By Wally Kennedy
MIAMI, Okla. —
Community meetings will be held Wednesday and Thursday to explain the findings from the Grand Lake Watershed Mercury Study.
The study, funded by a grant from the National Institute of Environmental Health Sciences, was conducted by the Harvard School of Public Health, L.E.A.D. Agency, and OU Health Sciences Center to determine mercury levels in fish from the Grand Lake watershed and mercury exposure in people who regularly eat fish from the watershed.
“This research study has been the most comprehensive in scope conducted in the state for any watershed and will serve as a model for others,” said Dr. Robert Lynch, with the OU Health Sciences Center.
Research team members will be available from 11:45 a.m. to 1 p.m. Wednesday at the Wyandotte Tribal Nutrition Center, 64700 East Highway 60, Wyandotte, and from 3 to 4:45 p.m. at the GRDA Eco Center, 420 Highway 28, Langley.
The team will be available from 9 a.m. to 11 a.m. Thursday at Grove City Hall, 104 W. Third St., Grove, and from 2 to 4 p.m. at the Peoria Tribal Office, 118 S. Eight Tribes Trail, Miami.
“Our results are good news for the Grand Lake community. The fish we tested generally did not contain mercury levels of concern for people with average rates of fish consumption,” said Dr. Laurel Schaider, a member of the research team.
“Mercury levels in most fish from Grand Lake and Lake Hudson were lower than those found in many other lakes in Oklahoma, according to results from Oklahoma Department of Environmental Quality.”
People who eat a lot of fish, especially large flatheads, may want to eat smaller fish and eat a variety of fish. In general, people who eat fish from Grand Lake are not exposed to high levels of mercury in their diet.
Methylmercury, the form of mercury commonly found in fish, is a neurotoxin that has been shown to affect the cognitive development of children so pregnant women, women of childbearing age and children under 15 should be mindful of guidelines that will help limit their exposure to mercury from fish.
The study did find levels of mercury above federal guidelines for children and women of childbearing age in 3 percent of the roughly 1,000 fish tested. Those species included flathead catfish, largemouth bass, blue catfish and drum.
In a previous report on the sampling, the concentrations of mercury in the fish were incorrectly reported in The Joplin Globe. Flathead catfish longer than 30 inches registered the highest mercury levels, averaging 276 parts per billion, while smaller flatheads averaged 188 parts per billion. Drum averaged 118 parts per billion, and largemouth bass averaged 84 parts per billion.
Based on the EPA guideline that mercury levels should not exceed 300 parts per billion for sensitive populations, the study recommended that children or women of childbearing age eat large flathead catfish no more than twice a month, smaller catfish and drum no more than once a week, and largemouth bass no more than twice a week.
The study, which started three years ago, involved about 150 participants recruited by the L.E.A.D. Agency in Miami. Those people completed questionnaires and kept diaries to track their fish consumption — 64 percent ate fish at least once a week, with 65 percent coming from local sources. They also permitted hair samples to be taken for testing.
Rebecca Jim, executive director of L.E.A.D. Agency, said, “We were able to analyze individual fish that are brought in as samples, and provide results to the fisherman about the fish they were eating.”