Newsday
1 February 2003

Study Probes Bodies' Toxicity Looks at race, age differences

By Dan Fagin

Children and minorities have more pesticides and industrial chemicals in their bodies than do other Americans, but in most cases levels are far below those that have been experimentally linked to cancer or other health problems, according to a landmark federal study released Friday.

The new study, which measured levels of 116 synthetic chemicals in the blood and urine of thousands of Americans, is the most ambitious effort yet to establish the toxic "body burden" of the general population. Its long-awaited release by the national Centers for Disease Control and Prevention fueled a running battle between environmentalists and industry officials over what it meant.

While manufacturers asserted the study proved that chemicals are generally not being detected at dangerous levels, activists argued that in many cases there's not enough information to know what levels are dangerous. Environmentalists said the study also provided the strongest confirmation yet that some segments of the population - including children and minorities - are facing significantly higher risks.

Just about the only thing that all sides agreed on Friday was that the study will play a crucial role in establishing a baseline of "typical" toxic exposures that can be used as a benchmark in environmental studies. A study of an alleged neighborhood cancer cluster near a hazardous-waste site, for example, will be able to determine if the chemical levels in the local population are truly unusual.

The study "is a quantum leap forward in providing objective, scientific information about what's getting into people's bodies and how much is getting in," said Dr. David Fleming, the deputy director for science at the CDC.

The $6.5-million study is actually the CDC's second attempt to measure chemicals in a broad spectrum of Americans. The first effort, released almost two years ago, covered just 27 chemicals and did not include information on how chemical exposures differ by race and age. Both have required complex detective work because many industrial chemicals, once inside the body, are metabolized into other compounds that had never before been reliably measured in blood or urine.

The study's authors said the race and age distinctions were some of the most significant findings. For example, blood lead levels in children under age 5 were more than 25 percent higher than in adults. Blacks and Mexican-Americans had lead levels 15 percent higher than non-Hispanic whites.

Levels of a metabolite of the pesticide chlorpyrifos, also known as Dursban, were almost twice as high in the urine of children ages 6 to 11 as in adults. A metabolite of a plastic-softener known as DEHP - used in toys, shower curtains and many other products - was found in the urine of young children at levels 60 percent higher than in adults.

Scientists cited several reasons levels tend to be significantly higher in children: They eat and drink much more per pound of body weight than do adults, they put their hands in their mouths more, and they spend more time close to dirt and carpets, where contaminants can accumulate. Researchers say that on average minorities are more likely to live in highly polluted areas.

The study also showed that some long-banned synthetic chemicals - including the insecticide DDT and the electrical insulators known as PCBs - are being detected at low levels in children who were born years after the products were banned, apparently because the chemicals were passed on during pregnancy.

A prominent federal scientist not connected with the study said Friday that the findings bolster the case for tougher regulation. "By definition, if you have body burdens of chemicals that have not been proven firsthand to be harmful but are not normal for a healthy body, then we should not have them in our bodies," said James Huff, an associate director at the National Institute for Environmental Health Sciences.

But industry officials said the study bolsters their long-standing assertion that chemical residues in most people are far too low to be a health threat.

"I see nothing in this study that would indicate a level of health concern for Americans," said Jay Vroom, president of CropLife America, a Washington-based association of pesticide manufacturers.

The CDC study is available on the Internet at www.cdc.gov/exposurereport.