2002 CPEO Military List Archive

From: CPEO Moderator <cpeo@cpeo.org>
Date: 18 Nov 2002 16:29:10 -0000
Reply: cpeo-military
Subject: [CPEO-MEF] APGSCC letter to Governor-Elect Ehrlich
A copy of the following letter was sent to Governor-Elect Robert Ehrlich
by Glenda Bowling <gbowling@comcast.net>, President of the APGSCC
(Aberdeen Proving Ground Superfund Citizens Coalition).  Please note
that copies of the "Perchlorate Fact Sheet" and the "Technical Basis for
the1 ppb Treatment Standard" are pasted immediately following the


November 12, 2002

Robert Ehrlich
315 Cannon House Office Building
Washington, D. C. 20515

Dear Governor-Elect Ehrlich:

Congratulations on your election as Governor of the State of Maryland.
For more than a decade, the members of Aberdeen Proving Ground Superfund
Citizens Coalition (APGSCC) have worked closely with Aberdeen Proving
Ground (APG), EPA Region III and Maryland Department of the Environment
to represent community stakeholders in the cleanup of Superfund sites at
APG. Our efforts have recently been focused on perchlorate contamination
in the drinking water wells in Aberdeen. We think this issue is of
highest importance, therefore we are supplying you with this briefing
packet, so that you will understand the community perspective of the
perchlorate contamination and the risks engendered by this

The chemical perchlorate has been detected in seven of the eleven City
of Aberdeen Production (CAP) wells that straddle the Aberdeen Area
boundary of APG in Maryland. Since July 2002 the detected concentrations
in the wells have ranged from 0.55 to 5 ppb. Although the concentrations
of perchlorate in the finished water do not currently exceed the State
of Maryland health advisory limit of 1 ppb (1), there is now clear
evidence that there is perchlorate in the finished water at
concentrations ranging from 0.61 to 1 ppb. Detections within the well
field range from 5 ? 14 ppb, therefore we expect concentrations within
the CAP wells to rise. We at APGSCC believe that there is a growing
consensus that sufficient scientific data exists to justify immediate
action to protect human health. We are now concerned that the delay in
action will result in unnecessary human exposures. Please refer to the
attached APGSCC Community Update, Perchlorate Fact Sheet for additional
information regarding perchlorate toxicity [*PASTED BELOW].

The perchlorate is from historic and current training activities in the
vicinity of Camp Stanton, Aberdeen Proving Ground, although no single
incident or source location can be pinpointed.  Given the complexity of
the aquifer in the Aberdeen Area and the extent of the contamination it
is difficult to predict if and when well concentrations will increase.
Thus, we are faced with a completed exposure pathway and are relying
solely on dilution to protect the health of local citizens. APGSCC
believes this is unacceptable.

Despite consensus at the local level that the perchlorate issue must be
addressed, it is the current policy of the Department of Defense to
oppose action to remediate perchlorate contamination in the absence of
enforceable standards (2). Both EPA Region III and the state of Maryland
are reviewing options to insure that APG addresses this contamination.

We have specifically recommended the implementation of an emergency
interim remedial action. This action must include the installation of
temporary, portable treatment systems on each CAP well containing
perchlorate contamination. This should be followed by the installation
of a permanent treatment system to treat all CAP wells.  We have
petitioned both EPA and the State to use the regulatory powers
established by CERCLA and SDWA to require APG to undertake an immediate
interim remedial action. Based on our close working relationship with
APG, we know that they want to take action, however, DoD will not permit
them to do so.   Such action would serve to ensure the protection of
public health.

The EPA and MDE have been reviewing enforcement options for over a
month. While we appreciate that it is essential to produce the necessary
legal justification for action in the administrative record, we are
concerned that the delay in action is sending the wrong message to the
DOD. More importantly, since the perchlorate is in the well field at
much higher concentrations, each day that treatment is delayed increases
the likelihood that residents will be exposed to unacceptable
concentrations in their drinking water.

The residents of the City of Aberdeen need your leadership in addressing
this issue. APGSCC knows from experience that the delay in APG treating
the solvent trichloroethylene in the adjacent Perryman aquifer resulted
in unnecessary public exposures.  We need to draw on the lessons learned
by the Perryman experience and be more proactive in our response to this
latest threat.

Despite the contamination both the Aberdeen and Perryman well fields are
extremely important groundwater resources. The recent drought has
highlighted the need to protect these well fields, and insure that they
continue to provide a safe, abundant source of drinking water for years
to come.

It is a fact of life that we must make risk-based decisions on a daily
basis in the absence of complete scientific knowledge. In the case of
perchlorate contamination in drinking water, there is strong scientific
evidence to justify a 1 ppb treatment level. Please refer to the
attached APGSCC Community Update on the Technical Basis for the 1 ppb
Treatment Standard for more detailed information [**PASTED BELOW].

