[Paleopsych] NYTBR: 'Evidence of Harm': What Caused the Autism Epidemic?

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'Evidence of Harm': What Caused the Autism Epidemic?
New York Times Book Review, 5.4.17
http://www.nytimes.com/2005/04/17/books/review/17MORRICE.html

    By POLLY MORRICE

EVIDENCE OF HARM
Mercury in Vaccines and the Autism Epidemic: A Medical Controversy.
By David Kirby.
460 pp. St. Martin's Press. $26.95.

    Back in November 2002, when the journalist David Kirby started
    researching ''Evidence of Harm,'' he couldn't have known how good his
    timing would be. His book on the contentious issue of whether mercury
    in vaccines led to an autism epidemic is appearing in the midst of
    what must be called an autism boom. In the past few months, this
    unexplained brain disorder -- which skews language and social skills,
    and can unloose fierce obsessions -- has hit a media trifecta.
    Television news segments, a magazine cover story and a host of
    newspaper articles have discussed its symptoms, treatments, effects on
    families and, most controversially, its apparently soaring incidence.

    Why so much autism now? In part, the deluge is cyclical, as
    journalists discover -- apologies to Yeats -- the fascination of
    what's difficult. Yet this year's coverage has had a particular note
    of urgency. Beginning in the late 1980's, the number of autism cases
    started to take off. The latest estimates are that one child in 166
    has some form of the disorder, with effects that range from mild to
    crippling. These figures have raised vital questions. Is the increase
    in autism real or the result of revised diagnostic criteria and
    improved awareness? If the syndrome has become epidemic, is some
    environmental factor partly to blame?

    Kirby, who has contributed to various sections of The New York Times,
    personalizes this dispute by introducing us to a collection of parents
    who began to suspect that genetic tendencies might not have induced
    their children's autism. Brought together by the Internet, this group
    soon focused on thimerosal, a mercury-based preservative once used in
    vaccines, including many that were added to the immunization schedule
    in the early 1990's. When infants received higher doses of thimerosal,
    it was suggested, the result was an autism epidemic.

    Many of Kirby's subjects have had sour encounters with the medical
    establishment. One such couple, Lyn and Tommy Redwood, struggled to
    obtain a diagnosis for their son Will, who at 17 months started to
    lose his language and withdraw socially. When Will turned 4, his
    latest ''expert'' doctor ran out of options: ''Why don't you just take
    him fishing?'' Like the Redwoods, the other parents in Kirby's book
    watched their children develop normally until the second year of life.
    After receiving measles-mumps-rubella (M.M.R.) vaccines, they
    regressed, developing symptoms of autism and severe gastrointestinal
    problems.

    Initially, the parents wrote off the rumors of a thimerosal-autism
    connection, even though the idea that vaccines contributed to the
    disorder wasn't new. In the mid-1980's, an antivaccine activist
    collaborated on a book linking autism to the
    diphtheria-tetanus-pertussis shot. And the British doctor Andrew
    Wakefield argued that autism was an immune-system disorder brought on
    by live measles virus in the M.M.R. vaccine (which does not contain
    thimerosal). Then, in July 1999, the United States Public Health
    Service and the American Academy of Pediatrics issued a statement
    calling for vaccines containing thimerosal to be phased out as soon as
    possible. The document noted that while babies had received cumulative
    doses of ethylmercury (in thimerosal) that exceeded a federal safety
    limit for methylmercury, its more toxic chemical cousin, there was no
    ''evidence of harm.''

    After reading the statement, Lyn Redwood toted up the micrograms of
    mercury Will had received during his first six months and realized
    that the government had averaged the mercury exposure on a per-day
    basis rather than acknowledging that infants got potentially more
    toxic ''bolus'' doses -- large amounts at one time. Meanwhile, other
    parents, who would join with Redwood to form the Coalition for Safe
    Minds, researched the similarities between mercury poisoning and
    autism. They found a striking parallel in acrodynia, a 1930's ailment
    that occurred in some children exposed to mercury in lotions and
    teething powders.

    From here on, Kirby follows the tug of war between government health
    agencies and the parents and their supporters. At a succession of
    hearings, the so-called Mercury Moms presented their research on
    acrodynia and thimerosal, and a neurologist described his research
    showing that tiny amounts of thimerosal triggered brain-cell death.
    The federal agencies, in turn, cited seemingly conclusive
    epidemiological studies. (Denmark, for example, removed thimerosal
    from vaccines in 1992 but saw a rise in autism cases rather than the
    expected drop.) The Safe Minds parents went home and picked the
    studies apart. Despite their efforts, in May 2004 a committee from the
    Institute of Medicine found no ''causal relationship'' between
    thimerosal-containing vaccines, or the M.M.R. vaccine, and autism.

    If this story has a smoking gun, it's the Vaccine Safety Datalink
    thimerosal study. Based on data collected from H.M.O.'s, this project,
    financed by the Centers for Disease Control, sought to determine
    whether there was a correlation between the timing and amounts of
    thimerosal infants received in vaccines and the emergence of
    neurodevelopmental disorders, including speech delay,
    attention-deficit disorder and autism. The Safe Minds statisticians
    contended that the government analyses of such data were flawed in a
    way that obscured or eliminated the original findings of statistically
    significant risks.

    ''Evidence of Harm'' is filled with abbreviations and statistics, but
    Kirby does an admirable job of clarifying most of the scientific
    background -- including an explanation of the complex biochemical
    process of methylation, which plays a central role in Safe Minds'
    arguments. (The idea, in its simplest terms, is that in susceptible
    people thimerosal blocks the ability of cells to regulate their
    functions; these individuals cannot shed mercury -- or other toxins or
    heavy metals -- from their bodies.) However, Kirby is less clear on
    the nature of autism, which he sums up as ''a hellish, lost world.''
    In his account of one government hearing, an angry activist denounces
    ''the traditional brain-and-genetics stuff'' of mainstream research,
    but readers who aren't familiar with that ''stuff'' might welcome a
    summary. Some researchers also suspect that thimerosal and the M.M.R.
    vaccine delivered a one-two punch to the immune system -- the first
    weakened it, the second finished it off. A fuller explanation of this
    theory would also have been helpful.

    KIRBY doesn't offer his own verdict on the debate, although he makes
    the unassailable point that American health agencies lagged in
    calculating the amount of mercury being injected into babies. He
    quotes Rick Rollens, a founder of the MIND Institute at the University
    of California, Davis, who thinks answers to the thimerosal-autism
    question may come from his home state, which has the country's most
    reliable system of tracking new cases. The decline in infants'
    exposure to thimerosal, Rollens estimates, began in 2001; he predicts
    the effects ''should start showing up in our system in 2005'' -- in
    other words, any day now.

    As for Will Redwood, his parents have tried applied behavioral
    analysis, vitamin B-12, folinic acid and chelation, the chemical
    removal of metals like mercury from the body. In third grade Will was
    admitted to a mainstream private school, and at the age of 10 he was
    becoming interested in girls. If one certain conclusion can be drawn
    from ''Evidence of Harm,'' it's that Will's parents made the right
    decision about going fishing.

    Polly Morrice has written for Redbook and Salon. She is working on a
    book about autism.