Babies are dying as you read this, says Tom Rodgers. "Gassed," is how he puts it on a Web site with alarming domain names: GassingAmerica.us, DeadlyFumes.us, HUDsToxicHell.us.

The problem, he says, is that HUD-manufactured homes — the millions of low-cost factory-built homes that fall under federal regulations — typically come equipped with furnace exhaust vents on the roof that are placed too close to the powered air-intake pipe. Under certain conditions — depending on wind direction and snow accumulation on the roof — the exhaust is sucked back in, he argues, and that means that carbon monoxide wafts unseen through the house.

Rodgers, a retired scientist, and his friend Jay Bishop, a retired chemical engineer, are adamant about this. For the past year they have doggedly tried to get the attention of state and local officials, as well as the U.S. Department of Housing and Urban Development, which oversees the homes.

To Rodgers and Bishop, it's simply a matter of common sense. You would never let a child play 3 feet from a car exhaust pipe, they argue, and yet HUD code allows the furnace exhaust vent to be located as close as 3 horizontal feet from the powered air intake. Most municipal codes put that distance at no closer than 10 feet (sometimes 12 feet) horizontally, or 3 feet vertically.

Despite a year of lobbying, their main success so far is an e-mail sent from HUD's office of press relations to the Deseret News, 10 months after the two men first contacted the federal department: "HUD has the matter under review. Based on the results of that review, it may be referred to the Manufactured Housing Consensus Committee for their recommendations."

According to HUD spokesman Lemar Wooley, Rodgers' inquiry is the first the department has received about the possible carbon-monoxide danger in HUD homes, although HUD has allowed the 3-foot vent-intake design for more than 30 years.

It's hard to know what to make of the lack of complaints. Does it mean that there haven't been any problems? Or that the problems have gone undetected and misdiagnosed? Like much in this saga, it's hard to tell what is proof and what is not. It's hard to know whether proof should matter.

One morning earlier this winter, Bishop and Rodgers were at the state Capitol trying to get some traction for their concerns. After trying unsuccessfully to get an appointment with Attorney General Mark Shurtleff, they ran into two members of the Bountiful City Council. Both Rodgers and Bishop live in Bountiful, so they were happy to see some friendly faces.

Bishop, who has a Ph.D. in chemistry, spent 20 years at the Tooele Army Depot, helping the military meet the requirements of the Environmental Protection Agency. Like Rodgers, his father was in the heating business. Rodgers, who once was a cattle rancher but now is a vegan, once worked as a pathologist.

"We're poisoning babies, right now, today," Rodgers told the Bountiful council members as they stood in the hall outside the attorney general's office. It's a sentiment Rodgers uses repeatedly. "We have dead people and sick people," he'll often say to anyone who will listen. All winter long he has walked the halls of the Capitol, trying to get the attention of lawmakers.

Rodgers and Bishop want the news media to alert the public so that people living in HUD homes can take some immediate temporary measures to solve the problem, and they want state governments to pass regulations to solve the problem permanently. They predict that HUD will never admit its code is dangerous.

Pressed for details, however, both Rodgers and Bishop have no hard data to prove that anyone has been killed or injured as a result of the HUD venting design.

Here's the problem: The lack of evidence could mean there have been no deaths or injuries, but it also could mean that carbon monoxide is a stealthy gas that produces symptoms so vague — flu-like headaches and nausea, chest pain, dizziness — that the people affected, and the doctors who treat them, don't blame the right culprit.

Hospitals do not routinely test for carbon-monoxide poisoning, so it's hard to get data. And low-level, chronic carbon-monoxide poisoning is even harder to detect than acute carbon-monoxide poisoning. Symptoms include depression and memory impairment, in addition to flu-like problems, according to David G. Penney, a professor at Wayne State University and an expert on carbon-monoxide poisoning.

The poisoning "is more often missed than found," says Penney. "It's not something physicians are trained in." A yearlong Rhode Island study published in 2008 in the Journal of Emergency Medicine, based on carbon-monoxide screenings of all emergency-room patients, estimated that as many as 11,000 cases of low-level carbon-monoxide poisoning go undetected each year in the United States.

"Chronic CO poisoning is often misdiagnosed as chronic fatigue syndrome, a viral or bacterial pulmonary or gastrointestinal infection, a run-down condition, immune deficiency, etc.," writes Penney on his Web site coheadquarters.com.

CT scans and MRIs generally show no lesions, he says, "even when neuropsychological and/or neurologic evaluations may detect functional deficits."

"I wouldn't want to live in a place where the separation (between the exhaust vent and supplemental air intake) is only 3 feet," Penney said in a recent interview. "Ten feet would be a minimal distance, as far as I'm concerned."

Penney, who has not reviewed the particulars of the HUD homes, is one of several professionals who have echoed Rodgers' and Bishop's general concerns, including former state Sen. Parley Hellewell of Orem, who owns a plumbing and heating company. But other experts are more cautious.

The odds of carbon monoxide poisoning because of the venting configuration are "incredibly low," notes Gordon Walker, director of the state division of Housing and Community Development. "But that doesn't mean it couldn't happen" under a "perfect storm" of weather conditions, he adds.

Rod Larson, industrial hygiene director of the Rocky Mountain Center for Occupational and Environmental Health in Salt Lake City, says that if he were building a house, he would want 10 feet between the exhaust vent and the air intake. But, he adds, the two men are making assumptions that aren't true.

