Common drugs seeping into lakes, fish
and water supply
By Susanne Quick
Milwaukee Journal Sentinel
Posted on the Ledger-Enquirer June 3, 2005
MILWAUKEE - (KRT) - It was barely a drop, but the effect
of the drug was astonishing.
Pointing to a digital recording of fathead minnows gasping
for breath in a milky, murky stew, researcher Rebecca
Klaper said: "We had planned to keep them in there
for a week, but we had to pull them the next day. They
were going to die."
Klaper, of the University of Wisconsin-Milwaukee's Great
Lakes WATER Institute, is investigating the effects of
common drugs, such as pain relievers, anti-depressants
and lipid regulators, on lake fish and invertebrates.
Many of these medications pass through the body, into
the sewer system and out to the environment largely unaltered.
And because they are designed to affect the biology of
a living organism - to reduce headaches, control seizures
or suppress coughs - she and other researchers think they
could have an impact on fish and other wildlife.
Standing in her lab at the WATER Institute, an old tile
warehouse on the banks of the Kinnickinnic River, Klaper
reviewed the minnow experiment. She pointed to the fishes'
gills, which were straining open and shut in a desperate
attempt to filter oxygen in the deadly murk surrounding
"The water was cloudy by the time we got in the
next morning," said Chris Rees, a research assistant,
recalling the day after a lipid regulator was introduced
into their tank.
But the milkiness wasn't from the drug itself, Klaper
said. It was the physical manifestation of the stressed
and dying fish - a cloudy stew of mucous and other piscine
It wasn't as if Klaper had heavily dosed the fish. She
had diluted the drug to one part per billion, or the equivalent
of a drop in a railroad tanker. That's a concentration
that has been detected in waters from Europe to South
America, and as close to home as Lake Ontario and the
It is estimated that more than 1,000 tons of active pharmaceutical
products are manufactured each year. Pharmaceutical sales
are increasing 7 percent to 8 percent annually, and nearly
45 percent of all sales in 2004 were in North America.
The U.S. Food and Drug Administration requires environmental
impact statements under some circumstances, but the circumstances
are so unusual that pharmaceutical companies essentially
don't have to worry about them.
Researchers say two primary and related concerns exist
when it comes to these drugs. First, the drugs going into
the water might affect the environment, particularly the
biological food chain. Second, the drugs could come back
to people in drinking water.
In both cases, "the big unknown" is what effect
these products might have on chronically exposed plants,
animals and people, said Christian Daughton, chief of
the environmental chemistry branch at the Environmental
Protection Agency's National Exposure Research Laboratory
in Las Vegas.
Because the concentrations are so small, the immediate
effects might be too subtle to notice, Daughton said.
But because the exposure is constant, the "long-term
cumulative consequences could be insidious."
Klaper and other researchers, such as Stanley Dodson
and Joel Pedersen at the University of Wisconsin-Madison,
are trying to sort it out.
Dodson has been focusing on biological food chain-aspect,
by looking at a small, shrimp-like organism called daphnia
- what he calls an environmental "keystone"
"They're like canaries in a mine shaft," he
said. If you see something start to go wrong with them,
it's a warning.
Preliminary studies have shown that commonly used drugs
can skew their sex ratios and slow their feeding behavior.
That's a problem not just for daphnia, but potentially
for animals, such as fish, that rely on them.
But Dodson realizes what might appear initially as a
recreational issue - a crash in fish populations - also
could develop into a human health issue.
Unlike other pollutants, these products have "enjoyed
several decades of unrestricted discharge into the environment,"
Daughton said. And very little is known about their long-term
effects on chronically exposed organisms.
Public awareness about the potential harm these compounds
could cause started in the 1980s when researchers noticed
that items such as antibiotics and hormones were making
their way into the environment.
From Seattle to Berlin, researchers were finding genetically
male fish that could produce eggs and egg proteins. Concerned
that birth control pills, hormone replacement therapies
and other chemicals that mimic hormones were causing this
wave of "she-male" fish, researchers began investigating.
