Investigation of radon and heavy metals in Xuanwei and Fuyuan, high lung cancer incidence areas in China.

Xuanwei and Fuyuan, two counties located in southwest China, are areas with known high lung cancer incidence. Pollution relative to coal combustion, especially serious air pollution generated by burning smoky coals in unvented households, has been thought to be the most predominant cause. Possible inorganic carcinogenic matter including radon in air and arsenic, lead, chromium, cadmium, nickel, and beryllium in water, soil, and coal were sampled and examined to find the current pollution status, distributions, characteristics, and relationships to the lung cancer incidence. The concentrations of mercury in air of Xuanwei and Fuyuan ranged from 1.7 to 205.3 ng/m3 (indoor), 1.3 to 7.5 ng/m3 (ambient). No radon concentration exceeded the World Health Organization standard. Results indicated that household stove improvement by changing stoves from unvented to vented obviously alleviated the indoor air pollution of carcinogenic metals. Most of the carcinogenic metals were also found at very low levels in water and soil, which therefore had little influence on human health. Concentrations of these elements at different sites did not vary in any relation to lung cancer incidence. The study described in this article added basic data; the results of the authors' study will be helpful in determining pollution status and to future studies on the etiology of lung cancer.