Last Wednesday this
press release came out of the U.S. Geological Survey's Toxic Substances
Hydrology Program. In his FY03 budget President Bush proposes to
eliminate funding for this program.
What's in that Water?
USGS Releases First Nationwide Look At Pharmaceuticals, Hormones And
Other Organic Contaminants In U.S. Streams
Report available at: http://toxics.usgs.gov/regional/emc.html
The U.S. Geological Survey (USGS), today,
unveiled the first-ever study of pharmaceuticals, hormones and other
organic waste water-related chemicals in streams across the nation.
And while the findings are significant in their own right, the work
points to the need for more research in the future.
Published today in the journal Environmental
Science & Technology, the study shows that pharmaceuticals, hormones,
and other organic wastewater-related chemicals have been detected
at very low concentrations in streams across the Nation. Many of the
chemicals examined (81 of 95) do not have drinking-water standards
or health advisories. Measured concentrations of compounds that do
have standards or criteria rarely exceeded any of them.
Limited information is available on
the potential health effects to human and aquatic ecosystems from
low-level, long-term exposure or exposure to combinations of these
chemicals. These new data can guide future research in these areas.
"Little is known about the environmental
occurrence of many chemicals we use to maintain and improve the quality
of our daily lives," said Dr. Robert Hirsch, USGS Associate Director
for Water. "This study begins a process of exploring the occurrence
of these chemicals in our nation's streams. The new techniques for
measuring these chemicals will be very helpful for the many scientists
who study contaminant movement, impacts on ecosystems, and human health
effects."
The USGS study found that chemicals
used in households, agriculture, and industry can enter the environment
through a variety of wastewater sources, according to Dana Kolpin,
a USGS research hydrologist and head of this national study. Those
compounds include human and veterinary drugs (including antibiotics),
natural and synthetic hormones, detergents, plasticizers, insecticides
and fire retardants.
The most frequently detected compounds
included: coprostanol (fecal steroid) cholesterol (plant and animal
steroid) N-N-diethyltoluamide (insect repellant) caffeine (stimulant)
triclosan (antimicrobial disinfectant) tri (2-chloroethyl) phosphate
(fire retardant) 4-nonylphenol (detergent metabolite).
"Overall, steroids, non-prescription
drugs and a chemical found in insect repellants were the chemical
groups most frequently detected," Kolpin said. "Detergent
metabolites, steroids and plasticizers were generally measured at
higher concentrations than the other chemical groups, but concentrations
measured in this study generally were very low (less than 1 part-per-billion)."
In addition, this study found that wastewater
chemicals often mixed in the streams sampled. In half the streams
sampled, seven or more compounds were detected and in one stream,
38 chemicals were present in a single water sample.
As part of this study, new laboratory
methods were developed in five USGS research laboratories, providing
the ability to measure the concentrations of 95 wastewater-related
chemicals in water samples. During 1999 and 2000, a network of 139
streams in 30 states were sampled and analyzed for the presence of
these chemicals. The streams drain watersheds of varied climate, geology,
land use, and size. Most sites were located downstream of areas of
intense urbanization and livestock activity, where wastewater is known
or suspected to enter the streams.
Because this study is the first to explore
the occurrence of these chemicals in the United States, the sites
were selected based on where the chemicals are most likely to occur.
Thus, this reconnaissance study sets the stage for future studies
that can answer questions such as: how far downstream from their sources
do these chemicals remain present in the stream, how do the concentrations
of these chemicals vary as a function of factors such as climate,
land use, flow rates, or waste characteristics or treatment methods.
The paper "Pharmaceuticals, hormones,
and other organic wastewater contaminants in U.S. streams, 1999-2000:
A national reconnaissance" can be found in the March 15 issue
of Environmental Science & Technology, or on the web at:
http://toxics.usgs.gov/regional/emc.html .