.2%, p =.021). Clean fuel adoption represents the most effective intervention for reducing HAP-related health impacts. Among households using unclean fuels; modern, well-designed chimneys with adequate height and appropriate placement significantly mitigate health risks.