Endocrine-disrupting chemical pollution: Why the epa should regulate these chemicals under the clean water act

Author:Jacki Lopez
Position:Staff attorney at the Center for Biological Diversity
by Jacki Lopez*
* Ms. Lopez is a staff attorney at the Center for Biological Diversity who, in Jan-
uary 2010, petitioned the EPA asking it to update and revise its National Rec-
ommended Water Quality Criteria to reflect the latest scientific knowledge that
endocrine-disrupting chemical pollution is harming aquatic life and water quality.
This article is based in part on Ms. Lopez’s work on the submitted petition.
The National Institute of Environmental Health Sciences
(“NIEHS”) defines endocrine disruptors as “chemicals
that may interfere with the body’s endocrine system and
produce adverse developmental, reproductive, neurological, and
immune effects in both humans and wildlife.”2 It notes that a
wide variety of substances, including pharmaceuticals, dioxins,
polychlorinated biphenyls (“PCBs”), dichlorodiphenyltrichloro-
ethane (“DDT”) and other pesticides, and plasticizers such as
bisphenol A (commonly known as “BpA”) can cause endocrine
Endocrine disruptors, also known as endocrine-disrupting
chemicals (“EDCs”), exist throughout our environment and
work in a variety of nefarious ways. They can mimic naturally
occurring hormones like estrogens and androgens, thereby caus-
ing overstimulation of the endocrine system.4 EDCs can bind
to receptors within cells and block endogenous hormones from
binding, causing interference with the production or control
of natural hormones and their receptors.5 The latest scientific
knowledge indicates that EDCs persist throughout the environ-
ment, including in our nation’s waters, and are having profound
effects on fish, wildlife, and humans.6
Yet, the U.S. federal government has done very little to
protect human health or the environment from these harms. A
patchwork of regulatory mechanisms exist—through the Federal
Food, Drug, and Cosmetic Act; Safe Drinking Water Act; Toxic
Substances Control Act; Resource Conservation and Recovery
Act; Consumer Product Safety Improvement Act; and the Clean
Water Act. However, as currently implemented, these mecha-
nisms at best provide a regulatory net full of holes whereby
EDCs enter and pervade our environment and have astonishing
effects. Perhaps the most promising of all existing frameworks
is the Clean Water Act (“Act”), which if implemented fully
could both limit human exposure to waterborne EDC pollution,
as well as protect aquatic environments and species from EDC
The Act aims “to restore and maintain the chemical, physi-
cal, and biological integrity of the Nation’s waters.”7 The
“national goal” of the Act is to guarantee “water quality which
provides for the protection and propagation of fish, shellfish, and
wildlife and provides for recreation.”8 Toward these objectives,
the Act provides a variety of tools to control water pollution
from all sou rces. Foremost, the Act requires that states adopt
water quality standards based on the National Recommended
Water Quality Criteria (“Criteria”).9
The Act requires the EPA to establish the Criteria,10 pub-
lish information on the protection of water quality,11 and guide
states in their adoption and periodic review of water quality
standards.12 The Criteria and information required by section
304 of the Act are significant because they establish a baseline
for nationwide implementation of the Act. State water quality
standards include designated uses, water quality c riteria su f-
ficient to protect the designated uses, and an anti-degradation
policy.13 Guided by EPA’s Criteria and information, states must
either adopt the Criteria in their water quality standards or pro-
vide a science-based explanation for their alternate criteria.14
Each state is also required to “identify those waters within its
boundaries for which the effluent limitations . . . are not strin-
gent enough to implement any water quality standard applicable
to such waters.”15 States must identify any water body failing
to meet any numeric criteria, narrative criteria, water body use,
or anti-degradation requirements, and the Act requires states to
establish total maximum daily loads (“TMDLs”) for pollutants
“at a level necessary to implement the applicable water qual-
ity standards.”16 Therefore, water quality standards provide a
mechanism for states to regulate all sources of pollution that are
degrading water quality.
Section 304 of the Act mandates that the EPA revise the
Criteria “fr om t ime to time ” to reflec t th e “l atest scientific
knowledge.”17 As the basis for state water quality standards and
pollution controls, it is crucial that the Criteria reflect the lat-
est science. The duty to review and consider the latest scientific
knowledge, among other factors, is a non-discretionary duty.18
The EPA’s Criteria are at the heart of protecting water
quality across the nation. In effect, the Criteria are the floor for
water quality standards (with states left free to establish a higher
ceiling), and, when federal criter ia do not exist, wat er quality
throughout the nation suffers. Despite the statutory mandate to
establish Criteria for EDCs, the EPA has failed to update and
revise its Criteria to establish limitations for EDCs sufficient to
protect against endocrine disruption.
