Environment and Breast Cancer: Science Review

Evidence From Humans
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A cohort mortality study of workers exposed to chlorinated organic solvents in Taiwan
Chang, Y. M., Tai, C. F., Yang, S. C., Chen, C. J., Shih, T. S., Lin, R. S., Liou, S. H. Annals of Epidemiology. 2003. 13:9, 652-60.
Topic area
Environmental pollutant - Occupation, organic solvents
Study design
Other: Cohort mortality
Funding agency
Council of Labor Affairs, Executive Yuan, Republic
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Not reported
Number in Cohort
Cohort:70735 females
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Employed in 1985 -1997 at electronics factory in Taiwan compared to population of Taiwan
Exposure Investigated
Exposures investigated
Duration and time period of employment in solvent-exposed job in a plant where trichloroethylene and tetrachloroethylene, among other compounds, were used.
Exposure assessment comment
Information on employment dates is incomplete. Specific chemical exposures are not well defined. Duration of exposure is short for many members of cohort.
Early life exposures considered
Exposure begins before age 20 for most workers.
Statistical Analysis
Breast cancer outcome investigated
Mortality from breast cancer in 1985-1997
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 taken into account.
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 mortality ratio
Strength of associations reported
SMR 1.14 (0.85-1.51) 51 cases
More than 5 years employment SMR 1.32 (p > 0.05)
Results Comments
Most workers were 30-50 years of age, young for breast cancer. Most were employed < 1 year; 40% for < one month. Community drinking water was polluted by the plant, affecting nonworkers, though perhaps this is a small group within the comparison population.
Author address
Graduate Institute of Life Sciences, National Defense Medical Center, Institute of Occupational Safety and Health, Council of Labor Affairs, Executive Yuan, Taipei, Taiwan, Republic of China.