Abstract

Restricting exposure to hazardous materials and epidemics is a primary step in reducing health concerns of the public. Radon and its progeny are known potential indoor air pollutants causing higher risk of lung cancer through chronic exposure. There is no known threshold concentration below which radon exposure presents no risk. Even at low concentrations, radon can result in an increase in the risk of lung cancer. We have made a preliminary study on the levels of indoor radon and thoron concentrations in selected populated locations in the city of Lae in Papua New Guinea using both active and passive methods of measurement. The basic source term of indoor radon, the flux from the soil air has also been determined. The overall average indoor activity of radon gas was 13.4 3 ± Bq m^-3, that for thoron was 2.5±1.1 Bq m^-3 and the annual average inhalation dose was 0.25±0.12 mSv. The radon flux from soil air was found to be 12.7 Bq m^-2 h^-1. The concentrations of radon and thoron progeny and their equilibrium factor were also determined. It is found that the dwellings have lower levels of radon as compared with the dwellings in many other regions of the world.