20SPRING 2010
Researchers have recently discovered that a number of
contaminants can have the potential for deleterious effects on
aquatic ecosystems.19 These con taminants incl ude pesticide s,
pharmaceuticals and personal care products (“PPCPs”), and
other compounds that can evoke hormonal responses in fish
and wildlife.20 EDCs can interfere with the synthesis, secretion,
transport, binding, or elimination of natural hormones in the
body.21 They can compromise normal reproduction, develop-
ment, growth, and homeostasis.22 EDCs have become ubiqui-
tous in our nation’s water bodies, entering them largely through
runoff and treated wastewater discharges.23
EDCs find their way into our environment through a sur-
prising array of unchecked mechanisms. Ingested drugs, for
example, are excreted in varying metabolized amounts (primar-
ily in urine and feces) and end up in municipal sewage treatment
plants where they then enter our
waterways as treated wastewa-
ter effluent.24 EDCs leach from
municipal landfills and can be
found in the runoff from con-
centrated animal feeding opera-
tions and medicated pet excreta.
EDCs also come from aquacul-
ture, spray-drift from agricul-
ture,25 and the direct discharge
of raw sewage.
An EPA internal planning
document recognizes that EDCs
discharged from wastewater
treatment plants are contami-
nants of emerging concern with
potentially widespread envi-
ronmental effects.26 Municipal
wastewater contains a multitude
of EDCs, many of which derive
from the domestic application of active ingredients found in
PPCPs.27 PPCPs are constantly entering rivers and groundwater
via treated municipal wastewater. Betablockers, antibiotics, anti-
phlogistics, estrogens, antiepileptics, and contrast agents have
been detected in many of our nation’s waters.28 These EDCs are
affecting the biological, chemical, and physical integrity of our
water, including having profound effects on the flora and fauna
that rely on clean U.S. waters.29
In 2008, the Associated Press reported the detection of
pharmaceutical residues in the drinking water of twenty-four
major metropolitan areas, serving forty-one million people.30
The pharmaceuticals detected included antibiotics, anticonvul-
sants, and mood stabilizers.31 Supporting these findings, the
United States Geological Survey (“USGS”) reports that a sam-
ple of 139 streams in thirty states, eighty percent of the sampled
sites contained organic wastewater contaminants and pharma-
ceuticals—including antibiotics, hypertension- and cholesterol-
lowering drugs, antidepressants, analgesics, steroids, caffeine,
and reproductive hormones.32
Many pesticides are also EDCs. According to a recent
USGS report, “[T]he most widespread potential impact of pesti-
cides on water quality is adverse effects on aquatic life and fish-
eating wildlife, particularly in streams draining watersheds with
substantial agricultural and urban areas.”33 All of the pesticides
surveyed in the study are known endocrine disruptors and enter
our nation’s water bodies through runoff and spray-drift.34
The Endangered Species Act (“ESA”) prohibits the “take”
of endangered species.35 The ESA defines “take” as “to harass,
harm, pursue, hunt, shoot, wound, kill, trap, capture, or collect”
endangered species.36 The U.S. Fish and Wildlife Service has
further defined “harm” to include “significant habitat modifica-
tion or degradation” that “actu-
ally kills or injures wildlife by
significantly impairing essen-
tial behavior patterns, including
breeding, feeding, or shelter-
ing.”37 EDCs enter our water-
ways pursuant to the authority
deleg ated to the EPA under
the Clean Water Act. There is
evidence that EDCs are signifi-
cantly degrading habitat, includ-
ing federally designated critical
habitat, and are likely injuring
fish and wildlife by disrupting
behavior patterns such as breed-
ing ability.38 Therefore, EPA
has a heightened duty under the
ESA to establi sh and enforce
Criteria for EDCs to prevent
harm to endangered species.
A litany of studies confirms
that EDCs are presently harming fish and wildlife throughout
the nation.39 A 2009 study by Jenkins, et al., investigated the
impacts of effluents from wastewater treatment plants using the
western mosquitofish as a surrogate fish model.40 They detected
fifteen organic wastewater compounds and EDCs, and samples
from the point sources of the wastewater effluent showed the
compounds with the highest influence on sex steroid hormone
activities, compared to other sample sites.41 In samples closest
to the wastewater treatment plants’ effluent discharges, male
mosquitofis h showed the most impairment of en docrine and
reproductive function, as evidenced by changes in sex steroid
hormone levels, secondary sex characteristics, organosomatic
indices, and sperm quality parameters.42 The study concluded
that exposure to EDCs and consequent impairment showed
the most significant effects at the wastewater treatment point
sources, with gradually lesser effects further away from the
point sources.43
The latest scientific
knowledge indicates that
EDCs persist throughout
the environment,
including in our nation’s
waters, and are having
profound effects on fish,
wildlife, and humans.
