National Status and Trends Program for Marine Environmental Quality 

Human Use Pharmaceuticals in the Estuarine Environment: 

A Survey of the Chesapeake Bay, Biscayne Bay and Gulf of 

the Farallones

CONH2 

C C 

N 

NOAA Technical Memorandum NOS NCCOS 7
Mention of trade names or commercial products does not constitute endorsement or recommendation for their 

use by the United States government. 

Citation for this Report: 

Pait, A.S., R.A. Warner, S.I. Hartwell, J.O. Nelson, P.A. Pacheco, and A.L. Mason. 2006. Human Use Pharmaceuticals in the Estuarine Environment: A Survey of the Chesapeake Bay, Biscayne Bay and Gulf of the 

Farallones. NOS NCCOS 7. Silver Spring, MD. NOAA/NOS/NCCOS/Center for Coastal Monitoring and 

Assessment. 21pp. 
Human Use Pharmaceuticals in the Estuarine Environment: 

A Survey of the Chesapeake Bay, Biscayne Bay and Gulf of 

the Farallones 

Anthony S. Pait1, Robert A. Warner1, S. Ian Hartwell1, 

Judd O. Nelson2, Percy A. Pacheco3, and Andrew L. Mason4

1Center for Coastal Monitoring and Assessment 

NOAA/NOS/NCCOS, 1305 East/West Highway, Silver Spring, MD 20910 

2University of Maryland 

Marine Environmental Estuarine Sciences Program, College Park, MD 20742 

3Special Projects Offi ce, NOAA/NOS/SPO 

1305 East/West Highway, Silver Spring, MD 20910 

4I.M. Systems Group, Center for Coastal Monitoring and Assessment 

NOAA/NOS/NCCOS, 1305 East/West Highway, Silver Spring, MD 20910 

NOAA Technical Memorandum NOS NCCOS 7 

August 2006 

United States Department of National Oceanic and National Ocean Service 

Commerce Atmospheric Administration 

Carlos M. Gutierrez Conrad C. Lautenbacher, Jr. John H. Dunnigan 

Secretary Vice Admiral (Ret.), Administrator Assistant Administrator 
Table of Contents

List of Tables .............................................................................................................................. iv

List of Figures............................................................................................................................ iv

I. Introduction ......................................................................................................................... 1

II. Materials and Methods ........................................................................................................ 2

III. Results and Discussion ........................................................................................................ 12

IV. Summary and Conclusions .................................................................................................. 18

IV. Acknowledgments ............................................................................................................... 19

V. Literature Cited .................................................................................................................... 20

iii 
List of Tables 

1. Ancillary water quality data collected at pharmaceutical sampling sites ......................................... 3

2. Selected properties of the pharmaceuticals analyzed........................................................................ 9

3. Pharmaceuticals detected at the Chesapeake Bay sites.....................................................................13

4. Pharmaceuticals detected at the Biscayne Bay and Gulf of the Farallones sites. .............................14

5. Reported detections of selected human use pharmaceuticals in the aquatic environment................18

List of Figures 

1. Sampling sites in the northern Chesapeake Bay ............................................................................... 4

2. Sampling sites in the southern Chesapeake Bay............................................................................... 5

3. Sampling sites in Biscayne Bay ....................................................................................................... 6

4. Sampling sites in the Gulf of the Farallones..................................................................................... 7

5. Concentration of compounds detected (excluding caffeine) in Chesapeake Bay water samples .....17

iv 

Human Use Pharmaceuticals in the Estuarine Environment: 

A Survey of the Chesapeake Bay, Biscayne Bay and the Gulf of the 

Farallones 

Introduction 

The assessment of emerging risks in the aquatic 

environment is a major concern and focus of environmental science (Daughton and Ternes, 1999). 

One significant class of chemicals that has received 

relatively little attention until recently are the human 

use pharmaceuticals. 

In 2004, an estimated 2.6 billion prescriptions were 

curring in groundwater, typically as a result of their 

disposal in landfi lls (Jones et al., 2001). 

Halling-Sørensen et al. (1998) noted that pharmaceuticals are developed with the intention of having 

a biological effect, and often have physico/chemical 

properties (e.g., ability to pass through membranes, 

persistence) chosen to avoid their inactivation prior 

written for the top 300 pharmaceuticals in the U.S. (RxList, 2005). 

Mellon et al. (2001) estimated that 1.4 

million kg of antimicrobials are used 

in human medicine every year. The 

use of pharmaceuticals is also estimated to be on par with agrochemicals

(Daughton and Ternes, 1999). Unlike 

agrochemicals (e.g., pesticides) which 

tend to be delivered to the environment in seasonal pulses, pharmaceuticals are continuously released through 

the use/excretion and disposal of these 

chemicals, which may produce the 

same exposure potential as truly per

sistent pollutants. 

Human use pharmaceuticals can enter 

the aquatic environment through a 

number of pathways, although the 

main one is thought to be via ingestion

and subsequent excretion by humans 

(Thomas and Hilton, 2004). Unused 

pharmaceuticals are typically flushed 

down the drain or wind up in landfills 

(Jones et al. 2001). 

o having a curative effect. Brain 

t al. (2004) concluded that while 

he concentrations of individual 

ompounds in the environment are 

ow, the combination of a varity of pharmaceuticals in natural 

aters could prove toxicologically 

ignificant. In addition, there is 

lso the possibility that pharmaeuticals could interact with other 

ollutant classes (e.g., pesticides 

r polycyclic aromatic hydrocar

ons (PAHs)) within the environent in unanticipated ways. 

In wastewater treatment plants (WWTPs), a number of pharmaceuticals are only partly removed by 

conventional biological treatments, resulting in their 

discharge to surface waters (Andreozzi et al., 2002). 

There have also been reports of pharmaceuticals ocCarbamazepine 

CONH2 

C C 

N 

O 

H 

N

CF3 

Fluoxetine 

Molecular structures of two compounds included in this study, the 

antiepileptic carbamazepine, and 

fluoxetine or Prozac®, an antidepressant.

­

t

e

t

c

l

e

w

s

a

c

p

o ­

b

m

The effects of pharmaceuticals 

in the aquatic environment are 

just beginning to be investigated. 

Some pharmaceutical types such 

as lipid regulators or antidepressants could, for example, interfere 

with an aquatic organism’s basic 

metabolism (e.g., energy transfer) 

or put it at a competitive disadvantage (e.g., behavioral effects). 

Boyd and Furlong (2002) noted that potential impacts 

of pharmaceuticals in the environment include abnormal physiological effects, impaired reproduction, increased cancer rates, and disruption of bacterial beds 

used to treat wastewater in many treatment plants. 

There is also concern that the continuous addition of 

antibiotics to the aquatic environment could result in 

1
the emergence of antibiotic-resistant, disease causing 

strains of bacteria (Yang and Carlson, 2004). 

