The Upper Midwest Health Study: industry and occupation of glioma cases and controls.
BACKGROUND
Understanding glioma etiology requires determining which environmental factors are associated with glioma. Upper Midwest Health Study case-control participant work histories collected 1995-1998 were evaluated for occupational associations with glioma. "Exposures of interest" from our study protocol comprise our a priori hypotheses.


METHODS
Year-long or longer jobs for 1,973 participants were assigned Standard Occupational Classifications (SOC) and Standard Industrial Classifications (SIC). The analysis file includes 8,078 SIC- and SOC-coded jobs. For each individual, SAS 9.2 programs collated employment with identical SIC-SOC coding. Distributions of longest "total employment duration" (total years worked in jobs with identical industry and occupation codes, including multiple jobs, and non-consecutive jobs) were compared between cases and controls, using an industrial hygiene algorithm to group occupations.


RESULTS
Longest employment duration was calculated for 780 cases and 1,156 controls. More case than control longest total employment duration was in the "engineer, architect" occupational group [16 cases, 10 controls, odds ratio (OR) 2.50, adjusted for age group, sex, age and education, 95% confidence interval (CI) 1.12-5.60]. Employment as a food processing worker [mostly butchers and meat cutters] was of borderline significance (27 cases, 21 controls, adjusted OR: 1.78, CI: 0.99-3.18).


CONCLUSIONS
Among our exposures of interest work as engineers or as butchers and meat cutters was associated with increased glioma risk. Significant associations could be due to chance, because of multiple comparisons, but similar findings have been reported for other glioma studies. Our results suggest some possible associations but by themselves could not provide conclusive evidence.
Division of Surveillance, Hazard Evaluations, and Field Studies, National Institute for Occupational Safety and Health, Cincinnati, Ohio 45226, USA. amr2@cdc.gov
Avima M
AM
Ruder
Martha A
MA
Waters
Tania
T
Carreón
Mary A
MA
Butler
Geoffrey M
GM
Calvert
Karen E
KE
Davis-King
Kathleen M
KM
Waters
Paul A
PA
Schulte
Jack S
JS
Mandel
Roscoe F
RF
Morton
Douglas J
DJ
Reding
Kenneth D
KD
Rosenman
D000382:Agricultural Workers' Diseases / Q000209:etiology; D001932:Brain Neoplasms / Q000209:etiology*; D016022:Case-Control Studies; D005260:Female; D005525:Food-Processing Industry; D005910:Glioma / Q000209:etiology*; D006306:Health Surveys; D006801:Humans; D008297:Male; D015146:Midwestern United States; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D012424:Rural Population; D011795:Surveys and Questionnaires; D013997:Time Factors