CDC Measures Pollution in Americans
Danger Level Unknown for Most of 116 Chemicals
WebMD News Archive
Jan. 31, 2003 -- Pollution is everywhere -- including our bodies. How much is harmful? Now the CDC has a powerful new way to find out.
Two years ago, the CDC released its first report, focusing on 27 chemicals polluting the environment. The new report includes 116 of these chemicals. It's not a guess. The data come from actual blood and urine measurements from thousands of Americans.
"We are pretty excited," David Fleming, MD, CDC deputy director for public health science, said in a news conference. "This is by far the most extensive assessment of exposure of the U.S. population to environmental chemicals. It is a quantum leap forward in providing information about what is getting into people's bodies and how much is getting in."
The 116 chemicals are a nasty lot. They range from secondhand tobacco smoke to pesticides, from metals such as lead and uranium to long-lasting industrial compounds such as dioxins and PCBs. Most of these chemicals are known to cause cancer or other health problems in animals.
Every one of the chemicals was found in some amount in at least some people. What that means isn't yet clear. Just because people have environmental chemicals in their bodies doesn't necessarily mean they will suffer disease. The body is well equipped to handle all kinds of exposures -- up to a point. The job now is to find out what that point is. And the new data will be a big help.
There's some good news. In the early 1990s, 4.4% of U.S. children 1-5 years old had dangerous levels of lead in their blood. Now this number has been cut in half -- although the 2.2% of these kids who today have too high blood-lead levels is still a major public health problem.
Of all the chemicals tested, one really troubles Richard Jackson, MD, MPH. Jackson is director of the CDC's National Center for Environmental Health, which issued the report.
"One-third of all cancers are from tobacco. It is one of the big killers in America," Jackson tells WebMD. "The fact that more than half of our kids still have environmental tobacco smoke exposure when it is known to be associated with sudden infant death syndrome, with respiratory infections, and the rest -- well, if we had to pick something to really go after, that would be one that is an extraordinarily high priority. And it is one people can really do something about."
Another worrisome chemical is called chlorpyrifos. It's a pesticide that wasn't banned until December 2001. Levels of this chemical are twice as high in children as in adults. The size of this problem isn't known. Nobody yet knows the chlorpyrifos level that's harmful to health.
Questions like this are exactly why the study was done, according to Jim Pirkle, MD, PhD, deputy director of the CDC's environmental health center.
"This report has a lot of information," Pirkle tells WebMD. "From a public health point of view, it is a giant step forward for us. It will make big differences in our ability to identify and prevent disease."