It’s true that high levels of exposure are more dangerous, and have been linked with cancer, memory loss, and Parkinson’s disease. But small amounts, such as those that many of us are exposed to on a daily basis, may also increase risk of health problems over time.
Here’s a glimpse at what the science has found, along with steps you can take to protect your family.
In 2011, researchers published a study linking persistent organic pollutants (POPs) like organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs—industrial waste chemicals), to the development of obesity and insulin resistance, both precursors to type 2 diabetes.
Scientists observed 90 participants who were diabetes-free at the beginning of the study, and 20 years later, those with higher levels of OCs were more likely to be overweight or obese, with higher levels of triglycerides, insulin resistance, and lower levels of HDL “good” cholesterol in their blood.
A later 2012 study found similar results, with high levels of pesticides linked with obesity, insulin resistance, high triglycerides, and low HDL cholesterol. Researchers also found, though, that participants who were obese but had lower levels of these chemicals in their blood were less likely to have the disease.
“In particular,” they wrote, “obesity did not seem to be related to type 2 diabetes among persons with very low serum concentrations to POPs, suggesting a more fundamental role of chlorinated POPs in the pathogenesis of type 2 diabetes.” They went on to state that if the findings hold true, reducing exposure to POP “would be necessary to decrease the social burden of type 2 diabetes.”
Several recent studies have suggested that the rise in autism diagnoses may be due to an increase in exposure to toxic chemicals. In 2010, a team of scientists from the University of Montreal and Harvard University found that children exposed to organophosphate pesticides were at an increased risk for Attention-Deficit Hyperactivity Disorder (ADHD).
Scientists looked at data from the National Health and Nutrition Examination Survey for over 1,000 children, and found that those with higher levels of pesticides in their urine were more likely to have been diagnosed with ADHD. Overall, with every tenfold increase in urinary concentration of pesticide residue, they found a 35 percent increase in the odds of developing ADHD.
“I was quite surprised to see an effect at lower levels of exposure,” Maryse F. Bouchard, lead author of the study, told Time magazine. Organophosphates are known to cause damage to nerve connections in the brain.
Atrazine is a weed-control pesticide still used in the U.S. and also found in groundwater throughout the Midwest. The Environmental Protection Agency (EPA) states it is one of the “most widely used agricultural pesticides in the U.S.” It’s also used on residential lawns.
A 2003 study found that agricultural pesticides used in the Midwest may have contributed to the reduction of semen quality in fertile men. A 2010 study found that male frogs exposed to atrazine could become so completely female that they could mate and lay viable eggs. Male frogs exposed to the pesticide also experienced depressed testosterone levels, decreased breeding gland size, and decreased fertility.
Beyond Pesticides notes that atrazine is the “most commonly detected pesticide contaminant of ground, surface, and drinking water.” It’s a hormone disruptor at even low levels, and was found in a 2012 study to result in the destruction of sperm DNA.
4. Birth Defects
A number of studies have linked maternal pesticide exposure to an increased risk of birth defects. In 2009, a study found that the highest rates of birth defects in the U.S. occurred among babies conceived in the spring and summer—the same time when increased levels of pesticides from agricultural areas reach surface water.
“While our study didn’t prove a cause and effect link,” said Dr. Paul Winchester, lead author, “the fact that birth defects and pesticides in surface water peak during the same four months makes us suspect that the two are related.”
In 2013, scientists from Stanford University Medical Center analyzed thousands of birth records and commercial pesticide application records for eight counties in California’s agricultural Central Valley. They found that some were associated with an increased risk of “hypospadias,” a birth defect in which the urethral opening is on the underside rather than on the tip of the penis.
A report by the California Birth Defects Monitoring Program noted that pesticide exposure is very common, and that studies so far have indicated that women living within a quarter mile of agricultural crops had at least a 1.5 times greater risk of having babies with neural tube birth defects. Those using pesticides in household gardening activities were 1.5 times more likely to have babies with certain types of neural tube and heart defects.
The EPA also notes that lab studies have shown pesticides can cause birth defects, and that they pose unique health risks to children.
