CDC Can’t Link Human Health to Great Lakes Water Pollution

Published April 1, 2009

The best available scientific data show no firm connection between Great Lakes water pollution and human health effects, the U.S. Centers for Disease Control Agency for Toxic Substances and Disease Registry has concluded after an eight-year study.

‘Areas of Concern’ Examined

In 2001, a joint commission of the U.S. and Canadian governments asked the Agency for Toxic Substances and Disease Registry (ATSDR) for assistance in evaluating the public health implications of environmental contamination in 33 Great Lakes Areas of Concern.

The Areas of Concern are defined as “ecologically degraded geographic regions that require remediation.”

The report, “ATSDR Studies on Chemical Releases in the Great Lakes Region,” affirms the existence of pollution in the Great Lakes but observes many of the areas in question have been remediated, while others are in the process of remediation. In addition, the best available data show no link to human health harms, the report concludes.

No Health Harms Found

“Current data do not allow us to draw firm conclusions about relationships between critical pollutants in the Great Lakes region and potential health effect,” states the report.

“Data that are routinely collected (such as information on cancer and birth defects) are not well matched to exposure data in time or by location and therefore cannot help to assess whether the identified environmental exposures have adverse health effects,” the report explains.

Leaked Reports Misleading

Earlier drafts of the report were leaked to the press in 2007, before the study was finished. Environmental activists seized on the incomplete information to assert a link between Great Lakes pollutants and human health problems.

Lead author Howard Frumkin, who is director of the National Center for Environmental Health at ATSDR, emphasized the care taken to ensure the most accurate possible results in the final report, officially released in December 2008.

“First, good science matters,” wrote Frumkin in the Director’s Preface of the report. “Earlier drafts did not clearly assemble and analyze the available data; as a consequence, the data as presented could have led to incorrect conclusions.

“[The final report] aims to be accurate, informative, and useful to health professionals, decision-makers, and the public,” Frumkin added.

Unsupported Health Scares

Professor Thomas Derr of Smith College, the author of an environmental ethics book, believes the entire episode of a leaked draft health report containing incomplete data and unsupported conclusions should serve as a warning to the public regarding leaked information.

“The story still sounds rather cautionary, emphasizing inconclusive evidence,” Derr said. “But there’s an important point in it. Health scares ungrounded in solid evidence come along pretty regularly, getting their traction from the few that are real—for example, the recent peanut butter salmonella scare.”

The mere presence of some pollutants does not equate to human health harms, Derr added.

“There’s an old saying among scientists in relevant fields: ‘The dose makes the poison.’ Salt in mega-doses can kill you, but is essential in smaller doses,” Derr explained. “In fact, there’s research [showing] small amounts of substances that would be toxic in bigger doses may have a reaction something like vaccines in smaller doses, and stimulate the body’s resistance.

“In the long run I think the natural evidence will cause a slow and maybe embarrassing retreat from these scares,” Derr predicted.

Thomas Cheplick ([email protected]) writes from Cambridge, Massachusetts.

For more information …

“ATSDR Studies on Chemical Releases in the Great Lakes Region”: