Study Reveals Dangers of Prenatal Pesticide Exposure

(EDITOR’S NOTE: California state regulators claim that certain pesticides – like methyl iodide, which was recently approved for agricultural use on crops such as strawberries - can be used safely, while many of the state’s environmental and health groups say that pesticide use in farming is fundamentally harmful to humans. Now, the results of a groundbreaking 12-year study by researchers at UC Berkeley and community medical centers in the Salinas Valley are shedding new light on the actual impact of pesticide exposure on farm workers and their families. This story, reported by NAM contributor Poornima Weerasekara, was made possible by an environmental health-reporting grant from New America Media, sponsored by the California Wellness Foundation.)

SALINAS, Calif. -- Endless rows of lettuce, celery and broccoli, covered by silver plastic sheets, surround the Natividad Medical Center, a community clinic located in the heart of this agricultural town, often called the salad bowl of America.
At about 10:30 a.m., Salinas Valley resident Marie, a Mexican-American farm worker who didn’t want to give her real name because she is participating in a research study, troops into one of the center’s research labs housed in an old trailer with her two children.
She has brought her 5-year-old son and 8-year-old daughter in for their routine blood and urine sampling. The research station is littered with toys, kids DVDs and various puzzles and activities. While her daughter grabs some crayons and a coloring book, Helen Aguirre, a research worker, gently prods Marie’s son onto a scale to record his weight.
Marie’s children are among 300 from Salinas participating in a groundbreaking study by researchers at the University of California, Berkeley, that tracks the health of children whose mothers were exposed to pesticides while pregnant. The 12-year study is being carried out by the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), a collaboration between UC Berkeley, the Natividad Medical Center, Clinica de Salud Del Valle de Salinas and other community organizations.
“I took part in this study from the time I was pregnant because I wanted to learn more about how pesticides affect my health and my kids’ health,” said Marie, who let researchers be by her hospital bed when she gave birth to her son, to collect samples of the umbilical cord blood.
The study has already revealed significant links between children who are exposed to pesticides while still in the womb and the occurrence of developmental disorders down the line.
Researchers found that prenatal exposure to certain types of organophosphate pesticides is significantly linked to attention problems in children, visible by the time they turn 5, with the effects apparently stronger among boys. The findings, published in the Environmental Health Perspectives journal last August, were the first to examine the influence of prenatal organophosphate exposure on the later development of attention problems.
Among their findings was a discovery that prenatal pesticide metabolites - compounds found in the human body that indicate an over-exposure to harmful chemicals - are linked to increased odds of 5-year old children scoring high on tests for attention disorders.
Dr. Asa Bradman, co-founder of the Center for Children's Environmental Health Research at UC Berkeley’s School of Public Health, and co-author of the study, points out that the group of pesticides they examined are widely used, and that the results from this study are a red flag that warrants precautionary measures.
UC Berkeley psychology professor Stephen Hinshaw, who was not part of the study, says the findings are significant because severe symptoms of attention deficit and hyperactivity disorder by age 5 contribute to poor school performance, increase injuries in the home and neighborhood, and affect peer relationships.
The long-term study, which is now tracking hundreds of women and children, is also examining the impact of prenatal pesticide exposure on the development of asthma, diabetes and obesity in children.
CHAMACOS staff and researchers also inform community members about key findings from the long-term study and ways to reduce exposure to pesticides, but it’s no easy task.
Growers are not mandated to provide protective gear to farm workers, and the lack of protective measures means that workers end up carrying pesticide residues back home in their clothes, shoes, and cars. Farm supervisors commonly report that workers are often times exposed when applicators fail to notify them before spraying pesticides in adjacent fields.
And, farm laborers in the fields aren’t the only ones affected.
Communities on the edge of fields are exposed to pesticides through drift or vapor contained in the air, dispersed by strong winds as fields are sprayed. In many cases, protective measures around schools consist of a thin wire mesh separating playgrounds from lettuce fields.
According to data from the County Agricultural Commissioner, one in five households in the region -- where more than 80 percent of residents are Mexican-Americans -- depend on farming for their livelihood. These numbers, researchers say, do not include migrant and undocumented workers who work only part of the year.
A preschool teacher recently told Marie that her son’s reading skills are below average. “I worry about him constantly,” Marie says. “I ask his older sister to read to him every day, because my English is not so good.”
Marie and her husband work in the fields, and armed with more information about the effects of pesticides on her children, she is taking all the steps she can to reduce the family’s exposure.
“I wash my husband’s clothes separately from the (rest of the) family’s laundry,” says Marie, adding that she also tries to buy organic food, at least a few times every month, despite the extra cost.
Jesus Lopez, a community leader in Salinas for over two decades and an outreach officer for California Rural Legal Assistance Foundation, says that for a family earning less than $30,000 a year, spending even $3 extra to launder work clothes separately can be tough.
His nonprofit has developed community-driven programs to help offset the burden on farm worker families. The group, in collaboration with the CHAMACOS research project, has set up facilities for farm workers to wash up before going home.
"Usually a farm worker picking celery bends about 18 to 22 times a minute," says Lopez, noting that in a nine-hour work day, that amounted to a farm worker bending down about 10,000 times.
“Do you think they have the energy to follow all the instructions on reducing pesticide exposure after work, like washing up at the work place?" Lopez said.
He added that safety and health concerns about pesticide use could be avoided with a shift to organic production. In the meantime, Marie is keeping a watchful eye on her son’s reading progress.
© 2011 New America Media
By Poornima Weerasekara

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