Background: Household environments can expose adults to carcinogens such as radon, secondhand smoke, solid-fuel emissions, cooking fumes, VOCs, pesticides, and water contaminants. This review synthesized evidence on the association between household environmental exposures and cancer risk in adults, with emphasis on environmental health and oncology perspectives.
Materials and Methods: A structured narrative review of Persian- and English-language studies (2000–March 2026) was conducted across PubMed/MEDLINE, Scopus, Web of Science, CIVILICA, and Google Scholar. Eligible studies assessed adult household exposures to radon, tobacco smoke, solid fuels, indoor chemicals, pesticides, or water contaminants with cancer outcomes. Findings were thematically synthesized by pollutant, pathway, outcome, evidence consistency, limitations, and prevention potential.
Results: Residential radon and secondhand tobacco smoke showed the most consistent association with increased lung cancer risk. Evidence for household coal combustion was strong, while biomass-fuel smoke and cooking fumes demonstrated moderate, context-dependent associations influenced by fuel type, stove design, ventilation, and exposure duration. Although benzene and formaldehyde are recognized carcinogens, evidence for cancer risk at typical household levels remained limited. Associations between household pesticide exposure and selected hematological malignancies, and between nitrate or trihalomethane exposure in drinking water and gastrointestinal or bladder cancer, were heterogeneous and generally of low-to-moderate certainty. Key limitations included exposure misclassification, reliance on self-reported exposure, and confounding by active smoking, socioeconomic conditions, diet, occupational exposure, and outdoor air pollution.
Conclusion: Radon, secondhand smoke, and solid-fuel combustion are key modifiable household exposures linked to lung cancer. Priority prevention includes radon testing and remediation, smoke-free homes and vehicles, cleaner household energy, improved ventilation, safer chemical use, water-quality monitoring, and systematic environmental exposure assessment in primary and oncology care.