4Polychlorinated biphenyls (PCBs) are toxic and persistent chemicals produced between
1930s and 1980s primarily for insulating fluids in heavy-duty electrical equipment in
power plants, industries, and large buildings. They persist in the environment and accumulate
in plants and animals, and have been classified as probable carcinogens to
humans. We performed a systematic review and meta-analysis of scientific literature
on the relationship between PCB exposure and human cancer. Two cohorts of people
highly exposed to PCBs through ingestion of contaminated rice oil and some cohorts
of occupationally exposed workers failed to show a definite increase in total cancer
mortality and provided inconsistent results regarding single cancers. Several cohort
and case-control studies investigated the association between PCBs and specific cancers,
showing an association between PCB serum levels and non-Hodgkin lymphomas
(NHL), with a summary odds ratio of 1.5 (95% confidence interval: 1.1–1.7), but no consistent
results for the other cancer sites and types. In conclusion, this review provides
some evidence for the role of PCBs in the development of NHL, although the inconsistent
results of studies performed on highly polluted people and occupationally exposed
workers do not allow a firm conclusion to be drawn.nonenoneZani C.; Toninelli G.; Filisetti B.; Donato F.Zani, Claudia; Toninelli, Giuseppe; Filisetti, Barbara; Donato, Francesc
