Consumption of PCB-contaminated freshwater fish and shortened menstrual cycle length.

Highly contaminated Lake Ontario sport fish represent an important human dietary exposure to polychlorinated biphenyls (PCBs) and other toxic contaminants that may disrupt endocrine pathways. New York State Angler Cohort women interviewed by telephone in 1993 provided menstrual cycle length (n = 2,223). Fish consumption at cohort enrollment in 1991 was categorized by duration and frequency and was used to calculate a PCB exposure index. Multiple regression analyses identified significant cycle length reductions with consumption of more than one fish meal per month (1.11 days) and moderate/high estimated PCB index (-1.03 days). Women who consumed contaminated fish for 7 years or more also had shorter cycles (-0.63 days).