Indoor Radon Levels and Contributory Factors in Southwest Nigeria

Abstract

Radon-222 has been found to be the main contributor to lung cancer after smoking. This makes the determination of the level of indoor radon activity concentration in dwellings an important health issue. This research was conducted to measure radon concentrations using alpha track detectors in dwellings in selected areas in Ondo State, Southwest Nigeria. Detectors were exposed in the area for a 90-day period. Radon concentration was related to the age of buildings, ventilation status, heating source and materials used for construction. Likewise, radiological health indices were calculated. Results showed that old buildings built with mud blocks and poorly ventilated had higher radon concentration than modern buildings built with cement blocks with good ventilation. Homes using natural gas had higher radon concentration than homes using charcoal and fire wood as cooking source. The average annual effective dose and other calculated radiological indices did not exceed the recommended limit. This showed that most of the dwellings in the area were safe for dwelling purposes.