NADD - An association for persons with developmental disabilities and mental health needs

From the NADD Bulletin Volume XI Number 3

Organophosphate Pesticides and Children’s Health

Pesticide Action Network North America

Pesticides - A Greater Threat to Children

Children are more vulnerable than adults to dangers of all kinds. We invest in car seats, babysitters, and childproofing our homes knowing that environments that seem safe for adults are wrought with potential disaster for the very young. However, we do not adequately protect kids from chemical pollution in our environment, even though it too may be much more dangerous to children than to adults. "The science is in: Children are born with lower levels of our bodies' natural defenses against toxic pesticides," said Dr. Gina Solomon, M.D., a physician and senior scientist at the Natural Resources Defense Council (NRDC). "Yet EPA too often ignores the clear scientific evidence and fails to protect the most vulnerable people from these dangerous chemicals." Recent research conducted at the University of California, Berkeley echoes this statement. The 2006 scientific study shows that children can be up to 164 times more sensitive than adults to pesticides that frequently contaminate agricultural communities.

Organophosphate Pesticides: A Case in Point

In 2001 and 2002, the U.S. Centers for Disease Control (CDC) tested the blood and urine of thousands of U.S. residents for signs of 148 chemicals, 43 of them pesticides. Prominent among the list of contaminants found in significant concentrations were organophosphates (OPs), potent nerve toxins used as pesticides in agriculture as well as home and garden, on pets, and in programs to control the carriers of disease. In the CDC study, the insecticide chlorpyrifos, one of the most infamous OPs, was detected in 76% of those tested. Chlorpyrifos concentrations in children aged 6–11 were four times higher than levels considered acceptable by the U.S. Environmental Protection Agency (EPA).

Unfortunately, recent research suggests that children may be much more sensitive to exposure to the OP chlorpyrifos than EPA has previously assumed when regulating pesticides. According to a research team led by Professor Brenda Eskenazi at the University of California, Berkeley, newborn children can be 65 to 164 times more vulnerable than adults to the common agricultural pesticides diazinon and chlorpyrifos (Lorsban). The study was published in the scientific journal Pharmacogenetics and Genomics in March 2006. The Berkeley researchers worked with 130 Latina mothers and children in the Salinas Valley agricultural region of California starting in 1998. Blood samples from both groups were analyzed for a key enzyme (known as PON1)which normally helps the human body detoxify the OP class of pesticides. Higher levels of the enzyme help protect people from being poisoned by these chemicals. The researchers examined levels of PON1 to predict the women and children's sensitivities to these pesticides. The Berkeley study indicates that both mothers' and children's sensitivity to certain pesticides may be substantially greater than the uncertainty factors used by EPA. NRDC and the Northwest Coalition for Alternatives to Pesticides are using the study as further evidence in their ongoing lawsuit charging that EPA fails to protect children from pesticide exposure in foods including fruits, vegetables, milk, eggs, meat, cereal grains and vegetable oils. The case is being heard by the 9th U.S. Circuit Court of Appeals in San Francisco.

Pesticide Action Network (PAN) North America Senior Scientist Dr. Susan Kegley notes that chlorpyrifos “interferes with fetal development of neurons, which leads to impaired development of motor function and cognitive skills in children. It’s time for us to eliminate this chemical once and for all.” Chlorpyrifos has also recently been found to depress levels of the nervous system enzyme cholinesterase in one out of ten farmworkers studied in the state of Washington. "We're all exposed to pesticides in the foods we eat," said Margaret Reeves, Ph.D., senior scientist at the PAN North America. "But it's the farmworkers and the fence line communities in agricultural areas that are hit the hardest." Altogether, these studies indicate that chemical-intensive agriculture extracts a high price from rural residents--especially the children.

EPA banned chlorpyrifos and diazinon for household use in December 2001 and December 2002 respectively largely because of hazards to children, but it allowed continued use on agricultural crops. The action did nothing to protect farmworkers, families and children in rural communities where chlorpyrifos continues to be widely used.

More than 2 million pounds of chlorpyrifos were used in California in 2005, the most recent year for which data are available. The top uses were on cotton, oranges, almonds, alfalfa, and walnuts. In 2001, the most recent year for which EPA has reported data, about 20 percent of all foods for sale had residues of one or more OP pesticides. The highest residues of chlorpyrifos tend to show up on apples from New Zealand, grapes from Chile, tomatoes from Mexico and domestically grown soybeans, according to the University of California report.

