Hanford strontium seeps into the Columbia River near H Reactor at a concentration that is about 200,000 times less than what would harm baby salmon, Pacific Northwest National Laboratory study results show.

Strontium concentrations along Hanford's Benton County shore from Vernita to the 300 Area are roughly similar.

And those concentrations are about the same as in 1990 to 1992, when a similar sampling and analysis was done of mulberry trees, reed canary grasses and other vegetation along the shore.

PNNL collected new samples in June and October to check radiation readings against the 1990-92 figures. June's figures were available Thursday, while October's figures are expected to be ready soon.

The PNNL sample collecting was done while the state health department and Norm Buske, a Government Accountability Project scientist, collected similar samples - all charting the flow of strontium-laced ground water into the river.

Numerous Northwest interests worry about Hanford's contaminants seeping into the Hanford Reach because that stretch is the last major salmon spawning area in the Columbia River.

Although strontium concentrations reaching the river are low today, that does not rule out much higher concentrations of contaminants entering the Columbia in the future, said Dana Ward, the Department of Energy's project manager for its surface and environmental surveillance program, and Ted Poston, his PNNL counterpart.

That's because central Hanford's underground contaminants are much more radioactive and are flowing toward the river in concentrations and speeds that scientists do not really understand.

There are two or three ways to measure the potency of radioactive strontium, which can cause bone cancer in great enough concentrations. It is one of the site's most dangerous radioactive substances to ingest. But humans do not drink Hanford's shore area water in the steady years-long volumes needed to get cancer from strontium.

The bottomline measurement is how much of a dose that a human, a plant or a fish absorbs, said Ward and Poston.

International dose absorption standards are one rad per day for humans, plants, animals and fish. It is likely the standard for land animals and humans will soon change to 0.5 rad per day, Ward said.

Here is what PNNL's study shows:

- A fish egg offshore from H Reactor would absorb about 0.000005 rad per day of strontium. The river offshore from H Reactor is a major salmon spawning area.

- A fish egg could absorb 0.00009 rad per day when all seeping radioactive substances are factored in. These other substances include uranium, tritium and technetium.

PNNL scientists picked a riverbed spot near H Reactor with the highest concentration of seeping nonradioactive chromium. Then they assumed in their calculations that the radioactive substances would seep in the greatest volumes through the same path as the chromium. Chromium is Hanford's most worrisome chemical affecting the health of salmon.

- Scientists did not look at salmon when examining the area offshore of N Reactor, which has the highest strontium concentrations, because it is not near any salmon spawning areas.

Instead, they looked at sculpin, a small, bottom-dwelling fish that does not move far from its home area, Poston said. A sculpin's dose absorption offshore from N Reactor was calculated to be 0.000044 rad per day.

The margin of error in all these numbers is a factor of 10 - meaning the doses could be 10 times greater or 10 times smaller, Poston said.

The state health department's results were roughly similar to PNNL's.

But Buske believes PNNL underestimated the potential threat to newly hatched salmon. "The public is getting more bland (false) assurances from PNNL,"he said.

Buske calculated that 75 picocuries of strontium per liter of water is bubbling up in one riverbed spot near H Reactor. PNNL calculated a median strontium concentration of 17 picocuries per liter, with the highest reading being 25 picocuries in the riverbed before the Columbia dilutes it. The federal drinking water standard is 8 picocuries.

Buske, an oceanographer and physicist, said he does not have the biology background to discuss in detail what concentrations are dangerous to baby salmon.

But he plans to hold a press conference soon in Richland, and to bring a biologist to discuss that issue.