While scientists had data showing compounds such as aspirin,
nicotine and caffeine also were leaching into wastewater
at this time, the implications didn't hit until the early
At this point, German researchers discovered the presence
of these more common drugs in treated and untreated sewage,
surface water, ground water and drinking water. Alarmed,
North American researchers started looking for them, too.
Chris Metcalfe, of Trent University in Peterborough,
Ontario, discovered them in both treated and untreated
samples of wastewater in eastern Ontario. He has found
them by treatment plants and more remote areas of the
And Glen Boyd, a researcher at Tulane University in New
Orleans, has found them in the Mississippi River, Lake
Pontchartrain and the Detroit River.
The drugs are so ubiquitous and pervasive, even researchers
not looking for them have stumbled upon them.
Pedersen, a soil scientist at UW-Madison, said that as
a graduate student in the late '90s, he studied runoff
from fields irrigated with treated wastewater, a method
commonly used in more arid areas. He was looking for pesticides
and other agricultural chemicals. But he found dozens
of these personal care products.
Since then, he's examined the fate of drugs, primarily
antibiotics, as they seep through soil, potentially leaching
their way into the groundwater below. He's now collaborating
with other UW scientists to investigate the fate of pharmaceuticals
that leach from septic systems.
"We're really just starting to understand the fate
of pharmaceuticals in the environment," he said.
"We have much to learn."
Admittedly, for people on the larger Great Lakes, the
concerns are not as great as elsewhere because the concentrations
here are so diluted. But as levels of common pharmaceuticals
increase, the possibility these compounds could work their
way back into drinking water magnifies.
"By their nature, pharmaceuticals are designed to
be highly bioactive - many exquisitely so," Daughton
wrote in a 1999 review for an EPA Web site. "Most,
however, also have numerous unintended effects."
For water headed out to Lake Michigan, the Milwaukee
Metropolitan Sewerage District is not treating sewage
effluent with these products in mind. The cost, they say,
to remove these drugs would be prohibitive. And although
they acknowledge the research is still "out"
on these drugs, they say current data doesn't warrant
an overhaul of the system.
As for water coming back in, officials at Milwaukee Water
Works, the largest provider of tap water in the area,
say they haven't looked for these compounds in the past
but will start this year.
Lon Couillard, water quality manager for Milwaukee Water
Works, is not concerned. He's convinced the city's water
treatment process will remove these products. If ozone
oxidation - a chemical filtration method the city set
up in 1998 - doesn't do it, other treatment processes,
such as filtration, will.
"If you've got a group of soldiers and you surround
them with a strip of raw razor wire, followed by land
mines, a water-filled moat, a trench and sand bags, the
enemy isn't going to be able to penetrate," Couillard
The problem, to borrow Couillard's analogy, is that if
the enemy arrives in helicopters, those conventional methods
don't add up to a pile of beans. That's what is so worrisome
to researchers. Pharmaceutical products aren't the traditional
enemy that water systems were designed to combat.
Chemical oxidation - the method Couillard cites as the
city's best line of defense - works by breaking up molecules,
encouraging compounds to convert into smaller components.
"These 'by-products' are generally smaller in size,
more polar (water soluble) and often pose less hazard"
than the original, Daughton said. "But sometimes
they might pose more hazard," altering the molecules
by making them even more biologically active.
"It is highly unlikely that any water-oxidation
process would prove 100 percent efficient for all organic
chemicals." And even though reverse-osmosis - a physical
system for filtering out chemicals - is probably the most
effective method, it, too, can't rid water of everything.
Even if it could, there's the question of what to do
with the waste particles filtered out. Where would they
go? Into landfills, where they could leach into groundwater?
The answer is not clear. And researchers are not sure
what the future holds.
Klaper and her colleagues at the WATER Institute plan
to head out this summer to test animals at the receiving
end of wastewater outflows. She's interested in examining
the effect these chemicals might have on gene expression
in minnows and daphnia.
"We're really just at the beginning" of understanding
the effects of these drugs on wildlife, she said.
But if her drug-exposed fathead minnows are any indicator
of the future, it's not looking good.