by Pesticide Action Network North America

The Centers for Disease Control and Prevention (CDC) yesterday released its Third National Report on Human Exposure to Environmental Chemicals, finding that more than 90% of U.S. residents carry a mixture of pesticides in their bodies. Many of these chemicals are linked to health effects such as cancer, birth defects and neurological problems. Children, who are particularly vulnerable to the effects of pesticide exposure, had higher levels of some pesticides in their bodies than adults.

CDC sampled the blood and urine of thousands of subjects across the country for 148 chemicals, 43 of them pesticides. This sample represents just over 3% of the 1,284 pesticide active ingredients currently registered in the U.S. that are formulated into tens of thousands of pesticide products for agricultural and home use.

Pyrethroids were included for the first time in this study, and CDC found one pyrethroid metabolite to be particularly widespread in the population, occurring in more than 75% of the subjects tested. Pyrethroids are insecticides widely used in agriculture, in home and garden pest products, and for lice control. They are a synthetic version of pyrethrins, a naturally occurring insecticide extracted from chrysanthemums. Unlike pyrethrins, which break down in the environment within hours, synthetic pyrethroids can last from days to months, creating a much greater risk of exposure.

The health effects of pyrethroids are well documented. Exposure can produce neurotoxic effects, vomiting, diarrhea and a tingling sensation on the skin (paresthesias). Pyrethroids are also suspected endocrine disruptors and possible carcinogens, and as a group are the second most common cause of pesticide poisoning reported to U.S. poison control centers.

Some pesticides were found in the CDC study at higher levels in children than adults. For example, the organophosphate pesticide chlorpyrifos was found at higher concentrations in children, indicating exposures more than four times the level EPA considers "safe." Home use of chlorpyrifos was banned in 2001 because of concern over health effects in children, but an estimated 10 million pounds continues to be used in agricultural fields every year. In the 2001/2002 period covered by this report chlorpyrifos was found in more than 75% of the population.

The organochlorine pesticides aldrin, dieldrin and endrin, banned in the U.S. for decades, were included in CDC's study for the first time and were detected in very low or un-measurable amounts. CDC also sampled for breakdown products of the organochlorine pesticide lindane, found in nearly half of the subjects tested. Unfortunately CDC did not test for other organochlorines that continue to be used in the U.S., such as endosulfan and dicofol. Organochlorines are known to persist in the environment, build up in people's bodies, and are passed from mother to child in the womb and through breastfeeding.

A body burden study released last week by the Environmental Working Group (EWG) reported findings similar to the CDC study, focusing specifically on chemical exposures infants received before they were born. EWG tested fetal cord blood of 10 healthy infants born at various locations around the U.S. in 2004, revealing exposures to a total of 287 chemicals. Among the most pervasive pesticides found in newborns were hexachlorobenzene, dieldrin and DDT (and its contaminants and byproducts).

PANNA issued a set of recommendations based on findings from the CDC study. These include:

Corporations like Bayer CropScience that continue to distribute organochlorine pesticide products should withdraw them immediately from the U.S. market.
Policymakers should use CDC's biomonitoring data to help develop policies that better protect public health, and particularly children.

CDC should make more detailed data (such as location and timing of sampling and occupational information) publicly available to help policymakers set priorities and evaluate impacts of state-level policies already in place, such as California's ban of lindane for pharmaceutical use.

Consumers should choose organic food and pesticide-free household and hygiene products to protect their families and support markets for healthy alternatives.

CDC's biomonitoring program is the largest in the U.S. and provides invaluable information on chemical exposures nationwide. The agency announced plans to expand the list of studied chemicals to more than 300 in the next study, to be released in 2007. This year's report provides important insights into the widespread nature of pesticide exposure in the U.S. and highlights the need to shift to less toxic approaches to pest management.

See CDC Releases 3rd National Report on the PANNA website, http://www.panna.org

Sources: CDC National Report on Human Exposure to Environmental Chemicals,http://www.cdc.gov/exposurereport/; Body Burden, The Pollution in Newborns, Environmental Working Group, http://www.ewg.org/reports/bodyburden2/release_20050721.php; Reigart, R.J., and Roberts, R.J. 1999. Recognition of Management of Pesticide Poisonings 5th Edition. Washington DC: U.S. Environmental Protection Agency. Contact: PANNA