A RETROSPECTIVE STUDY OF BRAIN TUMORS AND OCCUPATIONAL RISK FACTORS (PETROLEUM REFINING, SOLVENTS, CHEMICAL MANUFACTURING, ELECTRONICS WORKERS)

A retrospective study was conducted to evaluate brain tumor risk associated with exposures in the petroleum and chemical industries. Cases (N = 741) in Northern New Jersey, Philadelphia, Pennsylvania, and the Gulf Coast of Louisiana were identified from death certificates of white men age 30 or older whose underlying cause of death was listed as a malignant, unspecified, or benign tumor of the brain. Controls (N = 741) were selected from white men who died from causes other than brain tumor, epilepsy, or stroke and were matched to the cases on study area, age, and year of death. Interviews to obtain information on possible brain tumor risk factors were completed for 69% (Cases = 74%; Controls = 63%) of the 1266 study subjects (Cases = 654; Controls = 612) whose next-of-kin were located, while 31% (Cases = 26%; Controls = 37%) of the next-of-kin who were contacted refused to be interviewed. Brain tumor risks associated with specific industries, jobs, and exposures were evaluated by calculating maximum likelihood estimates of the relative odds (RO) and 95% confidence intervals (95%CI).;Analyses of lifetime work histories from the interview data indicated no excess risk associated with employment in the chemical, rubber or plastics industries; however, there was an elevated risk of mortality from astrocytic tumors among subjects whose jobs might have involved exposure to chemicals in petroleum refining (RO = 1.8; 95%CI = 0.7,4.5).;There was a significantly elevated risk of astrocytic tumor deaths among subjects ever employed in an industry (RO = 2.6; 95%CI = 1.5,4.5) or job (RO = 2.4; 95%CI = 1.3,4.4) associated with electronics. Risk was highest among men who had worked as electronics engineers/ teachers/ technicians/repairers (RO = 3.5; 95%CI = 1.4,8.6) and among those employed as electronics equipment assemblers (RO = 8.0; 95%CI = 0.9,190.2), and increased by duration employed and latency.;An analysis of usual occupation listed on death certificates did not show excess brain tumor risk among men whose usual employment was in petroleum refining (RO = 1.2; 95%CI = 0.6,2.6) or chemical manufacturing (RO = 1.0; 95%CI = 0.8,1.3); however, mortality risk was elevated among men whose usual occupation was in the manufacture of electrical and electronics equipment (RO = 1.7; 95%CI = 0.7,4.2). Elevated risks of death from brain tumors were seen for industrial engineers, health professionals, teachers, artists/designers. Precision metal workers (RO = 2.1; 95%CI = 1.2,3.6) who were machinists, tool and die makers, or sheet metal workers had a significantly elevated risk of brain tumor mortality.