Edo McGowan M.D.,
Ph.D. comments on the Drugs in Drinking Water story.
What is being reported by AP and the New York Times is
merely the tip of the iceberg. When one looks at the
pathogens in reclaimed water as well as drinking water
and then on top of that the levels of antibiotic resistant
pathogens, and the pharmaceuticals, the situation is
worrisome.
In either type of water---drinking or reclaimed, there
should be nothing but just water. That, however, is not
the case and the presence of these contaminants is well
known to the industry and those that regulate it. The
issue is the willingness of the regulatory agencies to
take action. The information has been available for some
time, especially with respect to pharmaceuticals. Additionally,
there is the issue that the pharmaceuticals may be able
to induce or maintain antibiotic resistance in pathogens
and then the pathogens themselves being in the water.
The most recent edition of Cutis, a journal for physicians,
discusses the increased rates of community acquired MRSA
in pediatric patients, especially those with atopy, the
allergic sensitivities. This tendency may be related
to the use of reclaimed water on playing-fields, parks,
and similar surfaces with high public access. More research
is warranted but the willingness of regulatory agencies
to step up to the plate is timid at best.
My group ran samples of the reclaimed (recycled) water
as produced by sewer plants from two different cities
in California for purposes of looking at antibiotic resistance,
which we found. This water, however, met state standards.
The operative question, then---in two parts—--
1) are the state standards protective and if not, 2)
what is the impact on the community? As a corollary question,
what of other areas of the U.S. are using reclaimed water,
and does such water also contain resistant pathogens?
My guess is that such water does and this may be a heretofore
unrecognized foci for the spread of resistance into the
community.
Joan B Rose, et al and Valerie Harwood, et al both looked
at reclaimed water from Florida, Arizona and California
and came to the conclusions that the indicators used
according to state health protocols did not reflect actual
pathogen loads. Indicators are used by the regulators
to ascertain pathogen loads. But if the indicators don’t
reflect what is actually there, one is given a false
sense of security.(Validity of the Indicator Organism
Paradigm for Pathogen Reduction in Reclaimed Water and
Public Health Protection Valerie J. Harwood,1* Audrey
D. Levine,2 Troy M. Scott,3 Vasanta Chivukula,1 Jerzy
Lukasik,3 Samuel R. Farrah,4 and Joan B. Rose. Applied
and Environmental Microbiology, June 2005, p. 3163-3170,
Vol. 71, No. 6).
The Rose report was conducted between 2003 and 2004
under a grant from the Water Environment Research Foundation
(WERF) which is the wastewater industry’s research
arm. Thus the industry as a whole is well aware of these
facts but appears to have done little to correct this.
Our project in California was an extension of a study
initiated last year. In the prior year we found antibiotic
resistant pathogens in reclaimed water that is used on
public parks, school yards, college playing fields and
golf courses. This year we found essentially similar
levels of drug resistance in this follow up study. Thus
what we are seeing is not just some irregular spike in
the system but a common background of resistance. Our
set up is a Kirby Bauer that dispenses 12 antibiotics
on Mueller Hinton agar. The bacteria that we found in
a preliminary run showed chlorine resistance and resistance
to 11 of the 12 antibiotics we used as challenges, including
resistance to vancomycin. The bacteria were presumptively
identified by colony characteristics. We did not proceed
with further identification. The bacteria were also chlorine
resistant.
The fact that these bacteria were also chlorine resistant
means that the immune system may also be affected. Hypochlorite,
a chlorine analogue, is released in bursts within the
leukocytes and is used to kill engulfed pathogens. This
finding indicates that the immune system may be compromised.
There also may be a synergistic effect when considering
chlorine resistance because several antibiotics are bacteriostatic
and they don’t kill pathogens but merely retard
growth. The overall control depends on the ability of
the immune system to take over where the antibiotic leaves
off. Thus, bacterostatic antibiotics depend on the fully
functioning immune system. Also because numerous antibiotics
as well as endocrine disrupters do make it through water
treatment systems, these will be in the recycled or drinking
water hence also impacting either the immune system or
the efficacy of treatment. Rose, et al as well as Harwood
et al looked recycled water produced by Santa Barbara
and other cities of the nation that met state standards
and concluded that the current indicators and standards
did not protect public health nor reflect the actual
suite of pathogens contained within the recycled water.
Amy Pruden, et al also looked at sewage effluent and
noted that antibiotic resistant genes (ARGs) were not
affected by chlorine levels used in water treatment and
the filters used did not stop the through-put of these
ARGs into the environment. These AGRs made it completely
through drinking water treatment plants and into the
domestic potable supply. Amy, Joan and I were on the
same national scientific panel that was put together
by EPA and WERF to look at pathogens and antibiotic resistance
in wastewater products. This panel was just started and
there are no results at this time. Since EPA does not
control reclaimed (recycled) water, it has left those
controls to the states. Thus depending on how astute
and aggressive the individual states are, the quality
of drinking water and reclaimed water can vary considerably.
California is often considered as a leader in environmental
matters, but in this case I would not give it a passing
grade.
I looked at the training required of those that operate
water treatment plants. In doing so I contacted several
national associations that supply training materials,
some of which were mentioned in the Times and AP reports.
These associations were asked if their training included
anything on antibiotic resistance of the transfer of
genetic information. The overall answer was---no there
were no requirements, hence those operating these plants
did not have that information. I also asked the State
of California agency that licenses these operators if
the tests for the operator’s license contained
any questions on these subjects. Again the answer was
no. Thus, those that operate water treatment plants may
be poorly prepared to appreciate these critical aspects
that can and do impact public health. Nonetheless these
plant operators do hold critical jobs that impact our
collective health.
Chad Kinney has looked at recycled water and determined
that numerous pharmaceuticals were passed through with
the finished water. Some bioaccumulate in the soil. Klaus
Kummerer of Germany looked at effluents and indicated
that the antibiotics were at levels that could either
maintain or induce resistance. Since many drugs do get
through sewer plants and thus are passed into this water,
that also may be an issue. The next downstream city has
its intake for drinking water in that same river. These
pathogens are then recycled numerous times and thus may
develop super bug status by the time they get to your
drinking water. Again there is nothing new about this,
it‘s just that the public at large has been kept
out of the loop.
We also looked at down-wind drift from sprinkler irrigation
of parks surrounded by neighborhoods. This is an avenue
for movement of pathogens in viable amounts to surfaces.
There is again a fairly robust literature base on this
but this seems to have been missed by those responsible
for regulating reclaimed water.
The indicator organisms used for recycled water commonly
include Escherichia coli and sometimes Salmonella. These
are the organisms that are normally killed by low-level
disinfection. They are vegetative bacteria that are highly
susceptible to both chemical disinfection and heat disinfection.
However, because the standards for recycled water do
allow for survival of some of these organisms and recycled
water contains a large range of organisms besides E.
coli, Salmonella one may find Staphylococcus. Also highly
susceptible and easily inactivated are the enveloped
viruses such as Hepatitis B., HIV, and influenza. The
non-enveloped viruses are another matter---not easily
killed by sewage processing. Thus what of those pathogens
that require high-level disinfection? These are almost
completely missed by the low-level disinfection processes
used by sewer plants and hence may be found in reclaimed
water.
The bacteria that get through into the open environment
are thus able to colonize environmental niches, and animals
through contact or ingestion. Once ingested, the antibiotic
resistant genes (ARGs) or virulence islands may be transferred
to normal flora, and subsequently to pathogenic bacteria
found in humans or animals, making later treatment with
particular antibiotics ineffective. Pruden, et al note
that because ARGs are not alive cells, they are not affected
by chlorine but they are small enough to be missed by
typical filter systems used by the waste water and drinking
water industries. Thus they wind up in the potable water
supply. That this is a reality is demonstrated by the
findings of one of our students that works part time
in two local pharmacies. He brought in water samples
to run from the “sterilized” water used in
these pharmacies to mix prescription drugs. That water
(both samples) contained bacteria that were resistant
to all our Kirby Bauer antibiotics (12 antibiotics) except
neomycin. We surmised that the filters had been contaminated,
a biofilm developed and continued to shed. Neither pharmacy
was aware of this fact until we ran the water. Why should
they have been concerned, was not the source water considered
safe?
