Maybe It's Everything Else

Outside of the debate over health care reform as a whole, one of the hottest medical topics of discussion in recent years has been the potential role of vaccines in the explosive growth of autism among American children.  Celebrity Jenny McCarthy, whose son is autistic, has been at the vanguard of the crusade against childhood vaccinations, and in a country where immunization was part and parcel of post-natal care for decades, many parents have begun to seriously question whether or not their kids should receive such preventative treatment.

The result?  The reappearance of meningitis and measles cases in numbers not seen in over a generation, and no comfort for the parents of autistic children.

Last week, however, a federal court reviewing the alleged link between immunization and autism issued a ruling that dealt a major setback to the parents pursuing more than 5,000 cases in which they claim that mercury-based thimerosal (a preservative no longer widely used) - or the Measels/Mumps/Rubela (MMR) vaccine itself - caused their children's autism.  While it should be noted that the ruling was a legal decision and not the results of scientific study, there was little question about the court's frame of mind:

The three separate decisions by the court's "special masters" were not close.

"To conclude that [autism] was the result of [this child's] MMR vaccine, an objective observer would have to emulate Lewis Carroll's White Queen and be able to believe six impossible (or, at least, highly improbable) things before breakfast," wrote Special Master Denise K. Vowell.

While I have deep sympathy for the challenges facing any parent whose child has autism, what has always been most striking to me about this debate has been the focus on vaccines to the exclusion of virtually all other inputs.  It may be that vaccines represent a coherent target on which to focus, but the reality is that environmental pollution now broadly affects almost the entire population of the United States.

A recently-released study by the U.S. Geological Survey (USGS), for instance, found that not only were every single one of the fish it sampled contaminated with some level of mercury, but that two-thirds were tainted at a "level of concern", and that more than a quarter contained amounts significantly higher than the safe upper bound for human consumption.  Given that the study examined waterways in every part of the nation - and that mercury is a potent neurotoxin - this seems like an area worth investigating for its potential links to autism and other conditions.  (Although a definitive link between mercury and autism has yet to be proven.)

Likewise, a study by the Environmental Working Group (EWG) found new evidence that babies are being being born "pre-polluted" by chemical agents transferred from their mothers:

Laboratory tests commissioned by Environmental Working Group (EWG) and Rachel's Network have detected Bisphenol A (BPA) for the first time in the umbilical cord blood of U.S. newborns. The tests identified the plastics chemical in 9 of 10 cord blood samples from babies of African American, Asian and Hispanic descent.

The findings provide hard evidence that U.S. infants are contaminated with BPA beginning in the womb.

Additional tests conducted by five laboratories in the U.S., Canada and Europe found up to 232 toxic chemicals in the 10 cord blood samples. Besides BPA, substances detected for the first time in U.S. newborns included a toxic flame retardant chemical called Tetrabromobisphenol A (TBBPA) that permeates computer circuit boards, synthetic fragrances (Galaxolide and Tonalide) used in common cosmetics and detergents, and perfluorobutanoic acid (PFBA or C4), a member of the notorious Teflon chemical family used to make non-stick and grease-, stain- and water-resistant coatings for cookware, textiles, food packaging and other consumer products.

The EWG study is the first to find perchlorate contamination in cord blood samples from multiple states. (A study by researchers at the U.S. Centers for Disease Control and Prevention recently found perchlorate in cord blood samples from infants born in New Jersey.) Nine of the 10 samples in the EWG study were contaminated with perchlorate, a solid rocket fuel component and potent thyroid toxin that can disrupt production of hormones essential for normal brain development.

There is unquestionably something driving the explosive growth of autism in the United States, which now affects 1 in every 150 children born.  Th origin might be genetics, it might be improved diagnosis, it might be environmental, or it might be some combination thereof.  If an environmental factor is wholly or partially responsible, however, it would seem that focusing on vaccines - compounds which, by the way, undergo significant testing before their use on human beings - is potentially counterproductive.  Simply stated, it appears that there is ample evidence that the cause might be pretty much everything else.