Radon concentration in well water from Namom district (Southern Thailand): a factor influencing cancer risk

The radon concentrations were determined in well water samples from Namom district, Southern Thailand, by using a RAD7 radon monitoring system. The measured values ranged from 0.1 to 483.0 Bq l −1 , while the average ±1 σ across all measured samples was 32.0 ± 9.2 Bq l −1 . Regarding the health risks from radon in household drinking water, some settlements had radon concentration exceeding 100 Bq l −1 , an upper limit set by the European Union Directive EC2013/51/EURATOM. It is of concern that the results indicate health risks, especially to those consumers who directly use well water with high radon concentration.