Andreozzi et al. (2003) concluded that detection of 

pharmaceutical residues in the environment raises 

questions about the impacts they may be having, 

and highlighted the need for data on exposure in the 

aquatic environment. To assess exposure, information is needed on the occurrence and concentration 

of these chemicals. One strategy is to first look for 

pharmaceuticals in waters adjacent or downstream of 

likely points of discharge, such as WWTPs. These 

areas would likely have higher concentrations of 

human use pharmaceuticals, and perhaps detectable 

impacts in aquatic organisms. 

Currently, the Environmental Protection Agency 

(EPA) and the U.S. Geological Survey (USGS) are 

investing significant resources to assess the contamination of freshwater systems with prescription 

and nonprescription pharmaceuticals (Daughton 

and Ternes, 1999; 

Kolpin, et al., 2002). 

To understand the 

implications in the 

coastal aquatic environment, NOAA’s 

National Status and 

Trends (NS&T) Program, of the Center 

for Coastal Monitoring and Assessment, 

conducted a pilot 

study to assess the presence of a suite of human use 

pharmaceuticals at selected sites in the Chesapeake 

Bay, Biscayne Bay, and the Gulf of the Farallones. 

The NS&T Program has monitored organic and 

inorganic contaminants and their effects in the 

Nation’s estuaries and coastal waters for over 20 

years (NOAA, 1998). As part of this effort, NS&T 

also investigates the occurrence of what have become 

known as “emerging contaminants of concern”, previously unknown or unidentified classes of contaminants that may be impacting the environment. Pharmaceutical compounds fall within this category. The 

goal of this pilot project was to assess the presence of 

a number of commonly prescribed human use pharmaceuticals in three coastal areas of the U.S. 

Materials and Methods 

Water samples were collected in conjunction with 

three NOAA monitoring/research projects to assess sediment contamination, macrobenthic infaunal 

communities, and bioeffects in the Chesapeake Bay, 

Biscayne Bay, and the Gulf of the Farallones. The 

primary sampling area for the pharmaceuticals pilot 

project was the Chesapeake Bay. All samples were 

collected in 2002. A description of sample collection 

and handling protocols follows. Ancillary data collected at each site is shown in Table 1. 

Chesapeake Bay. Water samples from the Chesapeake Bay and tributaries were collected in September 2002. Sampling sites were primarily located adjacent to WWTP outfalls. The rationale for using this 

approach was to create 

the best opportunity for 

detecting the pharmaceuticals of interest. If 

there were no detections at these sites, it 

would be unlikely they 

would be detected in the 

estuarine environment 

in general. 

Water samples were collected from the NOAA 

ship Ferrell, or from its 

launch in shallow water. 

Water samples were collected using a PVC Niskintype, 2 liter sampler rinsed with acetone and distilled 

water just prior to deployment. Composite (near 

surface and bottom) water samples were collected 

from 14 sites in the northern and southern portions 

of the Bay. Water samples from the Niskin sampler 

were emptied into certified clean 4 liter amber glass 

jugs, and the samples were kept on ice until they were 

extracted at the University of Maryland, within two 

weeks of sample collection. 

Eight of the 14 sites sampled in the Chesapeake 

were adjacent to WWTPs, and included Back River, 

NOAA ship Ferrell used to collect water samples in the Chesapeake Bay. 

2
3

Ancillary water quality data collected at pharmaceutical sampling sites. Table 1. 

Surface measurements Bottom measurements

Sample Water sample Location Station Map Latitude Longitude Depth Secchi depth Temperature Salinity Dissolved pH Temperature Salinity Dissolved

date type ID (DD) (DD) (m) (m) (oC) (ppt) Oxygen (oC) (ppt) Oxygen (mg/L) 

Chesapeake Bay9/26/2002 composite Back River Back River WWTP outfall BR 39.2936 -76.4786 3.4 0.5 24.0 2.9 7.8 23.0 5.5 4.2 

9/26/2002 composite Back River Back WWTP, 1 km downstream BR1 39.2885 -76.4635 1.7 0.5 22.1 5.7 11.6 22.1 5.9 10.7 

9/26/2002 composite Back River Back WWTP, 5 km downstream BR5 39.2629 -76.4444 2.3 0.5 22.1 8.8 10.5 22.4 8.7 1.1 

9/26/2002 composite Back River Back WWTP, 10 km downstream BR10 39.2423 -76.4035 3.7 1 22.0 10.7 9.5 22.1 10.8 7.7 

9/25/2002 composite Patapsco River Patapsco River WWTP outfall PR 39.2283 -76.5324 6.1 3.3 24.1 14.2 5.7 24.3 14.6 3.6 

9/25/2002 composite Patapsco River Patapsco WWTP, 1 km downstream PR1 39.2351 -76.5473 15.0 23.6 15.5 24.4 16.7 

9/25/2002 composite Patapsco River Patapsco WWTP, 5 km downstream PR5 39.2087 -76.5194 17.0 23.7 15.2 24.2 16.6 

9/25/2002 composite Patapsco River Patapsco WWTP, 10 km downstream PR10 39.1912 -76.4782 17.0 23.6 15.0 24.0 16.6 

9/25/2002 composite Patapsco River Cox Creek WWTP outfall CC 39.1859 -76.5196 3.7 23.9 14.3 7.7 23.8 14.3 0.1 

9/24/2002 composite Annapolis Annapolis WWTP outfall AN 38.9635 -76.4599 18.0 3 24.2 16.0 10.8 24.7 16.7 7.4 

9/27/2002 composite Norfolk Chesapeake-Elizabeth WWTP outfall CEP 36.9399 -76.1752 9.2 2.5 9/23/2002 composite Hampton Roads Nansemond WWTP outfall NTP 36.9319 -76.3970 51.0 2.5 25.4 23.4 8.7 25.5 23.3 8.3 

9/23/2002 composite Norfolk Virginia Initiative WWTP outfall VIP 36.8800 -76.3300 52.0 2.1 25.7 22.0 7.9 25.7 22.2 7.6 

9/28/2002 composite Virginia Beach Atlantic WWTP outfall AST 36.7834 -75.9287 11.5 1.5 30.3 

Biscayne Bay3/6/2002 surface Site #1 Princeton Canal mouth PCM 25.5190 -80.3306 10.0 21.7 4.5 6.1 7.9 

3/6/2002 surface Site #2 Military Canal MIC 25.4897 -80.3386 10.0 19.4 16.7 8.1 7.9 

3/7/2002 surface Site #3 Mowry Canal MC 25.4696 -80.3399 10.0 21.8 1.5 7.8 8.1 3/4/2002 surface Site #4 North Canal mouth NCM 25.4631 -80.3341 7.0 24.4 27.3 7.6 

3/7/2002 surface Site #5 Florida City Canal, E of mouth FC 25.4490 -80.3290 2.0 17.8 21.6 7.2 8.0 

