Three years ago, while my extended family was vacationing at my dad’s cranberry farm, he mentioned that one of his fields would be sprayed that evening. There were five children under 10 in the house, and I was eight months pregnant. The field was 100 feet away. I asked my dad about the pesticides, but he said, “Don’t worry. The government runs tests on the chemicals. They make sure they’re safe.”

The truth is plane to see.

Photo: iStockphoto.

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That night, through a closed window, I watched the plane rumble low over the field, the fog behind it drizzling softly to the ground. Behind me, in the house, the kids laughed and called, playing hide-and-seek. I started wondering about these tests.

I decided to do a little research. According to the U.S. EPA, about 5 billion pounds of pesticides were used in the U.S. in 2001. And researchers estimate only 1 to 2 percent of agricultural applications reach their target pest. Not surprisingly, these toxins can be found in almost every stream — and in most Americans’ bloodstreams.

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This country’s heavy reliance on synthetic pesticides is fairly new. We’re still on a learning curve that began in the 1940s. Around then, partially spurred on by chemical-warfare research, the new industry began to churn out products designed to kill everything from fungi to rodents. Until the 1960s, these toxins were tested mainly to make sure they were effective. But since Silent Spring, people have become increasingly wary about their health effects. Today, each new active ingredient must pass more than 100 safety tests to be legally registered. (Despite the fact that inert ingredients, which can constitute up to 99.9 percent of the total, can be just as toxic, tests are mandated only for active ingredients.)

At the EPA website, I found a seemingly thorough list of tests that examined chemicals’ effects on birds, mammals, fish, invertebrates, and plants. These tests checked for storage stability, residue on food, soil absorption, and short-term toxicity, as well as carcinogenic effects, prenatal harm, and damage to human fertility and genetic material. As I scanned the categories, a knot of worry inside me began to relax.

Field of bad dreams.

Photo: iStockphoto.

Until I learned all these experiments are completed by the manufacturers.

I called EPA press officer Enesta Jones, who said she had no problem with manufacturers overseeing safety experiments. Since the EPA is responsible for pesticide registration, she explained, it conducts compliance investigations, has developed strict guidelines, and reviews all data to ensure its integrity. (The agency’s role does not include enforcement of the tolerance levels it establishes, a duty that falls to the Food and Drug Administration and the Department of Agriculture.)

Now, I’ve always been impressed with science, which seems to be one of the few fields that hasn’t recently suffered some large scandal. Good science is based on transparency. Breakthroughs are reported in peer-reviewed journals, and experiments can be reenacted to verify the results. The openness of the system creates a consensus that heads toward truth.

Unfortunately, pesticide-safety experimentation is not transparent.

Although the analyses are performed by professional scientists, the results are often reported only to the EPA. They are rarely published in peer-reviewed journals, and must often be requested through the Freedom of Information Act, a process that can take years.

To get an idea of what’s behind the curtain, consider the findings of Tyrone Hayes. A professor of developmental endocrinology at the University of California-Berkeley, Hayes published an article in BioScience (yes, it’s peer-reviewed) in which he compared several previous experiments performed by others on the effect of atrazine on frogs’ sexual differentiation. Seven of the studies performed on this popular corn pesticide were paid for by Syngenta, the manufacturer; nine others were funded by independent sources. Every one of the Syngenta-funded studies concluded that atrazine did not affect amphibian gonads, while all but one of the independent studies found that the chemical did have an effect, sometimes at the level of one-tenth part per billion in water. That’s a stunningly small amount — about the same as dropping one tablespoon in almost 40 million gallons.

The Syngenta studies didn’t falsify data; they were simply designed to find “no effect,” by exposing both the control and experimental groups to enough atrazine to affect their gonads. This type of testing isn’t criminal. It’s just bad science.

And here’s more: last year, Alan Lockwood, professor of neurology and nuclear medicine at the State University of New York at Buffalo, published an analysis in the (peer-reviewed) American Journal of Public Health of the pesticide tests on humans that he could get access to through FOIA. In one, the consent form implied that the pesticide — a known neurotoxin — might make the subjects smarter. It didn’t mention the actual possibilities of vomiting, convulsions, or death. In another, when four of six participants got sick and had to drop out, the experimenters based their positive results on the two remaining subjects. Lockwood said all the studies had “serious ethical or scientific deficiencies — or both.”

The idea of testing on human volunteers, halted in 1998, has resurfaced thanks to industry pressure and a “sympathetic ear” in the form of EPA administrator Stephen Johnson. But the notion still has powerful opponents — Johnson’s confirmation was blocked until he cancelled a plan to study pesticides’ effects on low-income children — and controversy has surrounded EPA’s draft rules on such tests, released this fall. A public-comment period on the rules ends Dec. 12.

The son I was pregnant with when the cranberry bog was sprayed has developed slowly in different ways. He started talking so late the state sent a speech therapist over to tutor him. My older son, who was also there, can’t draw. He’s 5 now and gets frustrated trying to make even a stick figure. The one time he tried to draw me, it looked like an amoeba with three eyes.

Does this have to do with drifting pesticides? I can’t tell you. None of us will know for sure the effects of these chemicals until there’s good science involved — science that isn’t funded and reported by the very people making the chemicals in the first place.