This is the time of year when classroom responsibilities overwhelm my journalistic passions, and my writing tends to be more reflection than exposition. And let me tell you, nothing spurs reflexive contemplation like finding yourself in polar opposition to someone whose life work has profoundly influenced your own.
In my case, that someone is Dr. Philip J. Landrigan from the Mount Sinai School of Medicine, whose research at the Children's Environmental Health Center there first caught my attention in the late 1990s when I was a senior environmental writer at the Indiana Department of Environmental Management (IDEM). When I began exploring the links between toxic pollution and autism 17 months ago, a 2006 study Landrigan co-wrote titled "Developmental neurotoxicity of industrial chemicals " was the first link that Google produced when I searched for "autism and environment."
Nearly a year and a half later, I am persuaded that mercury and/or other chemicals in vaccines are among the industrial chemicals that caused the autism epidemic of the past two decades. I do not believe that vaccines caused the epidemic, but my work has convinced me that neurotoxins in them contributed to it. And in some children, they did cause autism. The question for them isn't whether, it's how, and it demands an answer.
"I do not believe that vaccines caused the epidemic, but my work has convinced me that neurotoxins in them contributed to it."
After having followed Phil Landrigan's work in this field for more than a decade, it's inconceivable to me that anyone familiar with it would deny that proposition. So, when I read, "There is no credible evidence that vaccines cause autism." in the abstract of Landrigan's new paper "What causes autism? Exploring the environmental contribution ," I was inspired to reflection.
I initially felt he was parsing words for the publisher, the journal Current Opinion in Pediatrics . Given the politics and history of vaccines in America, it's reasonable to assume that any pediatric researcher who deviates from the American Academy of Pediatrics  (AAP) mantra -- The case against vaccines is closed, never to be opened again. -- could suffer serious consequences.
Regardless, as more than one source I have interviewed or read since October 2008 has observed, science is only as good as the hypotheses it pursues. The American experience with mercury-containing vaccines and autism is unique. And, as the studies Landrigan cites in his paper show, those used to "debunk" the notion that vaccines may have contributed to autism have not explored the right hypotheses.
The American experience with mercury-containing vaccines parallels the autism epidemic to the letter.
In 1930, the pharmaceutical manufacturer Eli Lilly & Co. patented a mercury-based preservative called thimerosal for use in childhood vaccines. According to a 2003 congressional report , despite repeated requests through the years, Lilly never tested thimerosal for its human health impacts. For 70 years, Lilly relied on a "woefully inadequate" and "uncontrolled study" from the 1920s as proof thimerosal was safe, the report said.
"As more than one source I have spoken with or read since October 2008 has observed, science is only as good as the hypotheses it pursues."
In 1943, autism was first identified by Austrian psychiatrist Leo Kanner, whose study "Autistic Disturbances of Affective Contact " said he had noticed such children since 1938.
Starting in the 1940s, American children were vaccinated for diptheria, tetanus and pertussis (DTP). A polio shot was added in 1955, and measles, mumps, rubella (MMR) joined the list in 1971.
In 1989, a fully vaccinated child of 5 had received a total of 11 injections of these three vaccines. In 1990 and 1991, two more were added to the schedule with seven more shots, including hepatitis B at birth. And in 1995 and 1998, an additional two vaccines with five more shots were added, bringing the total number of injections to 23.
Four more vaccines were added in 2000, 2004 and 2006. The CDC and AAP's recommended vaccination schedule  today says American children should receive 36 shots before they enter first grade, the most aggressive vaccination schedule in the world.
Canada is a distant second with 28, according to a 2009 study published by Generation Rescue titled "Autism and vaccines around the world. " The average number of vaccinations among 30 industrialized countries is 18.
Meanwhile, between 1980 and 1994, the incidence of California children with autism jumped 373 percent, from 1 in every 2,272 live births to 1 in 480, according to a 2001 study published in the Journal of the American Medical Association.
