Environment and Breast Cancer: Science Review

Evidence From Humans
Print this page
Cancer morbidity in lamp manufacturing workers
Shannon, H. S., Haines, T., Bernholz, C., Julian, J. A., Verma, D. K., Jamieson, E., Walsh, C. American Journal of Industrial Medicine. 1988. 14:3, 281-90.
Topic area
Environmental pollutant - Occupation, solvent
Funding agency
Other: Canadian General Electric, Ontario Ministry
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Not reported
Number in Cohort
Cohort: 1044 women, including 203 who worked in coil and wire department; 826 males, including 46 who worked in coil and wire department.
Cohort participation rate
6-7% could not be traced, 2% had left the province
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Workers employed in a lamp manufacturing plant in Toronto for at least 6 months during 1960-1975 compared to Ontario
Exposure Investigated
Exposures investigated
Employment in coiling and wire drawing area, where methylene chloride and trichlorethylene have been used, though dates and patterns of use are not known.
Exposure assessment comment
Little is known about the chemicals, dose, timing, or pathway of exposure associated with the jobs studied.
Statistical Analysis
Breast cancer outcome investigated
Primary breast cancer from 1964-1982
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
Not controlled. However, the percentage married does not differ between women working in coil/wire and other departments. Authors state that the observed relative risk is too large to be likely to be explained by reproductive differences between these e
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Description of major analysis
Standardized morbidity ratio.
Strength of associations reported
Female coil/wire workers SMbR = 204 (95% CI 88, 402) (8 cases)
Female workers in other areas of the plant SMbR = 97 (95% CI 57, 166) (13 cases)
Female workers with at least 5 years of coil/wire work and at least 15 years since first exposure SMbR = 300 (129-590)
Results Comments
Results are consistent with an occupational risk related to work in the coil/wire department, but the nature of the exposure is not understood and confounding cannot be ruled out.
Author address
Occupational Health Program, McMaster University Medical Centre, Hamilton, Ontario, Canada.