CHEMICAL CHARACTERIZATION OF MUTAGENIC FRACTIONS OF PARTICLES FROM INDOOR COAL COMBUSTION - A STUDY OF LUNG-CANCER IN XUAN-WEI, CHINA

In the rural Xuan Wei County, Yunnan Province, lung cancer mortality rates for women are among the highest in China. Most of these women are nonsmokers, and studies have shown that lung cancer in Xuan Wei is associated with domestic use of smoky coal under unvented conditions. The objective of this study is to determine the chemical constituents that may be linked to the high lung cancer rates in Xuan Wei using the bioassay-directed fractionation method. Ten high-volume filter samples ( < 10 Am) collected from the home inhabited by a person with lung cancer during cooking periods on four consecutive days were subjected to Soxhlet extraction. This composite sample extract was fractionated on a normal-phase column into seven fractions. The second fraction was the most active in the bioassay, containing mainly polycyclic aromatic hydrocarbon (PAH) and alkylated PAH. The two polar fractions 6 and 7 were the next most active. The most active PAH fraction was further separated into 11 subfractions, based on the number of aromatic carbons. The results indicated that the presence of three to four-ring alkylated PAHs in the sample extract is a significant factor that may be linked to the high incidence of lung cancer in Xuan Wei, China.