risk of reacting with some drugs
to produce new, more toxic compounds.
“you can chlorinate a molecule
and change its geometry to be more
toxic than it was,” Snyder noted.
“you can form chlorinated aromatic
rings; for example, acetaminophen and
chlorine can react to form a more toxic com-
a study Snyder participated in showed that triclosan, an
antibacterial found in countless household products, reacts
with chlorine to form monochlorinated triclosan and dichlori-
nated triclosan. according to an article in Environmental Science
& Technology, acetaminophen reacts with chlorine to form
several products, including 1,4-benzoquinone and N-acetyl-
p-benzoquinone imine (napQI), the cause of death in acet-
the most promising alternative to chlorine is ozone, which
removes 80% of pharmaceuticals within 5 minutes, including
estrogens, according to the journal Ozone: Science & Engineering.
“the byproducts tend to be far more biodegradable and much
different from chlorine byproducts,” Snyder explained.
Municipalities largely abandoned ozone treatment 20 years
ago because of its high energy cost. Snyder expects a resurgence with new technology that operates more efficiently. an
ozone water-treatment plant under construction in las Vegas is
the first in the country designed to maximize removal of pharmaceuticals and other endocrine disruptors. Snyder and his colleagues are exposing fish to wastewater treated with ozone and
wastewater treated with chlorine to compare the effects.
Microbes to the rescue
Some of the newest studies on reducing pharmaceuticals in
water capitalize on microbes — also known as “nature’s jani-
tors.” Kung-hui Chu, an assistant professor of environmental
engineering at Texas A&M University in College Station, is
examining strains of bacteria that consume water contaminants.
She began by culturing bacteria
in wastewater sludge on an estro-
genic growth medium. a strain
she dubbed KC8 thrived on the
medium (indicating it completely
broke down the estrogen).
now, as she explains in an
article in Environmental Science &
Technology, she and her cohorts
are trying to figure out how to
apply their laboratory discovery to
water-treatment plants. “how can
we create an environment where
this strain can thrive and degrade estrogen?” she asked rhetorically. “Can it grow fast enough to outcompete other strains?”
Some members of her team are experimenting with ph levels and aeration to see what fosters the best environment for
KC8. others are searching for bacteria that degrade antibiotics
“It’s impossible for one microorganism to degrade them all,”
Chu observes. Better water treatment, drug-degrading bacteria, and consumer efforts (see “forget the flush,” on page 18)
might go far toward minimizing pharmaceuticals in water. But,
Snyder cautions, they’ll never remove every trace.
“ultimately, it will come down to people deciding how pure
they want their water to be,” he said. “the most economical
solution might be to provide pure drinking water and less pure
water for bathing, the toilet, and clothes washing.” iC
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by Chlorination produces the toxicants 1,4-Benzoquinone and N-acetyl-p-
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Benotti, Mark J. et al., “pharmaceuticals and endocrine disrupting Compounds in
u.S. drinking Water,” Environmental Science & Technology, 2009, 43 ( 3),
Betts, Kellyn S., “pharmed fish,” Environmental Health Perspectives, 2009, 117, pp
daughton, Christian, “ppCps in the environment: an overview of the Science,”
donn, Jeff et al., “drugs in the drinking Water,” http://hosted.ap.org/specials/
Jjemba, patrick K., Pharma-Ecology, John Wiley & Sons, 2008, 314 pages.
painter, Meghan M. et al., “antidepressants at environmentally relevant
Concentrations affect predator avoidance Behavior of larval fathead Minnows
(Pimephales promelas),” Environmental Toxicology and Chemistry, 2009, 28 ( 12), pp
roh, hyungkeun and Chu, Kung-hui, “a 17β-estradiol-utilizing Bacterium,
Sphingomonas Strain KC8: part I - Characterization and abundance in Wastewater
treatment plants,” Environmental Science & Technology, 2010, 44 ( 13), pp 4943–
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cynthia washaM is a freelance writer and one
time pharmacy major. She’s also a South Florida run-ner who probably washes more than her share of
deodorant, sunscreen, and linament down the drain.