Also one must consider transfer of genetic information
from these organisms to more robust organisms as highlighted
by Sjolund et al. (2005) indicating that resistance in
the normal flora, which may last up to four-years, might
contribute to increased resistance in higher-grade pathogens
through interspecies transfer.
Sjolund et al go on to note that since populations of
the normal biota are large, this affords the chance for
multiple and different resistant variants to develop.
This thus enhances the risk for spread to populations
of pathogens. Furthermore, there is crossed resistance.
For example, vancomycin resistance may be maintained
by using macrolides. Erythromycin is a macrolide not
well controlled by water treatment and it will bioaccumulate
in the soil.
While the next paragraphs relate to humans, the same
can be said for animals and thus may become critical
issues for rare zoo animals. Additionally in fairly crowded
conditions, there is the issue of reassortment by exposing
several species such as found within the human gut flora
or within different exotic species of animals in a zoo.
So, how fast does antibiotic resistance develop? Schentag,
et al. (2003), followed surgical patients with the subsequent
results. Pre-op nasal cultures found Staphylococcus aureus
100% antibiotic susceptible. Pre-op prophylactic antibiotics
were administered. Following surgery, cephalosporin was
administered. Ninety percent of the patients went home
at post-op day 2 without infectious complications. Nasal
bacteria counts on these patients had dropped from 10/5th
to 10/3rd, but were now a mix of sensitive, borderline,
and resistant Staphylococcus sp. By comparison, prior
to surgery, all of the patients’ Staphylococcus
samples had been susceptible to antibiotics. For the
patients remaining in the hospital and who were switched
on post-op day 5 to a second generation cephalosporin
(ceftazidine), showed bacterial counts up 1000-fold when
assayed on post-op day 7 and most of these were methicillin
resistant Staphylococcus aureus (MRSA). These patients
were switched to a 2-week course of vancomycin. Cultures
from those remaining in the hospital on day 21, revealed
vancomycin resistant enterococcus (VRE) and candida.
Vancomycin resistant enterococci infections can produce
mortality rates of between 42 and 81%.
Note in the above, that these patients harbored NO resistant
bacteria in their nasal cavities upon entry to the hospital.
But what would be the result if there had been inadvertent
acquisition of resistance from environmental contamination
such as through recycled water? Rusin, et al conducted
research about the passage from finger to mouth of pathogens
found on typical household objects. Others have documented
dust as a mechanical vector for pathogens. Thus what
of the numerous homes and businesses down wind from sprinkler
application of recycled water? What of the animals directly
exposed to this water in zoos? Our zoo uses this for
drinking water in some of the animal enclosures; I doubt
if the vets know what is in this water.
Because reclaimed water is being used on crops consumed
raw, including certified organic, we are seeing pharmaceuticals,
endocrine disrupters, flame retardants, pathogens, personal
care products put on and into these crops. Crops can
bioaccumulate these materials including heavy metals.
Thus there is a potential biomagnification. Those expecting
freedom from these contaminants by buying certified oranc
as well as other crops may wish to ascertain where and
how these crops are raised. The Salinas Valley and portions
of the crops from the Santa Maria Basin are raised on
reclaimed water. The former area irrigates around 12.000
acres
In looking at government to deal with these issues my
group has consistently run into a non-receptive group.
Each agency assures us that while this is an interesting
problem, it is not within their jurisdiction----but if
we would only call that agency over there, we are assured
that we will find help. We have gone full circle and
always the answer is the same---“not us, that agency
over there“. Try it, call around and see who if
anyone is looking seriously at these issues. You will
be surprised that few are really looking in a proactive
way at this problem.
Before the State of California’s Water Resources
Control Board, there is a newly proposed policy that
would allow expansion of reclaimed (recycled) water.
When confronted with the issues discussed above, that
agency punted. When it was required to do an environmental
impact report on the policy and these issues were brought
out, it again punted, as if there were no environmental
impacts. Thus to get clientele captured regulators to
look at these issues is difficult. They hear industry
but they don’t hear the public. The state health
authority for California, according to one of its senior
officials with whom I spoke said that if I wanted change
to get a politician to come up with a law that would
require the agency to look at this. Now that’s
proactive for the agency charged with protecting public
health.
Dr Edo McGowan.
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Environ. Sci. Technol., 40 (23), 7445 -7450, 2006. 10.1021/es060413l
S0013-936X(06)00413-5
Web Release Date: August 15, 2006
Copyright © 2006 American Chemical Society
Antibiotic Resistance Genes as Emerging Contaminants:
Studies in Northern Colorado
Amy Pruden,* Ruoting Pei, Heather Storteboom, and Kenneth
H. Carlson
Department of Civil and Environmental Engineering, Colorado
State University, Fort Collins, Colorado 80523
Received for review February 20, 2006
Revised manuscript received July 10, 2006
Accepted July 17, 2006
Abstract:
This study explores antibiotic resistance genes (ARGs)
as emerging environmental contaminants. The purpose of
this study was to investigate the occurrence of ARGs
in various environmental compartments in northern Colorado,
including Cache La Poudre (Poudre) River sediments, irrigation
ditches, dairy lagoons, and the effluents of wastewater
recycling and drinking water treatment plants. Additionally,
ARG concentrations in the Poudre River sediments were
analyzed at three time points at five sites with varying
levels of urban/agricultural impact and compared with
two previously published time points. It was expected
that ARG concentrations would be significantly higher
in environments directly impacted by urban/agricultural
activity than in pristine and lesser-impacted environments.
Polymerase chain reaction (PCR) detection assays were
applied to detect the presence/absence of several tetracycline
and sulfonamide ARGs. Quantitative real-time PCR was
used to further quantify two tetracycline ARGs (tet(W)
and tet(O)) and two sulfonamide ARGs (sul(I) and sul(II)).
The following trend was observed with respect to ARG
concentrations (normalized to eubacterial 16S rRNA genes):
dairy lagoon water> irrigation ditch water> urban/agriculturally
impacted river sediments (p < 0.0001), except for
sul(II), which was absent in ditch water. It was noted
that tet(W) and tet(O) were also present in treated drinking
water and recycled wastewater, suggesting that these
are potential pathways for the spread of ARGs to and
from humans. On the basis of this study, there is a need
for environmental scientists and engineers to help address
the issue of the spread of ARGs in the environment.
COMMENTS as printed in ES&T.
: Environ Sci Technol. 2007 Apr 1;41(7):2651-2.Links
Comment on:
Environ Sci Technol. 2006 Dec 1;40(23):7445-50.
Comment on "antibiotic resistance genes as emerging
contaminants: studies in northern Colorado".
McGowan E.
PMID: 17438829 [PubMed - indexed for MEDLINE]
These comments are merely qualifications, not criticisms
of Dr. Pruden’s fine paper [1]. Resistance has
been attributed to drug over-use. Pruden notes a less
well-understood mechanism for the amplification of multi-drug
resistance, sewage. The local sewer-treatment plant releases
pathogens and resistance to the environment and agriculture[2].
Wastewater treatment intermixes organisms otherwise seldom
coming together. Selective pressures increase survival
mechanisms [3].
Defense strategies include going dormant, entering the
viable but non-culturable (VBNC) state. These VBNC organisms
are essentially invisible to laboratory tests used in
the wastewater industry. Higgins & Murthy recently
reconfirmed this [4] in a paper that raises some serious
questions about the efficacy of current standards. Those
authors noted that during centrifuged dewatering of sewer
sludge, indicators in a VBNC state were resuscitated.
The results were several magnitudes greater than standard
plate counts had indicated [4]. Such findings raise logical
questions. If dewatering by centrifuge brought out the
essence of VBNC, would other products of sewage that
had not been subjected to the centrifuge also in the
VBNC state? If so would they revive in the field following
agricultural application of sludge or irrigation with
reclaimed wastewater? This seems plausible but needs
further study.
Additionally, as stresses increase organisms can acquire
genes from or transfer genes to non-related organisms,
organisms even within completely different kingdoms [5,6].
There are other materials dumped into the drain that
confer resistance. This includes industrial chemicals,
heavy metals, and disinfectants. Triclosan a ubiquitous
biocide is suspected of inducing resistance, as are many
other industrial materials found in sewage [7,8]. Changes
to the cellular machinery afford the ability to deal
with numerous insults, hence cross-resistance [9].
Many antimicrobials including metabolites enter sewage
essentially unchanged to induce resistance in the environment
[10]. Kummerer [11,12,13,14,15] and others [16] note
levels of antibiotics/pharmaceuticals in sewage able
to induce or maintain resistance, hence adding to the
risks in crop production through irrigation.
Based on wastewater (sewage) industry and regulatory
opinion, the standards, the released effluent, and its
use for crop irrigation or the land application of sewage
sludge are benign and beneficial activities [17]. If
however, one reviews the current medical and scientific
literature, a different picture emerges, one that raises
serious questions about the benevolence of this activity
and efficacy of the underlying standards [18]. Thus,
the issue takes on aspects of a political and not a scientific
argument [18,19]. In the interim, most regulatory agencies
have backed off [20]. This leaves the citizens and patient
base essentially standing naked.
In 2002 the NAS/NRC [21] called into question the U.S.
EPA Part 503 guidelines for land application of sewage
sludge (biosolids) and specifically EPA’s failure
to consider antibiotic resistance. As of writing this
comment, EPA has shown little if any progress in investigating
resistance. A Freedom of Information Act request to EPA
on this subject was submitted in February 2005. The agency
has not answered that request [20]. Additionally, the
agency has not done health hazards risk analyses for
pathogens. Notwithstanding these shortcomings, the agency
and the wastewater industry continue to promote the use
of sewage byproducts in crop production. Salinas Valley
is an example.
Citations
[1] Pruden, A.; Pei, R.; Storteboom, H.; Carlson, K.
H Antibiotic Resistance Genes as Emerging Contaminants:
Studies in Northern Colorado. Environ. Sci. Technol.;
(Article); 2006; 40(23); 7445-7450.
[2] Ribeiro-Dias JC, Vicente AC, Hofer E. Fecal coliforms
in sewage waters. I. Resistance to antibiotics, heavy
metals and colicinogeny. Appl Environ Microbiol 1983
Jul;46(1):227-32. Marcinek H, Wirth R, Muscholl-Silberhorn
A, Gauer M. Enterococcus faecalis gene transfer under
natural conditions in municipal sewage water treatment
plants. Appl Environ Microbiol 1998 Feb;64(2):626-32.
[3] Nakamura S, Shirota H. Behavior of drug resistant
fecal coliforms and R plasmids in a wastewater treatment
plant. Nippon Koshu Eisei Zasshi 1990 Feb;37(2):83-90.
[4] Higgins MJ, S Murthy. Examination of Reactivation
and Regrowth of Fecal Coliforms in Anaerobically Digested
Sludge WERF Report: Biosolids and Residuals (03-CTS-13T)
[5] Faguy DM. Lateral gene transfer (LGT) between Archaea
and Escherichia coli is a contributor to the emergence
of novel infectious disease.BMC Infect Dis. 2003 Jun
19;3:13.
[6] Nesbo CL. Phylogenetic analyses of two "archaeal" genes
in thermotoga maritima reveal multiple transfers between
archaea and bacteria.Mol Biol Evol. 2001 Mar;18(3):362-75
[7] Randall LP et al. Effect of Triclosan or phenolic
farm disinfectant on the selection of antibiotic resistant
Salmonella enterica. J. Antimicrob. Chemother.2004, 54,
621-27
[8] Kinney CA, et al. Survey of Organic Wastewater Contaminants
in Biosolids Destined for Land Application. ES&T
10.1021/es0603406 CCC, web pub 9/13/06.
[9] Al-Ahmad A, Daschner FD, Kummerer K. Biodegradability
of cefotiam, ciprofloxacin, meropenem, penicillin G,
and sulfamethoxazole and inhibition of waste water bacteria.
