Women Who Eat Lake Ontario Fish May Increase Their Time to Conceive, UB Study Shows

BUFFALO, N.Y. -- Women who regularly eat fish from Lake Ontario, known to be contaminated with PCBs and other hormone-disrupting chemicals, may be about 25 percent less likely to become pregnant than women who do not, researchers from the University at Buffalo have found.

Meanwhile, male consumption of fish taken from Lake Ontario appears to have no relationship to a couple's time to pregnancy or the number of months required to become pregnant.

Results of the study, thought to be the first epidemiologic assessment of consumption of contaminated fish and human fecundity, appear in the July issue of Epidemiology. The study was directed by Germaine M. Buck, Ph.D., professor of Social and Preventive Medicine in the UB School of Medicine and Biomedical Sciences.

"These findings suggest that reproductive-health endpoints may be early indicators of the adverse effects of environmental hazards on human health," Buck said. "Many environmental-health studies focus on cancer, which can take several years to develop. Reproductive endpoints can be studied earlier and do not necessarily have a long latency period following exposure."

The study was based on female participants in The New York State Angler Cohort Study who were considering pregnancy between 1991-94. The angler study was undertaken in 1991 to determine the health consequences of eating fish from Lake Ontario, known to be the most polluted of the Great Lakes.

The study has assembled a population-based cohort of licensed anglers and their spouses or partners from 16 counties surrounding Lake Ontario, involving 10,517 men and 7,477 women who were between the ages of 18 and 40 when the study began.

The sample for this investigation comprised 575 couples from the cohort who had a planned pregnancy between 1991-93 and who could state how long they had been trying to become pregnant without birth control. Buck and colleagues also had complete information on both partner's fish consumption and time-to-pregnancy.

Estimates of Lake Ontario fish consumed were based on participants' reports of eating the most heavily contaminated lake sport fish: lake, rainbow and brown trout; coho and chinook salmon; catfish, and carp.

The researchers measured consumption in three ways: the number of meals per month involving any of 12 specific fish in 1991; the number of years of eating fish from Lake Ontario between 1955-91, and the PCB index, calculated from the frequency, type and amount of fish eaten. Eating contaminated fish is reported to deliver a dose of PCBs much higher than background exposure through drinking water or inhalation.

Results showed that women who had eaten Lake Ontario fish for 3-6 years, and those who had more than one meal of such fish per month in 1991, were one-fourth less likely to become pregnant each month than women who didn't eat fish from that lake. However, all women in this study eventually did conceive, Buck noted.

While the results are preliminary, they support the need for continuing to advise women of childbearing age not to eat any fish from Lake Ontario, Buck said. Such advisories have been issued by New York State since 1976, but a population-based survey of people in the Great Lakes basin who ate lake fish, published in 1997, found that only about half of those surveyed were aware of the advisory.

Also contributing to this study were John E. Vena, Ph.D., Jacek Dmochowski, Ph.D., Paul Kostyniak, Ph.D., Hebe Greizerstein, Ph.D., and James Olson, Ph.D., all of UB; Enrique F. Schisterman, Ph.D., of the Harvard School of Public Health; Pauline Mendola, Ph.D., of the U.S. Environmental Protection Agency; Lowell E. Sever, Ph.D., of the University of Texas-Houston School of Public Health, and Edward Fitzgerald, Ph.D., of the New York State Health Department.

The study was funded by grants from the Great Lakes Protection Fund and the Agency for Toxic Substances and Disease Registry.