3/5/2002 surface Site #8 Channel leading to North Canal NCC 25.4575 -80.3150 5.6 19.4 30.9 6.8 7.9 

3/5/2002 surface Site #9 Turkey Point TP 25.4356 -80.3051 5.5 19.4 32.5 7.0 7.9 

3/5/2002 surface Site #12 South of Turkey Point STP 25.4236 -80.2938 4.1 19.2 34.8 6.7 8.0 3/5/2002 surface Site #16 SE of Pelican Bank PB 25.4180 -80.2706 6.0 19.4 36.4 6.5 7.9 

3/5/2002 surface Site #20 South of Featherbed Bank FB 25.4798 -80.2146 10.0 20.1 37.7 6.9 8.1 

3/6/2002 surface Site #31 Black Point BP 25.5345 -80.3246 8.2 20.5 7.5 5.6 8.3 

Gulf of the Farallones3/4/2002 composite San Francisco Coast North of WWTP outfall SF1 37.7060 -122.5683 10.9 12.2 31.4 8.7 11.9 31.9 8.8 

3/4/2002 composite San Francisco Coast South of WWTP outfall SF2 37.6968 -122.5711 10.9 12.0 31.7 8.8 11.2 33.0 8.9 

Abbreviations: WWTP, wastewater treatment plant; km, kilometers; DD, decimal degrees; m, meters; oC, degrees Celsius; ppt, parts per thousand; mg/L, milligrams/liter 
Chesapeake Bay 

Back River 

Patapsco 

Baltimore River BR

# # BR1

# BR5

PR # #

#

PR1 BR10 

#

PR5 # #CC PR10 

#AN

Annapolis 

Figure 1. Sampling sites in the northern Chesapeake Bay (see Table 1 for site code descriptions). 

Patapsco River, Cox Point and Annapolis in the 

northern part of the Bay (Figure 1), and near the Vir

ginia Initiative, Atlantic, Chesapeake-Elizabeth, and 

Nansemond WWTPs in the southern portion (Figure 

2). Water samples taken at these sites were collected 

as close as possible to the point of discharge. 

For the Back River (BR) site, locating the exact 

discharge point for the WWTP was fairly straightforward, as the outfall is an above water concrete 

conduit. At the Patapsco River WWTP, even though 

the diffuser is on the bottom of the river at a depth 

of approximately 7 meters, the effl uent plume was 

clearly visible on the surface of the water. However, 

for the remaining fi ve facilities sampled in the Chesapeake Bay, the point of discharge had to be estimated 

from latitude and longitude coordinates for the pipe, 

obtained from EPA’s online Permit and Compliance 

System (EPA, 2005) or from NOAA navigational 

charts. 

­

In addition to sampling adjacent to the WWTP discharge points in the Back River and Patapsco River, 

water samples were also collected 1, 5, and 10 km 

(e.g., BR1, BR5, BR10) downstream of these WWTP 

facilities (Figure 1). The goal was to assess how dilution and other physical or biological processes might 

affect downstream concentrations of the pharmaceuticals. 

Biscayne Bay. The second area sampled for this pilot 

project was Biscayne Bay. Eleven sites in and around 

the western shore of the Bay were selected (Figure 

3 and Table 1). Sampling sites were located at the 

mouth of drainage canals (e.g., Mowry Canal) or in 

areas further offshore where groundwater discharges 

to Biscayne Bay may be present. Long et al. (1999) 

reported a number of sites in Biscayne Bay to be 

toxic to benthic infauna using one or more bioassays. 

4
James River 

Chesapeake Bay 

CEP 

# NTP #

VIP 

#

Norfolk 

Virginia Beach #

AST 

Figure 2. Sampling sites in the southern Chesapeake Bay (see Table 1 for site code descriptions). 

All samples collected from Biscayne Bay were nearsurface water samples. Water samples were collected

by directly submerging a 4 liter certifi ed clean amber 

jug beneath the surface of the water, capping the container, and then placing it on ice in a cooler. 

As in the other locations for this study, the presence 

of human use pharmaceuticals could be used as an 

indicator of sewage-related inputs (WWTP or septic) 

and in Biscayne Bay, could conceivably be contributing to the observed sediment toxicity in the area 

(Long et al., 1999). 

Gulf of the Farallones. The fi nal collection area for 

this pilot project was the Gulf of the Farallones in the

Pacifi c Ocean, off the coast of San Francisco (Figure 

4). As in the Chesapeake and Biscayne Bays, samples were taken in conjunction with a NOAA project 

to assess the presence of contaminants and toxicity to 

benthic infauna. Samples were collected aboard the 

NOAA ship McArthur I. The fi rst sample site (SF1) 

was 0.6 km north of the location of the outfall for 

the Oceanside WWTP, as reported in EPA’s online 

Permit and Compliance System (EPA, 2005) and as 

shown on the NOAA nautical chart. The diffuser 

pipe is located approximately 6 km offshore at a 

depth of 24 meters. The second location was 0.6 km 

south of this location. Composite (near surface and 

bottom) water samples were taken using a rosettetype Niskin sampler at both sites. The water samples 

were emptied into certifi ed clean 4 liter amber glass 

jugs, and kept on ice until they were fi ltered and 

extracted at the University of Maryland. 

Sample Processing. All samples received were kept 

at 4oC, prior to fi ltration and extraction. The proto5
# BP 

# PC

Biscayne Bay 

# MIC 

FB 

#

MC # NCC #

# NCM 

# FC 

#TP 

STP 

#

# PB 

South 

Florida

Figure 3. Sampling sites in Biscayne Bay (see Table 1 for site code descriptions). 

cols used for the extraction were those of Cahill et al. 

(2004). A brief description follows. 

Samples were first fi ltered through a 0.7 μm Whatman glass fiber fi lter to remove particulate material. 

Each fi ltered water sample received 1 μg/L of phenacetin-1-ethoxy 13C as a surrogate analyte. One liter 

of the water sample was then passed through a conditioned Waters® Oasis HLB SPE cartridge at a rate of 

15 ml/min. The cartridge was then eluted using 2 ml 

aliquots of methanol and acidifi ed methanol. 

The methanol extracts were stored for an extended 

period of time (approximately 6 months) at -20oC 

at the University of Maryland prior to shipment to 

the U.S. Geological Survey (USGS) for analysis. 

Samples sent to the USGS were shipped overnight on 

dry ice. 

Sample Analysis. All sample analyses were carried 

out by the National Water Quality Laboratory of the 

USGS in Denver, Colorado. Below is a summary of 

the analytical protocols provided by USGS (Werner, 

pers. comm. and Cahill et al., 2004). 

