TRAVERSE CITY, Mich. - Wrapping up an eight-year investigation of possible links between industrial pollution and health risks in the Great Lakes region, U.S. government researchers said Tuesday information was too sketchy and called for more study.
The Agency for Toxic Substances and Disease Registry, part of the U.S. Centers for Disease Control and Prevention, released the final version of a much-scrutinized report after drawing criticism from a scientific review panel and accusations of a cover-up from members of Congress.
"The data we have, as good as it is, isn't complete," said Dr. Howard Frumkin, director of ATSDR and the National Center for Environmental Health.
"We hope we can focus researchers and decision-makers on the need for targeted and careful data-collection...so we can get a more complete picture."
The agency began its review in 2001 at the request of the International Joint Commission, a U.S.-Canadian agency that advises the two countries on the Great Lakes and other boundary waters. The commission wanted an analysis of health hazards in 26 "areas of concern" - rivers, harbours, lakes and other locations severely degraded by toxic pollution.
But the report said available data doesn't allow firm conclusions about cause-and-effect ties between pollution and illness in the region.
Statistics on problems such as cancer and birth defects cannot be matched with pollution data because of differences in location and timing, it said.
Earlier drafts had attempted to do so, correlating countywide health figures with environmental measurements from larger or smaller areas. CDC officials dropped such linkages from the final report, saying they were flawed.
"Good science matters," Frumkin said in a written statement, adding the early versions "could have led to incorrect conclusions."
The Institute of Medicine, an independent scientific panel, raised the same concern last September in a critical review of the preliminary drafts.
U.S. Representative Bart Stupak, chairman of the House of Representatives energy and commerce subcommittee on oversight and investigations, began looking into the CDC's handling of the report last year. In a statement Tuesday, he contended it was reasonable to link the region's pollution and health problems.
"It doesn't take a scientist to tell you that the toxins discussed in this report are detrimental to human health and need to be cleaned up," said Stupak, a Michigan Democrat.
"It is almost as though CDC is trying harder to protect the polluters than the victims."
The study presented other challenges that help explain why it took so long, Frumkin said.
ATSDR had evaluated 146 hazardous waste sites around the Great Lakes. But they were not identical to the 26 "areas of concern," although there was some overlapping, Frumkin said. That meant the agency had not examined many sources of contamination in the areas of concern.
Also, some data was outdated because sites had been cleaned up.
Still, the report includes a wealth of material from health assessments at hazardous sites and statistics from several federal databases. But it doesn't reflect all chemical contamination in the region, Frumkin said.
The report recommends further investigation, including epidemiological studies that could shed light on possible links between health problems and exposure to toxic chemicals.
Such studies could lead to public policies such as recommending cutbacks on Great Lakes fish consumption, it said. Michigan is among states that already publish guidelines on eating fish from its waters.
