BRIDGETON, Missouri - The 43,000 tons of radioactive waste and soil came from a top-secret initiative: The Manhattan Project, which built the atomic bombs America dropped on Japan in 1945.

In 1973, that waste ended up in an unlined landfill in Bridgeton, Missouri, a St. Louis suburb. Workers spread it to cover trash and construction debris. In 1990, the U.S. Environmental Protection Agency declared the West Lake Landfill one of the nation’s most contaminated sites requiring cleanup. Still, many who lived near the dump didn’t know about West Lake’s toxic history.

It wasn’t until 2012, when garbage was burning underground, that the landfill burst fully into public view. The stench smothered nearby neighborhoods. Parents shut their kids inside. Emergency responders drew up evacuation plans, worried the smoldering waste would cause a nuclear catastrophe. Residents mobilized, spotlighting stories of children dying from cancer. And they pressed waste-management giant Republic Services, the dump’s owner, to remove the radioactive waste. In 2017, HBO aired a documentary about their cause.

For all the radioactive publicity, though, Republic beat back neighbors’ claims. The nuclear waste is still there, and the government hasn’t said when a cleanup will begin.

In refuting neighbors’ complaints, Republic tapped an unlikely ally that U.S. corporations have leaned on for decades: a federal health agency set up to protect people from environmental hazards just like the West Lake dump.

A 2015 report by that small bureaucracy, the Agency for Toxic Substances and Disease Registry, did not identify any radioactive material outside the landfill. It declared that the landfill posed no health risk to the community and that radioactive gas would not leave the site. Its assessment contradicted findings from two sets of scientists: some hired by Missouri’s Attorney General and others from an environmental consulting firm working with residents. Republic still uses the ATSDR report to argue for a less expensive cleanup of the contamination, despite mounting evidence that the agency’s assessment was wrong.

Some residents told Reuters they resent the agency’s part in the drawn-out saga. Deborah Mitchell grew up in Spanish Village, less than a mile from the dump. She lost both parents to cancer and battled the disease herself. Dozens of neighbors have similar stories. Three cancer researchers told Reuters the number of cases in the neighborhood is worrisome and requires comprehensive study. That’s never been done.

“You just feel like you’re being gaslighted by your own government,” Mitchell said of the ATSDR’s role.

Republic Services, in an emailed response to Reuters questions, said it agrees with the ATSDR’s finding that the landfill poses no risk to the community. Its own experts reached a similar conclusion in 2015, it said.

The company has “always advocated for the responsible remediation of West Lake,” says the statement from Republic subsidiary Bridgeton Landfill LLC. The company has spent “tens of millions of dollars” studying the landfill and has “fully complied with every EPA directive.”

Also responsible for the site are mining firm Cotter Corp and the U.S. Department of Energy, manager of the U.S. nuclear weapons arsenal. The DOE declined to comment, and Cotter did not respond to questions about the cleanup plans.

Republic’s use of the ATSDR to argue for a less extensive cleanup of the West Lake Landfill is a strategy some companies wield at toxic sites across the U.S.

The ATSDR, part of the U.S. Department of Health and Human Services, is a public health agency that advises the EPA. It was created in 1980 by a landmark federal law that required polluters to clean up their toxic messes. The agency was meant to safeguard the public by identifying risks from those sites. Instead, it regularly downplays and disregards neighbors’ health concerns, a Reuters investigation found. Companies and other polluters wield the agency’s work against the people it is meant to protect.

The agency issued 428 reports containing 1,582 health-related findings from 2012 to 2023. In 68% of its findings, it declared communities safe from hazards or did not make any determination at all, a Reuters review found.

ATSDR’s record of finding little harm at the nation’s most contaminated waste sites strains credulity, said Judith Enck, a former regional administrator for the EPA. She is now president and founder of Beyond Plastics, a nonprofit that seeks to end plastics pollution.

“This is not at all surprising and why I advise community groups not to request ATSDR involvement,” she said. “ATSDR has a long history of minimizing environmental health problems, and that needs an independent investigation by Congress.”

'WE DIDN'T HAVE THE STAFF'

The agency’s frequent declarations of no harm often are rooted in faulty research, Reuters found. At least 38% of the time, agency reports show, its researchers relied on old or flawed data.

Reuters consulted with 15 sources with experience in environmental and public health for its analysis.

ATSDR officials did not respond to questions about its overall performance, errors in its work, or how polluters use its reports. In an emailed statement to Reuters, it noted that its report on the West Lake Landfill did identify one potential harm: that radioactive dust particles could be released if the surface of the landfill were disturbed. Those particles could be inhaled by workers and harm their health, the statement said.

“At the West Lake Landfill Site, ATSDR did not have evidence that residents were drinking landfill contaminated groundwater, eating or incidentally ingesting landfill contaminated soils, breathing landfill-related radon, or absorbing radiation emitted by landfill contaminants,” the statement said.

It is impossible to know how often the agency has been correct in declaring communities safe, because the search for harm often ends once the ATSDR reports its findings. Still, Reuters found at least 20 instances from 1996 to 2017 where the agency declared that a potential hazard posed no health risk – only to be refuted later by other government agencies or the ATSDR itself. Those reports relied on outdated or limited data, contained math errors or provided overly optimistic conclusions.

Patrick Breysse, who led the agency from 2014 until 2022, said that out of the hundreds of reports the ATSDR has published, 20 is a small number. And he noted that not all polluted sites are dangerous.

But he acknowledged that the agency often bases decisions on whatever information happens to be at hand rather than its own well-constructed studies.

“ATSDR often lacked the resources to collect data needed to fill in gaps in our understanding of the potential health risks,” Breysse said. “We didn’t have the staff.”

The agency told Reuters it uses “the best available science to protect communities from harmful health effects related to exposure to hazardous substances.”

“Because ATSDR is a non-regulatory federal public health agency, typically ATSDR relies on other agencies for environmental sampling data, including regulatory agencies such as the U.S. Environmental Protection Agency (EPA), whose purview is to perform environmental sampling,” the agency said.

Breysse highlighted instances in which the ATSDR has intervened to help the public. Among its successes, the agency’s recommendations helped prevent increased pollution from a proposed metal-recycling plant expansion in Chicago. It also helped identify a 2016 public health crisis in Flint, Michigan, where drinking water was contaminated with high levels of lead, triggering a federal emergency.

SEIZING UPON WEAKNESS

The Reuters analysis is the most comprehensive ever conducted of the agency, which has been the target of previous probes by Congress and the Government Accountability Office. Despite decades of criticism, the agency continues to publish research that relies upon practices its own review board, in a 2010 evaluation, called “virtually useless” and “not very good.”

Some companies have seized upon the agency’s weakness. They’ve used its research to fend off lawsuits, deny victims compensation, criticize their opponents, and argue to delay, reduce or cancel cleanup of their toxic messes. ATSDR’s work has helped polluters save at least tens of millions of dollars on cleanups, delayed billions of dollars in medical claims and exposed millions of people to potential harm.

In addition to Republic Services – the nation’s second-largest waste management operator – companies that have touted faulty ATSDR research include aerospace giant Boeing and Drummond Co Inc, an international coal company based in Alabama. The U.S. Navy and other government entities have benefited, too. (See related article.)

Their tactics follow a familiar corporate practice of trumpeting flawed science. The tobacco industry touted shabby research to claim cigarettes were safe. The fossil fuel industry used the strategy to call climate change a myth.

Republic began leveraging the 2015 ATSDR report about West Lake the day it was released. The trash giant had formed a group called the Coalition to Keep Us Safe to assert grassroots support for capping the radioactive waste rather than removing it. Republic says this cheaper option poses fewer potential health risks. The coalition blasted social media with the health agency’s conclusions. The coalition’s leader, Molly Teichman, taunted local activists through her personal account on Twitter, the social media platform since rebranded as X.

“Dear mombots of #westlakelandfill, your reality tv show is over," she tweeted. "Go home and hangout with your kids – they miss you."

The posts were deleted after Reuters attempted to contact Teichman, who did not respond to multiple requests for comment. Republic Services sent Reuters a written statement disassociating the company from her remarks.

“These comments were not in alignment with our views, objectives or approach,” the statement said.

Using the agency to defend polluters isn’t what lawmakers intended when they wrote the 1980 Comprehensive Environmental Response, Compensation, and Liability Act, commonly known as the Superfund law, said Rena Steinzor, a former congressional staff counsel who advised the law’s authors after it was enacted.

“It is a perversion,” said Steinzor, now a law professor at the University of Maryland. “I’m saddened but not shocked they’ve been subverted.”

