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HERO ID
3490321
Reference Type
Journal Article
Title
Risk of breast cancer following exposure to tetrachloroethylene-contaminated drinking water in Cape Cod, Massachusetts: Reanalysis of a case-control study using a modified exposure assessment
Author(s)
Gallagher, LG; Vieira, VM; Ozonoff, D; Webster, TF; Aschengrau, A
Year
2011
Is Peer Reviewed?
1
Journal
Environmental Health
EISSN:
1476-069X
Volume
10
Page Numbers
47
Language
English
PMID
21600013
DOI
10.1186/1476-069X-10-47
Web of Science Id
WOS:000292184300003
Abstract
BACKGROUND:
Tetrachloroethylene (PCE) is an important occupational chemical used in metal degreasing and drycleaning and a prevalent drinking water contaminant. Exposure often occurs with other chemicals but it occurred alone in a pattern that reduced the likelihood of confounding in a unique scenario on Cape Cod, Massachusetts. We previously found a small to moderate increased risk of breast cancer among women with the highest exposures using a simple exposure model. We have taken advantage of technical improvements in publically available software to incorporate a more sophisticated determination of water flow and direction to see if previous results were robust to more accurate exposure assessment.
METHODS:
The current analysis used PCE exposure estimates generated with the addition of water distribution modeling software (EPANET 2.0) to test model assumptions, compare exposure distributions to prior methods, and re-examine the risk of breast cancer. In addition, we applied data smoothing to examine nonlinear relationships between breast cancer and exposure. We also compared a set of measured PCE concentrations in water samples collected in 1980 to modeled estimates.
RESULTS:
Thirty-nine percent of individuals considered unexposed in prior epidemiological analyses were considered exposed using the current method, but mostly at low exposure levels. As a result, the exposure distribution was shifted downward resulting in a lower value for the 90th percentile, the definition of "high exposure" in prior analyses. The current analyses confirmed a modest increase in the risk of breast cancer for women with high PCE exposure levels defined by either the 90th percentile (adjusted ORs 1.0-1.5 for 0-19 year latency assumptions) or smoothing analysis cut point (adjusted ORs 1.3-2.0 for 0-15 year latency assumptions). Current exposure estimates had a higher correlation with PCE concentrations in water samples (Spearman correlation coefficient = 0.65, p < 0.0001) than estimates generated using the prior method (0.54, p < 0.0001).
CONCLUSIONS:
The incorporation of sophisticated flow estimates in the exposure assessment method shifted the PCE exposure distribution downward, but did not meaningfully affect the exposure ranking of subjects or the strength of the association with the risk of breast cancer found in earlier analyses. Thus, the current analyses show a slightly elevated breast cancer risk for highly exposed women, with strengthened exposure assessment and minimization of misclassification by using the latest technology.
Tags
OPPT REs
•
OPPT_N-methylpyrrolidone (NMP)_F. Human Health
Total – title/abstract screening
On topic
Peer review
Primary source
•
OPPT_Perchloroethylene (Perc)_C. Engineering
Total – title/abstract screening
Off topic
•
OPPT_Perchloroethylene (Perc)_D. Exposure
Total – title/abstract screening
On topic
Peer review
Primary source
•
OPPT_Perchloroethylene (Perc)_E. Fate
Total – title/abstract screening
Off topic
•
OPPT_Perchloroethylene (Perc)_F. Human Health
Total – title/abstract screening
On topic
Peer review
Primary source
On topic - additional tags for titles/abstracts
Human hazard ID
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