| May 15, 2008
Chemicals in drugs and personal care products could impact fish
By SUSAN WEST
people don’t see a stockpile of environmental contaminants when
they look in their bathroom cabinets, but pharmaceuticals and personal
care products contain thousands of chemicals that could impact aquatic
Agricultural and industrial chemicals, byproducts, and waste, such as
DDT, PCBs, and dioxins, have long been recognized as sources of
But now scientists are studying how chemicals in pharmaceuticals and
personal care products (PPCPs) affect fish and other marine organisms.
“The focus isn’t on what happens when someone flushed
unused drugs down the toilet, but rather on our daily
lifestyles,” said Sid Mitra, professor of geological sciences at
East Carolina University.
PPCPs include over-the-counter and prescription drugs, such as
antibiotics, antidepressants, painkillers, and hormones, and personal
care products, ranging from shampoos and deodorants to cosmetics.
Excreted or washed off, PPCPs flush down a drain into either a septic tank or a sewage treatment system.
Mitra said chemicals can leak into septic drainage areas or move
through a treatment system fairly freely, remaining biologically active.
“And new drugs are developed every year, so the total variety of chemicals keeps increasing,” he said.
Unlike agricultural and industrial pollutants, chemicals in PPCPs enter
the environment at low but often continual levels by thousands or
millions of people in towns and cities around the world.
Some of these chemical compounds are endocrine disruptors that act like hormones and can interfere with reproduction.
Perhaps the most widely publicized study of the impact of endocrine
disruptors came in the 1990s when researchers reported male alligators
with abnormally small penises and high blood levels of female hormones
in a Florida lake with a declining alligator population.
Mitra said scientists have discovered that fish stopped reproducing
within a few weeks after low levels of the active ingredient in birth
control pills was added to experimental lakes.
Endocrine disruptors aren’t found only in oral contraceptives and therapeutic hormones though.
Preservatives called parabens, found in many shampoos and sunscreens, are endocrine disruptors also.
And, at North Carolina State University, scientists found that adding a
small amount of a common antidepressant to the water altered the
reproductive behavior of freshwater mussels.
Other researchers are looking at whether low levels of prescription
antibiotics could promote pathogen resistance in aquatic species.
Mitra said the technology to reduce chemical levels in wastewater
treatment systems is available. Adding ozone or using ultraviolet light
will break down chemicals.
“The technology is expensive, though, and with so much of the
research being so new, I’m not sure many municipalities would be
ready to implement the technology now,” he said.
“But people should be aware of the impacts of the drugs and
products they use, make sure their septic systems are in good working
order, and start talking to town councils about this issue,” he