Paul E. Stackelberg talks
with ScienceWatch.com and answers a few questions
about this month's Fast Moving Front in the field of
Engineering.
Article: Persistence of pharmaceutical compounds
and other organic wastewater contaminants in a conventional
drinking-watertreatment plant
Authors:
Stackelberg,
PE;Furlong, ET;Meyer, MT;Zaugg, SD;Henderson,
AK;Reissman, DB
Journal: SCI TOTAL ENVIR, 329 (1-3): 99-113 AUG 15
2004
Addresses: US Geol Survey, 810 Bear Tavern Rd, W Trenton,
NJ 08628 USA.
US Geol Survey, W Trenton, NJ 08628 USA.
(addresses have been truncated)
Why do you think your paper is highly
cited?
The detection of pharmaceuticals and other organic wastewater-related
compounds (OWCs) in the environment has generated considerable interest in
the scientific community and with the general public. The scientific
community is focused on investigating potential adverse ecological and
human-health effects, whereas the general public is concerned about the
potential contamination of our water and drinking-water resources.
Our paper generated considerable interest because it reports for the first
time on the occurrence of a broad array of OWCs in drinking-water supplies
and, therefore, has caught the attention of both the scientific community
as well as non-technical audiences.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
"...increased public
awareness of the ways we handle and dispose of our
medications and other extensively used chemicals
and has resulted in an increased interest by
industries in waste-treatment
technologies..."
Prior to the publication of our paper there was little information in the
literature concerning the occurrence of OWCs in drinking-water supplies.
This study was the first to examine a wide variety of OWCs (over 100) in
both source and finished-drinking-water samples and we reported for the
first time the occurrence in drinking water for several OWCs (for example,
the prescription drug carbamazepine). Most of these compounds are currently
unregulated in drinking water and have not been routinely monitored for
their presence in streams and drinking-water supplies of the United States.
Would you summarize the significance of your paper
in layman's terms?
Our paper was one of the first to demonstrate that extensively used
chemicals such as prescription and non-prescription drugs, personal-care
products, detergent metabolites, plasticizers, flame retardants, and
fragrances are capable of surviving conventional drinking-water-treatment
processes and persisting in finished-drinking-water supplies. The long-term
human-health effects of exposure to these chemicals in drinking water are
not known and, therefore, this is an area of ongoing investigation.
Findings from this study demonstrate that the use of treated municipal
wastewater to augment raw-water supplies in urbanized areas is complicated
by the presence of OWCs in wastewater effluent and the inability to
completely degrade or remove these compounds through the use of
conventional water treatments.
How did you become involved in this research and
were there any particular problems encountered along the way?
Interest in this area of research was prompted by findings from European
colleagues who, in the mid-to-late 1990s, reported the nearly ubiquitous
occurrence of select pharmaceutical compounds in surface-water bodies that
receive effluent from sewage-treatment plants.
The initial obstacle for investigating the occurrence of these compounds in
the Unites States was the lack of analytical methods capable of measuring
these compounds at environmentally relevant concentrations. This obstacle
was addressed by the US Geological Survey which began developing analytical
capabilities for OWCs in the late 1990s.
These newly developed analytical methods were used to examine the
occurrence of OWCs in
streams across the United States in 1999–2000.
Results from this national stream reconnaissance provided the motivation
to examine the occurrence and persistence of OWCs in
drinking-water-treatment facilities whose source waters contain effluent
from municipal-sewage-treatment plants.
Where do you see your research leading in the
future?
Additional research has been conducted to further investigate the
occurrence of OWCs in drinking-water supplies, as well as the effectiveness
of water treatments at degrading or removing these compounds from the
aqueous phase. See, for example: "Efficiency of conventional
drinking-water-treatment processes in removal of pharmaceuticals and other
organic compounds," Stackelberg PE et al., Sci. Total
Environ. 377: 255-72, 2007.
In addition, the USGS, in partnership with other federal, state, and local
agencies, is actively involved in additional research to provide
information on these compounds for evaluation of their potential threat to
environmental and human health.
Current and future research activities include: (1) develop analytical
methods to measure chemicals and microorganisms or their genes in a variety
of matrices (e.g. water, sediment, waste) down to trace levels; (2)
determine the environmental occurrence of these potential contaminants; (3)
characterize the myriad of sources and source pathways that determine
contaminant release to the environment; (4) define and quantify processes
that determine their transport and fate throughout the environment; and (5)
identify potential ecologic and human-health effects from exposure to these
chemicals or microorganisms. Additional information on these areas of
research is available on the Web.
Do you foresee any social or political implications
for your research?
The objective of USGS-sponsored research is to provide reliable, impartial,
and timely information needed by decision-makers to more effectively manage
our water resources and also to protect and enhance these resources for
human health, aquatic health, and environmental quality. This information
also helps establish research priorities and future monitoring needs.
Findings from this and similar studies have already increased public
awareness of the ways we handle and dispose of our medications and other
extensively used chemicals and has resulted in an increased interest by
industries in waste-treatment technologies and best-management practices
that are most effective at removing trace organic chemicals from our water
resources and solid and liquid wastes.
Paul E. Stackelberg
US Department of the Interior
US Geological Survey
Troy, NY, USA