Think of all the antibiotics and other forms of medication the 40 million U.S. and Canadian residents who live in the Great Lakes region ingest and subsequently pass through their bodies, as well as all of the expired or unused pills, liquids, and inhalers they throw down their sinks, their toilets, or out with the trash.
Add to that what agriculture uses to grow crops and keep animals healthy.
Where does it all end up?
Nobody knows for sure, but microscopic traces of our growing, aging society's pharmaceuticals and personal hygiene products - from nasal drugs to steroids to the active ingredient in soap - are showing up in North America's rivers and streams, including those that flow into the Great Lakes.
The issue of pharmaceutical pollution that has made its way into the halls of science is making its way into the legal arena.
It was one of the topics of Friday's 10th annual Great Lakes Water Conference sponsored by the University of Toledo's college of law and its affiliated Legal Institute of the Great Lakes.
Panelists said it is inevitable: As scientists examine the cumulative, long-term effects of pharmaceutical pollution on human and wildlife hormones, conventional wisdom that levels of less than 1 part per billion are inconsequential faces an ever-greater challenge.
"It's ongoing and it's mind-boggling," one of the panelists, David Pitts, a Wayne State University pharmacology professor, said of the suspected volumes in question.
The panel also included Jeffrey Lape, deputy director of the U.S. Environmental Protection Agency's Office of Science and Technology. Mr. Lape left no doubt that pharmaceutical pollution is a grossly understudied issue with massive data gaps that need to be filled "before our comfort level can be satisfied."
Mr. Lape said he knows of no wastewater treatment plant in the country that discharges water free of pharmaceutical pollution.
"You're going to see this as an emerging issue," he said. "It's one we need a lot more understanding of from a science standpoint and a public health standpoint."
The issue sheds light not only on an often-overlooked source of pollution, but also raises new questions about how far scientists, public health officials, and environmental regulators should go in their quest to clean the nation's waters, panelists said.
"The fact is we're producing this stuff far faster than we can possibly understand what their impacts are," Mr. Lape said.
"There's a lot more work that needs to be done and not just of the chemicals, but also their complex interactions."
Nick Schroeck, a Wayne State law professor and executive director of the nonprofit Great Lakes Environmental Law Center, said the public should not be alarmed - but should realize that exposure at sublethal levels has the potential of tinkering with the body's chemistry.
Professor Schroeck's center and the nation's largest group of environmental lawyers, the Natural Resources Defense Council, petitioned the U.S. Food and Drug Administration this summer to rescind its 1 part-per-billion-threshold for pharmaceuticals and do more extensive research. The petition has not yet been ruled upon.
"We're not even screening for them, let alone taking them out," Mr. Schroeck said.
Few, if any, pharmacies accept unused drugs.
The government had a national drug take-back program on Sept. 25, but only for one day.
A number of challenges exist before they become more common, such as the U.S. Drug Enforcement Administration's ability to keep narcotics from getting into the wrong hands, Mr. Lape said.
The conference touched on myriad Great Lakes issues, from renewable energy to Asian carp to regional water rights and the competing U.S.-Canada philosophies about drilling.
Ohio Department of Natural Resources Director Sean Logan said the state is virtually "ready to go" with more wind power along and near the Lake Erie shoreline.
Keith Wilkowski, a local lawyer and former Toledo mayoral candidate, said Ohio has taken steps under its advanced energy law to diversify its sources of power.
The state now gets 86 percent of its electricity from coal-fired power plants, with 10 percent of it derived from nuclear, 2 percent from natural gas, and 1 percent from renewable sources such as wind, solar, and biomass.
He said a $15 million grant the Toledo-Lucas County Port Authority obtained from the U.S. Department of Energy could help leverage a $75 million local investment in renewable power because it carries a 4-to-1 requirement of matching funds before money can be released.
One of the speakers was Michigan Assistant Attorney General Robert Reichel, the lead counsel in a lawsuit Michigan Attorney General Mike Cox filed in July against the U.S. Army Corps of Engineers over Asian carp. Several Great Lakes states, including Ohio, are part of that litigation, which seeks a barrier to block the movement of Asian carp into Lake Michigan until a suit seeking a permanent separation of the lakes from the Mississippi River is decided.
He said a ruling on the injunction is expected next month.
The carp are feared because of their destructive potential.
The bighead species grows up to 110 pounds and eats up to 40 percent of its body weight each day.
The silver species grows up to 60 pounds, but leaps out of water upon feeling the sensation of motors and can hit boaters with the impact of an airborne bowling ball.
"The concern is that once they become established, it will become very difficult - if not impossible - to eradicate them," Mr. Reichel said.
"The risk for harm, the magnitude of harm, warrants action."
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