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What You Don't Know Could Hurt You

What You Don't Know Could Hurt You

Pesticides in California's Air
Friday, January 1, 1999

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EWG Air Monitoring Finds Toxic Pesticides Drifting From California Farm Fields

Airborne Poisons Found in More than 60 Percent of Tests

SACRAMENTO -- January 1999 -- Two years of independent scientific monitoring by the Environmental Working Group (EWG) detected an array of toxic pesticides drifting into the air Californians breathe -- the tip of a 100-million-pound iceberg of hazardous chemicals emitted statewide each year as a result of pesticide use.

From June 1996 to September 1998, EWG collected nearly 100 air samples in Sonoma, Contra Costa, San Mateo, Santa Cruz, Monterey, San Luis Obispo, Santa Barbara and Ventura counties, which were then analyzed by a certified laboratory in Oakland. Almost two-thirds of the EWG air samples contained pesticides known to cause cancer, brain damage, birth defects, acute poisoning or other illnesses.

At the same time, an EWG analysis of the latest available state data found that pesticides drifting into the air at the time of application are only a small part of the air pollution caused by pesticide use. An estimated 100 million pounds a year of smog-forming volatile organic chemicals contained in pesticides or formed by the breakdown of pesticides also evaporate into the air after application -- four times more than all the oil and gas refineries in California.

EWG and Californians for Pesticide Reform (CPR) said the monitoring results and statistical analysis provide strong evidence that the state is failing to adequately regulate pesticides in air, placing millions of Californians at risk of exposure. They called on the new Davis Administration to clean house at the state Department of Pesticide Regulation (DPR), and shift authority over airborne pesticides to the Air Resources Board (ARB).

"DPR is in denial about the public health risks of the excessive use of pesticides in California," said Bill Walker, state director of Environmental Working Group and a principal author of the group's report, "What You Don't Know Could Hurt You: Pesticides in California's Air." (Available online at "The evidence shows that pesticide use routinely exposes Californians to multiple hazardous chemicals in the air where they live, work or attend school. For the state to claim that's not a problem is unacceptable."

Levels of airborne pesticides detected by EWG monitoring were in most cases relatively small, but that does not necessarily mean they were safe. Health-based safety standards for most pesticides in air have not been established, and those that do exist are not set to protect children or other sensitive populations, but are based on supposedly safe levels of exposure for the average adult.

"For communities near heavy pesticide use, the issue is not whether DPR considers the amount of poison in the air to be safe," said David Chatfield, executive director of CPR. "The real issue is the right not to be poisoned at all."

EWG's monitors collected 55 air samples to test for multiple pesticides. Twenty-nine samples, or 53 percent, tested positive for pesticides known or suspected to cause cancer, birth defects or damage to the brain, nervous, endocrine or reproductive systems. Separately, 39 air samples were collected to test for methyl bromide, a fumigant known to cause nerve damage and birth defects and erode the ozone layer. Thirty-one samples, or 80 percent, tested positive.

In most of the counties where EWG found drifting pesticides, DPR has never conducted air monitoring. Between 1991 and 1995, DPR monitored only 50 times in 14 locations -- about one test for every 84,000 pesticide applications in the state.

But pesticide drift during applications is only part of the problem. After application, pesticides give off large quantities of reactive organic gases (ROGs, also known as volatile organic chemicals), which can cause cancer, birth defects, nerve damage and kidney and heart disease. ROGs also contribute to the formation of smog.

According to the ARB, some 98.9 million pounds of ROGs are emitted from pesticides each year -- nearly four times the total of ROG emissions from petroleum refining (25.5 million pounds annually) and more than double the ROG emissions from all other industrial sources (46 million pounds.) In the San Joaquin Valley, one of five areas in the state where air quality fails to meet federal standards, pesticides emit an estimated 34 million pounds of ROGs a year -- 13 percent of the region's total ROG emissions.

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