In two rural provinces of China residents are exposed to significantly elevated levels of natural radiation: in Gansu Province millions of people have been living in earth-dug cave dwellings for several generations; in Jiangxi Province several hundred thousand inhabitants reside in carbon-brick dwellings, containing elevated levels of 238U and 226Ra. In a pilot study regional lung cancer mortality rates were investigated in the affected areas and were found to be higher than for control groups in normal dwellings in the same area.
(C)1996Health Physics Society