'HIGHLY SUGGESTIVE OF A PROBLEM'

In June 2006, Deborah Mitchell returned to her childhood home in Spanish Village to help her father after her mother, Janice Majka, died of pancreatic cancer at age 64.

Mitchell, who wasn’t feeling well herself, says she went for a run in the neighborhood and stopped to use the restroom at a hotel. What she saw there scared her. First, blood in her stool. Then a notice about an EPA meeting to discuss radioactive waste buried in the landfill.

She was shocked. Mitchell and other kids grew up playing in the dirt around Spanish Village, a hilly enclave of cul-de-sacs, carports and above-ground swimming pools. She and others talk of riding their bikes to climb a giant pile known as Sand Mountain. They swung from a vine into a creek that flowed downhill from the direction of the landfill toward their homes. At the edges of the dump, they dug for Native American beads and arrowheads. They’d be so dirty when they got home, they’d have to hose off before going inside.

Mitchell attended the EPA meeting in 2006 with her father and asked the small gathering how many had cancer. Five people raised their hands, she says. Within a year, she and her father would be among them.

In July 2006, at age 38, Mitchell was diagnosed with colorectal cancer. The following year, her father, Robert Majka, a nonsmoker, was diagnosed with lung cancer at age 68. Around the same time, Valerie Shelton, a 59-year-old who lived across the street, was diagnosed with kidney cancer.

Mitchell’s father died in 2008, Shelton in 2013. In the houses surrounding them, five other neighbors died of cancer between 2019 and 2022.

Though Mitchell’s cancer has been in remission for more than a decade, she suffers from multiple sclerosis. There is no evidence linking the autoimmune disease to environmental radiation exposure, but she and other residents worry that could be the cause. Her health problems and frequent doctor visits make it impossible for her to work full time. Once an extremely active woman and avid cyclist, she now struggles to walk.

Reuters reporters tracked down current or former residents of half of the 92 homes in Spanish Village. At least 33 of those people have been diagnosed since the 1980s with cancers covered by the Radiation Exposure Compensation Act, a federal law that has compensated people exposed to nuclear waste from early atomic weapons programs. To verify the cases, reporters interviewed family members, friends and neighbors and reviewed medical records, death certificates, obituaries or social media posts.

Proving the existence of a cancer cluster is difficult, if not impossible, cancer researchers say, even when there's a glaring suspected cause such as radiation. That's because many factors are at play, including genetics, people moving in and out of areas, and duration of exposure to various carcinogens. Scientists also don’t fully understand what causes cancer.

Still, the Reuters finding of 33 cancer cases in Spanish Village is “highly suggestive” of a problem, said Sarah Chavez, a public health scientist at Washington University in St. Louis who reviewed the news organization’s research. Chavez heads the Missouri Cancer Consortium, a group that studies and tracks cancer disparities.

The health of people living near the landfill has never been comprehensively studied. In its statement to Reuters, Republic’s Bridgeton subsidiary pointed to a 2014 state review of cancer counts among current residents. It found some zip codes near the site had higher-than-expected rates of adult leukemia or childhood brain cancer. The study did not find elevated cancer rates in the zip code that includes Spanish Village. Chavez said the 2014 report covered too few illnesses and failed to track residents such as Mitchell who had moved away.

Testing of dust samples in Spanish Village homes resulted in dueling results, each the subject of criticism from opposing parties. Republic points to a 2017 EPA-funded study of dust samples from two Spanish Village homes, which reported no radiation from the landfill. But another scientist found high levels of radioactivity in at least eight Spanish Village homes. He conducted some of his testing for plaintiff’s attorneys.

Many in the community interviewed by Reuters recalled their hopes that the ATSDR would bring relief. But the agency’s 2015 report about West Lake said the community was not exposed to radiation from the dump. It did not investigate concerns about cancer and other illnesses.

In its statement to Reuters, the ATSDR said it relied on data the EPA provided in 2015 to form its conclusions about the landfill.

Earlier this year, led by Sen. Josh Hawley of Missouri, the U.S. Senate approved federal legislation that would compensate residents near the landfill as part of a $50 billion program for victims of Manhattan Project radiation. President Biden vowed to sign the bill into law if it passes the House, but Speaker Mike Johnson has not scheduled it for a vote.

“Locals have been telling the government that its studies were wrong for years,” Hawley said in an emailed response to Reuters questions. “The ATSDR’s faulty findings just underscore the blatant negligence at play here.”