Yes, Rodgers' Web site includes a video of exhaust being pushed, by a strong breeze, over to the air intake. But, Larson argues, "they're making assumptions that 100 percent of the exhaust is being picked up by the air intake. That's definitely never going to happen." Dilution with the ambient air would reduce the carbon monoxide in the exhaust to 1/100 of its original amount by the time it entered the house, he calculates.

You need to show some proof, Larson told the two crusaders; you need to provide carboxyhemoglobin tests of sick people, for example, and third-party evaluations showing how much carbon monoxide is actually being pulled into the homes. Otherwise, he says, "you're going to scare people," with no proof to back up the claims.

That's the response, too, from the Manufactured Housing Institute's vice president for regulatory affairs. "There has to be some documentation," Jeff Inks argues. "No evidence is being brought forward."

Rodgers and Bishop are frustrated by this Catch-22. They can't provide poisoning data because hospitals do not routinely test for carbon-monoxide poisoning, and nobody wants to spend money to test the homes. Larson guesses it would take at least $10,000 to do a proper third-party evaluation. "I'm operating on $750 retirement (income)," sighs Rodgers.

In his retirement Rodgers runs a nonprofit organization called LifeSave Biological Research, and he has many Web sites, on topics ranging from veganism to vaccines. Passionate and sincere, he tends to start his harangues in the middle, leaving his listeners struggling to catch up, often exhausted by his details. And sometimes his lobbying is unorthodox. Standing in Attorney General Mark Shurtleff's office one day, hoping to get an audience, he told the receptionist to tell Shurtleff he needs to "clean up his diet." He readily admits that he has angered ranchers and public health officials for his stances on veganism and fluoridation. Because some of the HUD trailers house illegal immigrant farm workers, his efforts to call attention to the venting problem has resulted in death threats, he says.

Rodgers and Bishop believe they do have one piece of evidence: the case of a baby named Daniel, the son of Dave and Mary Conrad of Manti. The Conrads live in a manufactured home, one of 9 million such occupied units nationwide.

Last winter, Daniel, then six months old, was sluggish and spit up constantly. He eventually ended up at Primary Children's Medical Center. Daniel was not tested for carbon-monoxide poisoning and was instead diagnosed with malnutrition, a thyroid problem and a rare genetic disease, Kabuki Syndrome, according to Dave Conrad.

Before Daniel was hospitalized, neighbors had contacted the Utah Division of Child and Family Services, concerned about Daniel's wan appearance. The Conrads believe that the neighbors were concerned because the Conrads are vegans.

The Conrads are friends of Rodgers. When he came to the hospital to visit Daniel, he says he knew right away that the family had been exposed to carbon-monoxide poisoning. Dave Conrad's face, Rodgers says, was jaundiced and showed signs of rosacea, two symptoms of the poisoning.

The division ordered the Conrads to adopt a treatment plan for Daniel that included extensive tests. When the Conrads failed to comply, they were initially charged with contempt of court, but the case was later dismissed following a hearing.

While not willing to comment on the specifics of the Conrad case, Dr. Ed Clark, medical director of Primary Children's Medical Center, says his hospital does not routinely test all patients for carbon-monoxide poisoning. "The cost-benefit level (of testing everyone) would be questionable," he says. "We do carbon-monoxide testing when it's indicated … It's something we do on a fairly frequent basis, especially in the winter and depending on symptoms."

Rodgers says he helped the Conrads fix the carbon-monoxide problem before Daniel was brought home from the hospital by tying a plastic bag over the air intake and instructing the Conrads to open a window one-half inch, on the side of the house opposite to the exhaust vent. (Carbon-monoxide detectors are helpful, says Bishop, but aren't foolproof: Some only go off when the carbon-monoxide level reaches 400 ppm, and by then a baby may already be dead, he says.)

Videos on the Web site DanielInTheLionsDen.us show a robust, energetic baby playing with his siblings seven months after his hospitalization. Daniel is now 16 months old and, according to his father, is healthy. Dave Conrad is convinced that his son's illness was caused by the closeness of the exhaust vent and supplemental air supply.

Dave Conrad says that the previous owners of the house had "a lot of unexplained health problems, including multiple miscarriages and a learning disability in one child. He says he has also visited 15 HUD homes in his neighborhood and that some of the people had "unexplained health problems."

"I don't care about retribution or whatever," Dave Conrad says. "I just want the public to be warned." He wants them to know that the problem is easy to fix, at least temporarily, with some plastic and duct tape.

Dave Conrad, Rodgers and Bishop are upset that local inspectors do not inspect HUD homes. Wayne Holman, Chief Investigator with the Utah Department of Occupational and Professional Licensing, explains that "local building officials don't really have any responsibility or jurisdiction" to inspect HUD homes, except to make sure that they have been properly set on their foundations and that plumbing and electrical systems have been attached properly.

Bishop has written a draft executive order that he hopes Gov. Jon M. Huntsman Jr. will issue, including the stipulation that "building safety inspectors must stop giving permits to HUD homes or those like them, until they are made safe."

Neither he nor Rodgers stand to make any money off their crusade. They don't even have any family members who live in manufactured housing. It's the poor and the disenfranchised, Rodgers says, that he wants to help: Mexican immigrants living in the homes, American Indians, people who can't afford to live anywhere else, babies.

"I'm just trying to save lives," he says.

E-mail: jarvik@desnews.com