The sample methanol extracts were transferred to borosilicate glass test tubes, and 100 μl of reagent water 

was then added. The methanol was removed from the

samples using a Zymark® TurboVap sample concentrator with a water bath set at 40oC and nitrogen flow 

at 5 PSI. Samples were reduced to approximately 

100 μl fi nal volume and reconstituted with 850 μl of 

formate buffer solution and 50 μl of an internal standard solution in methanol. 

The samples were analyzed by High-Performance 

Liquid Chromatography/Mass Spectroscopy (HPLC/ 

6
San Francisco Bay 

Gulf of the Farallones San Francisco 

# SF1 # SF2 

Figure 4. Sampling sites in the Gulf of the Farallones (see Table 1 for site code descriptions).

MS) using positive mode electrospray ionization 

(ESI) and selective ion monitoring to detect selected 

analytes. 

HPLC separation of analytes was achieved using a 

reverse-phase analytical column with a C18 stationary

phase. The chromatographic eluents used consisted 

of a 10 mM formate buffer in reagent water and 

acetonitrile. A multi-step gradient profile was used to 

achieve an optimized separation of analytes. 

The HPLC column was coupled to a mass spectrometer using ESI for detection and quantitation of individual separated analytes. ESI is used for these polar 

organic compounds because it will efficiently produce a charged ion (a protonated molecular ion) with 

relatively little fragmentation. This results in high 

sensitivity. To improve selectivity, the ESI source is 

operated so that in-source, collisionally-induced molecular dissociation occurs, producing characteristic 

patterns of fragment ions used to specifically identify 

the compound of interest. Measured ratios of ion 

abundances of these fragments and of the molecular 

ions are used to either confirm an analyte detection or 

to discount matrix interferences. 

Addition of the internal standard (D4

 nicotinamide) 

immediately prior to analysis was used to correct for 

variations in final extract volume when quantifying 

analyte results and calculating sample concentrations. 

Compounds Analyzed. Selected properties of the 24 

human use pharmaceuticals and related compounds 

included in this pilot project, along with their molecular structures are shown in Table 2. The pharmaceuti7
cals include a number of antibiotics, analgesics, lipid 

regulators and antidepressants. Selection of the compounds was based on a variety of factors including 

number of prescriptions, persistence and the possibility of having an environmental impact, probability of 

being able to develop sensitive analytical protocols 

for water samples, and the availability of analytical 

standards. 

Twenty-one of the compounds in Table 2 (excluding 

caffeine, 1,7-dimethylxanthine, and cotinine) are 

dispensed through a doctor’s prescription. A number 

of the compounds such as caffeine and cotinine have 

been used as traditional markers of human sewage. 

Table 2 also includes a number of metabolites. Dehydronifedipine is a metabolite of the antianginal medication nifedipine. A metabolite of the antidepressant 

paroxetine was also 

included. Similarly, 

the presence of 1,7­

dimethylxanthine, a 

metabolite of caffeine 

was characterized as 

well. 

Of the human use 

pharmaceuticals 

listed in Table 2, 

eight (asterisked) 

were among the top 

100 prescribed medications, accounting 

for nearly 180 million 

prescriptions in the U.S. annually (RxList, 2005). 

Four antibiotics, including azithromycin, erythromycin-H2

O (erythromycin degradate), sulfamethoxazole, 

and trimethoprim were included. Erythromycin and 

azithromycin belong to a class of antibiotics known 

as macrolides, used to treat a wide variety of infections. In the U.S. in 2004, an estimated 2.5 million 

prescriptions were written for erythromycin, which 

is produced by Streptomyces erythraeus, a strain of 

filamentous bacteria. 

In this document, detections of erythromycin-H2

O 

are reported rather than concentrations. Because of 

the low recovery levels of erythromycin-H2

O from 

water samples (typically around 10%), and the possibility of interferences (similar ion fragments) from 

other sources (Furlong, pers. comm.), quantification 

of erythromycin-H2O was not possible. 

Sulfamethoxazole belongs to another large group of 

antibiotics known as sulfonamides or sulfa medicines. 

Trimethoprim is a synthetic antibacterial. Sulfamethoxazole and trimethoprim, often used in combination are especially effective in treating infections 

in urinary and digestive tracts, along with sinus and 

bronchial infections. There is concern regarding the 

possible overuse of antibiotics leading to increased 

antibiotic resistant, possibly pathogenic strains of 

bacteria, in humans and in the environment. 

Fluoxetine and 

paroxetine are two 

widely used antidepressants, both 

belonging to a class 

of compounds known 

as selective serotonin 

reuptake inhibitors. 

An estimated 35 

million prescriptions 

were written for these 

two pharmaceuticals 

in 2004 (RxList, 

2005). Low levels of 

serotonin have been 

linked to depression, 

and both fluoxetine and paroxetine work to elevate 

levels of this neurotransmitter. In addition, fluoxetine (Prozac®) also has a strong energizing effect, 

helping in the treatment of clinical depression cases 

involving a lack of energy. Anxiety disorders can 

also lead to low levels of serotonin, needed to metabolize stress hormones, and fluoxetine can be beneficial by making more serotonin available. 

Paroxetine is also a widely prescribed selective serotonin reuptake inhibitor. Recently, however, there has 

been concern regarding the use of these and other antidepressants, related to possible increases in suicidal 

behavior. 

Launch from the NOAA ship Ferrell used to collect water samples 

from shallow areas. 

8
Table 2. Selected properties of the pharmaceuticals analyzed. 

Compound Structure Use Brand/Common 

Name MW CAS 

1,7-dimethylxanthine Caffeine metabolite Paraxanthine 180.16 611-59-6 

*Acetaminophen Analgesic and 

antipyretic Tylenol® 151.17 103-90-2 

*Azithromycin Antibiotic Zithromax® 748.88 83905-01-5 

Caffeine Stimulant Caffeine 194.19 58-08-2 

Carbamazepine Antiepileptic, 

antidepressant Tegretol® 236.27 298-46-4 

Cimetidine Antacid Pepcid® 252.34 51481-61-9 

Codeine Analgesic Codeine 299.36 76-57-3 

Cotinine Nicotine metabolite Cotinine 176.22 486-56-6 

Dehydronifedipine 

Nifedipine (parent of dehydronifedipine) 

Antianginal Procardia® 

metabolite 344.32 67035-22-7 

Abbreviations: CAS, Chemical Abstract Service; MW, molecular weight; ®, Registered trademark 

*Top 100 prescribed pharmaceutical according to RxList (2005) 

9
Table 2. Selected properties of the pharmaceuticals analyzed (continued). 

Compound Structure Use Brand/Common 

Name MW CAS 

*Diltiazem Antianginal Cardizem® 450.98 33286-22-5 

Diphenhydramine Antihistamine Benadryl® 291.82 147-24-0 

Erythromycin-H2O Antibiotic E-mycin® 733.93 114-07-8 

*Fluoxetine Antidepressant Prozac® 345.8 54910-89-3 

Gemfibrozil Lipid regulator Lopid® 250.35 25812-30-0 

*Ibuprofen Analgesic and 

antipyretic Motrin® 351.83 15687-27-1 

*Metformin Antidiabetic Glucophage® 129.17 657-24-9 

Miconazole Antifungal Micatin® 416.12 22916-47-8 

Abbreviations: CAS, Chemical Abstract Service; MW, molecular weight; ®, Registered trademark 

