Articles

RSS

Human volunteers—recruited by Loma Linda University Medical Center and paid U.S.$1000 apiece—are testing pills containing the industrial pollutant perchlorate (found in rocket fuel) for the chemical's physiological effects.

Lockheed Martin is funding the experiment with the intent to develop data that could influence the setting of national- and state-drinking-water standards.

The experiment is not unique since several small, industry-funded tests on human volunteers have been conducted in recent years for some compounds, including perchlorate, where the risks of consuming low levels are poorly understood.

However, the Lockheed Martin perchlorate test, which began in August, reportedly is the first on a large-scale.

In the perchlorate tests, 50 volunteers ingest up to 3 milligrams daily—83 times the amount a person would get from drinking water's containing the amount allowed by the California Department of Health Services. Another 50 swallow a placebo. They will be doing so into January.

Seeking Certainty
At high doses, perchlorate can inhibit production of thyroid hormones and, in rare cases, in fact, it is used medically to treat hyperthyroidism.

What the researchers are attempting to determine is whether small doses interfere with human thyroid function. Until now, the evidence has been mixed.

"As an endocrinologist, this is of interest to me because clearly we don't know what the effects of the contaminant are on thyroid function," said Anthony Firek, who is directing the perchlorate study at the medical center.

Firek said that if perchlorate were only a pollutant and not a drug, he would have declined to conduct the human tests.

Exposing human volunteers to industrial chemicals mostly is a recent development and still relatively rare.

On the other hand, air-pollutant testing using humans has been routine for more than half a century. And today, researchers in several institutions—including the EPA—use smog chambers to expose volunteers to ozone, particulates, and other air pollutants.

Concerned about recent examples of human testing of pesticides, the U.S. Environmental Protection Agency (EPA) sought advice from its scientific advisory board. The panel, in a report issued in September, supported human testing on a limited scale but urged "the greatest degree of caution."

No government agency regulates human experiments. But every institution has a review board that must approve each study before it can take place.

Precautions Taken
In the case of the Loma Linda study, the boards of three medical institutions approved the perchlorate tests, Firek said. In addition to Loma Linda, they are Boston University—which employs one of the researchers—and the Jerry L. Pettis Memorial VA Medical Center, where some of the tests are being done.

The volunteers in the Loma Linda experiment undergo extensive medical testing to ensure that they face no threats while ingesting the compound. Included are monthly tests to measure their thyroid, liver, and kidney functions. Unhealthy individuals and fertile women are excluded. Volunteers exhibiting physiological change during the course of testing must discontinue taking their pills.

Concern about perchlorate in drinking water began in 1997, after a test was developed in California to enable detection of small concentrations of the substance in water.

The EPA does not regulate perchlorate, but it has mounted a review to consider setting a standard.

The California Department of Health Services has set an "action level" that recommends shutdown of wells with water containing more than 18 ppb perchlorate. State officials are expected to recommend a more stringent public health goal. Nationwide perchlorate testing of water supplies begins in 2001.

The previous case study was adapted from the report, "Volunteers Ingest Pollutant in Drinking Water Study," prepared by Marla Cone, Los Angeles Times environmental writer. It appeared in the Times' Nov. 27 edition.