Arch Environ Contam Toxicol. 1999 Aug;37(2):158-63.
[10] Kinney CA, et al. Presence and distribution of wastewater-derived
pharmaceuticals in soil irrigated with reclaimed water.
Eniron Tox Chem 2006 Feb;25(2):317-26
[11] Kummerer K. Resistance in the environment. J Antimicrob
Chemother. 2004 Aug;54(2):311-20. Epub 2004 Jun 23.
[12] Kummerer K. Promoting resistance by the emission
of antibiotics from hospitals and households into effluent.
Clin Microbiol Infect. 2003 Dec;9(12):1203-14.
[13] Kummerer K. Standardized tests fail to assess the
effects of antibiotics on environmental bacteria. Water
Res. 2004 Apr;38(8):2111-6.
[14] Kummerer K. Biodegradability of some antibiotics,
elimination of the genotoxicity and affection of wastewater
bacteria in a simple test. Chemosphere. 2000 Apr;40(7):701-10.
[15] Kummerer K. Drugs, diagnostic agents and disinfectants
in wastewater and water--a review. Schriftenr Ver Wasser
Boden Lufthyg. 2000;105:59-71.
[16] [17] Rooklidge SJ. Environmental antimicrobial contamination
from terraccumulation and diffuse pollution pathways.
Sci Total Environ. 2004 Jun 5;325(1-3):1-13. Review.
[17] 503 Appendix B, subpart D of Part 503 Regulations,
CFR Title 40, Vol 21, revised July 1,1998.
[18] Snyder C. The Dirty Work of Promoting “Recycling” of
America’s Sewage Sludge. Int J. Occup Health. 2005;
11:415-27.
[19] Mintz JA. “Treading Water”: A Preliminary
Assessment of EPA Enforcement During the Bush II Administration.
[20] Personal communications with both EPA and CDC.
[21] National Research Council of the National Academy
of Sciences (NAS) Biosolids Applied to Land: Advancing
Standards and Practices. Washington, DC: National Academy
Press, 2002.
The Importance of Municipal Sewage Treatment in the Spread
of Antibiotic Resistance
106th General Meeting of the American Society for Microbiology
May 21-25, 2006, Orlando, Florida
For more information on any presentation at the 106th
General Meeting of the ASM contact Jim Sliwa, ASM Office
of Communications at jsliwa@asmusa.org
EMBARGOED UNTIL: Monday, May 22, 9:00 a.m. EDT
(Session 041/Q, Paper Q-032)
Sara Firl
University of Minnesota
Minneapolis, MN, United States
Phone: 612 626 8865
firl0002@umn.edu
Our study determined that substantial numbers of antibiotic-resistant
bacteria were present in municipal wastewater, and that
the existing treatment infrastructure did not adequately
prevent release of antibiotic-resistant bacteria into
the environment. Many of the bacteria found in the wastewater
treatment plant and in the plant effluent were tentatively
identified as potential pathogens and were also resistant
to multiple antibiotics, raising public health concerns.
We believe that wastewater treatment plants could be
modified to further prevent the release of resistant
bacteria to the environment.
Sara Firl and Leslie Onan performed this study under
the supervision of principal investigator Dr. Timothy
LaPara at the University of Minnesota, Department of
Civil Engineering. Funding was provided by the Center
for Urban and Regional Affairs at the University of Minnesota
and Geomatrix Consultants, Inc. The work is being presented
as a poster at the 106th General Meeting of the American
Society for Microbiology in Orlando on May 22.
The spread of antibiotic-resistant bacteria is a major
public health concern. Infections previously treatable
are increasingly resistant to antibiotics. Scientists
believe that the spread of antibiotic resistance results
from both misuse of antibiotics and transfer of resistance
between bacteria. A potentially large reservoir for antibiotic-resistant
bacteria is municipal wastewater. People release resistant
bacteria with fecal matter into the wastewater stream,
which is collected and treated at municipal treatment
facilities before release to the environment. The objective
of this study was to investigate how many resistant bacteria
were present at municipal wastewater plants and if the
existing infrastructure of waste treatment was adequate
to remove resistant bacteria before discharge.
