BUFFALO, N.Y. -- University at Buffalo chemists have for the
first time identified at wastewater treatment plants the
metabolites of two antibiotics and a medical imaging agent.
The data, which the UB scientists will present tomorrow at the
Pittsburgh Conference on Analytical Chemistry and Applied
Spectroscopy being held in Orlando, will allow wastewater treatment
plants to begin monitoring for these byproducts.
The results also reinforce concerns about excreted
pharmaceutical compounds from wastewater systems that may end up in
the water supply, potentially resulting in adverse effects for
humans and the environment.
For example, antibiotics and their metabolites can significantly
increase antibiotic resistance in the population. Synthetic
hormones can act as endocrine disruptors, by mimicking or blocking
hormones and disrupting the body's normal functions.
The UB presentations will be made as part of a day-long
symposium to be held March 16 on "Degradation and Treatment of
Pharmaceuticals in the Environment." It will be chaired by Diana
Aga, Ph.D., assistant professor of chemistry in UB's College of
Arts and Sciences and leader of the UB team.
According to Aga, it has been only in the past five years that
analytical-chemistry techniques have become sufficiently affordable
and practical to allow researchers to detect pharmaceuticals and
their metabolites efficiently at the parts-per-billion and
"Current wastewater treatment processes are optimized to reduce
nitrates and phosphates and dissolved organic carbon, the major
pollutants of concern in domestic wastes," said Aga. "However,
treatment facilities don't monitor or measure organic
microcontaminants like residues of pharmaceuticals and active
ingredients of personal care products."
Aga said that most previous studies looked for drugs' active
ingredients in treated wastewater.
"But now we are doing laboratory studies to characterize what
these ingredients degrade into during wastewater processing," she
added. "The lesson is that not detecting active ingredients in the
effluent doesn't mean the water is clean. The pharmaceuticals we
monitored are not degraded completely in the treatment plants; most
of them are just transformed into other compounds that still may
have adverse ecotoxicological effects."
The UB researchers have identified the metabolites for
sulfamethoxazole and trimethoprim, commonly prescribed antibiotics,
and for a synthetic estrogen, a common ingredient in birth control
pills and in hormone replacement therapy.
In research published in January in Analytical Chemistry, the UB
chemists also found that iopromide, a pharmaceutical imaging agent
that patients consume before taking MRI tests, is barely degraded
in the conventional activated sludge process.
However, they found that when conditions in biological treatment
systems are optimized for nitrogen removal, this imaging agent does
Aga said that these findings have important implications because
it means that wastewater treatment processes can be optimized to
remove persistent pharmaceuticals in wastewater.
The UB researchers obtained samples during fall and spring from
local wastewater treatment plants in the Western New York towns of
Amherst, East Aurora, Lackawanna, Tonawanda and Holland,
representing suburban, urban and rural areas.
They sampled effluent before and after each water-treatment
stage to examine relative efficiencies of each treatment
Aga noted that based on the team's findings, a combination of
biological, chemical and physical processing techniques probably
will be the most successful to remove completely pharmaceutical
compounds and their metabolites from wastewater.
"Originally, it was hoped that during the disinfection process,
through chlorination or ultraviolet techniques, removal of the
drugs that we studied would be enhanced, but, in fact, neither of
these is effective," she said.
The researchers did find, however, that that most wastewater
treatment processes are effective in significantly degrading some
common antibiotics, such as ciprofloxacin and tetracycline.
The UB research was funded by the National Science
The University at Buffalo is a premier research-intensive
public university, the largest and most comprehensive campus in the
State University of New York.