'DOUBT IS WHAT THEY WANT'

The ATSDR is responsible for evaluating health hazards at Superfund sites. It is supposed to help prevent or reduce exposure to those hazards and the illnesses they can cause. The agency issues findings and makes recommendations for reducing risk, but it has no rule-making or regulatory authority.

The EPA, which does have regulatory authority, determines how much waste polluters must clean up at Superfund sites. It considers the ATSDR’s findings and recommendations when making those decisions.

The reviews have the potential to protect the health of millions of Americans. Approximately 78 million live within three miles of a Superfund site.

From the outset, two influential industry groups became unlikely champions of the agency. The Chemical Manufacturers Association and the American Petroleum Institute joined an environmental group in a 1982 lawsuit to force the federal government to create the ATSDR. Its work, they said in court filings, was important to determine whether contaminants were making people sick.

In reality, however, studies of pollution often yield inconclusive results about risks to human health. Using that uncertainty to deflect regulation and liability is a long-standing corporate strategy, six professors who study corporate influence on public health told Reuters.

In the case of toxic waste sites, weak and inconclusive ATSDR reports give polluters authoritative, government-backed uncertainty to argue against extensive cleanups, Reuters found.

Spokespersons for the two industry groups that joined the 1982 lawsuit declined to comment on the case because it was filed so long ago.

“The last thing industry wants is an effective ATSDR that can say with more precision how dangerous these chemicals are,” said Thomas Burke, who was deputy assistant administrator of the EPA’s Office of Research and Development until 2017. Burke helped write the 1980 Superfund law and now teaches at Johns Hopkins University’s School of Public Health.

“Doubt is what they want,” Burke said.

Republic Services took exception to Burke’s assessment. “Bridgeton Landfill, LLC wants an effective ATSDR that helps the public understand who is truly exposed and who is not, and what genuine risks exist and do not exist,” a company spokesman said in an email to Reuters. “We believe ATSDR has done that at West Lake."

By 1993, the Washington Legal Foundation was encouraging industry to get involved in the ATSDR’s process to try to influence the agency’s health assessments. Funded by companies like Koch Industries and Philip Morris, the legal organization has filed briefs in lawsuits supporting companies like Exxon and Monsanto.

In a 1993 publication, the WLF said that tough ATSDR assessments could be costly for industry but that “early participation” in ATSDR reviews “can be highly advantageous.” The WLF noted that some reports had led to less extensive cleanups.

That same year, the foundation held an off-the-record luncheon for industry titled, "How to Minimize Superfund Liability by Successfully Handling the ATSDR Health Assessment Process.” Among the promoted speakers: Barry Johnson, then ATSDR’s assistant administrator. In recent interviews, Johnson said he does not remember the event or efforts by industry to influence the agency.

The WLF declined to comment on its earlier activities and said the ATSDR is no longer a focus for the organization.

Agency employees meet often with industry representatives while collecting information for assessments, said Burt Cooper, who retired in 2016 after 20 years as an ATSDR environmental health scientist. It was not unusual for companies or the military to pressure the agency, he said, though he could not recall specific incidents.

“You get beat up,” Cooper said. “These are high-paid attorneys, and you’re there trying to do the best you can with more meager resources.”

Despite the pressure, Cooper said agency officials never directed him to make a change in a report that wasn’t based on public health. “I was very proud of the ethics and devotion to public health that the agency had,” he said.

OUTSIDE INFLUENCE

A 2008 congressional inquiry into the ATSDR’s performance found that industry and political influence was contributing to deficient research. Among the examples the committee found: The ATSDR bowed to pressure from a company executive and elected officials while studying contamination from a Brush Wellman beryllium plant in Elmore, Ohio.

The multinational company, now called Materion, is the sole U.S. producer of beryllium, a soft metal used in the aerospace, automotive and other industries. In 2006, the company was considering expanding its Elmore plant.

Beryllium is a carcinogen and can also cause lung disease. At the request of then-U.S. Sen. Mike DeWine, the ATSDR assessed air emissions from the plant in 2001 and found no health concerns. But the report's authors said more work was necessary to be sure. In 2006, the ATSDR announced plans to test blood from up to 200 people in the community to look for signs of exposure to the metal.

The company’s president and chief operating officer, Richard J. Hipple, didn’t like that plan. He wrote to DeWine and then-Governor Bob Taft.

