Primary investigation of quartz as a possible carcinogen in coals of Xuanwei and Fuyuan, high lung cancer incidence area in China

Xuanwei and Fuyuan, located in southwest China, are two counties with extremely high lung cancer incidence. Pollution, relative to coal combustion, especially serious air pollution generated by burning smoky coals in unvented households was the most predominant cause. Quartz as a possible inorganic carcinogen in all typical coals (18 sites in Xuanwei and 14 sites in Fuyuan) were sampled and examined to determine the relationships between quartz content and lung cancer incidence. Scanning electron microscope-energy dispersive X-ray apparatus and X-ray diffractometer were employed for quartz analysis. It showed that it coincided with studies reported before in Xuanwei. Coal samples from high cancer incidence areas were all examined with high content of quartz, while coal samples from low cancer incidence areas with no content of quartz. However, data in Fuyuan received reverse results; many samples from low lung cancer incidence areas were found with quartz, but some samples from high lung cancer incidence areas were not found at the same detection limits. It indicated that quartz content in local coals has no significant relationship to lung cancer. This study added basic data and should be helpful to the future study on the etiology of lung cancer.