Household biomass fuel use and associated visual impairment in Enugu state, Nigeria

Background: Biomass fuels are widely used for household cooking in developing countries and are a major source of indoor air pollution. Exposure to biomass smoke has been associated with adverse health outcomes, but its relationship with ocular health remains under-explored in Nigeria.

Aim: This study investigated the prevalence of visual defects among household members using biomass cooking fuels in Enugu State, Nigeria.

Methods: A community‑based cross‑sectional study was conducted among 502 respondents from 232 households across six Local Government Areas (LGAs) in Enugu State. Multistage sampling was used to select households. Data were collected using structured questionnaires and ocular examinations, including visual acuity assessment by an ophthalmologist, using Snellen chart. Associations between cooking fuel types and visual defects were analysed using chi‑square tests and odds ratios (OR) with 95% confidence intervals (CI).

Results: Biomass fuels were used by 94% of households, with firewood being the predominant fuel (73%). Visual defects (mainly cataract, glaucoma, and pterygium) were observed in 32.6% of firewood users and 11.4% of charcoal users, while no cases were observed among sawdust users. Firewood use was strongly associated with visual defects compared with non‑biomass fuels (OR = 17.5; 95% CI: 9.8–31.2; p < 0.001).

Conclusion: Biomass fuel use, particularly unprocessed firewood, is associated with a higher prevalence of visual defects among household members in Enugu State. Promotion of cleaner cooking fuels and improved combustion technologies is essential to reduce ocular health risks.