The ATSDR’s plans “are likely to seriously damage Brush Wellman’s reputation in the Elmore community, unfairly elevate concerns about potential beryllium health effects … and increase the likelihood of litigation by plaintiff’s lawyers using the ATSDR as justification,” Hipple told DeWine in a March 2006 letter reviewed by Reuters.

After hearing from Hipple, Taft sent a handwritten note to the secretary of the U.S. Department of Health and Human Services. Taft complained that the ATSDR’s actions could dissuade Brush Wellman from expanding the plant. “Please have someone look into this and get back to me,” Taft wrote.

Brush Wellman announced its decision to expand in Elmore in September of that year. In November, the ATSDR announced that it had tested the blood of 18 people – 91% fewer than it had planned before politicians intervened. The tests showed no major health issues linked to beryllium from the site, the agency reported.

The agency’s approach was “scaled back significantly” based partly on concerns raised by elected officials and the company, according to a 2006 ATSDR document titled "ATSDR Brush Wellman Background Paper."

Emissions at the company's Elmore plant have remained "well-below" state and federal safety regulations for decades, said Materion spokesman Jason Saragian. He said the company could not speculate about past events.

DeWine, Hipple and Taft declined to comment on the 2006 events.

FINDING ‘NO EFFECT’

The Reuters review of 428 agency reports found the agency commonly cites outdated data and often lacks adequate air, water and soil samples. In 83 reports, the agency based assurances of no harm on studies, samples or equipment it admitted were flawed. This includes its West Lake Landfill report. Despite acknowledging the use of faulty equipment to collect air samples, the report said those samples showed no radiation leaving the site.

The lack of accurate and current information makes it difficult to reach definitive conclusions about health risks, more than a dozen independent scientists told Reuters.

“The methods they use and assumptions they apply often result in studies that find no effect,” said David Michaels, an epidemiologist at the George Washington University School of Public Health.

Breysse, the former ATSDR director, said the agency’s lack of adequate funding makes it a challenge to conduct more thorough studies. The agency will operate with $86 million this year and a staff of roughly 200 workers – half the number it had in 2004, federal payroll data shows. It responds to about 700 requests a year to address health risks. The companies it examines often dwarf ATSDR: Republic Services has about 42,000 employees and posted revenue of $15 billion last year.

When the agency receives resources, it can do groundbreaking work, Breysse said. He cited its work to link contaminated drinking water to cancers and other illnesses suffered by Marines and civilians who worked at the Camp Lejeune military base in North Carolina. The Camp Lejeune studies, which began in 2014, cost about $40 million, according to congressional testimony and federal contracting data. That is equal to about half the agency’s annual budget. It took an act of Congress, followed by threats from two North Carolina senators, to force the U.S. Navy to fund the work.

The agency rarely receives such support at other sites. Even with this political backing, Breysse said the Defense Department tried to dictate how to conduct studies at Camp Lejeune and insisted on seeing all findings in advance. “We had to fight to maintain our independence,” Breysse said.

The Defense Department declined to comment for this story, referring questions to the Navy. The Navy did not respond to questions about whether it tried to influence the ATSDR’s work on Camp Lejeune.

The agency’s finding meant up to 1 million former base residents and workers now have an opportunity for compensation. Still, the Camp Lejeune report came long after a flawed ATSDR report in 1997 in which the agency declared the water did not harm adults.

‘LIVING IN A GRAVEYARD’

The Missouri Attorney General sued Republic Services in 2013, accusing the company of allowing toxic, black water to run off the landfill and emitting highly offensive odors and hazardous substances into the air. In October 2015, the ATSDR published its report declaring that radioactive material in the West Lake Landfill had not left the site and posed no significant risk to the surrounding community. Two weeks later, Republic Services filed 15 expert reports in defense of the suit. Five mentioned the ATSDR health assessment.

Two press releases on a Republic website use the ATSDR report to buttress the company’s own scientific reports that declare the landfill safe. The federal public health agency “concluded that ‘groundwater, air, and soil data do not indicate a health risk to communities surrounding West Lake Landfill,’ ” one release says.

The EPA also embraced the report. Nine days after it came out, the St. Louis Post-Dispatch published an opinion piece by the EPA’s then-regional administrator, Mark Hague.

“I want to assure you that we at the Environmental Protection Agency are committed to protecting public health from the radiological contamination buried at the West Lake Landfill,” Hague wrote. “Recently, the federal Agency for Toxic Substances and Disease Registry completed a health consultation for EPA that confirmed there is no current offsite health risk.”

