Household Air Pollution from Solid Fuels and Lung Carcinogenesis in Rural Cooks: Meta-Analysis of Evidence from Asia and Europe

Introduction:Household air pollution (HAP) from solid fuel combustion exposes over 2.4 billion people worldwide, predominantly rural women in Asia and parts of Europe, to carcinogenic pollutants such as fine particulate matter (PM2.5) and polycyclic aromatic hydrocarbons. Although HAP has been associated with lung cancer, inconsistencies across recent studies highlight the need for an updated quantitative synthesis. Methods:Following PRISMA 2020 guidelines, a systematic review and meta-analysis of observational studies was conducted using PubMed, Embase, Web of Science, and Cochrane Library through September 2025. Eligible studies reported lung cancer risk estimates (odds ratios or hazard ratios) among rural primary cooks exposed to solid fuel HAP compared to clean fuel or low exposure. Random-effects models pooled effect estimates, with subgroup analyses by fuel type, smoking status, and exposure duration. Results:Seven studies including more than 125,000 participants (60–80% women) from Asia and Europe were included. Solid fuel use was associated with a significantly elevated lung cancer risk (pooled OR 1.59; 95% CI: 1.30–1.95; I²=78.3%). Coal exposure posed higher risk (OR 1.90; 95% CI: 1.40–2.58) compared to biomass, and prolonged exposure (>10 years) further increased risk (OR 1.70; 95% CI: 1.35–2.14). Never-smokers exposed to HAP also showed increased risk (OR 1.50; 95% CI: 1.25–1.80). Conclusions:HAP from solid fuel combustion significantly increases lung cancer risk among rural primary cooks. Clean fuel interventions and targeted public health policies are urgently needed to reduce this preventable burden..