Endocrine Disrupting Chemicals

Practice Endocrine-disrupting Chemicals
Prevention
Many chemicals often used
from the Learning and Developmental Disabilities Initiative, September 2009
by industry and in consumer
products, are considered
endocrine-disrupting
Your endocrine system: A brief review
chemicals, or EDCs. This
column presents a
Your endocrine system creates
Hormones travel through your
summary of what is known
and releases hormones that
body and attach – or bind – to
about EDCs and human
regulate the growth and
hormone receptors on or in cells.
health.
development of your organs and
The hormones regulate many
Some known EDCs:
body’s systems, your metabolism,
processes inside cells, including
bisphenol A (BPA)
puberty, and many of your body’s
regulating gene activity, growth
functions. Hormones are
and tissue formation, immune
dioxins
produced in glands including the
function, cell death, and so on. In
fuels, including
thyroid, the pituitary, sex glands
this manner, hormones can affect
perchlorate*
(ovaries and testes), and others. If
mood, reproduction and other
many industrial
your hormones do not work
activities. Changes in our external
chemicals
properly, many other aspects of
environment, such as a change in
organochlorinated
your body can be affected or
temperature or light, can trigger a
pesticides*
harmed, including the
change in hormone releases.
PCBs*
development and functioning of
phthalates and other
the brain and neurological system.
plasticizers
plastics*
preservatives, including
What are EDCs?
parabens, in cosmetics
and pharmaceuticals
Endocrine-disrupting chemicals
cosmetics, and many more.
A more detailed list of EDCs
(EDCs) are either man-made or
Hormones work in your body in
can be found at
naturally occurring chemicals that
www.ourstolenfuture.org/
interfere with the body’s ability to
very tiny amounts, so even small
basics/chemlist.htm
regulate its growth, development,
exposures to EDCs can affect
metabolism and other functions.
development and function. Unlike
* See previously published
most other toxic substances, low
columns and fact sheets
EDCs are sometimes referred to
doses of EDCs may be more
from LDDI for more
as hormone mimics or, for those
harmful than higher doses. Higher
information on these topics.
that behave like estrogen,
estrogen mimics.
exposures may overwhelm the
Much of the information in
endocrine system and cause less
this column comes from a
There are hundreds of EDCs in
response to the chemical. This is
report and policy statement,
the environment, in food, and in
a concern because safety testing
both published in 2009, by
consumer products. They include
of chemicals assumes that low
the Endocrine Society, a
components of plastics* and
doses are not harmful if higher
professional organization
plasticizers (including BPA and
doses do not show effects. Most
for basic and clinical
phthalates), dioxins, PCBs*,
EDCs have not been thoroughly
endocrine research and the
PBBs, pesticides*, heavy metals*,
tested for health effects at very
treatment of endocrine
industrial chemicals and fuels,
low exposures.
disorders.
preservatives and fragrances in

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Endocrine-disrupting Chemicals
What are the health effects of EDCs?
EDCs mimic your body’s natural hormones, binding
the impact that EDCs may have on the developing
to cells and causing changes that your natural
neurological system and brain. Normal prenatal
hormones would otherwise initiate. As a result, your
brain development is highly dependant on thyroid
body responds as though your own hormones are
hormones* from both the mother and the
sending signals for cells to grow, die, turn genes on
developing fetus. An insufficient supply of thyroid
or off, reproduce and so on. This can cause
hormone can cause lower intelligence, higher rates
particularly devastating and lifelong health problems
of attention deficit disorders and problems with
if the wrong signals are received by cells, starting at
motor coordination, balance and other psychomotor
conception and going through adolescence when
skills.
organs and tissues are developing. As a result,
fetuses and children are at high risk of harm from
A broad range of chemicals common in our
exposures to EDCs, though adults can also be
environment can interfere with how the thyroid
affected either from exposures early in life or from
hormone binds and harm the development of the
cumulative exposures over a lifetime
brain and nervous system. For example, exposure
to PCBs* is associated with lower full-scale IQ,
EDCs can contribute to a wide range of diseases
reduced visual recognition memory, attention
and disabilities including obesity, diabetes, cancer,
deficits and motor deficits. BPA has also been
heart disease, reproductive health problems and
shown to interfere with thyroid hormone binding,
neurodevelopmental and neurodegenerative
and BPA-exposed rats exhibit symptoms similar to
disorders (see the Endocrine Society statement –
attention deficit-hyperactivity disorder. Several
#2 in the Sources section on page 5 – for more
studies show that some EDCs disrupt prenatal brain
information).
sexual differentiation – the changes before birth that
distinguish male and female brains.
The outcome of EDC exposure may not be seen for
many years. If a fetus is exposed to a chemical that
Some laboratory studies indicate that some effects
alters the way the reproductive system develops
of EDC exposure during fetal development can be
and functions, for example, the changes may not be
passed from one generation to the next without
apparent until puberty or later.
additional exposures. How this might happen, and
whether it happens in humans, is not well
This LDDI Practice Prevention column focuses on
understood.
How am I exposed to EDCs?
Humans can be exposed to EDCs through water,
dichlorodiphenyltrichloroethane (DDT)
air, food, consumer products or contaminated soil.
fungicides: vinclozolin
This is a partial list of chemicals that are known or
suspected to be EDCs:
pharmaceutical agents: diethylstilbestrol (DES)
and the synthetic estrogen ethinylestradiol in
synthetic chemicals used as industrial
birth-control pills
solvents/lubricants and their byproducts:
polychlorinated biphenyls (PCBs*),
Endocrine disrupting chemicals – both natural and
polybrominated biphenyls (PBBs), dioxins
man-made – can be found in thousands of places
and products throughout the world. Because they
plastics*: bisphenol A (BPA)
are so widespread, and because manufacturers are
plasticizers: phthalates*
not required to tell people what is in their products,
most of us are exposed from many sources every
pesticides*: methoxychlor, chlorpyrifos,

