[Pharmwaste] Prozac in the Water - Governing Magazine
Laurie.Tenace at dep.state.fl.us
Thu Sep 7 09:10:06 EDT 2006
PROZAC IN THE WATER
Sophisticated new tests reveal small amounts of steroids and other drugs in
drinking water. How big a threat are these contaminants?
By Tom Arrandale
A decade ago, Shane Snyder headed to Las Vegas. He was working on a doctorate
in ecological toxicology, and federal government biologists had detected that
something strange was happening to the fish in nearby Lake Mead: Male carp
were turning into females.
Snyder's initial findings about the source of the problem were inconclusive.
But understandably disturbed by the situation, the Southern Nevada Water
Authority in 2000 hired Snyder as its research and development director.
Since then, he and fellow scientists have confirmed that natural and
synthetic chemicals in Lake Mead are deforming some fish and disrupting their
capacity to reproduce.
The culprit isn't factory discharges or polluted runoff from farms. Rather,
it's the 1.8 million metro area residents and 38 million tourists who visit
the city annually. Every day, the pharmaceuticals, personal care products and
human hormones they secrete or rinse from their bodies are flushed down the
drain. Those substances accumulate in the sewage effluent that Las Vegas
releases into the reservoir behind Hoover Dam.
For Nevada's water agencies, as well as those in big cities in California and
Arizona, the question now is whether these newly detected "emerging
contaminants" pose any danger to the millions of people who drink water from
the Colorado River.
The country has 53,000 drinking-water systems, and most have all they can
handle ensuring an adequate supply for growing populations, coming up with
billions of dollars to upgrade sewage treatment plants and installing
expensive new technology to ensure that water flowing through household taps
will meet existing federal contaminant limits. But a handful of water
utilities are on the forefront of scientific research to determine whether
they'll also need to deal with thousands of additional substances that are
showing up in increasingly sophisticated water-quality tests.
In the mid-1990s, fishermen in Great Britain recognized that downstream from
aging sewage-treatment plants all the fish they caught had female organs.
Meanwhile, herpetologists found that male alligators and frogs exposed to
pesticides were also developing female characteristics. More recently,
researchers have found feminized fish in wastewater effluent in the Potomac
River outside Washington, D.C., near Denver and in the Pacific Ocean just
offshore from Los Angeles and Orange County, California.
It's clear that chemicals discharged into the environment can alter some
organisms' endocrine systems, which secrete hormones into the bloodstream to
control reproduction, growth and development. Congress has responded by
ordering the U.S. Environmental Protection Agency to start reviewing whether
endocrine-disrupting chemicals also threaten human health. Federal regulators
have proposed limits on perchlorate, a compound from rocket fuel known to
affect endocrine glands, but EPA's review of thousands of pesticides,
plastics and other commonly used compounds is dragging on.
At the same time, concern has emerged that frequently prescribed
pharmaceuticals and ubiquitous personal care products such as soap, shampoo
and detergents could be causing similar environmental damage.
Increasingly accurate laboratory technology makes it possible to identify
much smaller chemical residues, down to minuscule parts-per-trillion levels,
in sewage effluent and drinking-water samples. "Birth-control pills have been
around since the 1960s, but now we are actually able to detect them at these
lower concentrations," notes Joe Gully, an environmental scientist for the
Los Angeles County Sewer District's ocean research program.
Meanwhile, Snyder and others have documented that Las Vegas' treated sewage
plant discharges carry traces of codeine, Prozac, Valium, common antibiotics,
insect repellents and a host of chemicals termed endocrine disruptors into
the Lake Mead reservoir. And they have linked those human byproducts to
abnormal female characteristics in carp, bass and razorback suckers, which
swim and feed in the effluent the city's treatment plants release into the
So far, the results have detected "essentially no human health concern,"
according to Snyder. But the National Park Service manages a national
recreation area along the lake, and Los Angeles, San Diego, Phoenix and
Tucson draw much of their supplies from the Colorado River reservoir. "It's a
really politically motivated body of water," he adds, and downstream
residents naturally recoil at the thought that they're unwittingly ingesting
somebody else's medicine.
So water and sewer utilities feel compelled to follow up on even cursory
findings that drugs, chemical residues and even natural human hormones
flowing through municipal sewers are disrupting reproduction in fish that
swim downstream. With the science so uncertain, local officials worry that
the U.S. Environmental Protection Agency will eventually feel compelled to
order communities to install expensive treatment upgrades to dispel the
public's fear that emerging contaminants pose similar threats to human
As the data accumulates, governments in some areas are taking steps to give
patients alternatives to flushing unused prescription drugs down their
toilets. Three years ago, psychiatrists persuaded the Maine Legislature to
provide prepaid envelopes for mailing drugs past their expiration dates to
the state's drug enforcement program for safe disposal. Chicago has
experimented with drug-return programs, and Washington State this summer
launched a pilot collection effort giving consumers a way to drop off unused
medications at drugstores. But pharmaceuticals also leach from landfills and
seep into streams in animal waste from feedlots where livestock are fattened.
