This study finds evidence that exposure to PCBs is associated with increased risk of adult onset diabetes 25 years after exposure (PCB concentrations greater than 5 ppb in blood samples) was confirmed. The association only applied to women. There was no link with PBBs. PCBs are still found in food, decades after strict controls were introduced.
Evidence from:
O Vasiliu et al. Epidemiology (2006) Vol.17 p 352 – 359
“Polybrominated Biphenyls (PBB), Polychlorinated Biphenyls (PCB), Body Weight, and Incidence of Adult-Onset Diabetes Mellitus”
Further detail: