Are Environmental Agents Behind The Autism Epidemic?
November 17, 2002
Martha R. Herbert
A recent study from the University of
California at Davis has validated reports of an unprecedented and
baffling nationwide epidemic of autism, at the same time it
challenges current scientific thinking about how diseases are
caused.
Once blamed on emotionally distant mothers, more recent theories of
autism invoke mainly genetic causation. But if we are facing an
epidemic, the new research implicates environmental agents.
Autism, once thought to be rare, is as heartbreaking as it is now
widespread. Parents often describe normally developing infants who
inexplicably begin to deteriorate in the second year of life.
Language is impaired; many cannot even speak. Social interaction is
limited. The children make little or no eye contact and do not
engage with playmates. Severe behavior issues arise. Cognitive
abilities may decline. Seizures, clumsiness, gastrointestinal
problems, immune imbalances, metabolic abnormalities and other
conditions are often present. These children require increased
medical care, specialized education and constant - usually lifelong
- supervision. Families are stressed, schools can't cope and doctors
have very little to offer.
The M.I.N.D. Institute at UC-Davis reviewed data from the California
Department of Developmental Services, which showed nearly a
statewide tripling of the most severe autism in little more than a
decade, from 1987 to 1998. It ruled out other possible causes for
the reported increases, such as better diagnosis or immigration into
the state.
Beyond California, figures from the U.S. Department of Education
show a nationwide average increase of 544 percent in autistic
students from 1992-93 to 2000-01. Studies in Atlanta and New Jersey,
by the Centers for Disease Control, turned up autism among 1 in 250
to 300 children. And these numbers reflect only the most severe
cases: Including milder forms raised the rate in New Jersey to 1 in
150 children. Prior to 1980, studies showed autism rates of 1 in
2,000.
It is time to rethink the emphasis on genetics in autism research.
As M.I.N.D. Institute study leader Dr. Robert Byrd said, "Genes
don't cause epidemics." Autism research dollars have flowed to
support genetic studies designed to find aberrant genes, but the
only effective treatments have been expensive behavior-based
interventions.
The new study strongly suggests that something else must be
involved, because the human genome simply doesn't change this fast.
So we must look where such rapid change does occur - in the
environment.
If we are having an epidemic, then environmental influences, which
could include chemicals, metals, vaccines and viruses, must be
overwhelming more children than ever before. Since genes that affect
the brain also affect the body, environmental triggers of autism
would affect both. And in fact this "behavioral" disorder is often
accompanied by gastrointestinal or immune diseases or other illness.
The cost of autism lies not only in human suffering. In California
alone, nine new children are diagnosed with autism every day.
Conservative estimates of $2 million for each autistic child's
lifetime care do not include lost wages of the child or family
members. Meanwhile, the National Institutes of Health spends $56
million per year on autism research - much better than the $5
million budgeted just five years ago but not sufficient for such an
epidemic.
We must focus attention - and research dollars - on our environment
and not just our genes. If we do not, we face more rising epidemics
of unexplained diseases.
Martha R. Herbert is a pediatric neurologist at Massachusetts
General Hospital and Harvard Medical School, and a board member of
the Council for Responsible Genetics. This article was distributed
by the National Environmental Trust, an op-ed service in Washington.
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