Halt to Pesticide Tests on Humans Is Sought

More than 100 volunteers in San Diego were intentionally exposed to a pesticide in one of two dozen scientific experiments worldwide that have come under attack by California members of Congress who are urging the Bush administration to stop accepting data from human testing they call unethical and dangerous.

At UC San Diego, 127 adult volunteers -- mostly students -- were exposed to a low-dose vapor of chloropicrin, a soil fumigant, between March 2002 and June 2004, according to university officials. Some were placed in a small room containing the vapors while others sniffed or exposed their eyes to vapors in glass cones or steel tubes, said Leslie Franz, a university spokeswoman.

Chloropicrin is applied to kill fungus on strawberries, other crops and nursery plants. It was used as a tear gas in World War I because it is extremely irritating to eyes, noses and lungs. At high levels, it causes coughing and breathing problems.

The ethics of human tests conducted by the pesticide industry have been debated by scientists, regulators and politicians for years. But in recent months, the U.S. Environmental Protection Agency’s use of data from such testing has been under fire in Congress.

On Thursday, California Sen. Barbara Boxer and Rep. Henry A. Waxman of Los Angeles, both Democrats, released a report compiled by their aides detailing 22 of 24 human experiments that the EPA has reviewed or plans to review when regulating the safety of pesticides.

Waxman called the tests “rife with ethical and scientific defects.” Boxer said their report “proves the Bush administration is encouraging dangerous pesticide testing on humans with no standards.”

The Boxer-Waxman report singled out the San Diego experiments as being especially egregious because some volunteers received doses as much as 120 times greater than federal workplace standards for the chemical.

UC San Diego officials said no volunteers were injured, although irritated noses and eyes were reported. They said that the study, led by professor William S. Cain of the university’s Chemosensory Perception Laboratory, provides valuable information to the EPA about how to safely use chloropicrin. The experiment sought to determine at what levels the chemical was an irritant, which would help the EPA decide whether it could be used in agricultural fields near homes and businesses.

Under a court order, the EPA is allowing the industry’s human test data to be used on a case-by-case basis until it develops regulations overseeing the experiments. A panel of the National Academy of Sciences reported in 2004 that such studies should be limited by the EPA -- but not banned -- because they are valid if the societal benefits outweigh the volunteers’ health risks.

Testing pesticides on people is rare. Typically, pesticide manufacturers hire scientists to test the effects on lab animals. But industry representatives and some scientists say that human experiments at low doses are sometimes needed to answer the EPA’s questions about the risks of pest-killing chemicals.

UC San Diego officials said the subjects in the tests were exposed to “concentrations at low enough levels to have no adverse effects, other than irritation.”

Franz said the volunteers were asked to rate their symptoms of eye tearing and other irritation on a scale of zero to three, with zero being no symptoms and three being defined as “hard to tolerate and can interfere with activities of daily living or sleeping.” Some subjects recorded the severest rating but none asked to leave the chamber although they were free to do so. The average rating at the highest concentration was a one, “minimal awareness, easily tolerated.”

“The symptoms went away when the exposure ended,” Franz said.

Various scientific studies have shown no evidence that exposure to chloropicrin can cause permanent or chronic harm such as cancer or other disease, or any genetic or reproductive effects.

All of the San Diego volunteers, who were paid $15 an hour, signed consent forms and were informed that risks were involved, the university said. The study was approved by a UC San Diego review board.

Of the 24 human experiments submitted to the EPA, six were performed in the United States. In some studies, according to the Boxer-Waxman report, subjects were instructed to swallow capsules containing pesticides and volunteers were often inadequately notified of the health risks.

In May, the House of Representatives approved an amendment coauthored by Rep. Hilda L. Solis (D-El Monte) to the EPA’s annual appropriations bill that would prevent the agency from using data from human pesticide tests over the next year.

Boxer plans to introduce the same amendment in the Senate when the appropriations bill is brought there in a couple of weeks. She also said she would introduce legislation that would permanently restrict such experiments unless the EPA adopts regulations soon.

EPA policies related to human testing have often shifted.

In 1998, under the Clinton administration, the EPA put a moratorium on human studies in regulating pesticides. Three years later, under the Bush administration, the EPA announced it would start using the studies again, but changed its position after criticism from environmental groups.

Then, in 2003, a U.S. Court of Appeals ruled in a case brought by the pesticide industry that the EPA cannot refuse to accept the human tests unless it develops a regulation banning them. As a result, the EPA lifted the moratorium and announced that it would develop a new policy. In the interim, the EPA announced in February that it would allow use of the human data “on a case-by-case basis, applying statutory requirements, the Common Rule, and high ethical standards as a guide.”

The Common Rule sets ethical standards for human research sponsored by federal agencies.

International standards for human testing, such as the Nuremberg Code developed after Nazi scientists experimented with World War II concentration camp prisoners, have been in place for decades.

But the Boxer-Waxman report said that it found “serious violations of these fundamental standards” in the 22 studies reviewed. “Nearly one-third of the studies reviewed were specifically designed to cause harm to the human test subjects or to put them at risk of harm,” the report says.

Erik D. Olson, a senior attorney with the environmental group the Natural Resources Defense Council, said the report “reveals the shocking truth about immoral chemical industry experiments.”

“It’s outrageous that this kind of human experimentation is being tolerated or even encouraged by the U.S. government,” he said.

CropLife America, a pesticide manufacturers trade group, has said that “only a handful of studies” use human volunteers and only when the data are essential to answer key questions for registering legal uses of pesticides.

Banning human testing of pesticides “could jeopardize public health” because it would impair the ability of scientists and regulators to use accurate data in determining safe levels for pesticide exposure, the group said in a statement last month.