The endangered razorback sucker is found in Las Vegas
Bay and Lake Mead and has federally designated critical habitat
throughout these water bodies.44 Razorback suckers are long-
lived fish that can grow up to three feet long. Habitat loss and
competition with other fish species threatens the species’ sur-
vival.45 Blackbird Point at Las Vegas Bay—know n spawning
habitat for the razorback sucker—is fed by treated wastewa-
ter effluent from four wastewater treatment plants upstream.46
Researchers have found distinct differences between razorback
suckers from Las Vegas Bay and razorback suckers from other
locations.47 One study found significantly higher concentra-
tions of estradiol (“E2”), lower concentrations of 11-ketotes-
tosterone (“11KT”), and a higher ratio of E2 to 11KT in male
razorback suckers from Las Vegas Bay than those from Echo
Bay.48 DDT residues accounted for more than half the detected
OC concentrations in the fish, and
PCBs accounted for a third of
the total detected OC concentra-
tions.49 The USGS is currently
doing much to study the effects
of EDCs in Lake Mead and
their effects on the razorback
California’s Salton
Trough’s only endemic species,
the endangere d des ert p upfish,
is listed as endangered because
of habitat alteration and the
effe cts of water con tamina -
tion.51 The species is threatened
by contamination from EDCs
born from pesticides and efflu-
ent.52 Pesticides suspected of
endocrine disruption are used at
high rates throughout the adja-
cent Imperial Valley.53 Fish and bed sedim ent in the Imperial
Valley have higher concentrations of hydrophonic pesticides,
and some believe that exposure to the pesticides chlorpyrifos,
diazinon, and malathion used in the Imperial Valley, is contrib-
uting to endocrine disruption.54 After similar exposure to these
pesticides, western mosquitofish exhibited endocrine disruption
in the form of lower levels of the sex hormone 17 beta-estradiol
in females, skewed ratios of estrogen to testosterone in males,
altered secondary sex characteristics in males, reduced gonopo-
dium size, and significantly lower sperm counts and proportions
of mature sperm.55 In addition to pesticides, Imperial Valley
irrigation water comes from the lower Colorado River, a water
source that causes concern due to potential EDC effects.
Effluents from wastewater treatment plants and urban run-
off impact the Santa Ana River. The Santa Ana River basin is
one of the only river basins supporting native populations of the
endangered Santa Ana sucker. Thirty EDCs have been detected
in water from the Santa Ana River, and sex steroid hormone
levels, secondary sex characteristi cs, organ osomatic indices,
and sperm quality parameters indicate endocri ne and repro-
ductive disruption.56 In studies of the western mosquitofish in
these waters, mean E2 values were well above the 1.0 male ratio
and were closer to the female value.57 The study found a strong
negative correlation between levels of the plasticizer di(2-ethyl-
hexyl) phthalate (“DEHP”) and testosterone levels in males.58
These endocrine and reproductive effects are likely also nega-
tively impacting the Santa Ana sucker.
One critical concern and obstacle to identifying EDC expo-
sure and harm in humans is that there can be a significant lag
time, possibly decades, between
exposure and the manifestation
of a clinical disorder. Another
difficulty is the timi ng of expo-
sure as there may be develop-
mental periods having increased
susceptibility to EDCs. Even so,
multiple studies already show
that EDCs are affecting human
A multi-state epidemio-
logic study found that women
exposed to the plasticizer DEHP
had a two day longer gesta-
tion length and higher odds for
caesarian section delivery.59
These findings suggest that
DEHP may interfere with the
hormonally controlled signaling
that initiates birth.60 Another
study found that women with
detectable levels of DDT and
chlorophenyl)ethenyl]benzene (“DDE”) higher than typical
of U.S. women had menstrual cycles approximately four days
shorter and decreased progesterone metabolite levels.61
An EPA-funded study discovered that breast-fed girls
exposed to high levels of polybrominated biphenyl (“PBB”) in
utero had an earlier age of menarche than breast-fed girls exposed
to lower levels of PBB in utero.62 It also found that women with
high exposures to PBB in serum had shorter menstrual cycles
and l onger bleed lengths than women whose exposure lev els
were undetectable in serum.63 Another study identified a link
between persistent pesticides in human breast milk and cryptor-
chidism (undescended testicles) in male offspring.64
Another EPA-funded report found that exposure to fungi-
cides and herbicides is associated with a 1.5- or two-fold risk of
endometriosis in women eighteen to forty-nine years of age.65
An epidemiologi cal study discovered a positive association
One critical concern and
obstacle to identifying
EDC exposure and harm
in humans is that there
can be a significant lag
time, possibly decades,
between exposure and
the manifestation of
a clinical disorder.