*Top 100 prescribed pharmaceutical according to RxList (2005) 

10
Table 2. Selected properties of the pharmaceuticals analyzed (continued). 

Compound Structure Use Brand/Common 

Name MW CAS 

*Paroxetine metabolite 

Paroxetine (parent compound) 

Antidepressant Paxil® 

metabolite - -

Ranitidine Antacid Zantac® 350.87 66357-35-5 

Salbutamol Antiasthmatic Proventil® 239.3 51022-70-9 

Sulfamethoxazole Antibiotic Bactrim® 253.28 723-46-6 

Thiabendazole Anthelmintic Mintezol® 201.26 148-79-8 

Trimethoprim Antibiotic Proloprim® 290.3 738-70-5 

*Warfarin Anticoagulant Coumadin® 308.33 129-06-6 

Abbreviations: CAS, Chemical Abstract Service; MW, molecular weight; ®, Registered trademark 

*Top 100 prescribed pharmaceutical according to RxList (2005) 

Two antianginal medications, diltiazem and a metab- muscle). Calcium channel blockers act to slow down 

olite of nifedipine, were included in the pilot project. the force of the contraction of the heart, lowering 

Approximately 12 million prescriptions were written blood pressure. 

for diltiazem and nifedipine in 2004 (RxList, 2005). 

Both drugs are known as calcium channel block- In 2004, approximately 6 million prescriptions were 

ers and are used in the treatment of hypertension, or written for the lipid regulator gemfi brozil (RxList, 

angina (chest pain due to a lack of oxygen to the heart 2005), used to lower triglycerides (fats) and cho11
lesterol in the blood. Gemfibrozil acts to increase 

the activity of the peroxisome proliferator-activated 

receptor-alpha, involved in the metabolism of fats and 

carbohydrates. Use of this pharmaceutical is thought 

to decrease the amount of fat produced by the liver. 

The antidiabetic drug metformin (over 25 million 

prescriptions in 2004) is used to treat type 2 (noninsulin-dependant) diabetes. Insulin is a polypeptide 

hormone that helps regulate the metabolism of carbohydrates. The mechanism of action of metformin is 

unclear, but it may reduce the rate of hepatic gluconeogenesis and also improve the peripheral uptake 

and utilization of glucose in the body. Cimetidine 

belongs to a group of antacid medications known as 

H2

-receptor antagonists, which block the action of 

histamine on the parietal cells of the stomach, decreasing the amount of acid produced by these cells. 

Carbamazepine is used in the treatment of epilepsy 

and sometimes for bipolar disorders. The mechanism 

of carbamazepine is not well understood, but appears 

to act primarily through inhibition of sodium channels, important in the process of muscle contraction 

and nerve impulse conduction. As will be seen, 

this compound appears to be fairly persistent in the 

aquatic environment. 

Finally, three analgesics, acetaminophen, ibuprofen 

and codeine were included. Analgesics or pain killers, are a diverse group of drugs. The term analgesic comes from the Greek term for “without pain”. 

Ibuprofen is a commonly prescribed pain medication 

(25 million prescriptions in the U.S.), and is also 

available as an over the counter medication in lower 

strengths. Ibuprofen is known as a COX-2 inhibitor. 

This class of pharmaceuticals selectively blocks the 

action of the COX-2 enzyme involved in the production of prostaglandins, which have a role in pain and 

fever responses in the body. Acetaminophen (16 

million U.S. prescriptions in 2004 and also available 

in over the counter preparations) is believed to reduce 

pain by reducing the production of prostaglandins. 

Codeine, the methylated form of morphine, is available in the U.S. by prescription. In the body, only 

about 10% of codeine is converted into morphine, 

producing a less potent effect than morphine itself. 

Codeine, like morphine, works directly on the central 

nervous system to relieve pain, and in particular at 

the synapses of the arcuate nucleus, located in the 

hypothalamus. 

Results and Discussion 

The results of the pharmaceutical analyses are shown 

in Table 3 (Chesapeake Bay) and Table 4 (Biscayne 

Bay and Gulf of the Farallones). Most often, chemicals were below quantifiable detection; those that 

were detected were in the low ng/L range. In the 

Chesapeake Bay, 13 of the 24 compounds (54%) 

analyzed were found at least once. In Biscayne Bay, 

only three compounds were detected; in the Gulf of 

the Farallones two were found. In their reconnaissance of wastewater contaminants in 139 streams 

in the U.S., the USGS detected 84% of these same 

pharmaceuticals (Kolpin et al., 2002). In Germany, 

Ternes (1998) detected over 80% of a variety of pharmaceuticals in WWTP effluents, and roughly 60% in 

surface waters. 

Chesapeake Bay. The primary study area for this 

pilot project was the Chesapeake Bay, which is also 

where most of the detections of the pharmaceuticals 

occurred. The four WWTPs in the northern part of the 

estuary (Figure 1) had a greater average number of 

detected compounds (6.5) per WWTP site compared 

to the southern Bay (1.7). One explanation for this 

is that the effluent plumes from the WWTPs near 

Baltimore were typically more visible and therefore 

samples were known to be taken in proximity of the 

discharge. In the southern part of the Chesapeake, 

there was no indication of the effluent plume, and 

the location of the outfalls had to be estimated using 

latitude and longitude coordinates. At the Annapolis sampling site in the northern part of the Bay, the 

effluent plume was also not visible, and may have 

been one reason only two compounds were detected, 

similar to the number of detections at the WWTPs in 

the southern portion of the Bay. 

From Table 3, a number of patterns emerge. The most 

frequently detected pharmaceutical was carbamazepine, found at all sites in the northern Bay, and at one 

site in the southern Bay. The maximum concentration 

of carbamazepine was 0.030 μg/L (Table 3) at the 

outfall of the Back River WWTP. 

12
13

Pharmaceuticals detected at the Chesapeake Bay sites. Table 3. 

