Evaluating the health impact of indoor radon concentration in laboratory environments: a focus on lung cancer risk

This investigation assessed indoor radon concentrations across 11 laboratories using CR-39 solid-state nuclear track detectors to measure alpha particle emissions. Following exposure, detectors were chemically etched in 6.25 N sodium hydroxide solution at 70.0 ± 0.5 °C for 8 h to visualize alpha tracks, which were subsequently examined via optical microscopy. Measurements demonstrated considerable variability in radon levels between laboratories, even among those situated on identical floors. Radon concentrations ranged from 38.99 Bq m −3 (Laboratory 11, third floor) to 61.66 Bq m −3 (Laboratory 3, ground floor), yielding a mean value of 47.48 Bq m −3 . Correspondingly, annual effective doses varied from 0.99 mSv y −1 to 1.56 mSv y −1 , with an average of 1.20 mSv y −1 . These dose estimates remained substantially below ICRP recommended reference range of 3–10 mSv y −1 . Excess lifetime cancer risk calculations showed values between 3.786 × 10 −3 (Laboratory 11) and 5.989 × 10 −3 (Laboratory 3). A statistically significant variation in radon concentration was also observed across different age groups ( P -value <0.001). Critically, all measured concentrations fell below the UNSCEAR safety threshold of 200 Bq m −3 , confirming that laboratory occupants face negligible health risks from radon exposure. The findings indicate no actionable radon hazards in the studied facilities. • Determine indoor radon concentrations in 11 laboratories. • In this study, CR-39 detector was used. • Health risk parameters were examined. • Mean values fall well below the recommended reference level as set by ICRP.