Assessment of radon concentrations and associated health risks via surface and groundwater consumption in the Utmah, Yemen

Radon, a naturally occurring radioactive gas, poses health risks through water consumption. In seismically active regions like Utmah, Yemen, geological factors may elevate radon levels in water, requiring monitoring. This study analyzed radon concentrations in groundwater and surface water used for drinking, domestic purposes, and irrigation in Utmah Nature Reserve, Dhamar Governorate, Yemen. Thirty-four water samples were collected: 14 surface water samples (depth <15 m) and 20 groundwater samples (depth 110–320 m) from Al-Azraa and Tahayjer. Radon and radium were measured using CR-39 nuclear track detectors. Results showed surface water radon levels ranged from 0.09 ± 0.03 to 0.25 ± 0.03 Bq/L (average 0.17 ± 0.04 Bq/L), while groundwater levels were higher: 0.20 ± 0.03 to 0.52 ± 0.09 Bq/L (average 0.34 ± 0.06 Bq/L), well below the international safety standard of 11.1 Bq/L set by the U.S. Environmental Protection Agency (EPA). Annual radiation exposure from surface water (inhalation/ingestion) ranged from 0.23 ± 0.08 to 0.64 ± 0.08 μSv/year (average 0.43 μSv/year). Groundwater exposure was higher: 0.50 ± 0.08 to 1.33 ± 0.23 μSv/year (average 0.86–0.87 μSv/year), still below the World Health Organization (WHO) limit (100 μSv/year). The analysis revealed that depth plays a role in radon distribution, with variations observed between surface and groundwater samples. This is likely influenced by geological characteristics or seismic activity in the area. The findings suggest that water sources in the studied locations do not pose significant radiological health risks due to radon exposure. This research highlights the urgent need for ongoing radon monitoring, especially in seismically active regions. The study provides valuable insights into the potential health impacts of radon in drinking water, contributing to improved international health and safety practices.