Practice Prevention
Page 3
day without our knowledge. Even if our exposure
amniotic fluid arising from their mothers’ exposures.
from one product is considered a “safe” level, we
After birth, exposure can continue through both
need to consider all the EDCs in products and items
breast milk and formula. Soy formula or milk-based
that we encounter to get a picture of our total
formula stored in cans lined with BPA plastic is
exposure level.
especially likely to contain EDCs, as are beverages
served in BPA-laden bottles and sippy cups.
Even though new production of some man-made
chemicals, such as PCBs, has been banned for
Natural chemicals called phytoestrogens (chemicals
decades, these chemicals still lurk in water and soil
from plants that behave like estrogen hormones)
and continue to expose animals and humans today.
are found in many food plants such as soy and
other legumes, nuts, grains and flaxseed. Some
Water
essential oils, including lavender and tea tree oil,
In many places, both surface water (rivers and
are also phytoestrogens. Research on health
lakes) and ground water have been contaminated
effects of phytoestrogens is inconclusive about
with EDCs from septic systems and treated waste
possible harmful effects, and some beneficial
water, storm water runoff, industrial waste, oil spills,
effects have been seen from them, including
agriculture, household products or fallout from the
anticancer effects. Much more research on the
air. Most waste treatments facilities do not filter all
benefits and risks of phytoestrogens is needed,
EDCs from sewage, and so these chemicals are
especially for pregnant and nursing women and
discharged into surface water.
small children.
Food
Personal care products
Fish and seafood from contaminated water can
EDCs can be found in many personal care
have EDCs in their flesh and fat. EDCs
products, including lotions, creams, gels, powders,
“bioaccumulate” in animals – they are found in
deodorants and other cosmetics. EDCs are also
higher concentrations in animals that eat other
present in baby wipes, creams and countless baby-
animals. Predatory fish, such as walleye, pike, tuna
care products*. Known or suspected EDCs in these
and swordfish, are more likely to have higher
products include parabens, phthalates and
concentrations of EDCs and other toxic chemicals.
essential oils such as lavender and tea tree oil.
Similarly, larger fish are more likely to have high
Several studies have shown that EDCs can be
concentrations than smaller fish of the same
absorbed through skin from these products, and
species.
intact paraben esters (which are EDCs) have been
Food can also be contaminated through the use of
found in human body tissues.
pesticides that have endocrine-disrupting
Plastic*
properties. Further, some livestock that provide
Household items made of plastic may contain
meat and dairy products are treated with hormones
phthalates or BPA, both of which are endocrine
and/or steroids (a form of hormone) to enhance
disruptors. Phthalates are used in polyvinyl chloride
growth or milk production. There is ongoing
(PVC, or vinyl, marked #3 on packaging), which is
controversy about whether these hormones and
used in making thousands of products including
steroids affect the endocrine functioning of people
toys, appliances, shower curtains, furniture, window
who eat the meat and milk from treated animals.
blinds, plumbing pipes, flooring, lunch boxes and
Food that is stored in BPA-lined metal cans or
packaging. BPA is a component of polycarbonate
plastic storage containers absorbs some of the BPA
plastic used to make drinking bottles, baby bottles
from the container. This is especially true when the
and other items. Recent research shows that BPA
containers are heated.
levels in urine increase when people drink from
polycarbonate plastic. BPA is also an ingredient
Children are exposed before birth to EDCs in
used in plastics and resins that line metal food and

