 A Homeowner's Guide to Perchlorate
Prepared
by the New Jersey Department of Environmental
Protection's Division of Water Supply and Geoscience -
Bureau of Safe Drinking Water and Division
of Science, Research and Technology
Updated: November
2005
Q1. What is perchlorate?
A1. Perchlorate is a naturally occurring
inorganic chemical compound that can also
be manufactured. One source of perchlorate
is found as naturally occurring deposits
in Chile that are mined and used as fertilizer
in the United States. Much of the perchlorate
manufactured in the United States is used
as the primary ingredient in solid rocket
propellant. Perchlorate is also used in a
wide variety of industrial processes and
fireworks, matches, lubricating oils and
air bags. Wastes from the manufacture and
improper disposal of perchlorate-containing
chemicals are increasingly being discovered
in soil and water. In recent years, there
has been growing interest nationwide in perchlorate
levels in soil, groundwater, drinking water
and irrigation water, and the potential health
effects of exposure to perchlorate.
back to top
Q2. Where has perchlorate-contaminated
water been found?
A2. Perchlorate has been detected
in water in more than 20 states throughout
the nation. The U.S. Environmental Protection
Agency (EPA), other federal agencies, states,
water suppliers and industry are addressing
perchlorate contamination by monitoring for
perchlorate in both drinking water and source
water. The extent of perchlorate contamination
is not known at this time. Perchlorate has
been found in some public and private water
systems in New Jersey. Measures are being
taken to ensure the safety of surrounding
wells and water systems.
back to top
Q3. How can perchlorate
affect human health?
A3. The National Research Council
of the National Academy of Sciences reviewed
the health effects of ingested perchlorate
and issued its conclusions in January 2005.
At sufficient doses, perchlorate interferes
with iodide uptake into the thyroid gland.
Because iodide is an essential component
of thyroid hormones, higher doses of perchlorate
disrupt thyroid functions and decrease the
production of thyroid hormones T3 and T4.
In adults, the thyroid helps regulate metabolism.
In children, the thyroid plays a major role
in proper development of the central nervous
system and skeleton, in addition to regulating
metabolism. In expectant mothers, impairment
of thyroid function may have adverse effects
on the fetus and the newborn, including behavior
changes, delayed development and decreased
learning capability.
Short-term exposure to perchlorate is expected
to have effects similar to chronic exposure
because the inhibition of iodide uptake occurs
within a short time. Further, perchlorate
does not accumulate in the body even with
constant exposure.
back to top
Q4. Does perchlorate
cause cancer?
A4. According to the National Academy
of Sciences report, laboratory animals develop
benign tumors only when given very high doses
of either perchlorate or other chemicals
that interfere with thyroid function. The
National Academy of Sciences concluded that
it is unlikely that perchlorate at levels
usually found in the environment would cause
thyroid cancer or benign tumors in humans,
citing the differences in thyroid function
in animals and humans.
back to top
Q5. Is there a standard
for perchlorate in drinking water?
A5. As of now, there is no drinking
water standard for perchlorate, but the federal
EPA finalized its human health risk assessment
for perchlorate ingestion following the National
Academy of Sciences review. The "Reference
Dose" (RfD)1 adopted directly
from the National Academy of Sciences review
is based on the finding that daily ingestion
of up to 0.0007 milligrams per kilogram of
body weight can occur without adversely affecting
the uptake of iodine into the thyroid. At
this level, no effects on thyroid function
are expected, and the RfD is protective for
the most sensitive persons. This is equivalent
to approximately 0.045 milligrams per day
(or 45 micrograms) in a pregnant woman or
0.05 milligrams per day in an average-weight
man. A protective drinking water concentration
is based on the following assumptions: 1)
adults drink two liters of tap water per
day; 2) tap water consumption accounts for
20 percent of an adult's daily exposure to
perchlorate; and 3) perchlorate also occurs
in some foods. Based on these assumptions,
a health-based drinking water concentration
would be 5 parts per billion (ppb)2.
back to top
Q6. Is perchlorate-contaminated
water safe to drink or use?