5. Food Allergies
This is a recent area of research, but some studies have suggested that pesticide exposure may also increase risk of food allergies. In a 2012 study, researchers analyzed records of participants aged 6 years old and older who had pesticides in their urine. They found that the presence of one or more metabolites of these pesticides “was significantly associated with sensitization to food and environmental allergens. Food but not environmental allergen sensitivity was positively associated with the use of home pesticides and urban living.”
Tips to Protect Your Family
To reduce your exposure to pesticides and other POPs, take these precautions:
- Buy organic whenever possible—studies have found it to be consistently lower in pesticides than commercial produce.
- Avoid artificially scented air fresheners. Use natural options instead, like essential oils, open windows, and candles made with natural waxes like vegetable, beeswax, and soybean. (Parrafin-based can give off toxic chemicals like astoluene and benzene.)
- Avoid using synthetic bug sprays in the home, especially if you have young children. Try natural options instead, like cedar oil, which is a natural repellant. Find other natural bug repellants here.
- Use a water filter.
- Look for GMO-free options. (Try the True Food Shoppers Guide for help on finding GMO-free foods.)
- Avoid canned food that’s lined with BPA.
Do you have other tips for avoiding exposure to pesticides? Please share them with our readers.
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Leah Zerbe & Emily Main, “10 Crazy Things Pesticides Are Doing to Your Body,” Rodale News, June 22, 2013, http://www.rodalenews.com/agrochemicals.
Duk-Hee Lee, et al., “Low Dose Organochlorine Pesticides and Polychlorinated Biphenyls Predict Obesity, Dyslipidemia, and Insulin Resistance among People Free of Diabetes,” PLOS One, January 26, 2011, http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0015977.
Duk-Hee Lee, “Persistant Organic Pollutants and Obesity-Related Metabolic Dysfunction: Focusing on Type 2 Diabetes,” Epidemiol. Health, 2012; 34: e2012002, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3272548/.
Maryse F. Bouchard, David C. Bellinger, Robert O. Wright, and Marc G. Weisskopf. Attention-Deficit/Hyperactivity Disorder and Urinary Metabolites of Organophosphate Pesticides. Pediatrics, 2010; http://pediatrics.aappublications.org/content/125/6/e1270
Alice Park, “Study: A Link Between Pesticides and ADHD,” Time, May 17, 2010, http://content.time.com/time/health/article/0,8599,1989564,00.html.
“Atrazine Updates,” EPA, January 2013, http://www.epa.gov/oppsrrd1/reregistration/atrazine/atrazine_update.htm.
Shanna H. Swan, et al., “Semen quality in relation to biomarkers of pesticide exposure,” Environ. Helath Perspect. Sep 2003; 111(12):1478-1484, http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1241650/.
Tyrone B. Hayes, et al., “Atrazine induces complete feminization and chemical castration in male African clawed frogs,” PNAS, 2010, http://www.pnas.org/content/early/2010/02/12/0909519107.abstract.
“More Resesarch Links Atrazine to Sexual Abnormalities in Amphibians,” Beyond Pesticides, March 3, 2010, http://www.beyondpesticides.org/dailynewsblog/?p=3217.
Sajad Feyzi-Dehkhargani, et al., “Atrazine in sub-acute exposure results in sperm DNA disintegrity and nuclear immaturity in rats,” Veterinary Research Forum. 2012; 3(1): 19-26, http://www.urmia.ac.ir/vrf/Shared%20Documents/pdf/vol-3%20no-1/19-26%20-%200102.pdf.
Susan L. Carmichael, et al., “Hypospadias and Residential Proximity to Pesticide Applications,” Pediatrics November 1, 2013; 132(5): e1216-e1226, http://pediatrics.aappublications.org/content/132/5/e1216.
Pesticides & Birth Defects, California Birth Defects Monitoring Program, April 1999, http://www.cdph.ca.gov/programs/CBDMP/Documents/MO-CBDMP-Pesticides.pdf.
“Study Links Pesticides to Birth Defects,” U.S. News, March 31, 2009, http://health.usnews.com/health-news/family-health/womens-health/articles/2009/03/31/study-links-pesticides-to-birth-defects.
Elina Jerschow, et al., “Dichlorophenol-containing pesticides and allergies: results from the US National Health and Nutrition Examination Survey 2005-2006,” Annals of Allergy, Asthma & Immunology, December 2012, 109(6): 420-425, http://www.annallergy.org/article/S1081-1206(12)00671-0/abstract.