Concentration (μg/L) 

Back Back River Back River Back River Patapsco Patapsco Patapsco Patapsco Chesapeake- Virginia Atlantic Compound Cox Creek Annapolis Nansemond River 1km 5km 10km River River (1km) River (5km) River (10km) Elizabeth Initiative Sewage 

1,7-dimethylxanthine <LRL <LRL <LRL <LRL 0.21 <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Acetaminophen <LRL <LRL <LRL <LRL 0.0022 <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Azithromycin <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Caffeine <LRL <LRL <LRL <LRL 0.24 0.0091 0.0045 <LRL 0.016 <LRL 0.0050 <LRL <LRL <LRL 

Carbamazepine 0.030 0.023 0.012 0.0056 0.010 0.0021 0.0021 0.0021 0.0067 0.0013 <LRL 0.0011 <LRL <LRL Cimetidine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Codeine <LRL <LRL <LRL <LRL 0.0089 <LRL <LRL <LRL 0.0014 <LRL <LRL <LRL <LRL <LRL 

Cotinine 0.0097 0.013 0.0087 0.0052 0.020 0.0039 0.0037 0.0037 0.0052 0.0024 0.0026 0.0025 0.0014 √

Dehydronifedipine 0.0027 0.0018 √ √ <LRL <LRL <LRL <LRL √ <LRL <LRL <LRL <LRL <LRL 

Diltiazem <LRL <LRL <LRL <LRL 0.0032 <LRL <LRL <LRL 0.0018 <LRL <LRL <LRL <LRL <LRL 

Diphenhydramine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Erythromycin-H O 2 √ √ √ √ √ <LRL <LRL √ √ <LRL <LRL <LRL <LRL <LRL 

Fluoxetine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 0.0026 <LRL Gemfibrozil <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Ibuprofen <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Metformin <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Miconazole <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Paroxetine metabolite <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Ranitidine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Salbutamol <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Sulfamethoxazole <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 0.011 <LRL <LRL <LRL <LRL <LRL 

Thiabendazole <LRL <LRL <LRL <LRL 0.0038 <LRL <LRL <LRL √ <LRL <LRL <LRL <LRL <LRL 

Trimethoprim <LRL <LRL <LRL <LRL √ <LRL <LRL <LRL 0.0014 <LRL <LRL <LRL <LRL <LRL 

Warfarin <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL Note: Table entries with the symbol√ refer to samples where the compound was detected, but due to either low recoveries (i.e., erythromycin-H2 O) or lower analyte concentration, could not be quantified.

Abbreviations: km, kilometers downstream of wastewater treatment plant outfall; μg/L, micrograms/liter; <LRL, below laboratory reporting level. 
Pharmaceuticals detected at the Biscayne Bay and Gulf of the Farallones sites. Table 4. 

Concentration (μg/L) 

Biscayne Bay Gulf of the Farallones

South of Princeton Military Mowry North Canal Florida City Channel to Turkey South of SE of Black Compound Featherbed 114A SW-00 Canal Canal Canal Mouth Canal North Canal Point Turkey Point Pelican Bank Point Bank 

1,7-dimethylxanthine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Acetaminophen <LRL <LRL 0.0033 <LRL 0.0019 <LRL <LRL <LRL <LRL <LRL 0.0029 <LRL <LRL 

Azithromycin <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Caffeine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Carbamazepine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Cimetidine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Codeine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Cotinine <LRL <LRL <LRL <LRL <LRL √ √ <LRL <LRL √ <LRL √ <LRL 

Dehydronifedipine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL √ <LRL Diltiazem <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Diphenhydramine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Erythromycin-H O 2 <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Fluoxetine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Gemfibrozil <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Ibuprofen <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Metformin <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Miconazole <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Paroxetine metabolite <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Ranitidine <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Salbutamol <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Sulfamethoxazole <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Thiabendazole <LRL <LRL √ <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Trimethoprim <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Warfarin <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL <LRL 

Note: Table entries with the symbol√ refer to samples where the compound was detected, but due to lower analyte concentration, could not be quantified.Abbreviations: km, kilometers downstream of wastewater treatment plant outfall; μg/L, micrograms/liter; <LRL, below laboratory reporting level. 

14
A number of other studies have also detected this 

pharmaceutical in surface waters. Boyd and Furlong 

(2002) found carbamazepine to be one of the most 

frequently detected pharmaceuticals in the Las Vegas

Wash, an urban river which drains the city of Las 

Vegas and empties into Lake Mead. Ternes (1998) 

concluded this compound was ubiquitously present 

in rivers and streams in Germany. In 2004, approximately 2.7 million prescriptions were written for 

carbamazepine in the U.S. (RxList, 2005). Yet, there

are many other compounds such as azithromycin (37 

million) and metformin (25 million) that were not 

detected, but have a far greater number of prescriptions written. 

Studies have shown carbamazepine to be fairly 

persistent in the environment. Heberer (2002) found 

that less than 10% of 

carbamazepine is typically degraded during 

the sewage treatment 

process. Lam et al. 

(2004) calculated a 

mean half-life for car

bamazepine in outdoor 

field microcosms of 82 

days, over four times 

higher than any of 

the other compounds 

(acetaminophen, 

atorvastatin, caffeine, 

levofl oxacin, sertraline, 

sulfamethoxazole, and 

trimethoprim) in that study. Andreozzi et al. (2003) 

calculated a half-life approaching 100 days for exposures in northern latitudes. 

There has not been much work to date to assess the 

toxicity of carbamazepine to aquatic organisms. The 

information generated to date appears to indicate 

that acute toxicity to a number of species of bacteria, 

green algae, diatoms, rotifers and a few crustaceans 

is on the order of mg/L, at least an order of magnitude higher than typical environmental concentrations (Ferrari et al., 2004). A chronic toxicity study, 

however, indicated a 7-day no effect concentration on 

reproduction in the crustacean Ceriodaphnia dubia as 

low as 25 μg/L (Ferrari et al., 2004). Carbamazepine 

has a reported bioconcentration factor of approximately 15 (Jones et al., 2002) in daphnia, indicating 

it is not strongly accumulated from water column 

exposures in this organism. 

The antibiotic degradate erythromycin-H O was de­ 2

tected at 50% of the sites sampled in the Chesapeake 

Bay, including all those in the northern portion. 

In their assessment of pharmaceuticals and other 

organic contaminants in U.S. streams, Kolpin et al. 

(2002) found erythromycin-H O in over 21% of the 2

water samples taken, the second highest of any antibiotic included in their inventory. Boyd and Furlong 

(2002) also found erythromycin in samples from the 

Las Vegas Wash, but not Lake Mead. Ashton et al. 

(2004) found erythromycin in 44% of fi nal WWTP 

effluent samples, and 38% 

of downstream samples in 

the U.K. Erythromycin 

was below the limit of detection in samples in five 

U.K. estuaries (Thomas 

and Hilton, 2004). 

There does not appear to 

be much data generated 

yet on the aquatic toxicity 

of erythromycin. Jones 

rd the NOAA ship Ferrell. et al. (2002) modeled a 

predicted environmental 

concentration (PEC of 0.81 μg/L), compared that 

with a predicted no effects concentration (PNEC) 

for fish and invertebrates, and calculated a PEC: 

PNEC ratio of 0.01. Ratios greater than one indicate 

the predicted environmental concentration would be 

above the no-effects concentration, and using this 

approach, would be cause for greater concern. Brain 

et al. (2004), found no significant phytotoxicity in 

the duckweed Lemna gibba (EC50 > 1,000 μg/L). 