There are the national perchlorate issues, which are unfortunately,
impacting the comparatively simple decision that needs to be made at
APG. We urge you to focus on the needs of the city of Aberdeen and
support the 1 ppb treatment standard.

Thank you for your time and attention on this important matter. We look
forward to discussing this issue further at your earliest convenience. I
may be contacted at (...).  APGSCC?s technical advisor, Dr. Cal
Baier-Anderson, from the University of Maryland, Baltimore, can be
reached at her home office, (...). Once again, congratulations on your
election. We look forward to working closely with you and your
administration over the four years.


Glenda Bowling
President, APGSCC
198 Sunnyside Drive
Aberdeen, Maryland 21001

 (1) Letter from Robert M. Summers, Director, Water Management
Administration, Maryland Department of the Environment to Peter A.
Dacey, City Manager, City of Aberdeen, Maryland, dated August 20, 2002.

(2) Memorandum for Deputy Assistant Secretary of the Army (Environment,
Safety, and Occupational Health) Deputy Assistant Secretary of the Navy
(Environment) Deputy Assistant Secretary of the Air Force (Environment,
Safety, and Occupational Health) Staff Director, Environment and Safety,
Defense Logistics Agency Support Services (DSS-E). Subject: Interim
Guidance on Sampling for Ammonium Perchlorate Contamination, Signed by
John Paul Woodley, Jr., Assistant Deputy Under Secretary of Defense

Donald S. Welch, EPA Region III, Regional Administrator
Steven Hirsh, EPA Region III, Remedial Project Manager
Frank Vavra, EPA Region III, Remedial Project Manager
Richard F. Pecora, Secretary, Maryland Department of the Environment
Richard Collins, Director, Hazardous Waste Division, Maryland Department
of the Environment


*Perchlorate Fact Sheet

Prepared for APGSCC by Cal Baier-Anderson, PhD
University of Maryland, Program in Toxicology
November 2002
What is Perchlorate?
According to the Army, perchlorate is used as a chemical oxidizer in
propellants and rocket fuel. It is also found in smokes and in several
pyrotechnic formulations. Perchlorate is very soluble in water, so once
released to the environment, rapidly moves through the soil and into the
groundwater. Since it is very stable, it can persist in groundwater for
decades. At Aberdeen Proving Ground, perchlorate has been found in the
vicinity of an active training area, both near and within the City of
Aberdeen Production wells. Perchlorate is known to affect thyroid
function in humans.

Thyroid Function
The thyroid secretes hormones, which influence many different body
functions such as metabolism, growth, development and reproduction.
Hormones are chemical messengers that circulate in the blood and
influence the function of cells and tissues throughout the body. Perhaps
the most noticeable effects of thyroid hormones are that they increase
the body?s consumption of oxygen and generation of heat (increase
metabolism). Resting heart rate and pumping capacity are increased,
which promotes the delivery of oxygen throughout the body.

Thyroid hormones influence growth and maturation in children; this is
particularly evident in the growth and development of bones. Thyroid
hormones are essential to the development of the central nervous system
in fetuses, infants and children. If low hormone levels are present
during gestation or at the time of birth and go untreated, severe,
irreversible mental retardation can occur. Thyroid hormones also enhance
wakefulness, alertness, awareness of hunger, memory and learning

In adults, thyroid hormones play an important role in the regulation of
reproduction. Deficiencies in thyroid hormones can lead to disruption of
the production of eggs and sperm.

Since hormones are powerful chemicals, their production must be
regulated. When thyroid hormones (such as T3, tri-iodithyronine and T4,
thyroxine) in the blood are low, the pituitary, which contains thyroid
hormone sensors, makes thyroid stimulating hormone, or TSH. TSH is a
chemical signal that acts on the thyroid to trigger the production and
release of thyroid hormones. When the level of thyroid hormones in the
blood is appropriate, then the pituitary stops producing TSH. In the
absence of TSH, the thyroid ceases hormone production.

Iodine and the Thyroid
Iodine is required to make thyroid hormones.  The thyroid cannot absorb
iodine without the help of a transport system.  The transport system is
a protein that contains ?seats?; the iodine takes a seat on the
transporter outside of the thyroid along with sodium. Once the ?seats?
are filled, the transporter changes shape to bring the iodine and the
sodium into the thyroid.  The transporter that moves the iodine into the
thyroid is called the iodine-sodium symporter. Once the iodine is inside
the thyroid, it can be used to make thyroid hormones.