In our study, the effect of effluent treatment (clarification
and disinfection) and biosolids treatment (sludge digestion)
on the removal of antibiotic-resistant bacteria was investigated
at three wastewater treatment facilities. We found substantial
numbers of resistant bacteria at the wastewater treatment
facilities and that, although effluent treatment reduced
the numbers of bacteria, large quantities of resistant
bacteria were discharged. Numerous bacteria isolated
from the effluent stream were resistant to multiple antibiotics
and closely related to potentially pathogenic bacteria.
Our research suggests that the existing wastewater treatment
infrastructure should be modified to better prevent release
of these potentially dangerous bacteria to the environment.
+++++++++++++++++
Appl Environ Microbiol. 2005 June; 71(6): 3163–3170.
doi: 10.1128/AEM.71.6.3163-3170.2005. PMCID: PMC1151840
Copyright © 2005, American Society for Microbiology
Validity of the Indicator Organism Paradigm for Pathogen
Reduction in Reclaimed Water and Public Health Protection†
Valerie J. Harwood,1* Audrey D. Levine,2 Troy M. Scott,3
Vasanta Chivukula,1 Jerzy Lukasik,3 Samuel R. Farrah,4
and Joan B. Rose5
Department of Biology, SCA 110, University of South Florida,
4202 E. Fowler Ave., Tampa, Florida 33620,1 Department
of Civil and Environmental Engineering, ENB 118, University
of South Florida, 4202 E. Fowler Ave., Tampa, Florida
33620,2 Biological Consulting Services of N. Florida,
Inc., 4641 N.W. 6th Street, Suite A, Gainesville, Florida
32609,3 Department of Microbiology and Cell Science,
University of Florida, Gainesville, Florida 32611,4 Department
of Fisheries and Wildlife and Crop and Soil Sciences,
13 Natural Resources Building, Michigan State University,
East Lansing, Michigan 488245
*Corresponding author. Mailing address: Department of
Biology, SCA 110, University of South Florida, 4202 E.
Fowler Ave., Tampa, FL 33620. Phone: (813) 974-1524.
Fax: (813) 974-3263. E-mail: vharwood@cas.usf.edu.
Received September 27, 2004; Accepted December 20, 2004.
+++++++++++++
Environ Toxicol Chem. 2006 Feb ;25 (2):317-26 16519291
(P,S,E,B) Presence and distribution of wastewater-derived
pharmaceuticals in soil irrigated with reclaimed water.
[My paper] Chad A Kinney, Edward T Furlong, Stephen L
Werner, Jeffery D Cahill
National Water Quality Laboratory, U.S. Geological Survey,
Denver Federal Center, P.O. Box 25046, Building 95, MS
407, Denver, Colorado 80225-0046, USA.
Three sites in the Front Range of Colorado, USA, were
monitored from May through September 2003 to assess the
presence and distribution of pharmaceuticals in soil
irrigated with reclaimed water derived from urban wastewater.
Soil cores were collected monthly, and 19 pharmaceuticals,
all of which were detected during the present study,
were measured in 5-cm increments of the 30-cm cores.
Samples of reclaimed water were analyzed three times
during the study to assess the input of pharmaceuticals.
Samples collected before the onset of irrigation in 2003
contained numerous pharmaceuticals, likely resulting
from the previous year's irrigation. Several of the selected
pharmaceuticals increased in total soil concentration
at one or more of the sites. The four most commonly detected
pharmaceuticals were erythromycin, carbamazepine, fluoxetine,
and diphenhydramine. Typical concentrations of the individual
pharmaceuticals observed were low (0.02-15 microg/kg
dry soil). The existence of subsurface maximum concentrations
and detectable concentrations at the lowest sampled soil
depth might indicate interactions of soil components
with pharmaceuticals during leaching through the vadose
zone. Nevertheless, the present study demonstrates that
reclaimed-water irrigation results in soil pharmaceutical
concentrations that vary through the irrigation season
and that some compounds persist for months after irrigation.
+++++++++++++++