Three Centers for Disease Control (CDC) studies of children born in 1992, 1994 and 1996 -- after physicians began immunizing children at birth with vaccines containing mercury and aluminum -- showed continued, alarming increases at multiple sites nationwide. The first two, published in 2007, showed the autism rate had jumped to 1 in 150. The second, published in December 2009, put the figure at 1 in 110.
A CDC survey of parents released in October 2009 said 1 in 90 has a child on the autism spectrum.
In a move that some have called an example of the "precautionary principle," U.S. Public Health Service, the AAP and drug manufacturers issued a joint statement  in 1999 that said "thimerosal-containing vaccines should be removed as soon as possible." The precautionary principle actually says chemicals should be considered guilty until proven innocent, not innocent until proven guilty, as happened here.
A letter from a U.S. Food and Drug Administration  associate commissioner to U.S. Rep. Dave Weldon, R-Fla., dated June 18, 2003, said drug companies had reported that the last of the thimerosal vaccines in circulation had expiration dates in 2002. Anecdotal evidence from parents, however, suggests that children still received thimerosal-containing vaccines in 2003.
Some vaccines in use today, annual flu shots and the H1N1, for example, still contain mercury.
Not every vaccine used during the thimerosal era contained mercury. But most did, along with aluminum, another potent neurotoxin. And millions of American children were exposed to ominously large doses of both of these industrial chemicals.
"The American experience with mercury-containing vaccines and autism is unique. And, as the studies ... show, no one has explored the right hypotheses, yet."
The post-1991 AAP schedule called for children to receive one vaccine at birth, five at two months, five more at four months and an additional four at six months.
And that, according to the 2003 congressional report, authored by Indiana Congressman Dan Burton, R-Indianapolis, was tantamount to poisoning a generation of children. "In July 2000, it was estimated that 8,000 children a day were being exposed to mercury in excess of federal guidelines through their mandatory vaccines," the report said.
In some cases, when parents would miss one of their "well-baby visits," doctors would double up the shots. Some American children received 125 times the amount of mercury that the U.S. Environmental Protection Agency (EPA) says is safe in a single visit.
And in tens of thousands of cases, like Generation Rescue  co-founder J.B. Handley's son Jamie in Portland, Ore., their parents carried them into their pediatricians' offices normal and healthy and watched them "systematically decline" over the course of their "well-baby" visits where they "received multiple shots," Handley said in an e-mail.
And Handley has spoken to hundreds of parents who shared the experience of Congressman Burton, who watched his grandson immediately and permanently regress into autism. In a speech on the House floor  in 2002, Burton described the experience: "He actually got nine shots in one day, seven of which had mercury. Two days later he was banging his head against the wall, flapping his arms, had chronic diarrhea and constipation at the same time, and we lost him. He wouldn't talk to us. He became incommunicado."
Before addressing specifics in Landrigan's section on "Vaccines and autism," I should note that I have corresponded with him over the past 18 months and quoted him often in my stories, columns and blogs on children's environmental health. Just last week I featured the rest of his autism study in a piece called "Landrigan calls for more research into autism-environment link. " In my experience, he has been a man of few words who preferred to let his published work speak for him.
"In 1989, a fully vaccinated child of 5 had received a total of 11 injections of these three vaccines."
So I wasn't surprised that, after I e-mailed him about the no-credible-evidence line in his autism paper, he sent me the full study and referred me to the vaccines portion. When I questioned the relevance of the studies he cites to my proposition that mercury-containing vaccines caused some of the autism epidemic in the United States, he responded that no study is definitive, but a 2005 Japanese one was close.
"In Yokohama, Japan, the MMR vaccination rate declined significantly between 1988 and 1992, and no MMR vaccine was administered in 1993 or thereafter," Landrigan wrote in his autism study. "Despite declining immunizations, cumulative incidence of ASD (autism spectrum disorder) increased significantly each year from 1988 through 1996 and rose especially dramatically beginning in 1993. Overall incidence of autism nearly doubled in those years."