While the ?seats? in the transporter are fairly specific for iodine and
sodium, perchlorate can fit in the iodine ?seat?. In doing so, it
prevents iodine from getting into the thyroid. Without the iodine, the
thyroid cannot make thyroid hormones.

Thyroid Responses
In healthy adults the thyroid can compensate for short-term inhibition
of iodine uptake since the thyroid can store hormones for months. In
health adults exposed to perchlorate, the thyroid will release the
stored hormones in response to TSH, thereby maintaining adequate
circulating thyroid hormone levels.

Once the stored hormones are depleted, the cells of the thyroid may
respond to TSH by increasing in size (called hypertrophy) or increasing
in number (called hyperplasia).  By increasing cell size and number, the
thyroid is trying to promote hormone production. Sustained stimulation
of the thyroid by TSH, followed by hypertrophy and hyperplasia has been
shown to lead to thyroid cancer.

Possibly more important than the potential risk of cancer, which could
require years of continued stimulation by TSH, the absence of thyroid
hormones in the blood can result in non-cancer effects.

Potential Toxicological Effects
The main concerns are for the potential effects on fetuses, infants and
children.  There have been several recent studies of newborns in
communities that are currently being exposed to perchlorate in their
drinking water, yet the results are difficult to interpret, due to the
many confounding factors (such as dietary iodine intake, differences in
birth weight, gender and ethnicity). The most detailed study to date
(Schwartz, 2001) found significant, dose-dependent decreases in T4
levels in newborns exposed to perchlorate.

There have been several studies of the effects of perchlorate on iodine
uptake in healthy human adults. Although there is evidence of transient
decreases in iodine uptake during short-term perchlorate exposure,
iodine uptake resumes once the exposure is stopped. Once again, since
healthy adults can compensate for decreased iodine uptake in the short
term, these results cannot be used to predict potential impacts on
fetuses, which have no hormone storage capacity. Babies, children, or
even adults suffering from other health problems may also be more
sensitive to the toxic effects of perchlorate.

Other studies suggest the potential for perchlorate to alter immune
system function.  Specifically, there seems to be an association between
perchlorate exposure and skin rashes and white blood cell dysfunction as
well as changes in blood cell counts, including the potentially deadly
aplastic anemia. The relationship between perchlorate and immune system
function is not well understood, and needs more research.

There have been many studies on the effects of perchlorate on laboratory
animals. It should be noted that the mechanism of toxicity in rats and
humans ? the inhibition of iodine uptake into the thyroid - is the
same.  This is important, because it makes comparisons between
laboratory animals and humans easier. The use of laboratory animals is
advantageous because exposures and analyses can be conducted in a
controlled environment, which cannot be done with humans. These studies
help us to understand the specific impacts of perchlorate.

In the laboratory animal studies, perchlorate causes a dose-dependent
decrease in thyroid hormone production, and a dose-dependent increase in
TSH production.  Female rats seem to be more sensitive to perchlorate
than male rats. Longer exposures result in increased thyroid size due to
cellular hypertrophy and hyperplasia (increased cell size and number).

One particular study demonstrated that exposure of pregnant rats to
perchlorate resulted in size changes within specific regions of the
brain in the pups. There is also an indication that perchlorate
increases motor activity in rats.

Safe Exposure Limits for Perchlorate
The weight of evidence of the available studies leads the EPA to
recommend a reference dose of 0.00003 mg/kg/day. The reference dose
represents a conservative estimate of the maximum amount of a chemical,
in this case perchlorate, to which we can be safely exposed. Since the
main exposure route for perchlorate is via the drinking water, our
concern is setting a safe limit for perchlorate in the drinking water.
A reference dose of 0.00003 mg/kg/day translates into a limit of 1
micrograms/L in the drinking water.

Recently, EPA Region 3 recommended an exposure limit of 1.0 micrograms/L
in the Aberdeen drinking water. Maryland Department of the Environment
issued a Health Advisory for perchlorate in the drinking water above 1.0
micrograms/L.  We believe that based on the available scientific
information this represents a reasonable limit that will be protective
of the community.


**Technical Basis for the1 ppb Treatment Standard

Prepared for APGSCC by Cal Baier-Anderson, PhD
University of Maryland, Program in Toxicology
November 2002
Setting a Standard: The MCL
The US Environmental Protection Agency is tasked with setting standards
for chemical contaminants in the drinking water. These standards, called
Maximum Concentration Limits (MCL), are based on the toxicity of the
chemicals. Not all chemicals are equally toxic: for instance, the MCL
for the solvent trichloroethene is 5 ppb, while the MCL for vinyl
chloride is 2 ppb and the MCL for toluene is 1000 ppb.

