RIDGEWOOD — A past atomic bomb project site is finally receiving government attention to protect current workers and nearby residents after decades of elevated radiation levels at the building.

The former site of Wolff-Alport Chemical Company — which includes a giant warehouse that currently houses an auto-body shop and construction company and an abandoned lot — has been contaminated with the radioactive element thorium since the 1930s, government officials said. Last month, the Environmental Protection Agency started to work on shielding the site on the Ridgewood-Bushwick border.

"We just got a referral from the state to perform shielding Aug. 31," said Eric Daly, the EPA's on-scene coordinator at Wolff-Alport, a site at 1125 — 1139 Irving Ave., where the city has known of radioactivity since it did a study in 2007.

A 2009 EPA survey determined there was “no immediate risk to people, but that more evaluation was needed,” the agency’s spokeswoman Mary Mears said.

Some work done by Wolff-Alport was performed under contract to the Atomic Energy Commission and the Manhattan Project, a research and development program that produced the first atomic bomb during World War II, according to EPA documents. The company, which operated from the 1920s to 1954, imported monazite sand on a railroad spur behind the facility. Wolff-Alport processed the monazite to extract rare earth elements, leaving thorium and to a lesser degree uranium byproducts, according to the EPA.

"These waste byproducts were disposed of into a nearby sewer and other wastes may have been buried onsite," according to an EPA document released last month.

The EPA, the city’s Department of Health, the state’s Department of Health, and the state’s Department of Environmental Conservation all were unable to explain why the EPA is taking sudden action at the site.

“There has been further evaluation that led the agencies to determine the EPA should take the lead,” Mears said.

Daly and his colleagues are now building a fence on Cooper Avenue to stop people from entering the lot, and are testing various types of shielding (including placing steel plates and concrete on the sidewalk) to lower the levels of radiation for workers and customers at Primo Auto Body and Terra Nova Construction, he said.

They are also beginning radon testing of the site and of the nearby Audrey Johnson daycare center.

"We always look at kids’ places if they’re nearby. It’s precautionary,” Daly said of the testing at the daycare, which he said seemed too far from the site to be affected. “If we find higher-than-normal levels we’ll install a mitigation system for the air.”

Daly and other EPA officials, as well as a spokesman from the city’s Department of Health and Mental Hygiene, said no elevated radiation or radon levels had been found outside the site.

David Brenner, director of radiological research at Columbia University Medical Center, said the heightened radiation at the site did fall above the standard for the general public, but that the level was “not uncommon.”

The level of radiation for a worker would fall at 120 millirem (the unit used to measure radiation's effect on the human body) per year, 20 percent more than the recommended 100 millirem per year for an average person.

“A cleanup is clearly warranted,” Brenner said. "But I can see why it might not be considered a super-high priority situation.”

A worker at Primo Auto Body, for instance, would raise his chance of contracting fatal cancer by 1 in 25,000, according to the information available.

For workers at Wolff-Alport, as well as some local residents, the word of radiation and radon certainly warranted concern.

“I’m scared. I’ve worked here for two years but my husband has worked here for 14 years,” Hilda Rodriguez, assistant to Primo Auto Body’s manager, said in Spanish. “He’s had health problems and others say they’ve had heart problems, breathing problems. But we don’t know if it’s connected to the radiation.”

Rodriguez said the workers felt confused about the risk they encounter each day.

“They said they’re going to come to see if there’s a problem,” she said of the EPA workers.

When EPA representatives at a recent Bushwick Community Board 4 meeting asked residents to perform radon tests in their homes, neighbors who had never heard about the radiation issue grew nearly hysterical.

“This is the first time we’re hearing about this in 20 years, and if I hadn’t come to this meeting I wouldn’t have even known,” said Yvonne Gaffney, 55, who has lived the past 20 years down the street from the former chemical company. She noted that her relatives who lived in her basement had asthma.

“We’ll get a radon test, but if it comes out with a problem the city should help," she said. "We can’t just pick up and move.”

Officials noted that they had distributed fliers in the neighborhood for a recent information session about the radiation at a local public school, and that they would hold more meetings as the community requested. Daly noted that he would also speak at an upcoming Community Board 5 meeting in Ridgewood.

But for Vivian Lott, whose family has lived by the site the past 40 years, the news comes too late.

“Of course I’m concerned,” she said. “We’ve been here 40 years, and they hadn’t said a word.”