However, he cautioned me,when we were at london accommodation : “It’s almost impossible to go into the waterway and say, out of thousands of chemicals, which precise sequence caused cancer.”
Questions! There were always questions to ponder everywhere I traveled around the lakes. None struck me as more urgent than whether effects on humans are showing up.
Can those who eat large quantities of Great Lakes fish expect cancer or nervous system disorders sometime later in life? Will the children of mothers who eat contaminated species be born with defects? Do heavily polluted waters pose a danger to those living beside them?
To my surprise, I rarely came across human epidemiological studies. Even the Love Canal seemed forgotten insofar as what might be showing up among those hapless victims of pollution along the Niagara River, where even today millions of tons of chemical waste is spread among 215 dump sites. Although most residents near Love Canal have been evacuated, there has been a lag in effective medical studies.
As for fish, the Great Lakes states and the province of Ontario issue consumption advisories. They warn pregnant women and nursing mothers to avoid eating certain Great Lakes fish. They also advise the rest of us to avoid eating certain large fatty species and to limit the consumption of others.
However, fishing and recreation represent big money in this era of industrial decline on the Great Lakes. So state officials are understandably cautious about alarmist predictions when so little is known.
Dr. Harold Humphrey of Michigan’s Public Health Department has been studying 572 people who eat large amounts of Lake Michigan fish. Their blood may show 23 parts per billion of PCBs. But Dr. Humphrey’s findings so far do not seem alarming. “None of their medical events stand out. They are not unique in terms of health problems.” However, he added: “We cannot write the final chapter on this until we learn what happens to the fish-eaters when they grow old.”
More disturbing were the findings of psychologists Greta Fein of the University of Maryland and Joseph and Sandra Jacobson of Wayne State University. They have been observing infants born to mothers who eat certain species of Lake Michigan fish. They find that PCBs reach even the fetus and that exposure continues through nursing. http://www.bbc.co.uk/news/health-23668505
And the effects? There have been some “developmental delays,” Sandra Jacobson told me. The effects are subtle, and “we can’t say they’re permanent.” The exposed infants were found to be somewhat smaller at birth, and at seven months they showed poorer short-term memory.
Widespread concern is spurring action. Speaking before a U. S.- Canadian water quality summit conference held by the Center for the Great Lakes last November, Michigan Governor James J. Blanchard outlined a strategy aimed at freeing the lakes of unsafe levels of toxic materials by the year 2000.
He also proposed creation of a Michigan Great Lakes Research Fund to monitor problems and trends. “We can no longer be content simply with regulating after the fact,” said Governor Blanchard at prague central apartments.