Evidence Mounts That Pesticides Cause Autism

Chemicals in agriculture are big business in California.

Every year, farms using pesticides, herbicides, and fertilizers in California produce crops valued at $38 billion in the field, which are turned into food products that sell for hundreds of billions of dollars around the world.

California farmers use 200,000,000 pounds (a little under 100,000,000 kilos) of agricultural chemicals every year. The use of these chemicals is regulated by the State of California, and in farm communities, there is an unwritten code that one does not criticize the agricultural chemical industry.

That doesn't mean, however, that agricultural chemicals are safe. 

The study, conducted at the University of California at Davis Mind Institute, found that the added risk of autism after exposure to these agricultural chemicals is about 2/3, and that exposure in the second and third trimesters is more dangerous than exposure earlier in pregnancy. And, study author and principal investigator Irva Hertz-Picciotto, a professor of public health, notes that this most recent study confirms the findings of two studies before it.

The UC Davis researchers conducted the study by correlating a database of applications to spray pesticides with medical records of 1,000 mothers participating in the study. The data were available for mothers and children in who lived in California's Bay Area, Sacramento Valley, and north Central Valley.

The study examined the possible effects of three kinds of pesticides:

• Pyrethroids, which are a "natural" pesticide,
• Organophosphates, which are in the same class of chemicals as nerve gas, and
• Carbamates, once considered non-toxic to humans and even used in chemotherapy, but now known to be toxic to the nervous system.

The researchers theorized that women who lived within 1 mile (1600 meters) of farms where these chemicals were sprayed would be at higher risk of having children with autism. The study found that children of women who lived in one-mile proximity to pesticide spraying during their second trimester had a 50 to 640% greater frequency of autism than children of women who did not, and that children of women who lived in one-mile proximity to pesticide spraying during their third trimester had a 10 to 260% greater frequency of autism than children of women who did not.

Why would women expose their children to pesticides?

In many cases, there simply is not anywhere else to go. Researchers at the nearby University of California of San Francisco interviewed women who were exposed to pesticides during pregnancy and learned that generally women who lived next to, or on, toxic farms were generally more concerned about getting the food they need for themselves and the baby and paying their rent.

Doctors, the UC San Francisco surveyors found, were not especially well equipped to help these mothers.

See Also: Pesticides- how dangerous is our nutrition?

Only 1 in 5 obstetricians even asks about exposure to agricultural chemicals, even though chemical based agriculture is a huge industry in Central California.

Is Pregnancy Safe Down On The Farm?

This Northern California– based Childhood Risk of Autism from Genetics and the Environment (CHARGE) Study examined chemical exposure in 361 developmentally normal children, 168 children who had developmental delays (DD), and 486 children who had autistic spectrum disorders (ASD). Developmental delay is a blanket term that encompasses failure to crawl, talk, walk, and develop motor skills at expected times during the first three years of life, although pediatricians have strict guidelines for making the diagnosis.  The newer terminology autistic spectrum disorder includes the condition better known as Asperger's syndrome. 

Just how dangerous are pesticides during pregnancy, really? Many mothers would do anything they could to avoid a one in a million chance of their child's being born with developmental delays or autism. The odds overall are:

• For autism, about 1 chance in 90 for children of women who are not exposed to pesticides in pregnancy, to somewhere between 1 chance in 40 and 1 in 10 for children of women who are.
• For developmental delays, about 1 chance in 300 to 1 chance in 160 for children of women who are not exposed to pesticides during pregnancy, and about 1 chance in 100 for children of women who are.

Many women find that to be too big a risk to take, and that's not even taking into consideration the fact that exposure to these chemicals in smaller amounts may cause children to have problems with reading, nightmares, insomnia, and anxiety (although there is a lack of "good science" to support that concern). So what are the options for ensuring the best outcomes for the baby?

See Also: Flu And Fever During Pregnancy Boost Autism Risk

• If you can't move, stay indoors when there is spraying nearby. If you ordinarily work in the fields, ask for safer work when you find out you are pregnant.
• Make sure you get your B vitamins (they're cheap), and if you are of Hispanic descent, take a supplement called methylfolate. About 20% of Latinos in the US carry a gene that keeps their bodies from using the B vitamin folic acid efficiently. Even though folic acid is added to all kinds of cereals and bakery products specifically to make sure pregnant women get it, the kind of folic acid that is in these products does not help the baby's nervous system grow properly. A kind of folic acid called methylfolate is needed. This product is actually cheap, less than $10 for a 90-day supply. Some unethical vitamin vendors, however, will ask ten times as much for it.
• Fresh fruits and vegetables contain the antioxidants that can offset the effects of pesticides, but fresh fruits and vegetables that have been sprayed with the pesticides really won't help. If you can't afford organic, at the very least make sure the fresh produce you eat is well washed before you eat it.