Mortality Study of Workers Exposed to PCBs
Author Information
Author(s): Prince Mary M, Hein Misty J, Ruder Avima M, Waters Martha A, Laber Patricia A, Whelan Elizabeth A
Primary Institution: Centers for Disease Control and Prevention (CDC)
Hypothesis
Does exposure to polychlorinated biphenyls (PCBs) increase mortality rates among electrical capacitor manufacturing workers?
Conclusion
The study found persistent excess mortality from liver and biliary cancers among PCB-exposed workers, particularly among women, but did not establish a clear link to duration of employment.
Supporting Evidence
- Mortality from biliary, liver, and gall bladder cancer was significantly elevated.
- Mortality from intestinal cancer was elevated among women.
- Mortality from myeloma was highest among workers employed for 10 years or more.
- Mortality from rectal cancer was not significantly elevated.
- Mortality from non-Hodgkin's lymphoma was moderately elevated.
- Small numbers of deaths preclude definitive conclusions regarding PCB exposure.
Takeaway
This study looked at workers who were around PCBs and found that they got sick more often from certain cancers, especially liver cancer, but it wasn't clear if working longer made it worse.
Methodology
The study updated mortality data through 1998 for 2572 workers and calculated standardized mortality ratios (SMRs) using U.S. referent rates.
Potential Biases
Potential misclassification of exposure due to using duration of employment as a surrogate for cumulative PCB exposure.
Limitations
Small cohort size, low number of deaths, lack of data on potential confounders, and possible misclassification of exposure.
Participant Demographics
The cohort included 2572 workers, with 48% men and 52% women, predominantly white (98%).
Statistical Information
P-Value
p<0.05
Confidence Interval
CI 1.05 – 3.77
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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