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Endocrine-disrupting Chemicals
drink cans, and some research shows it leaches
fields, and on wooden structures such as decks,
into food packaged in these cans.
fences and outdoor furniture
dental sealants
Other Sources of Exposure
pesticides and preservatives used in homes, in
industrial lubricants
yards and gardens, on playgrounds and sports
birth-control pills
How can I reduce/prevent exposures?
Food
health and safety concerns.
Look for and follow warnings from federal, state,
tribal and local governments about fish
Plastic*
consumption. Sport fishermen can usually find
Reduce your use of plastic items in your home and
warnings at fishing-supply stores, or check the US
at work, especially PVC (#3) and polycarbonate
Environmental Protection Agency’s online advisory
plastic (#7). Avoid plastics that contain phthalates,
site: www.epa.gov/waterscience/fish/states.htm.
especially infant toys and teethers. There are many
alternatives to plastic toys, dishes, and other
When selecting and preparing foods with animal fat,
common items.
reduce the amount of fat you eat. Buy low-fat
products, trim visible fat from meat and fish, and
Pesticides*
broil or grill meats instead of frying them to let the
Reduce the use of pesticides in your home and
fat drip away.
yard, your schools, playgrounds, churches,
businesses and work places. The US
To the extent that you can, purchase organically
Environmental Protection Agency and many other
grown food. Wash fresh foods thoroughly to remove
organizations provide information on alternatives.
pesticide residues.
See www.epa.gov/opp00001/factsheets/ipm.htm,
for example.
Reduce your use of plastic food containers,
especially those made from polycarbonate plastic
Pregnant women and children especially should
(#7). Do not heat foods in plastic containers, and
avoid places where pesticides have been sprayed,
avoid using plastic dishes with heated foods,
including downwind areas. Remove your shoes
including baby formula. Avoid food packaged in
when you enter your home to prevent bringing
lined metal cans if not labeled BPA-free.
residues inside, and keep floors, carpets and other
surfaces clean. Always wash your hands, and
Personal care products
children’s hands, before handling food or eating.
Check ingredients on products before you buy,
avoiding phthalates, DEHP, fragrances and other
National and global policy
chemicals that include the word “paraben.”
With EDCs in our water and soil, and sometimes
Unfortunately, manufacturers don’t have to list inert
even the air, we cannot individually avoid
chemicals, so EDCs may still be present even
exposures. Instead, we must act to reduce the
though not listed in the ingredients. Sometimes
contamination by industry, by agriculture and by
ingredients that contain parabens and/or phthalates
consumers. Ask your elected representatives to
are marked simply as “fragrance” on a label. Look
work to regulate EDCs in the environment based on
for items marked “paraben-free” for greater
unbiased research covering both low-level and
assurance that there are no hidden parabens. You
high-level exposures. You can also encourage
can also check an online database called Skin
lawmakers to fund more research and screening
Deep: Cosmetic Safety Reviews at
programs. Ask your health professionals to
www.cosmeticsdatabase.com. This database lists
advocate for more research and oversight of EDCs.
thousands of personal care products and details

Practice Prevention
Page 5
Sources for this column
1. Center for Health, Environment and Justice. PVC -
8. National Cancer Institute, US National Institutes of
The Poison Plastic. www.besafenet.com/pvc/about.htm,
Health. www.cancer.gov/Templates/
viewed August 17, 2009.
db_alpha.aspx?CdrID=330175, viewed July 7, 2009.
2. Diamanti-Kandarakis E et al. 2009 Endocrine-
9. Takao Y, Lee H C, Kohra S, Arizono K. Release of
disrupting chemicals: An Endocrine Society Scientific
bisphenol A from food can lining upon heating. Journal of
Statement. Endocrine Reviews 30(4):293-342. Available
Health Science (Tokyo, Japan). http://sciencelinks.jp/j-
online at www.endo-society.org/journals/
east/article/200218/000020021802A0653963.php,
scientificstatements/
viewed August 17, 2009.
3. Environmental Working Group. Skin Deep: Cosmetic
10. The Endocrine Society. Position Statement:
Safety Reviews, www.cosmeticsdatabase.com/, viewed
Endocrine-Disrupting Chemicals. June 2009. www.endo-
July 8, 2009.
society.org/advocacy/policy/upload/Endocrine-
Disrupting-Chemicals-Position-Statement.pdf, viewed
4. Environmental Working Group. Bisphenol A: Toxic
July 6, 2009.
Plastics Chemical in Canned Food. March 2007.
www.ewg.org/reports/bisphenola, viewed August 17,
11. US Environmental Protection Agency. Integrated
2009.
Pest Management (IPM) Principles.
www.epa.gov/opp00001/factsheets/ipm.htm, viewed July
5. Health Care Without Harm. Phthalates/DEHP.
8, 2009.
www.noharm.org/us/pvcDehp/phthalatesDehp, viewed
August 17, 2009.
12. Warren BS, Devine C. Phytoestrogens and Breast
Cancer. Cornell University Program on Breast Cancer
6. Hotchkiss AK, Rider CV, Blystone CR, Wilson VS,
and Environmental Risk Factors.
Hartig PC, Ankley GT, Foster PM, Gray CL, Gray LE.
http://envirocancer.cornell.edu/FactSheet/Diet/fs1.ph
Fifteen years after "Wingspread" -- environmental
yto.cfm, viewed July 7, 2009.
endocrine disrupters and human and wildlife health:
where we are today and where we need to go.
Toxicological Science. 2008 Oct;105(2):235-59.
7. Jiang JQ, Yin Q, Pearce P, Zhou J. A survey of
endocrine disrupting chemicals in sewage and a
preliminary treatment trial. Water and Science
Technology. 2005;52(8):1-7.
* See previously published columns and fact sheets from LDDI for more information on these topics:
www.healthandenvironment.org/working_groups/learning
The Learning and Developmental Disabilities Initiative is a working group
of the Collaborative on Health and the Environment (CHE). For more
information or for other Practice Prevention columns, visit CHE online at
www.healthandenvironment.org or call 360-331-7904.