Occupational risks for nasopharyngeal cancer in Shanghai

To investigate occupational determinants of nasopharyngeal cancer (NPC) in the urban area of Shanghai, occupational information for 996 incident NPC patients diagnosed during 1980 to 1984 was compared with 1982 census data on employment. Standardized incidence ratios for NPC were estimated for broad and detailed occupational classifications. For the broadest level of classification, no excess risk was observed among craftmen and related manufacturing workers, but within this group significant excess risks were observed for specific occupations of textile weavers and knitters; metal smelting, converting, and refining furnacemen; boiler firemen; blacksmiths, hammersmiths, and forging-press operators; bakers, pastry cooks, and confectionery makers; welders and flame-cutters; and metal grinders, polishers, tool sharpeners, and machine-tool operators. Some of these findings are new; others are consistent with previous studies in other areas of the world. This study provides further evidence for the role of occupational factors in NPC.