Public housing authorities across the country have refused to find and remove radioactive gas from inside tenants’ homes, leaving children, senior citizens and other vulnerable people unnecessarily exposed, an investigation by The Oregonian/OregonLive has found.

While Denver has done some testing for carcinogenic radon, 70 percent of its public housing units have yet to be checked. When testing by The Oregonian/OregonLive found high levels in specific units that Denver hasn’t tested, the housing authority said it wouldn’t follow up.

Radon seeps in through flooring and is the second-leading cause of lung cancer in the United States, killing an estimated 21,000 Americans each year. Federal health officials declared indoor radon a “national health problem” more than 30 years ago.

But local housing authorities ignored the danger.

And the U.S. Department of Housing and Urban Development let them, disregarding a decades-old legal mandate from Congress to ensure the problem got fixed.

The Oregonian/OregonLive distributed test kits in Denver to tenants last year as part of a national investigation into carcinogenic radon in public housing.

In two rounds of testing, three apartments at the Westridge Homes development just west of downtown Denver had radon above the level radon contractors say calls for specialized ventilation systems to remove it. The threshold is set by the U.S. Environmental Protection Agency.

Separately, two units at Quigg Newton Homes in Sunnyside tested high on one out of two tests. The Denver Housing Authority’s executive director, Ismael Guerrero, dismissed the testing by tenants because it wasn’t performed by a radon professional.

“We’re not going to comment on those test results,” Guerrero said.

Guerrero said Denver will follow its existing plan to look for radon when buildings come up for major renovations. The schedule runs past 2025, agency records show.

Norma Flores, 69, lives in a unit the Denver Housing Authority won’t check on even after being confronted with positive radon results. Flores deployed radon test kits at her Westridge apartment and found radioactivity at double the level the federal government says should be fixed.

“I’m really concerned,” said Flores, who moved in 15 years ago after a sickness left her unable to work. “Scared to death, actually.”

Guerrero, the housing authority’s executive director, said he had “no immediate knowledge” that radon was present in units occupied by Flores and others — even after the newsroom shared its findings with him.

The Denver Housing Authority has itself discovered radon in the past. Spokeswoman Stella Madrid told the newsroom in 2018 that Denver had not tested public housing for radon and there were “no prevalent issues” in apartments owned by the housing authority.

But the agency changed its story this year, saying Denver had, in fact, done some radon testing. And documents obtained through an open records request show the housing authority turned up big problems.

Radioactivity in a maintenance storage room in the basement of a public housing tower, the Thomas F. Connole, just west of City Park, was 177.1 picocuries per liter, 44 times the federal action level. That was in 2005.

Two of four units sampled at Westwood Homes, on South Irving Street, had high radon levels in 2010. Even after crews installed a radon removal system throughout the complex, new testing two years later still found one unit above the federal standard.

And in 2013, the agency tested a set of apartments on South Lowell Street. Officials found high radon levels in 21 of the 28 units tested. While those discoveries prompted repairs, Denver has yet to conduct any testing across most of its public housing units.

Guerrero said it will happen when buildings are renovated.

“We feel we are being proactive in addressing this across the entire portfolio,” Guerrero said.

Robert Minty, 64, said the housing authority should have already checked his building and the many others that await the housing authority’s action. The apartment where Minty and his grandson live averaged 5 picocuries of radioactivity over two tests, just above the federal action level.

Professional radon testing typically costs about $60, and a radon removal system costs roughly $1,500 to $2,500 per public housing unit, according to one industry expert.

“As low cost as it is, they could have done the testing out of wasted money,” he said.

More than 400,000 public housing residents live in areas that, like Denver, are at gravest risk for indoor exposure to the carcinogen, according to an analysis of federal data by The Oregonian/OregonLive. As many as half of all tests from private homes in these areas reveal radon concentrations so high that owners are advised to install specialized ventilation systems. Tens of thousands have done so.

But when it comes to homes the government owns for the benefit of America’s poorest families, officials in radon hot zones commonly do not test, according to the media outlet’s reporting on 64 local housing authorities nationwide.

In three cities where authorities tested only occasionally, only in the 1990s or not at all, The Oregonian/OregonLive and affiliates of its corporate parent, Advance Local, readily found high levels of radon. One location was an in-home day care. Others were home to elderly people who’d breathed the air for years.

Housing agencies can neglect radon because HUD doesn’t require them to do testing on the nation’s 1 million public housing units. The most the federal housing department did was to “strongly encourage” housing authorities to test in 2013.

HUD never bothered to see if anyone listened. So The Oregonian/OregonLive checked. The newsroom contacted housing agencies from Portland, Oregon, to Portland, Maine, spanning 26 states and nearly 125,000 units of public housing. Reporters distributed test kits to public housing residents and filed dozens of public records requests with housing authorities, reviewing thousands of pages of congressional records, HUD documents, federal radon studies and local agencies’ testing results.

The effort took more than a year, producing the only national picture of radon efforts by public housing authorities and HUD.

The investigation found that:

HUD shrugged off requirements set by law. Congress in 1988 ordered the agency to write a policy ensuring public housing tenants “are not exposed to hazardous levels of radon.” HUD leaders did not deliver even after government auditors admonished them for failing to meet the basic requirements of the radon law, repeatedly missing deadlines and making promises they didn’t keep.

The housing department tossed aside its own 2013 advice encouraging radon testing in public housing. During the five years following that recommendation, HUD did not test a single apartment owned by the 10 troubled local housing authorities that it operated directly.

Local housing authorities show little interest in tackling radon, despite concrete evidence the danger is real. Fewer than one in three agencies surveyed by the newsroom could provide testing records showing they looked for radon as of last year. Most that did test found high radon levels in at least one home or common space. Two agencies have discovered more than 100 units containing radioactive air.

Informing tenants is a low priority. In Oregon, Portland’s housing authority requires workers to tell a supervisor if they plan to spend more than five hours in an apartment with radon inside. They’re told to open all windows and bring in a fan to circulate air. But when the housing authority discovered radon in dozens of units earlier this year, residents who breathed the air all day long weren’t given any such advice. In fact, many first learned about the test results from a reporter.

Some housing authorities neglect to eliminate the radon they find. As with Maine, officials in Omaha and Pittsburgh didn’t fix units that tested high until being questioned about it by The Oregonian/OregonLive. Pittsburgh’s housing authority blamed poor internal communication amid a leadership change. “It wasn’t really brought to the level it should have been,” Chuck Rohrer, a housing authority spokesman, said in 2018.

The Portland, Oregon housing authority has recently changed its policy to say a tenant must be notified within six weeks of a high test result.

At HUD, officials declined repeated requests to make Secretary Ben Carson available for an interview and did not respond to written questions. But the agency has taken action since the newsroom began its inquiries last year.

Federal officials in September proposed rules to require radon testing in one narrow situation: when housing authorities renovate a public housing development and switch the type of subsidy that pays the rent. An estimated 100,000 units are expected to fall into that category in coming years, about 10 percent of public housing.

Separately, HUD formed a radon “workgroup,” spokesman Brian Sullivan said in early October. The agency was “very close” to an announcement that would be shared with housing authorities nationally, said Sullivan, who has since left HUD.

“We have to give credit where credit is due,” Sullivan said at the time, “even if it means getting a kick in the pants from The Oregonian.”

The agency would not say what new policy changes, if any, it planned to make.

Read The Oregonian/OregonLive’s full report at oregonlive.com/radon. Contact reporter Brad Schmidt at bschmidt@oregonian.com and Denver Post politics editor Cindi Andrews at candrews@denverpost.com with questions or information.