State officials, alarmed by government researchers' discovery of potentially toxic levels of selenium in the middle Green River drainage, are considering whether measures to guard public health are needed.

In a recently completed two-year preliminary study of the eastern Utah drainage's Stewart Lake Waterfowl Management Area and the Ouray National Wildlife Refuge, a multiagency scientific team found levels of selenium well above federal and state limits.The findings of U.S. Geological Survey, U.S. Fish and Wildlife and Bureau of Reclamation researchers have sparked a review by the Utah Environmental Health Division's water pollution office.

State officials will consider whether fishing, hunting and other activities at Stewart Lake, 12 miles southeast of Vernal, may have to be restricted because of the potential danger of selenium - a naturally occurring trace element essential to nutrition in minute amounts, but toxic in larger doses.

The Ouray refuge, 30 miles southwest of Vernal, falls under federal jurisdiction.

However, environmental health scientist Mike Reichert stressed that it "would be premature to discuss any bans" at Stewart Lake until state officials have a chance to completely study the federal report's data.

"Our initial reaction was there wasn't enough information to make any decision concerning health effects," he said. "Now we have copies of the report, but the staff here hasn't had a chance to discuss it yet."

But what state officials have seen of the report has convinced them to seek a closer working relationship with federal scientists who are now following up their preliminary "reconnaissance investigation" of the middle Green River basin with a more extensive two-year study.

The second study, at $400,000 twice as expensive as its predecessor, will be completed in early 1990, said USGS hydrologist Doyle W. Stephens.

"We're looking specifically at selenium, primarily at Stewart and Ouray," he said. "We want to quantify what the long-term effects are, where it's coming from and where it's going."

The preliminary study was part of a 1986-87 multistate federal investigation in which researchers looked at contamination linked to irrigation water.

Besides Utah, other study sites included the lower Colorado-Gila River Valley spanning the Arizona-California border region; California's Salton Sea and Tulare Lake areas; Montana's Sun River and Milk River reclamation projects; Nevada's Stillwater Wildlife Management Area; the lower Rio Grande-Laguna Atascosa National Wildlife Refuge area in Texas, and Wyoming's Kendrick Reclamation Project.

Stephens, fish and wildlife biologist Bruce Waddell, and Jerry Miller, BOR water quality branch chief for the upper Colorado region, found selenium levels ranging from 14 to 140 parts per billion in Stewart Lake groundwater drains.

Fish taken from the lake contained 31 parts per million, and the livers of waterfowl at the site had a range of selenium content ranging from 4.9 to 26 ppm.

At Ouray, coot livers taken at the North Roadside Pond contained an average of 32 ppm of selenium, while the pond's water itself measured 93 ppm - nearly 9,000 times the Environmental Protection Agency's limit of 0.01 ppm for selenium in drinking water.

Stephens said that while it will be up the state to determine what, if any, restrictions to impose at Stewart Lake, the area of the Ouray refuge found with high selenium levels poses little public hazard since it has never been opened for fishing, hunting or swimming.

However, scientists suspect selenium already has had its impact on the non-human inhabitants of the contaminated Ouray pond, where deformed embryos were found in eggs taken from ground-nesting coots.

And while researchers did not find deformed fish at either the Ouray refuge or Stewart Lake, they are concerned high concentrations of selenium - known to effectively sterilize such species as the bluegill - could decimate fisheries.

In humans, selenium poisoning can, among other things, lead to sterility and heart and lung lesions.

Miller, while stressing that more study is needed before making any assumptions, said preliminary findings "behoove us at this point to warn the public about Stewart Lake and the pond at Ouray.

"What we know about Stewart Lake is there are levels that are elevated enough to cause concern but not elevated to the point where we know there would be a toxic effect on organisms," he said.