Effect of Chronic Exposure to Low-Level Radon Gas from Tertiary Institutions Workplaces in Western Nigeria

The carcinogenic effect of exposure to radon on human health is a concern globally. Hence, the objective of this paper was to assess the effect of chronic exposure to low-level radon gas from tertiary institutions workplaces in Western Nigeria using dosimetric and Monte Carlo simulation (MCS). Data obtained show that 84.09% of 132 workplaces investigated are within 100 Bqm-3 (0.01 WL) action level recommended for indoor radon. The average values obtained for the estimation of excess lifetime cancer risk at each studied institution ranged from 0.28% to 0.50% for the dosimetric method and 0.32% to 0.58% for the probabilistic method. The sensitivity analysis revealed that annual occupational exposure to radon decay products is the highest contributor to the risk estimate, followed by the mean life time duration, while the risk factor contributes least. Thus, chronic exposure to low-level indoor radon can lead to lung cancer, most especially for a non-smoker, at a certain stage in life if adequate precautionary measures are not taken to reduce the concentration of indoor radon. Hence, the use of air conditions should be minimized at the workplaces by cultivating a healthy life style of allowing sufficient diffusion of indoor radon-induced air with outdoor air.