The EPA is in the process of evaluating the data on perchlorate. The
process of evaluating perchlorate toxicity will provide the foundation
for setting the MCL.  One of the first steps in developing the MCL is to
determine the Lowest Observable Adverse Effect Level (LOAEL). The LOAEL
for perchlorate is based on the following observations: perturbation in
thyroid and pituitary hormones, thyroid cell changes and changes in
brain size and shape. Based on a review of numerous laboratory studies,
the EPA determined that the LOAEL for perchlorate is 0.01 mg/kg/day.
This means that exposure to perchlorate at this level is likely to
result in changes in thyroid and pituitary hormones, thyroid cell
changes and brain size and shape.

Since it is the goal to set a limit that will not result in adverse
effects, safety factors are applied to this number to extrapolate from
the LOAEL to the No Observable Adverse Effects Level (NOAEL). Additional
safety factors must be applied to account for differences in response
between individual humans, the increased sensitivity of the fetus in
utero, and for database inadequacies. For instance, we know that
perchlorate can affect immune system function, but we currently do not
understand how this happens.

The application of safety factors to the LOAEL is then used to calculate
the Reference Dose (RfD).  The reference dose is an exposure
concentration that is expected to represent a safe level of exposure.
In the revised draft toxicity assessment, which was released in January
2002 a reference dose of 0.00003 mg/kg/day was proposed for perchlorate.

When it is assumed that all perchlorate exposures will come from
drinking water (a reasonable assumption in the case of Aberdeen Proving
Ground) the Risk Based Concentration (RBC) = 1.1 micrograms/L, which has
been rounded down to 1 micrograms/L. (Note that micrograms/L = ppb.)

Based on this information, the state of Maryland has set a Health
Advisory Limit that indicates that when the drinking water supply is
above 1 ppb, the consumers must be notified, and sensitive populations
(defined as pregnant women, young children and people with
hypothyroidism) should avoid drinking the water.
Scientific Controversies
Controversies surrounding the calculation of the RBC are based on the
studies included in the analysis, the endpoints used to determine
toxicity, and the application of factors to account for uncertainty.

For example, a proposed 4 ppb exposure limit is based on the inhibition
of iodide uptake by the thyroid as the endpoint. In contrast, the new
endpoints described above - changes in thyroid and pituitary hormones,
thyroid cells and brain size and shape - are directly linked to
pathologies stemming from perchlorate exposure, and include the
neurological effects.

The state of Massachusetts used a different approach to calculating a
limit for perchlorate in the drinking water. The 1.5 ppb exposure limit
is based on inhibition of iodine uptake in children. US EPA and EPA
Region III argue that since the most sensitive receptor is the fetus,
then we must base exposure limits on consumption of water by adults
(pregnant women).

The state of California includes a human study (Greer, et al,
Environmental Health Perspectives, September 2002) whereby healthy
adults were given perchlorate for two weeks and the uptake of iodine was
measured. Therefore this study used as an endpoint the uptake of iodine,
as opposed to observed pathology. This study also makes the assumption
that there is no thyroid deficiency in the US. The current proposed
state Public Health Goal (PHG) is 6 ppb. A representative from the
California Office of Environmental Health (Robert Howd) acknowledged
that it is impossible to extrapolate potential exposure to the fetus
based on this study. He also noted that the state is in the process of
reassessing perchlorate toxicity, and while he could not reveal the
likely outcome, he indicated that the new PHG is likely to be lower than
the current PHG.

The primary unanswered concerns are potential impacts on the developing
fetus, infants and children. The thyroids of healthy adults contain
several months worth of thyroid hormone; therefore healthy adults are
relatively insensitive to short term perchlorate exposure. In contrast,
the fetus does not have any storage capacity, so even short-term
exposure to perchlorate can result in harm. There is evidence that
perchlorate can accumulate in breast milk, posing a risk to nursing
babies.  These areas require more research to determine specific risks.

Political Pressure used to Influence Interpretation of Science
The Department of Defense and their defense contractors have
unintentionally introduced perchlorate into the groundwater at sites all
across the country. Particularly hard hit are groundwater resources in
California and Nevada. The projected treatment costs may be estimated in
the billions of dollars. Therefore the DOD is attempting to influence
the interpretation of scientific data to justify a less stringent
treatment standard.  We are concerned that these political and economic
concerns will prevent the scientists and risk assessors at EPA from
doing their job. While cost may be a legitimate concern, it must be
secondary to human health.

It is important to note that it is simply not possible to wait until we
have complete scientific knowledge before we make risk-based decisions.
In our view, a national consensus is building in support of the 1 ppb
treatment standard for perchlorate, with the understanding that this
level will be protective of sensitive human receptors. We believe that
it makes sense from a scientific perspective to advocate a Risk Based
Concentration of 1 ppb for perchlorate at Aberdeen Proving Ground.

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