Understudied and overlooked: Radiological, ecological and biological risk pathways from oil and gas production

Naturally occurring radioactive materials (NORM) mobilized during oil and gas extraction become Technologically Enhanced NORM (TENORM), creating localized but significant radiological hazards. Radionuclides from the ²³⁸U and ²³²Th decay chains, particularly ²²⁶Ra, ²²⁸Ra, ²¹⁰Pb, and ²¹⁰Po, concentrate in produced water, scales, sludges, drill cuttings, and residual oil ash. Activity concentrations span eight orders of magnitude, reaching up to 10⁷ Bq/kg in scale, and their environmental behavior is governed by complex geochemical and microbial interactions. Produced water discharges, evaporation ponds, and road spreading of brines facilitate transfer of TENORM into soils, sediments, and groundwater, while radon release and airborne radioactive particulates contribute to inhalation exposure. Workers are primarily affected by external gamma radiation and radon inhalation, whereas nearby communities and ecosystems experience chronic low-dose exposures through contaminated water and sediment pathways. Although regulatory limits generally constrain short-term exposures, inconsistent global oversight, the persistence of radium decay products, and the paucity of biological data complicate accurate risk evaluation. Direct laboratory and field studies reveal genotoxicity, oxidative stress, and subtle ecological disruptions at low doses, yet the long-term implications of alpha- and beta-emitter exposure remain underexplored.