And as millions of Americans take their medicine every day, they're also
passing residues through their bodies into community sewer systems.
The pharmaceutical byproduct stream is renewed daily, and the volume is
growing as doctors prescribe new drugs that go on the market. In addition,
even the healthiest people excrete some of the natural hormones their bodies
produce, and more of those are flowing into wastewater systems as urban
populations expand. The levels of natural estrogen in Las Vegas' wastewater
is 10 times higher than synthetic estrogen used to make birth-control pills,
Snyder points out. "There's not much we can do about that; it's not like an
industrial chemical that you can ban or restrict."
Most studies that detected damage to aquatic life haven't demonstrated that
sexual deformities are widespread enough to threaten entire populations of
fish or amphibians. In Lake Mead, however, a 2002 U.S. Geological Survey
study warned that sexual deformities conceivably could decimate the razorback
sucker, an endangered species that tends to concentrate near Las Vegas'
sewage outfall to feed on nutrients in the effluent. The Clark County Water
Reclamation District is considering spending $585 million on a 17-mile-long
pipeline that would pump most of Las Vegas' 170 million gallons of effluent
per day to be diluted in 250-foot-deep waters above Hoover Dam. Biologists,
however, worry that approach would send emerging contaminants over the dam,
threatening Colorado River fish populations along the Arizona-California
Snyder's research has found that treating effluent with ozone or reverse
osmosis can remove more than 70 percent of most suspected pharmaceutical and
endocrine-disrupting contaminants. However, he notes, "the cost of
implementing those types of processes can be enormous."
In contrast to well-documented threats such as Cryptosporidium or
water-treatment byproducts, "I haven't seen any compelling evidence that
emerging contaminants in drinking water" are harming people who drink it,
Snyder says. Pharmaceuticals are commonly used to stimulate livestock growth
and milk production, "and people get a much greater dose from eating a steak
or drinking milk."
Snyder now is working with the American Water Works Association and some of
California's biggest water-supply systems on a project that is studying what
kind of treatment most effectively removes 15 widely used pharmaceuticals and
eight suspected endocrine disruptors that have been found in drinking-water
supplies. Environmental groups keep prodding EPA to move more quickly to
identify and control emerging contaminants, and state and local governments
are well aware that regulations could eventually be imposed.
The Pennsylvania Environmental Protection Department and USGS have started
screening streams and groundwater for unregulated contaminants, and the
Philadelphia Water Department continues monitoring its supply after studies
two years ago found minor traces, measuring in the parts per trillion, of 13
painkillers, antibiotics, antidepressants and other drugs, as well as
estrogen and the insect repellent DEET in the city's water.
Christopher S. Crockett, Philadelphia's watershed protection manager, sees no
risk to city residents but acknowledges that press accounts of the research
have caused public concern. Philadelphia draws water from the Schuylkill and
Delaware River basins, and "5 percent of the U.S. population lives in our
watershed," he says. Most city residents nonetheless don't understand that
"not all the water comes from the top of the Rocky Mountains," so learning
that tap water carries minute amounts of hormones and pharmaceuticals that
have passed through upstream residents' bodies "is really shocking to a lot
Negative public reaction could be even more worrisome for water-short
Southwestern cities that share the Colorado River's overcommitted supply.
Fast-growing desert cities are counting on expanding their resources by
recycling sewage effluent for irrigating golf courses and eventually
replenishing drinking-water supplies. Studies led by Gully, the Los Angeles
County researcher, suggest a possible solution: Let treated effluent trickle
through layers of soil. This appears to effectively remove estrogen from the
wastewater that California and Arizona cities have begun using to recharge
groundwater aquifers to replenish drinking-water reserves. While there's no
evidence that the water is dangerous for drinking, "it's part of our mission
to make sure our water is safe for reuse," Gully says. "This is a really new
field, and it's one that's worthy of investigation."
Common pharmaceuticals detected in drinking-water supplies
LITERS/DAY OF TREATED
DRINKING WATER AN ADULT
THERAPEUTIC WOULD NEED TO DRINK
DRUG DOSE TAKE IN
Atenolol 25 mg/day 26,315,789
Carbamazepin (Tegretol) 10 mg/day 1,960,784
Phenytoin (Dilantin) 100 mg/day 6,666,667
Gemfibrozol 1,200 mg/day 2,857,142,857
Sulfamethoxazole 400 mg/day 1,052,631,579
Sources: Richard C. Pleus, Intertox Inc.; and Shane A. Snyder, Southern
Nevada Water Authority
Laurie J. Tenace
Florida Department of Environmental Protection
2600 Blair Stone Road, MS 4555
Tallahassee, Florida 32399-2400
PH: (850) 245-8759
FAX: (850) 245-8811
Laurie.Tenace at dep.state.fl.us
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