tie between lake toxins, cancer rates unravels

Reports linking pollution to high levels of cancer and infant mortality in Great Lakes hot spots -- including in the Twin Ports area -- can't be trusted.

Reports linking pollution to high levels of cancer and infant mortality in Great Lakes hot spots -- including in the Twin Ports area -- can't be trusted.

That's according to an independent review of the reports released Friday.

Draft reports leaked to the public in February by a nonprofit watchdog group found that residents of St. Louis and Carlton counties have higher-than-usual rates of stroke and Douglas County residents have high levels of stroke, heart disease, colon cancer, breast cancer, infant mortality and post-birth infant mortality.

The reports noted that Twin Ports counties are home to several polluted toxic hot spots along the harbor, though the report stopped short of linking the two issues. The local counties were among several around the Great Lakes pointed out as having high rates of certain cancers and infant mortality, as well as polluted areas in harbors, rivers and the Great Lakes.

But a panel of independent experts now says scientific problems are enough to cast doubts on the report's link between pollution and health.


Robert Wallace, professor of epidemiology and internal medicine at the University of Iowa's College of Public Health and head of the review panel, said the reports have several issues.

"We found problems in how each draft was developed, which data were used and what conclusions the authors drew," Wallace said in a statement.

The panel did not say that there definitely was no link between disease and the pollution.

"Our task was to focus solely on the scientific quality of the drafts and not to assess whether pollution around the Great Lakes poses health concerns," Wallace said.

The reports in question were compiled over seven years by the Centers for Disease Control and Prevention by request of the International Joint Commission. The reports came amid concerns that decades-old pollution around the Great Lakes might pose a health problem.

The Centers for Disease Control and Prevention had refused to release the draft results, saying they might cause unnecessary concern and lacked context. But the reports were made available in February by the Center for Public Integrity.

The Centers for Disease Control and Prevention was widely criticized for stalling release of the report -- including by several members of Congress. But the review panel now says the agency may have been warranted in keeping the study under wraps.

One key issue raised by the independent panel is that environmental data from specific contaminated sites, such as those on the St. Louis River in the Twin Ports, were lumped together with health data taken from entire counties.


The review said that "pollution and health data were lumped together despite differences in where and when the information was collected'' and without explanation of how a particular toxin might lead to any identified health problem.

"This juxtaposition of data without explanation or support could lead readers to assume links between contamination and health problems regardless of whether they actually exist,'' the report concluded.

Scientists involved in compiling the report said they never meant to attribute any specific disease to the pollution, only to show a geographic overlap.

What To Read Next
Get Local