Researchers at the National
Institute of Standards and Technology (NIST) have published
an interesting study that sheds light on the fate of a
familiar pharmaceutical as it enters the waste stream.
In work initially described in NIST TechBeat last year,
NIST chemists investigated probable chemical reactions
involving acetaminophen when the drug is subjected to
typical wastewater processing. Acetaminophen is the most
widely used pain reliever, and a study of 139 streams
by the U.S. Geological Survey found that it was one of
the most frequently detected man-made chemicals.
The scientists found that the drug
readily reacts in chlorine disinfection to form at least
11 new products, at least two of which are known to be
toxic. The results, according to lead author Mary Bedner,
demonstrate that environmental scientists need to be concerned
about downstream reaction products as well as the original
waste materials. "The issue is what you should be
looking for in the environment," she says. "When
you are looking for the effects of pharmaceuticals in
the environment, you need to ask what they're going to
turn into."
The full paper, "Transformation
of Acetaminophen by Chlorination Produces the Toxicants
1,4-Benzoquinone and N-Acetyl-p-benzoquinone Imine"
will appear in Environmental Science and Technology, and
is available from the journal's ASAP Web site http://pubs.acs.org/journals/esthag/index.html.
