Assessment of Environmental Radioactivity Levels and Their Health Implications: Systematic Review

Environmental radioactivity contributes to population radiation exposure and originates from both natural and man-made sources. Understanding these levels and their health implications is critical for public health, environmental protection, and radiation safety policies. This work systematically reviews published evidence on environmental radioactivity levels across various environmental media and to evaluate associated health implications, including estimated radiation doses and reported health outcomes. PRISMA guidelines were followed in this review. Databases including PubMed, Scopus, Web of Science, Embase, and Google Scholar were screened for studies published between 2000 and 2025 quantifying environmental radioactivity in air, soil, water, food, or building materials and/or estimating human health risks or radiation doses were eligible studies. Study characteristics, measurement methods, radionuclides, dose estimates, and health outcomes were extracted. Used adapted Newcastle–Ottawa and exposure-assessment appraisal tools to assess bias. Due to heterogeneity, findings were narratively synthesised. Studies consistently found 238U, 232Th, 40K, 226Ra, 222Rn, and 137Cs in environmental media. Mining and granite-rich regions had elevated concentrations, but most regions were within global averages. In most studies, dose estimates were below the 1 mSv/yr public exposure limit, except in high natural background radiation areas and radon-prone homes. Long-term stochastic effects from ingestion pathways and lung cancer risk from radon exposure were the main health concerns. Regional radioactivity levels vary but are generally within international safety limits, with localised hotspots. Public exposure and health risk are most caused by radon. Radon mitigation, monitoring, and education are advised.