SURVEILLANCE OF NASAL AND BLADDER-CANCER TO LOCATE SOURCES OF EXPOSURE TO OCCUPATIONAL CARCINOGENS

Objective-To locate sources of occupational exposure to nasal and blad der carcinogens for surveillance follow up in British Columbia, Canada . Methods-Incident cases of nasal cancer (n=48), bladder cancer (n=105 ), and population based controls (n=159) matched for sex and age, were interviewed about their jobs, exposures, and smoking histories. Odds ratios (ORs) were calculated for 57 occupational groups with stratifie d exact methods to control for age, sex, and smoking. Results-Occupati onal groups at increased risk of nasal cancer included: textile worker s (six cases, OR 7.6); miners, drillers, and blasters (six cases, OR 3 .5); welders (two cases, OR 3.5); pulp and paper workers (three cases, OR 3.1); and plumbers and pipefitters (two cases, OR 3.0). Nasal canc er ORs were not increased in occupations exposed to wood dust, possibl y due to low exposures in local wood industries. Strongly increased ri sks of bladder cancer were found for sheet metal workers (four cases, OR 5.3), miners (19 cases, OR 4.5), gardeners (six cases, OR 3.7), and hairdressers (three cases, OR 3.2). Among occupations originally cons idered at risk, the following had increased risks of bladder cancer: p ainters (four cases, OR 2.8); laundry workers (five cases, OR 2.3); ch emical and petroleum workers (15 cases, OR 1.8); machinists (eight cas es, OR 1.6); and textile workers (three cases, OR 1.5). Conclusions-Oc cupational groups with increased risks and three or more cases with si milar duties were selected for surveillance follow up. For nasal cance r, these included textile workers (five were garment makers) and pulp and paper workers (three performed maintenance tasks likely to entail stainless steel welding). For bladder cancer, these included miners (1 2 worked underground), machinists (five worked in traditional machinin g), hairdressers (three had applied hair dyes), and laundry workers (t hree were drycleaners).