Autism spectrum disorders include Autism Disorder, sometimes called full-blown autism; Asperger's Disorder, sometimes called high-functioning autism; and Pervasive Developmental Disorder-Not Otherwise Specified.
The counterarguments to the Yokohama study reject its application to the American experience.
First, it's a study of but one vaccine out of the 11 that American children received over the decade and a half when thimerosal was heavily used. And, as the study itself says, under Japanese law children received only three vaccinations during the study period -- measles, rubella and MMR -- and in nowhere near the same doses as in the United States. Japanese children today receive 11 shots over the course of their childhoods. American kids receive 36. And the MMR has never contained thimerosal.
The Yokohama study's "Conclusion" states: "The significance of this finding is that MMR vaccination is most unlikely to be a main cause of ASD, that it cannot explain the rise over time in the incidence of ASD."
No credible source I've encountered has argued that the MMR, thimerosal or any other single vaccine or ingredient in vaccines are solely responsible for the autism epidemic. To argue that would be as foolhardy as denying the possibility that mercury in vaccines may have caused or helped cause some kids' regression into autism, or that this particular hypothesis isn't worth pursuing.
"The post-1991 AAP schedule called for children to receive one vaccine at birth, five at two months, five more at four months and an additional four at six months."
Landrigan cites seven studies from the United States, United Kingdom and Japan as support for his no-credible-evidence assertion. One, a Danish study  published in the New England Journal of Medicine in 2002, is often cited as the last word on the matter.
The Danish study compared autism rates in immunized and unimmunized children between 1991 and 1998, Landrigan wrote in his study. It found "no association between age at immunization or season at immunization and rate of autism."
Handley, however, said in an e-mail that the study used the term unimmunized to mean children who did not receive the MMR. All of the children had been inoculated against other diseases. And, he and others point out, the Danes removed thimerosal from their vaccines in 1992.
Citing the Danish study is, as many in the autism community have argued, comparing apples to pears.
One California study  published in the New England Journal of Medicine in 2007 that did look at American children from the thimerosal era analyzed "neuropsychological function" in 1,047 children, Landrigan wrote, but it "found no consistent correlation between neuropsychological functioning at age 7-10 years and early exposure to thimerosal-containing vaccines."
"Japanese children today receive 11 shots over the course of their childhoods. American kids receive 36."
The study, however, intentionally did not include autism. "Since the CDC is conducting a separate case-control study of autism in relation to mercury exposure, a measure of autism was not included in the test battery," it explained.
And while the study did reach the conclusions Landrigan outlines, some of them provide fodder for contemplation.
The study, titled "Early Thimerosal Exposure and Neuropsychological Outcomes at 7 to 10 Years," found that exposure to mercury between birth and 28 days was related to significantly poorer "speech articulation." It also found a "significant negative association with verbal IQ" among girls.
"Although the effect sizes were very small, the speech-articulation findings among all children and the lower verbal IQ findings among girls suggest a possible adverse association between neonatal exposure to mercury and language development," the study concludes.
Communication deficits are signature symptoms of autism. Children on the "full-blown autism" end of the spectrum frequently stop talking altogether.
While the study "found no association between neonatal exposure to mercury from thimerosal and total IQ," among boys it found "a significant positive association with performance IQ." Boys are four times more likely to develop autism than girls, and exceptional intelligence is common with Asperger's disorder.
I've spent most of the past 28 years journalistically investigating conflicts between environmental victims and experts in the relevant fields. And, I can say without qualification, the victims have been right and the experts wrong in every significant story I've covered. I can't think of a single exception.
"Some American children received 125 times the amount of mercury that the EPA says is safe, in a single visit."
And with respect to vaccines and autism, I say again, without reservation, parents like J.B. Handley and grandparents like Dan Burton are right about vaccines and autism. The experts are wrong, and their behaviors -- their vitriolic attacks upon those who disagree, their underhanded political tactics  -- suggest they know they were wrong.
