samedi, février 27, 2010

environmental links to autism, cancer, etc.?

I recently posted the article below to Facebook and got a few comments from friends. One called the article pure speculation. Another pointed out the danger of these types of articles to parents desperate to find a "cure" and improve the lives of their children with autism -- his parents tried chelation therapy on his brother, and it made things "10x worse". Here is how I responded to the comments that were posted, and more about my mindset and motives for sharing the article.

O, your family has endured so much. Over the years, I've been sad each time I hear about what's happening with your brother and the toll it takes on all of you. I can't begin to imagine what it has done to each of you.

D, I don't think pure speculation makes sense. I also don't think the tone of Kristof's article is about pure speculation. He's citing mainstream scientific work and makes a point of calling out that we just don't know enough yet to draw a conclusion. He's doing what he believes is his duty as a journalist, asking questions in the interest of the public. Lastly, he's not some fringe crackpot -- he's a responsible journalist who also happens to have won two Pulitzer prizes.

So where does this leave us? I've seen the FDA and other federal agencies fail to acknowledge the growing number of studies proving that phthalates, organic solvents, Bisphenol-A, etc. are hormone disruptors. Do these chemicals cause autism? Who knows? But when I consider that each study is looking at a chemical in isolation, and not evaluating the aggregate effect of all of the chemicals to which we're exposed, I cringe. And every so often, I cheer, as I did when public pressure forced the FDA to pay attention to BPA and other substances that are finally being acknowledged for making epigenetic changes that lead to cancer.

Meanwhile, like Nicholas Kristof, I've adopted the precautionary principle. That's for a few reasons. The biggest is my own health history (kidney cancer at 28 with no genetic factors in play -- as confirmed by recent tests). The others boil down to:
  1. My skepticism about whether government interests beholden to lobbyists are really going to be neutral and act in the best interest of the public (DDT, smoking, and Agent Orange come to mind) -- which is why I tend to look at the EU's response to many of these policy questions
  2. Luck in having the income level to afford to spend more (because all of this costs more)
  3. My own tendency to choose the 'safer' option, rather than the riskier one.
For me, the precautionary principle means that:
  • I eat on and drink out of glass/ceramic/ porcelain/ stainless steel, when possible. (And not just because it's phthalate-free, but because it's much greener than plastic or styrofoam.)
  • I limit my exposure, when possible, to heavy metals [insert Beavis and Butthead joke here] because mercury and other heavy metals are known neurotoxins and I really don't need the mercury exposure that happens via conventional mascara and certain fish.
  • I've eliminated most shampoos, lotions, and cosmetics that are chock-full of the nasties (phthalates, parabens, mercury, lead, fragrances). (The EU has much more stringent labeling requirements and has already banned most of these substances in cosmetics and requires much more stringent labeling than the US does.)
  • I eat organic and local, when possible. I know my farmer and his family and trust the produce he delivers via my CSA share. I drink organic milk and eat organic meat whenever it's an option. Part of it is because there might be pesticide residues in the food. Part of it is because organic is much better for the environment and the people growing it than petrochemical-fertilized-and-transported food. And part of it is because I think the taste, quality, and freshness are better.
  • I'll choose organic or second-hand clothes for my children (when I eventually have them), because they don't need to be exposed to the hormone disruptors and neurotoxins present in the flame retardants that conventional new baby and kid's clothes sold in the US have on them. (The EU has banned the flame retardants on kid's clothing, in mattresses, etc.)
  • I'll vaccinate my kids, but will spread out those vaccinations as much as possible and probably postpone vaccines like Hep B until the children are older (it is given to every infant these days a few days after birth), because the probability of an infant contracting Hep B is so unlikely that it just doesn't make sense.
Op-Ed Columnist: Do Toxins Cause Autism?
Published: February 24, 2010

Autism was first identified in 1943 in an obscure medical journal. Since then it has become a frighteningly common affliction, with the Centers for Disease Control reporting recently that autism disorders now affect almost 1 percent of children.

Over recent decades, other development disorders also appear to have proliferated, along with certain cancers in children and adults. Why? No one knows for certain. And despite their financial and human cost, they presumably won’t be discussed much at Thursday’s White House summit on health care.

Yet they constitute a huge national health burden, and suspicions are growing that one culprit may be chemicals in the environment. An article in a forthcoming issue of a peer-reviewed medical journal, Current Opinion in Pediatrics, just posted online, makes this explicit.

The article cites “historically important, proof-of-concept studies that specifically link autism to environmental exposures experienced prenatally.” It adds that the “likelihood is high” that many chemicals “have potential to cause injury to the developing brain and to produce neurodevelopmental disorders.”

The author is not a granola-munching crank but Dr. Philip J. Landrigan, professor of pediatrics at the Mount Sinai School of Medicine in New York and chairman of the school’s department of preventive medicine. While his article is full of cautionary language, Dr. Landrigan told me that he is increasingly confident that autism and other ailments are, in part, the result of the impact of environmental chemicals on the brain as it is being formed.

“The crux of this is brain development,” he said. “If babies are exposed in the womb or shortly after birth to chemicals that interfere with brain development, the consequences last a lifetime.”

Concern about toxins in the environment used to be a fringe view. But alarm has moved into the medical mainstream. Toxicologists, endocrinologists and oncologists seem to be the most concerned.

One uncertainty is to what extent the reported increases in autism simply reflect a more common diagnosis of what might previously have been called mental retardation. There are genetic components to autism (identical twins are more likely to share autism than fraternal twins), but genetics explains only about one-quarter of autism cases.

Suspicions of toxins arise partly because studies have found that disproportionate shares of children develop autism after they are exposed in the womb to medications such as thalidomide (a sedative), misoprostol (ulcer medicine) and valproic acid (anticonvulsant). Of children born to women who took valproic acid early in pregnancy, 11 percent were autistic. In each case, fetuses seem most vulnerable to these drugs in the first trimester of pregnancy, sometimes just a few weeks after conception.

So as we try to improve our health care, it’s also prudent to curb the risks from the chemicals that envelop us. Senator Frank Lautenberg of New Jersey is drafting much-needed legislation that would strengthen the Toxic Substances Control Act. It is moving ahead despite his own recent cancer diagnosis, and it can be considered as an element of health reform. Senator Lautenberg says that under existing law, of 80,000 chemicals registered in the U.S., the Environmental Protection Agency has required safety testing of only 200. “Our children have become test subjects,” he noted.

One peer-reviewed study published this year in Environmental Health Perspectives gave a hint of the risks. Researchers measured the levels of suspect chemicals called phthalates in the urine of pregnant women. Among women with higher levels of certain phthalates (those commonly found in fragrances, shampoos, cosmetics and nail polishes), their children years later were more likely to display disruptive behavior.

Frankly, these are difficult issues for journalists to write about. Evidence is technical, fragmentary and conflicting, and there’s a danger of sensationalizing risks. Publicity about fears that vaccinations cause autism — a theory that has now been discredited — perhaps had the catastrophic consequence of lowering vaccination rates in America.

On the other hand, in the case of great health dangers of modern times — mercury, lead, tobacco, asbestos — journalists were too slow to blow the whistle. In public health, we in the press have more often been lap dogs than watchdogs.

At a time when many Americans still use plastic containers to microwave food, in ways that make toxicologists blanch, we need accelerated research, regulation and consumer protection.

“There are diseases that are increasing in the population that we have no known cause for,” said Alan M. Goldberg, a professor of toxicology at the Bloomberg School of Public Health at Johns Hopkins University. “Breast cancer, prostate cancer, autism are three examples. The potential is for these diseases to be on the rise because of chemicals in the environment.”

The precautionary principle suggests that we should be wary of personal products like fragrances unless they are marked phthalate-free. And it makes sense — particularly for children and pregnant women — to avoid most plastics marked at the bottom as 3, 6 and 7 because they are the ones associated with potentially harmful toxins.

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