Subject(s)
2-Naphthylamine/poisoning , Carcinogens, Environmental/poisoning , 2-Naphthylamine/chemistry , 2-Naphthylamine/toxicity , Animals , Carcinogenicity Tests , Carcinogens, Environmental/toxicity , Government Regulation , Guidelines as Topic , Humans , Mice , Molecular Structure , Occupational Exposure/adverse effects , Occupational Exposure/legislation & jurisprudence , Occupational Exposure/standardsABSTRACT
OBJECTIVE: To examine the cause-specific mortality experience of an occupational cohort with probable past exposure to beta-naphythylamine (BNA). METHODS: Subjects were 374 male and 26 female workers employed at a Pennsylvania chemical plant that produced or used beta-naphthylamine (BNA) between 1940 and 1981. Vital status through 1998 was determined for 97.5% of the cohort and cause of death for 100% of 79 deaths. Limited industrial hygiene data and reports from former employees were used to categorize workers as high, medium, or low risk for BNA exposure. Statistical analyses included US and local county-based standardized mortality ratios (SMRs). RESULTS: We observed statistically significantly elevated county rate-based SMRs for all causes combined (SMR = 1.98, 95% confidence interval (CI) = 1.56-2.49), all malignant neoplasms combined (28 deaths, SMR = 3.08, 95% CI = 2.05-4.46), respiratory system cancer (12 deaths, SMR = 3.91, 95% CI = 2.02-6.83), and bladder cancer (four deaths, SMR = 16.83, 95% CI = 4.59-43.1). Three bladder cancer cases were classified as high risk (SMR = 26.79, 95% CI = 5.53-78.29). Mortality risks were also elevated for most other malignant and non-malignant cause of death categories examined. CONCLUSIONS: Bladder cancer risk remains highly elevated among Drake/Kilsdonk workers and appears to be causally related to past BNA exposure. While lifestyle and behavioral risk factors may explain some of the mortality excesses for non-urological cancers, the possibility remains that BNA exposure may have also played a role in these and other observed cancer excesses.
Subject(s)
2-Naphthylamine/poisoning , Carcinogens , Cause of Death , Occupational Exposure , Adult , Cohort Studies , Female , Humans , Male , Pennsylvania , Registries , Risk Factors , Urinary Bladder Neoplasms/chemically induced , Urinary Bladder Neoplasms/mortalityABSTRACT
Serum properdin levels were determined for 21 benzidine operators at 6-month intervals for 2 years after termination of exposure to this carcinogen. Of this group, 7 developed bladder cancers within a 4-month period prior to the initial assay, and all 7 showed properdin levels below the median for the group as a whole. Two of the 3 workers who had had a brief exposure previously to beta-naphthylamine developed benign bladder tumors but had no malignant neoplasms up to 13 years later. The properdin assays of these 3 men remained consistently at or above the median values. No man developed a bladder tumor who was exposed less than 6 years to benzidine, even though 2 of these men showed low properdin levels. Of the 4 whose properdin levels were initially above the median but dropped below in subsequent assays, 3 developed bladder cancers 0.5, 4, and 9 years later. Only 1 man whose properdin level remained high in 1958-59 developed a bladder cancer 7 years later, and his immunologic picture may have been complicated by recovery from a larynx tumor in 1954. Recurrence of bladder tumors among the original 9 cases has occurred only among the 5 whose properdin levels remained below the median. The 1 whose ranking fell most dramatically (from 13 to 19) has had 13 recurrences in 13 years.