For noble reasons, the most common argument against unfettered scientific analysis of the thimerosal era is that talking about vaccines and autism will scare parents away from vaccination, which could lead to outbreaks of dangerous illnesses, perhaps of epidemic proportions.
The most obvious counterargument is that we are in the middle (probably the beginning) of epidemics of horrific proportions -- of autism, of attention-deficit hyperactivity disorder, of cognitive disabilities, of learning delays. One in six American children in public schools today receive special education for those and other conditions. I've identified school districts in Southern Indiana where it is more than one in four.
Americans need to know what caused these epidemics. And open, honest, rigorous debate and study is the only path to that end.
Where to start that process also seems obvious. Every area of environmental contamination I've ever explored, from PCBs in the early 1980s to thimerosal today, began with studies of populations that were subjected to extreme exposures.
"Some vaccines in use today, annual flu shots and the H1N1, for example, still contain mercury."
The earliest PCB studies involved Japanese and Taiwanese who accidentally ate food cooked in PCB-contaminated rice oil in 1968 and 1979, respectively. Early studies of mercury poisoning analyzed victims contaminated by industrial discharges into Japanese waterways in the 1950s and bread cooked with mercury-contaminated grain in Iraq in 1971 and '72.
Well, we have a generation of American children today, who range in age from roughly 7 to 19, who were acutely exposed to high levels of two known neurotoxins through their vaccinations, and whose medical histories are comprehensively documented.
How difficult or costly could it be to identify a statistically significant population of children who received 125 times the recommended EPA level of mercury exposure and study their health histories? Or of kids who received 50 times the recommended exposure? Or 25 times?
Many parents refused to have their children vaccinated for hepatitis B at birth. How hard would it be to compare their children to those who were vaccinated? There are millions of both.
Most of the reasons why the politically powerful, pro-vaccine forces virulently oppose research of any kind into America's thimerosal experience are obvious and predictable, such as money and liability.
"The study ... found that exposure to mercury between birth and 28 days was related to significantly poorer 'speech articulation.'"
The political and legal history of the autism-and-vaccine debate is replete with dire warnings that parents recovering jury awards for damages caused by vaccines would wreak economic havoc on the industry and impede its ability to protect public health.
Corporations, after all, manufactured and sold the toxins, and doctors injected them into the children's developing bodies. In trial lawyer parlance, both have deep pockets.
Indeed, laws passed by Congress starting in the mid-1980s have made it virtually impossible for parents to be compensated for vaccine-induced injuries to their children.
Why public health officials abdicated their responsibilities to protect citizens from environmental toxins like mercury and aluminum is likewise clear. The agencies were run by Bush-Clinton-Bush appointees, whose jobs were to not do their jobs.
And their bosses came from the pharmaceutical industries. President George H.W. Bush was a Lilly board member before he was elected president. President George W. Bush's first budget director in 2000 was then-Lilly Vice President and now-Indiana Governor Mitch Daniels, who has opened the door to a 2012 bid for president.
Beyond their personal liability, the docs add a new twist to an old tale.
"Laws passed by Congress starting in the mid-1980s have made it virtually impossible for parents to be compensated for vaccine-induced injuries to their children."
Every person I have told the mercury-in-vaccine facts to has been dumfounded. Unless they have a special-needs child in their families, educated, curious, engaged citizens have no clue that one in six American children has a developmental disability, or that they had dangerously high levels of known neurotoxins injected into their developing, infant bodies, by their doctors. They're appalled when they hear it.
But all the guys I knew who became doctors, and all the docs I've ever spoken to as a reporter or a patient, have been the smartest people in the room. Yet, I wrote about mercury's neurotoxic properties when I worked at IDEM in 1996. And their fellow doctors in other countries, like Denmark, stopped using mercury in vaccines a decade before they finally did.
Another question that demands an answer is: Why did the AAP perpetuate for so long what can arguably be called the poisoning of a generation? Isn't one of a doctor's sacred credos, "First, do no harm"?
Steven Higgs can be reached at .