In a recent interview with Reuters, Hague said he understands the community concerns but is confident the site is being managed appropriately. “I think the EPA are working really hard to get this site remedied,” he said.

Less than two weeks after publication of Hague’s opinion piece, the Missouri Department of Natural Resources, working with the EPA, found soil contaminated with radioactive material at a private business near the landfill. It had been carried there by rainwater, said Christine Jump, EPA remedial project manager for West Lake. The area was covered with rock to prevent exposure. The EPA has found other contaminated soil and groundwater near the site and says it is still assessing potential risks.

The EPA’s cleanup plan has evolved as it received results of new scientific testing, agency officials told Reuters. They said they are aware of community concerns, but based on air, soil and water testing they are confident that radioactive material in the site “as it sits today” does not pose a harm to nearby residents. Conditions at the site could change, they said. And they have not finished a health analysis of groundwater outside the landfill where they found elevated levels of radium and dioxane. The EPA classifies the solvent as a likely carcinogen. It can damage the central nervous system and kidneys.

Republic, in its responses to Reuters, said the groundwater samples appeared to contain “naturally-occurring” radium “consistent with other groundwater in the region.” EPA officials told Reuters that Republic lacks enough information to make such a claim. Ongoing testing is meant to determine if radium detected in surrounding groundwater is coming from the landfill.

Republic says none of those tests show unsafe levels of radiation that would cause people harm. The company continues to cite scientific studies, including the 2015 ATSDR report, as evidence that there is no need for a full cleanup.

Some current and past residents nearby don’t buy it. Melissa Mitchell – unrelated to cancer patient and neighbor Deborah Mitchell – moved with her two children into a three-bedroom ranch in Bridgeton in 1994. Eight years later, she was diagnosed with Grave’s disease, a thyroid condition. Her son developed a benign tumor the size of a tennis ball on his femur in 2012. Her dog died of stomach cancer. Mitchell wonders if all of their maladies were caused by radiation exposure.

Over the years, she says, she watched as neighbors fell ill all around her – next door, across the street, catty corner to her house. In five houses on the block, 10 people had cancer.

“I felt like I was living in a graveyard,” she told Reuters.

The EPA says it is now considering a plan that would require Republic and the other responsible parties to remove 94,200 cubic yards of radioactive-contaminated waste. That’s enough to fill 82 Boeing 747s.

Thirty-four years after the landfill’s designation as a Superfund site and more than eight years after the ATSDR published its report, the waste remains and trash continues to smolder underground. Because more off-site contamination has been uncovered, EPA administrators told Reuters they don’t know when the cleanup will begin. They say they hope it will be in the next decade.

HOW REUTERS IDENTIFIED WEAKNESSES IN A US HEALTH AGENCY'S WORK

It is a little-known federal health agency with an unfamiliar name: the Agency for Toxic Substances and Disease Registry. Congress conceived it as part of the 1980 Comprehensive Environmental Response, Compensation, and Liability Act, commonly known as the Superfund law, meant to hold polluters responsible for the nation’s most toxic messes.

The law requires the agency to identify potential health risks at such sites to protect the people living and working around them. Reuters reporters had encountered several examples of the ATSDR failing its mission and decided to take a closer look.

To assess the agency’s work, they reviewed 428 health reports published on its website between 2012 and 2023. Those reports contained 1,582 conclusions regarding potential harms at Superfund sites or other concerns brought to the agency by communities or government agencies.

The agency often produces the reports in partnership with state agencies.

Reporters examined the ATSDR risk classification listed for each finding and categorized the conclusion: harm or potential harm found, no harm or no potential harm found, inconclusive findings. A handful of findings could not be categorized.

Fifteen people with expertise in environmental and public health vetted the Reuters methodology. They included former ATSDR employees, and state environmental health officials, academic researchers and community health advocates.

The data collected from the reports, available for download here, enabled the reporters to document:

-- How frequently the agency declared potential health hazards, found no hazard or failed to issue a conclusive finding.

-- How often the authors used outdated data to support their findings.

-- Reports in which the authors detailed serious limitations in the data or analysis that undermined their conclusions.

Reporters flagged reports for using outdated data when conclusions relied on data that was at least four years old. No federal standard exists for how fresh data must be to support health assessments like those the ATSDR produces. But generally, relying on data four years old or older would result in questionable findings, five public health and environmental regulatory specialists told Reuters.