A6. It is important to recognize
that conservative assumptions are used to
develop the RfD. Exposures at levels above
the RfD will not necessarily result in adverse
health effects. However, the RfD and the
drinking water concentration of 5 ppb for
perchlorate are intended to protect public
health, particularly sensitive populations
including pregnant women, children and those
with health problems or compromised thyroid
function.While there currently is no regulatory
standard for perchlorate, the New Jersey
Department of Environmental Protection (DEP)
recommends that people avoid drinking water
known through confirmed testing to contain
more than 5 ppb of perchlorate. If you elect
to use bottled water, you should consider
contacting the producer to determine if sampling
for perchlorate is done as discussed below.
Also, avoid cooking with water containing
perchlorate levels above 5 ppb because boiling
the water may increase the perchlorate concentration
in the food being prepared.Water contaminated
with perchlorate can be used for showering,
bathing and washing clothes and dishes. However,
children should be closely watched during
bathing to ensure they do not ingest the
water.
back to top
Q7. Who should test
their drinking water for perchlorate?
A7. Although a drinking water standard
for perchlorate has not yet been established,
some public water systems voluntarily conduct
sampling for perchlorate. Contact your water
system to find out if perchlorate sampling
is being performed.If you are served by a
private well, the DEP recommends testing
by a New Jersey certified lab if you are
concerned about possible perchlorate contamination
or are aware of perchlorate contamination
nearby. Contact your local health department
for more information about perchlorate testing
or possible contamination in your area.For
more information on private wells, visit
the DEP's Private Well Testing Act website or
the EPA's Private Well Web site at http://www.epa.gov/ogwdw/privatewells/index2.html.
back to top
Q8. Where can I get
my well tested?
A8. Analysis should be done by a
New Jersey certified lab. The DEP's Office
of Quality Assurance offers a list of New
Jersey certified labs at https://www.nj.gov/dep/oqa/index.html or
by calling (609) 292-3950.
back to top
Q9. Do bottled water
manufacturers test for perchlorate?
A9. Neither the U.S. Food and Drug
Administration (FDA) nor the Bottled Water
Program in the New Jersey Department of Health has established a standard
for perchlorate in bottled water. Current
regulations for bottled water do not require
bottlers to test for perchlorate. The bottled
water industry is aware of the potential
for perchlorate contamination in source waters,
and some bottlers may voluntarily test for
perchlorate. Consumers should contact the
producers of their favorite brands for more
information.
back to top
Q10. How is perchlorate
removed from water?
A10. Currently, New Jersey has little
experience with perchlorate treatment. DEP
expects based on other States' experiences,
the following types of treatment will be
most appropriate for the treatment of perchlorate
at the levels found in drinking water: ion
(anion) exchange, membrane technology, and
potentially whole house carbon adsorption.
Additionally, point of use treatments, such
as reverse osmosis and distillation, may
remove perchlorate from drinking water.
back to top
Q11. Where else has
perchlorate been found?
A11. Available information indicates
that perchlorate is present in the food supply,
including cow's milk and lettuce. Perchlorate
has also been found in breast milk. The FDA
is currently conducting additional studies
of perchlorate in food. For more information,
visit the FDA's Web site at http://www.fda.gov.
back to top
Q12. Where can I get
more information?
A12. The EPA Web page, http://www.epa.gov/safewater/ccl/perchlorate/perchlorate.html,
can provide the most recent perchlorate information.
You can also contact the DEP's Bureau of
Safe Drinking Water at watersupply@dep.state.nj.us or
(609) 292-5550.
back to top
1"Reference Dose"
is defined as an estimate of a daily oral
exposure to the human population (including
sensitive subgroups) that is likely to
be without an appreciable risk of deleterious
effects during a lifetime.
2 The New Jersey Drinking
Water Quality Institute has made a recommendation
of 5 ppb as a MCL to the DEP. The DEP anticipates
proposing a regulation reflecting the recommendation
prior to January 31, 2006. In the interim,
the DEP recommends that anyone with a New
Jersey certified lab result for perchlorate
that exceeds 5 ppb take remedial measures. |
