Four researchers from government and academia told a panel of U.S. senators on Aug. 3 that exposures to environmental toxins are a likely cause of autism in genetically predisposed individuals.

"ASDs [Autism Spectrum Disorders] could result from a variety of factors, including combinations of genes, environmental exposures and gene-environment interactions," EPA's Assistant Administrator for Research and Development and Science Advisor Paul Anastas said in a written version of his remarks to the Senate Environment and Public Works' Subcommittee on Children's Health.

MOUNT VERNON, IND. -- Lisa Roach is alive with memories of Rozella Stewart. Until she entered Roach’s 26-year-old son’s life, no one quite knew what to do with him. Travis was the first autistic student in the local school system. He could talk and read like the other kids, but he couldn’t sit still and presented all sorts of challenges.

After Travis was finally diagnosed with autism at age 8, Stewart, who in the early 1990s headed the Institute for Study of Developmental Disabilities (ISDD) at Indiana University, delivered the Roach family one of its first glimpses of hope when she brought a team of experts to town to educate the educators about autism. Her tongue-in-cheek predictions of when the family’s life would settle down elicits a belly laugh today from Roach, who laughs long, hard and often when discussing life with Travis.

MOUNT VERNON, IND. -- Every conversation I've had with parents of autistic Americans has been riddled with salient moments, when essential truths are revealed about this extraordinarily complex developmental disorder. "Ah ha!" moments, so to speak. Such was the case with my July 2 conversation with Lisa Roach, who lives just outside the Ohio River town of Mount Vernon, Ind.

I had driven to the Posey County capital with Bloomington Alternative intern Megan Erbacher, who had grown up just down the road and has been friends with Roach's daughter Chelsea since childhood. Stan and Lisa Roach's oldest, 26-year-old Travis, has Asperger's Disorder, which is commonly known as "high-functioning autism." While his symptoms had been evident for years, Travis wasn't diagnosed until he was 8. At that time, Lisa learned her son was the first autistic child in the Mount Vernon school system.

ROCKPORT, IND. -- Crossing the Ohio River into Indiana from Owensboro, Ky., travelers are greeted with an image far more symbolic of Hoosier life than the tiny little "Indiana Welcomes You" sign that greets them now, or the billboards that dot Southwest Indiana highways featuring Abraham Lincoln, who spent part of his childhood just a few miles to the west of the William H. Natcher Bridge.

Indeed, the Hoosier state's howdy dominates the horizon a couple hazy miles before the bridge, when fat plumes of opaque-white air pollution from the Rockport Power Plant first appear. The coal-fired plant's twin cooling towers greet passing motorists with a hearty, "Welcome to Indiana, Land of Pollution." Minutes up U.S. 231, the box-like AK Steel plant rises just off the roadway to the east, adding an exclamation point to the greeting.

Between them, these two industrial facilities told the U.S. Environmental Protection Agency (EPA) that they released nearly 26 million pounds of toxic chemicals into the air, water and land in 2008. In their Toxic Release Inventory (TRI) reports to EPA, AK Steel reported 19.1 million pounds, American Electric Power's Rockport plant 6.7 million.

I spent the past week organizing and reviewing my research on the connections between autism and the environment, which once again reminded me just how little anyone -- experts, doctors, parents, journalists, whoever -- actually knows about the subject. The only truth I’ve found in almost two years immersed in the subject is that definitive answers to the most fundamental questions about autism -- What is it? What causes it? What can be done about it? -- are virtually nonexistent.

On a journalistic level, that’s pretty damned exciting. There’s always something new to explore and write about. But on a societal level, it’s downright scary. Take the what-is-it angle. Here we have a range of mental disorders that, depending on how the spectrum is defined, impacts the lives and families of roughly one out of every 100 American children. Scientists and experts have studied it for more than 70 years. And yet, they haven’t even agreed to a firm diagnosis.

