Anyone who wants more than public assurances that radiation levels aren’t rising in Washington can find out exactly what the readings are.

Average daily readings from four radiation monitoring sites in Shoreline, Tumwater, Richland and Spokane are now available online. The state Department of

Health added the information to its website Friday.

The move is in response to growing public concern about possible radiation exposure from Japan’s earthquake-damaged nuclear plants.

The posted readings begin March 3, more

than a week before Japan’s earthquake and tsunami that crippled the Fukushima nuclear power plant in Okuma.

“I think this is a terrific resource for the community,” said Dr. Gary Goldbaum, health officer for the Snohomish Health District. “Everyone in the state can look at the data. We will know if there is any change in the background radiation.”

The state Department of Health has been tracking radiation levels for about 40 years, spokesman Donn Moyer said. It’s part of the Environmental Protection Agency’s national radiation monitoring system.

The challenge in posting the numbers on the state health department’s website was providing the information in a way that the public could understand, he said.

What the monitors continue to show is normal background levels of radiation.

“We don’t expect to see anything of any public health significance,” Moyer said. “It may be hard to distinguish something from Japan from normal fluctuations.”

That’s because there’s radiation in the environment all the time from sources as varied as the sun, X-rays, computer monitors and cell phones, he said.

At one of its monitoring sites in Tumwater, outside of Olympia, readings varied last year from a low of 5 to a high of 105 counts per minute of gross beta, a radiation measure that refers to all radioactive materials that emit beta radiation.

“We use it for a good reason,” Moyer said. “It’s easy to calculate and gives you a quick turnaround when things change.”

The numbers will change from day to day, he said. But the public shouldn’t be concerned about a reading that increases, say, from 25 one day to 80 the next.

The high would have to be several hundred thousand times higher — closer to a million — before any public health warnings would be considered, he said.

Before those levels were reached, scientists would conduct further tests to see which specific type of radioactive isotope was being detected, Moyer said.

Moyer said he hopes that having regularly updated information will build public confidence in assurances that have been made by public health and government officials that no unusual levels of radiation have been detected.

“We’re posting information so people can see for themselves what we’re seeing,” Moyer said.

“We wouldn’t try to calm people’s fears just to calm people’s fears,” he added. “We’re giving them factual information. The motive is to inform them.”

Sharon Salyer: 425-339-3486; salyer@heraldnet.com.

Radiation levels

The daily checks of radiation levels in Washington are available at: http://tinyurl.com/statemonitor