A new study says that workers at the Department of Energy’s (DOE) Fernald Plant near Cincinnati faced more danger from radon emissions than previously thought. An older study had identified two silos on the west side of the Fernald plant as the only source of radon exposure.  But researchers from the University of Cincinnati  said that review, conducted by the federal government, overlooked six other  silos cited in their study as a source of radon emissions.

The Cincinnati researchers said that the six silols, which once stored uranium in the plant’s production area exposed 12 percent of the workers at the Fernald plant to dangerously high levels of radon.  More than half of the workers at the plant would have been exposed to low levels of radon, the study said.

According to the study, workers on the third shift faced the most danger from the six silos, and at times may have been exposed to three times the radon as workers on other shifts.  The researchers said this heightened exposure was attributable to decreased air movement and less dispersion of radon gas during the night.

“Now we know workers in the plant’s production area prior to 1959 may be at increased risk for developing lung cancer and other exposure-related health problems,” Susan Pinney, corresponding author of the study, said in a press release.

The Fernald plant is now closed, and is now called the Fernald Reserve, a park area with wetlands, forests and prairies. Federal officials say the site will be safe for visitors when it opens this fall.  However, state officials in Ohio maintain that radioactive waste left in could linger for a century.

In July, the DOE agreed to pay a record $13.75 million to settle a lawsuit that the Ohio Environmental Protection Agency filed in 1986. The money will be used to help restore Paddys Run, a small stream that runs for a mile through the Fernald site. The stream was the main path the uranium waste took to get into the groundwater.

In 1989, the DOE and National Lead of Ohio, the company that operated the Fernald plant through, settled a class action lawsuit with people living around the plant.  The lawsuit was filed after the lead plantiff, Lisa Crawford, had discovered that the well that she and her family had been using for drinking water was contaminated with uranium. She also found out that the DOE and NLO had discovered the contamination four years earlier.