22SPRING 2010
between diabetes and elevated serum PCBs, DDE, and hexa-
chlorobenzene (“HCB”) in Native Americans.66 There is over-
whelming evidence of unnecessary human exposure to EDCs
and of resulting harmful effects.
With regar d to what the EPA coins “Conta minants of
Emerging Concern” (“CECs”) (largely referring to EDCs),
“[w]idespread uses, some indication of chemical persistence,
effects found in natural systems, and public concerns have made
clear the need for EPA to develop criteria that can be used to
help assess and manage potential risk of some CECs in the
aquatic environment.”67
Currently, Criteria for aquatic life are based on criterion
maximum concentration (“CMC”) to protect against acute
effects and criterion continuous concentration (“CCC”) to pro-
tect against chronic effects.68 CMC is derived from forty-eight to
ninety-six hour tests for lethality or immobilization while CCC is
from longer-term tests measuring
survival, growth, or reproduc-
tion.69 Criteria for human health
are designed to protect against
long term human health effects
based on a lifetime of exposure,
and exposure to a poll utant is
interpreted as through ingestion
of water and contaminated fish
and shellfish.70
However, EDCs defy the
typical “dose makes the poison”
paradigm of toxicology.71 The
EPA Guidelines, “anticipat[ing]
that rote application of the basic
procedures may not yield the
most approp riate criteria,” provide flexibility in moving away
from normal procedures whenever:72
Sound scientific evidence indicates that a national cri-
terion produced using these Guidelines would probably
be s ubstantially o verprotective or underprotect ive of
aquatic organisms and their uses on a national basis
On the basis of all available pertinent laboratory and
field information, determine if the criterion is consis-
tent with sound scientific evidence. If it is not, another
criterion, either higher or lower, should be derived
using appropriate modifications of these Guidelines.73
In reviewing the latest scientific knowledge and promul-
gating the new water quality standards, EPA must incorporate
EDC-relevant knowledge. For example, EDCs differ from tradi-
tional pollutants in that (1) the timing of exposure is highly criti-
cal to the outcome of the exposure (with fetal or early post-natal
exposure being the most detrimental due to potential permanent
effects); (2) EDCs act at environmentally relevant doses with
complex dose-response curves; and (3) the effects of EDCs may
not be limited to the exposed individual but can be transmitted to
subsequent generations via the germ line.74 The standard proce-
dures for deriving CMC and CCCs use only toxicity tests meet-
ing certain requirements, but the Guidelines mandate that the
collation and examination of other data should be considered.75
The case of tributyltin should serve as an example for the
EPA in establishing and revising its Criteria for other EDC pol-
lutants. The final acute value using standard derivation proce-
dures for tributyltin was .0658 µg/L even though concentrations
linked to imposex and immuno-suppresion in snail and bivalves
was in the range of 0.0093-0.334 µg/L.76 The EPA rightly took
this new scientific knowledge into account and lowered the CCC
for tributyltin to .0074 µg/L.77
The EPA has established Criteria for some known EDCs.
Some EDCs, such as PCB, have Human Health Criteria cal-
culations, however, they are not on the matrix because of their
endocrine-disrupting potential but because of their carcinogenic
potential.78 New scientific information indicates these EDCs are
having substantial effects on fish and wildlife at levels previ-
ously deemed acceptable by the
EPA. The EPA recognizes that
frequency alone is not enough to
establish Criteria and that Crite-
ria development “needs to focus
efforts on chemicals that dem-
onstrate a reasonable potential to
adversely affect aquatic life.”79
It also acknowledges that “there
may be chemicals for which reg-
ulatory guidance is needed, but
for which toxicological data are
insufficient to meet the minimum
standards of the Guidelines”
and that in those cases, “there
may still be a need for alternate
approaches to derive interim regulatory guidance values on which
to base decisions that must be made before sufficient information
for a complete water quality criterion can be gathered.”80
The EPA has a mandatory duty to establish Criteria protec-
tive of our nation’s waters. Currently, the EDCs entering and
persisting in these water bodies are having profound effects on
wildlife, fish, and humans. Although the EPA has established
Criteria for some of the EDCs, the limits were not designed to
protect against EDC harm. Section 304(a) of the Act requires the
EPA to develop and publish and “from time to time thereafter
revise” Criteria and information.81 New information that contro-
verts previously held beliefs about water quality and pollutants
triggers the EPA’s duty to review and revise the Criteria. There-
fore, the EPA must revise the Criteria and information to reflect
the latest science on EDCs.
There is overwhelming
evidence of unnecessary
human exposure to
EDCs and of resulting
harmful effects.
Endnotes: Endocrine-Disrupting Chemical Pollution
continued on page 48