However, Jones et al. (2002) calculated a bioconcentration factor for erythromycin of approximately 45, 

and suggested this pharmaceutical could accumulate, 

at least to some degree in aquatic biota. 

Collection of water samples aboa

­

15
In the Chesapeake Bay, dehydronifedipine, a metabolite of the antianginal medication nifedipine, was 

found in five water samples, mainly from the Back 

River sites, at a maximum concentration of 0.003 μg/ 

L. In their study of U.S. streams, Kolpin et al. (2002) 

found dehydronifedipine in approximately 14% of 

the samples. Boyd and Furlong (2002) also found 

dehydronifedipine in water samples from the Las 

Vegas Wash, but not from Lake Mead. No information was located on the aquatic toxicity of nifedipine 

or dehydronifedipine. 

The antibiotic trimethoprim was found twice (Patapsco River and Cox Creek) in the Chesapeake 

Bay samples, at a maximum concentration of 0.001 

μg/L. Ashton et al. (2004) detected trimethoprim 

in 65% of WWTP effluent water samples, and 38% 

of downstream samples in five rivers in the U.K. In 

Germany, Hirsch et al. (1999) detected trimethoprim 

in approximately 90% of the WWTP effl uents and 

20% of samples from streams and rivers. Kolpin et 

al. (2002) detected trimethoprim in 27% of samples 

from streams in the U.S., the highest of any antibiotic 

included in their study. In microcosm experiments, 

Lam et al. (2004) calculated an average half-life of 

5.7 days. Brain et al. (2004) reported no significant 

phytotoxicity in L. gibba. 

Sulfamethoxazole was detected at one sampling location, Cox Creek, at a concentration of 0.011 μg/L. 

Kolpin et al. (2002) detected this antibiotic in 19% of 

stream samples. Boyd and Furlong (2002) detected 

sulfamethoxazole in both the Las Vegas Wash and in 

Lake Mead. In Germany, Hirsch et al. (1999) found 

this compound in all 10 WWTP effl uents sampled, 

and in 50% of downstream samples. Ashton et al. 

(2004) detected sulfamethoxazole in 9% of WWTP 

effluents, but it was undetectable downstream in the 

U.K. Thomas and Hilton (2004) did not detect this 

compound in U.K. estuaries. 

In their microcosm studies, Lam et al. (2004) found 

that sulfamethoxazole was one of the more persistent 

compounds tested, with a half-life of 19 days. In 

addition, Brain et al. (2004) found that sulfamethoxazole was the most phytotoxic antibiotic tested, significantly reducing the weight of L. gibba (EC50 of 81 

μg/L). 

The antianginal medication diltiazem was found 

twice in the Chesapeake Bay, with a maximum 

concentration of 0.003 μg/L. Kolpin et al. (2002) 

detected this pharmaceutical in approximately 14% of 

their water samples. Jones et al. (2002) calculated a 

PEC:PNEC of 0.34. 

Fluoxetine was detected once in the southern portion 

of the Chesapeake Bay at a concentration of 0.003 

μg/L. Kolpin et al. (2002) detected fluoxetine in 1% 

of their samples. In Louisiana, Boyd et al. (2003) did 

not detect fluoxetine in any surface water samples. 

Brooks et al. (2003) investigated the acute and sublethal toxicity of fluoxetine on a number of fi sh and 

invertebrates, with the results indicating that effects 

concentrations were an order of magnitude higher 

than the highest reported municipal effl uent concentration. 

The analgesic acetaminophen was detected at the 

Patapsco River site at a concentration of 0.002 μg/L. 

Ibuprofen was not detected at any of the sites in the 

Chesapeake Bay, although it was detected in approximately 10% of the streams sampled by Kolpin et al. 

(2002). 

The pharmaceuticals detected in the Chesapeake Bay 

water samples (excluding caffeine and the caffeine 

metabolite 1,7-dimethylxanthine) are plotted by site 

in Figure 5. Carbamazepine was the most frequently 

detected pharmaceutical followed by the erythromycin degradate, erythromycin-H2

O. Cotinine, the metabolite of the stimulant nicotine (commonly associated with tobacco), was detected in all water samples. 

Figure 5 also provides some evidence of a downstream (1, 5, and 10 km) gradient or transport. Carbamazepine, erythromycin-H2

O and dehydronifdipine 

were detectable in water samples 10 km downstream 

of the Back River. In the Patapsco River, a downstream gradient was not apparent. Interestingly, there 

was a detection of erythromycin-H2O at the 10 km 

Patapsco River, but not at the 1 or 5 km sites (Figure 5). The reason for this is unknown, but could be 

related to discharges from the Cox Creek WWTP, 

which had a detection of erythromycin-H2

O, and is 

adjacent and somewhat upstream of the Patapsco 

River 10 km site (Figure 1). 

16
0 

0.005 

0.01 

0.015 

0.02 

0.025 

0.03 

0.035 

0.04 

0.045 

0.05 

Concentration (ug/L) 

Back River 

Back River 1km 

Back River 5km 

Back River 10km 

Patapsco River 

Patapsco River (1km) 

Patapsco River (5km) 

Patapsco River (10km) 

Cox Creek 

Annapolis 

Chesapeake- Elizabeth 

Nansemond 

Virginia Initiative 

Atlantic 

Site 

Acetaminophen Carbamazapine 

Codeine Cotinine 

Dehydronifedipine Diltiazem 

Fluoxetine Sulfamethoxazole 

Thiabendazole Trimethoprim 

* 

* 

* 

* 

* 

* 

* 

Figure 5. Concentration of compounds detected (excluding caffeine) in Chesapeake Bay 

water samples. *Erythromcyin-H2

O detected in these samples but not quantified. 

Biscayne Bay. Three compounds were detected at 

the sites in Biscayne Bay: cotinine, acetaminophen, 

and the anthelmintic thiabendazole. The maximum 

acetaminophen concentration (0.003 μg/L) in Biscayne Bay (Table 4) was similar to that found at the 

Patapsco River site (Table 3). 

Fewer detections of pharmaceuticals at the Biscayne 

Bay sites compared with Chesapeake Bay is perhaps 

not surprising, as the sites in Biscayne Bay were not 

adjacent to WWTPs, but located near drainage canals 

which receive inputs from a variety of sources. There 

was speculation that sediment toxicity observed in an 

earlier study in Biscayne Bay (Cantillo and Lauenstein, 2004) could have been related to the presence 

of pharmaceuticals entering the Bay from wastewater 

or groundwater discharges. The results from this 

pilot project, however, would appear to make this less 

likely. 

