Sludge Watch ==> Pesticide link to autism suspected

[Maureen Reilly]

Sludgewatch admin:

Here is a companion story:
"...Over 80 percent of schools in America are applying pesticides on a 
regular basis, whether they have a pest problem or not..."
http://www.sciencedaily.com/releases/2007/07/070721221346.htm


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Pesticide link to autism suspected
A state study suggests two farm sprays may raise chances of having a child 
with the disorder.
By Marla Cone, Times Staff Writer
July 30, 2007

Women who live near California farm fields sprayed with organochlorine 
pesticides may be more likely to give birth to children with autism, 
according to a study by state health officials to be published today.

The rate of autism among the children of 29 women who lived near the fields 
was extremely high, suggesting that exposure to the insecticides in the womb 
might have played a role. The study is the first to report a link between 
pesticides and the neurological disorder, which affects one in every 150 
children.

But the state scientists cautioned that their finding is highly preliminary 
because of the small number of women and children involved and lack of 
evidence from other studies.

"We want to emphasize that this is exploratory research," said Dr. Mark 
Horton, director of the California Department of Public Health. "We have 
found very preliminary data that there may be an association. We are in no 
way concluding that there is a causal relationship between pesticide 
exposure of pregnant women and autism."

The two pesticides implicated are older-generation compounds developed in 
the 1950s and used to kill mites, primarily on cotton as well as some 
vegetables and other crops. Their volumes have declined substantially in 
recent years.

Examining three years of birth records and pesticide data, scientists from 
the Public Health Department determined that the Central Valley women lived 
within 500 meters, or 547 yards, of fields sprayed with organochlorine 
pesticides during their first trimester of pregnancy. Eight of them, or 28%, 
had children with autism. Their rate of autism was six times greater than 
for mothers who did not live near the fields, the study said.

Susan Kegley, senior scientist of Pesticide Action Network North America, a 
San Francisco-based advocacy group, said the report adds to an existing body 
of evidence that endosulfan and dicofol, already banned in some countries, 
are harmful.

"This is one of the first papers that links use of pesticide to incidence of 
a disease, and autism in particular," she said. "The findings are very 
strong. This is a sixfold risk factor in comparison to someone who is not 
exposed. There aren't too many studies that come out like that."

Even though small numbers of children were involved, "it is still one of 
those things that make you sit up and pay attention," she said.

The findings suggest that 7% of autism cases in the Central Valley during 
the years studied — 1996 through 1998 — might have been connected to 
exposure to the insecticides drifting off fields into residential areas. 
Births during those years were analyzed because children born later might 
not yet be diagnosed with autism.

Children with autism spectrum disorders have impaired social and 
communication skills. The causes are unknown, but because diagnoses have 
been increasing, scientists have been exploring various environmental 
factors, including children's vaccines and chemical pollutants.

"The good news is we've used a new research technology to generate 
hypotheses and possible associations, so we are making progress in the 
battle to get more information" about the cause of autism, Horton said.

The goal of the study was to "systematically explore the general hypothesis 
that residential proximity to agricultural pesticide applications during 
pregnancy could be associated with autism spectrum disorders in offspring," 
the authors wrote in their study, published online today in the scientific 
journal Environmental Health Perspectives.

The scientists collected records of nearly 300,000 children born in the 19 
counties of the Sacramento and San Joaquin river valleys. Of those children, 
465 had autism. The scientists then compared the addresses during pregnancy 
to state records that detailed the location of fields sprayed with several 
hundred pesticides.

For most pesticides, no unusual numbers of autism cases were found, but the 
exception was a class of compounds called organochlorines. Most, including 
DDT, were banned in the United States several decades ago because they were 
building up in the environment. Only dicofol and endosulfan remain.

The autism rate was highest for children of those mothers who lived the 
closest to the fields and it declined as the distance from the fields 
increased.

There is no other human or animal evidence that the two chemicals can cause 
autism. But both affect nerves and the brain — and cause reproductive 
effects and alter hormones in animal tests. In addition, dicofol is a 
possible human carcinogen.

The scientists concluded that "the possibility of a connection between 
gestational exposure to organochlorine pesticides and autism spectrum 
disorders requires further study."

A July report by the state Department of Pesticide Regulation said 
endosulfan can spread far from fields via the air and expose the public, 
based on air monitoring in Fresno, Monterey and Tulare counties. The agency 
is likely to designate endosulfan as a toxic air contaminant soon, and 
dicofol could follow. That designation triggers a review by the agency to 
see whether steps should be taken to minimize the chemicals drifting off 
fields into nearby communities.

Glenn Brank, spokesman for the pesticide agency, said officials there are 
"very interested" in the new autism data but say that "more work" on the 
potential link is needed before it can carry much weight in assessments of 
the chemicals' risks.

The two insecticides are now used much less often than in the years in which 
the possible connection to autism was found. As a result, there is less 
likelihood that pregnant women are exposed today. Nearly 774,000 pounds were 
applied in 1996, compared with 277,000 pounds in 2005, down nearly 64%, 
according to state records.

"In the past couple years, the bottom has dropped out of these two," Brank 
said.

Insects have built up resistance and cotton farmers have switched to new 
compounds.

The two chemicals are not found in household or yard pesticides. Traces are 
found in food, but the study looked only at possible exposure from the air. 
The chemicals are used most extensively in Fresno, Kings, Imperial and 
Tulare counties. Dicofol is mostly used on cotton, oranges, beans and 
walnuts. Endosulfan is used primarily in tomato processing and on lettuce, 
alfalfa and cotton crops.

marla.cone at latimes.com

http://www.latimes.com/news/local/la-me-autism30jul30,0,6609909.story?coll=la-home-center