After having endured multiple viewings of the PBS documentary "The Vaccine War" and reconstructive surgery on my right knee in recent weeks, I can't say emphatically enough what a breath of sweet, clean oxygen it was to find a copy of Philip and Alice Shabecoff's book Poisoned for Profit in my P.O. box when I got out of the hospital.

The book, the subtitle of which is How Toxins Are Making Our Children Chronically Ill, is no feel-good read, to be sure. Not by any stretch. But it serves as a reminder that there are honest, truth-telling journalists out there who engage their craft the way it's supposed to be engaged.

The Shabecoffs are not stenographers to power, a role the FRONTLINE documentary on vaccines and autism and the mainstream media play so well and so profitably. They're don't regurgitate what experts or focus groups say and call it journalism. No, they seek out, recognize and tell the truth as they find it, as the facts and common sense dictate, despite the fact that their message is one that few humans understandably can, or want to, wrap their heads around.

A new U.S. Environmental Protection Agency (EPA) study lends support to the argument that some children are susceptible to autism as a consequence of their exposures to environmental toxins.

At least part of the dramatic increase in autism diagnoses the past two decades cannot be explained by improving and expanding diagnostics, Michael E. McDonald and John F. Paul from EPA's National Health and Environmental Effects Research Laboratory conclude in a seven-page study in the March 15 issue of the journal Environmental Science & Technology.

"From a precautionary standpoint, it seems prudent to assume that at least some portion of this increase in incidence is real and results from environmental factors interacting with susceptible populations," they wrote in the paper titled "Timing of Increased Autistic Disorder Cumulative Incidence."

When J.B. Handley told me about Jackson County, Ore., a few weeks ago, I wondered why no one had looked at autism rates there. The county of about 200,000 located just north of the California border has one of the largest populations of unvaccinated children in the nation. And, as Handley suggested, those kids' medical histories are natural subjects for studies on the cause-effect relation between autism and vaccines.

Well, as I contemplated whether I might find a way to follow up on this angle from 2,000 miles away, I learned that the PBS series FRONTLINE will air a documentary titled "The Vaccine War" this Tuesday, April 27, that will explore not only the conflict between the vaccine industry and parents who believe immunizations caused their children's autism, but also the situation in Jackson County.

In a news release on "The Vaccine War," FRONTLINE says it will lay bare the science of vaccine safety and examine the "increasingly bitter debate" between the "public health establishment" and a "formidable populist coalition of parents, celebrities, politicians and activists."

J.B. Handley concluded long ago that mercury is but one component in childhood vaccines that could be contributing to the epidemics of autism and developmental disabilities in American children. And after following two decades of ferocious debate and misdirected, inadequate study, he finds the topic a bit outmoded, the question a non sequitur. He answers it with a series of questions.

"Do I know that it and it alone is why we have all these kids with autism?" the co-founder of Generation Rescue said of mercury, a neurotoxin used for decades in childhood vaccines. "... How am I supposed to know whether it was the (mercury-laden) thimerosal, the aluminum, the antigen, the timing of the shot, the combination of the shots or all of the above? How in the world could I divine that?"

The studies that have been done on these questions were conducted for the wrong reasons, Handley said. And the children whose regression into autism corresponded with their vaccinations have not been studied at all. In fact, they have been deliberately avoided.

Nothing makes J.B. Handley laugh more quickly than the suggestion that he and other parents who question the safety of the American vaccine schedule are "radicals." The Portland, Ore., businessman is a managing partner in a leverage buyout fund. And when it came to vaccinating their first two children, he and wife Lisa religiously followed the vaccination schedule set by the Centers for Disease Control (CDC) and American Academy of Pediatrics (AAP).

"We were as mainstream as they come," the father of three said during a telephone interview. "We were the ones who followed the letter of the law."

Questioning their doctor about the risks of vaccination never occurred to them, Handley continued. The same goes for hundreds of parents he has spoken with who watched their children's health steadily decline following their vaccinations, eventually regressing into autism, like 7-year-old Jamie Handley did as an infant.

"Almost to a person, we were the ones who fully vaccinated," he said. "You know?"