Gulf of the Farallones. There were only two compounds detected in the samples collected in the Gulf 

of the Farallones, cotinine (the metabolite of nicotine), and dehydronifedipine, a metabolite of the antianginal medication nifedipine. The low detections in 

the Gulf of the Farallones site were likely due in part, 

to the difficulty in identifying the effluent plume from 

the Oceanside WWTP, along with strong currents in 

the area. The diffuser heads are located 7 km offshore at a depth of 24 m. 

Comparison with Other Work. Table 5 contains 

published values for the detection of a number of the 

pharmaceuticals included in this study. In general, 

the concentrations found in the pilot project are somewhat lower than that reported elsewhere. The reason 

for this may be related to the amount of time that 

elapsed between the extraction of the water samples 

and the actual analysis, roughly 6 months. Although 

the extracts were kept at -20oC, it is likely that some 

17
Table 5. Reported detections of selected human use pharmaceuticals in the aquatic environment. 

Compound Conditions Concentration Frequency Reference 

(ug/l) (%) 

Carbamazepine WWTP effluent BDL 0 Weigel et al. (2004) 

Carbamazepine WWTP effluent BDL 0 Weigel et al. (2004) 

Carbamazepine WWTP effluent 0.3 - 1.03 NA Andreozzi et al. (2003) 

Carbamazepine surface waters 0.008-0.263 57-83 Kolpin et al. (2004) 

Carbamazepine surface waters 0.14 NA Boyd and Furlong (2002) 

Dehydronifedipine surface waters 0.0003-0.002 10 Kolpin et al. (2004) 

Dehydronifedipine surface waters 0.03 14 Kolpin et al. (2002) 

Diltiazem surface waters 0.002-0.106 20 Kolpin et al. (2004) 

Diltiazem surface waters 0.049 13 Kolpin et al. (2002) 

Fluoxetine surface waters BDL 0 Kolpin et al. (2004) 

Fluoxetine surface waters BDL 0 Boyd et al. (2003) 

Fluoxetine surface waters 0.012 1 Kolpin et al. (2002) 

Sulfamethoxazole WWTP effluent BDL - 0.09 NA Andreozzi et al. (2003) 

Sulfamethoxazole WWTP effluent 0.18 NA Yang and Carlson (2004) 

Sulfamethoxazole surface waters BDL-0.063 7 Kolpin et al. (2004) 

Sulfamethoxazole surface waters 0.07 (max.) NA Kolpin et al. (2004) 

Sulfamethoxazole surface waters 0.52 19 Kolpin et al. (2002) 

Trimethoprim WWTP effluent 0.66 (max.) NA Hirsch et al. (1999) 

Trimethoprim surface waters BDL-0.035 NA Kolpin et al. (2004) 

Trimethoprim surface waters BDL - 0.569 NA Thomas and Hilton (2004) 

Trimethoprim surface waters 0.042 (max.) 38 Ashton et al. (2004) 

Trimethoprim surface waters 0.30 NA Kolpin et al. (2002) 

Abbreviations: WWTP, wastewater treatment plant; BDL, below detection level; NA, not available; 

max., maximum concentration detected; %, frequency of detection for the pharmaceutical 

degradation of the pharmaceuticals present in the 

extracts had taken place. As a result, the concentrations reported for the Chesapeake Bay, Biscayne Bay, 

and the two sites in the Gulf of the Farallones, can be 

viewed as conservative estimates of the concentrations originally present in the water samples. 

Summary and Conclusions 

The goal of this pilot project was to assess the presence of 24 human use pharmaceuticals and associated 

chemicals in selected estuarine and coastal waters. In 

the Chesapeake Bay, samples were collected adjacent 

to and downstream of wastewater treatment plants 

(WWTPs). In Biscayne Bay, samples were collected 

at the mouth of drainage canals and offshore areas 

that might be affected by inputs from the drainage 

canals or possibly groundwater discharges. In the 

Gulf of the Farallones, two sites were sampled near 

the reported location of a WWTP outfall discharging 

to the Pacific Ocean. 

Analysis of the Chesapeake water samples revealed 

the presence of 13 of the 24 compounds. In Biscayne 

Bay, three compounds were detected; in the Gulf of 

the Farallones, two were found. In the Chesapeake 

Bay on the Back River there was evidence of a downstream gradient; two pharmaceuticals (carbamazepine 

and erythromycin-H2

O (erythromycin degradate)) 

were detected 1, 5, and 10 km downstream of the 

WWTP. 

The antiepileptic medication carbamazepine was 

detected in 11 of the 14 sites in the Chesapeake Bay. 

The published literature has documented the pres18
ence and persistence of carbamazepine in the aquatic 

environment. Erythromycin-H2O was detected, but 

not quantified at seven sites. Fewer detections of 

pharmaceuticals in Biscayne Bay was not surprising 

as none of the sites sampled were adjacent to WWTP 

outfalls. 

The effects of the pharmaceuticals in estuarine and 

coastal waters is currently unknown. An important 

first step is to document which compounds are present and in what concentrations, so that the appropriate studies (laboratory and field) can be designed to 

assess possible impacts. 

Future work, particularly in the Chesapeake Bay is 

recommended to assess pharmaceuticals in both the 

water column and sediments. In the Chesapeake Bay, 

the western shore has a higher human population, 

while the eastern shore is home to signifi cant poultry CAFO (concentrated animal feeding operations) 

activity. A study to assess the differences in the types 

(human versus animal use) and concentrations of 

pharmaceuticals present, and a concurrent assessment 

of antibiotic resistant populations of bacteria in both 

the western and eastern shores of the Chesapeake Bay 

would provide information needed to begin assessing 

the impacts (both human and environmental) of pharmaceuticals in estuarine and coastal environments. 

Acknowledgements 

The authors would like to thank Drs. Edward Furlong 

and Stephen Werner of the National Water Quality Laboratory, USGS for the sample analysis and 

numerous discussions of the results. The captain 

and crew of the NOAA ships Ferrell and McArthur I 

helped collect the water samples in the Chesapeake 

Bay and Gulf of the Farallones, respectively. We 

would also like to thank Dr. Russell Callender of NOAA’s Center for Coastal Monitoring and Assessment 

for supporting this work, Drs. Peter Key and Michael 

Fulton of NOAA’s Center for Coastal Environmental Health and Biomolecular Research (Charleston, 

South Carolina) for collecting samples from Biscayne 

Bay, and Dr. George Gibson of the US EPA for use of 

the Niskin water sampler in the Chesapeake Bay. 

19 
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21


United States Department of Commerce 

Carlos M. Gutierrez 

Secretary 

National Oceanic and Atmospheric Administration 

Vice Admiral Conrad C. Lautenbacher, Jr. USN (Ret.) 

Under Secretary of Commerce for Oceans and Atmospheres 

National Ocean Service 

John H. Dunnigan 

Assistant Administrator for Ocean Service and Coastal Zone 

Management