Breast cancer and occupational exposures in women in Finland

Am J Ind Med. 1999 Jul;36(1):48-53. doi: 10.1002/(sici)1097-0274(199907)36:1<48::aid-ajim7>;2-2.


Background: The etiology of breast cancer is not fully understood. Environmental and occupational exposures may contribute to breast cancer risk.

Methods: We linked 324 job titles from the 1970 census of 892,591 Finnish women with incidence of breast cancer (23,638 cases) during 1971-1995. We converted job titles to 31 chemical and two ergonomic agents through a measurement-based, period-specific, national job-exposure matrix. Poisson regression models were fit to the data, with adjustment for birth cohort, follow-up period, socioeconomic status, mean number of children, mean age at first delivery, and turnover rate.

Results: For premenopausal breast cancer, medium/high level of occupational exposure to ionizing radiation was associated with a standardized incidence ratio (SIR) of 1.3 (95% confidence interval (CI) 0.7-2.5; trend P = 0.03). For postmenopausal breast cancer, we found on SIR of 1.2 (1.1-1.3) for low level and 1.4 (1.1-1.8) for medium/high level of ionizing radiation (trend P = 0.001); and an SIR 1.3 (1.1-1.7) for medium/high levels of both asbestos and man-made vitreous fibers. Aromatic hydrocarbon solvents showed a significant trend for a modest excess of postmenopausal breast cancer.

Conclusions: Our study indicates that occupational exposure to ionizing radiation may be associated with an increased risk of female breast cancer. High-quality studies on environmental and occupational etiology of breast cancer are needed for further elucidation of risk factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Breast Neoplasms / epidemiology*
  • Breast Neoplasms / etiology
  • Confidence Intervals
  • Databases, Factual / statistics & numerical data
  • Female
  • Finland / epidemiology
  • Humans
  • Middle Aged
  • Occupational Diseases / epidemiology*
  • Occupational Diseases / etiology
  • Occupational Exposure / adverse effects
  • Occupational Exposure / statistics & numerical data*
  • Occupations* / classification
  • Occupations* / statistics & numerical data
  • Odds Ratio
  • Postmenopause
  • Premenopause
  • Regression Analysis
  • Retrospective Studies
  • Women's Health*