Banning All Uses of the Organophosphate Pesticide Chlorpyrifos:

A Priority for Children's Health & Justice

To address this highly problematic class of pesticides, PAN, farmworker, and environmental health and justice groups have launched a campaign to work for elimination of the most hazardous OPs. The campaign’s initial targets include the pesticides chlorpyrifos and malathion. In October 2006, PAN and 19 partners submitted public comments to the EPA regarding the Agency’s years-overdue Cumulative Risk Assessment of OPs. In January 2007, PAN and partners filed a public comment letter on malathion with EPA. The comments highlighted years of documented dissent by EPA scientists regarding EPA’s assessment of malathion’s health effects, including its carcinogenicity and developmental neurotoxicity. According to EPA’s July 2006 Malathion Risk Assessment, the OP malathion also is used as a pediculicide for the treatment of head lice on children.

It’s not news that, in the Bush years, EPA has promoted business interests over public health. But what is new is the scale of the internal revolt that has been growing. In mid 2006, EPA’s career scientists protested the decision by the Agency’s politically appointed administrators to re-register OPs without adequate scientific evidence that these acutely hazardous pesticides are safe to use. In the face of convincing data to the contrary, EPA eased pressure on malathion manufacturers by lowering the chemical’s purported cancer risk from “likely” to merely “suggestive.” Meanwhile, press reports have revealed that key documentation substantiating the need for the higher risk level had vanished from EPA files. During Senate hearings, Barbara Boxer upbraided EPA Chief Stephen Johnson, noting, “according to your own staff, in one of the libraries, 600 to 700 linear feet of the chemical library collection was discarded.”

During May 2007, PAN and partners from the statewide coalition Californians for Pesticide Reform (CPR) released the results of three years of air monitoring for chlorpyrifos in California’s Central Valley town of Lindsay. The third year included results from biomonitoring of eight women and four men, showing chlorpyrifos levels in all but one of the participants’ bodies at levels above those considered acceptable for pregnant and nursing women. As a result, community members have redoubled efforts to pressure county authorities to establish protective no-spray zones around schools, homes and other sensitive sites. In December 2007 Lindsay area residents joined PAN and CPR in requesting the CA to formally recognize chlorpyrifos as a developmental toxicant. On January 18 CA’s Office of Environmental Health Hazard Assessment announced it’s plans to move forward on its consideration of listing chlorpyrifos as a developmental toxicant.

In the meantime, PAN is plaintiff with representation by partners NRDC, Earthjustice, Farmworker Justice and California Rural Legal Assistance, Inc. on two legal proceedings calling for an all-out ban on chlorpyrifos.

Sources:

Centers for Disease Control and Prevention, Third National Report on Human Exposure to Environmental Chemicals, 2005.

2004 PAN North America report, Chemical Trespass.

Farm Worker Pesticide Project, Columbia Legal Services, Farmworker Justice Fund, and United Farm Workers. 2006. More Messages from Monitoring: Year 2 of Washington State's Farm Worker Medical Tracking Program. http://www.fwpp.org/?page=MedicalMonitoring

Furlong, Clement E., Nina Holland, Rebecca J. Richter, Asa Bradman, Alan Ho and Brenda Eskenazi. 2006. "PON1 status of farmworker mothers and children as a predictor of organophosphate sensitivity," Pharmacogenetics and Genomics 16:183-190.

NRDC Press Backgrounder. 2003. "NRDC Sues EPA (Again) for Failing to Carry Out Pesticide Control Law." www.nrdc.org/media/pressreleases/030915a.asp

For further information, contact Kathryn Gilje, Executive Director, Pesticide Action Network North America (PANNA) at kathryn@panna.org .

The NADD Environmental Health Project, funded by the John Merck Fund, provides professionals, families, and the general public with relevant information concerning toxic agents and their affects on neuro-development. For further information visit www.thenadd.org and click on “Environmental Health Project,” or contact Ed Seliger, Project Coordinator, at eseliger@thenadd.org.

* Sponsored by the John Merck Fund *