is a "body burden"?
Toxic chemicals, both naturally occurring and man-made, often get
into the human body. We may inhale them, swallow them in
contaminated food or water, or in some cases, absorb them through
skin. A woman who is pregnant may pass them to her developing fetus
through the placenta. The term " body burden " refers to the total
amount of these chemicals that are present in the human body at a
given point in time. Sometimes it is also useful to consider the
body burden of a specific, single chemical, like, for example, lead,
mercury, or dioxin.
Some chemicals or their breakdown products (metabolites) lodge in
our bodies for only a short while before being excreted, but
continuous exposure to such chemicals can create a "persistent" body
burden. Arsenic, for example, is mostly excreted within 72 hours of
exposure. Other chemicals, however, are not readily excreted and can
remain for years in our blood, adipose (fat) tissue, semen, muscle,
bone, brain tissue, or other organs. Chlorinated pesticides, such
as DDT, can remain in the body for 50 years. Whether chemicals are
quickly passing through or are stored in our bodies, body burden
testing can reveal to us an individual's unique chemical load and
can highlight the kinds of chemicals we are exposed to as we live
out each day of our lives. Of the approximately 80,000 chemicals
that are used in the United States, we do not know how many can
become a part of our chemical body burden, but we do know that
several hundred of these chemicals have been measured in people's
bodies around the world.
all humans carry this chemical body burden?
A: Scientists estimate that everyone alive today
carries within her or his body at least 700 contaminants, most of
which have not been well studied (Onstot and others). This is true
whether we live in a rural or isolated area, in the middle of a
large city, or near an industrialized area. Because many chemicals
have the ability to attach to dust particles and/or catch air and
water currents and travel far from where they are produced or used,
the globe is bathed in a chemical soup. Our bodies have no
alternative but to absorb these chemicals and sometimes store them
for long periods of time. Whether we live in Samoa or San Diego,
Juneau, or Johannesburg, all our bodies are receptacles for a
multitude of industrial chemicals. Wherever we live, we all live in
a chemically contaminated neighborhood.
*Onstot J, Ayling R, Stanley J. Characterization of HRGC/MS
Unidentified Peaks from the Analysis of Human Adipose Tissue. Volume
1: Technical Approach. Washington, DC: U.S. Environmental Protection
Agency Office of Toxic Substances (560/6-87-002a), 1987.
of the chemicals residing in our bodies are pesticides, and
some are used in or produced by other forms of industrial
production. Many are found in a wide variety of consumer products.
Some chemicals like dioxins and furans are created unintentionally
by industrial processes using chlorine and from the manufacture and
incineration of certain plastics. Scientists estimate that
there are many other unintentionally created by-products which have
not yet been "discovered" since no tests have yet been developed
that would fully identify or describe these by-products.
How did this happen? How have I been exposed?
A: Humans are exposed to chemicals through the food
we eat, the air we breathe, and the water we drink and bathe in.
Chemicals often coat the surface of dust particles, which we handle
or inhale. Contaminated dust is an especially important route of
exposure for children who commonly put their hands into their
mouths. We are also exposed to hundreds of chemicals in everyday
products we use. Paints and varnishes, gasoline, glues, cosmetics,
clothes dry-cleaned with solvents, plastic food containers, and home
and garden pesticides are just a few examples. The chemical
landscape created as a result of intensive and continuing chemical
use during the 20th century has been internalized. Because the
chemicals found within our bodies are not labeled with return
addresses, it is difficult to identify where they come from.
For example almost all of the dioxin found inside your body got
there from eating contaminated food. However, it may have originated
in a local medical waste incinerator or it may have been created by
a distant, chlorine-based, paper manufacturing plant located
thousands of miles from your home. Whatever its source, somewhere it
entered the food chain and made its way into the food you ate.
Similarly, a pesticide found inside your body may have come from
pesticide spraying done at a local school, in your garden or
kitchen, or it may have arrived on foodstuffs grown with pesticides
in the U.S. or abroad. Its origin will be difficult to identify.
Another source of exposure is the chemical body burden of our
mothers. During pregnancy, the chemicals stored in a woman's body
have the ability to cross the placenta where they may cause harm.
Some chemicals from a mother's body are also mobilized and
transferred to the breasts as she produces breast milk. These
chemicals are then transferred to the baby during breastfeeding.
Breast milk remains the best food for babies, as recent studies
show, because of its immunological, nutritional and psychological
benefits. The fact that industrial chemicals have contaminated
breast milk is tragic. Ironically, breastfeeding appears to offset
some of the damage created by contaminants during fetal development.
Some of the chemicals we receive from our mothers in utero and
through breastfeeding remain with us for years, an unintended legacy
that our mothers pass on as their body burdens become our own.
What is the evidence for body burden? How long have we known about
A: It has been known for centuries that chemicals
can enter the body and cause health effects. Since the middle of the
20th century, scientists have been able to detect and measure
chemicals in wildlife and humans and sometimes link these chemicals
to health outcomes. For example, in 1944 researchers found residues
of DDT in human fat, and in the early 50's, naturalists rightly
concluded that DDT was directly responsible for thinning eggshells
and declining populations of bald eagles and other birds. In fact,
at about the same time, DDT was detected in Antarctic penguins
living an extremely long distance from where DDT was being used.
Since then, analytic techniques have improved and many other
chemicals have been detected in human and wildlife tissues. For
decades, tests for some substances that make up the total chemical
body burden have been conducted by government agencies around the
world. These hundreds of studies include analyses of adipose (fat)
tissue, breast milk, semen, blood, or urine for chemical content,
documenting the amount and kinds of chemicals found. This website
gives a list of some of these body burden studies.
What are the health effects of this body burden?
A: Chemicals can have different effects in people
or in wildlife, depending on the amount, timing, duration, and
pattern of exposure as well as the properties of the specific
chemical. Chemicals can have toxic effects through a variety of
example, sometimes a chemical attacks and damages or kills cells or
tissues in the body. Some chemicals attack the genetic material in
the nucleus of a cell, causing damage directly to the DNA, which may
create an inheritable defect that is passed on to the next
generation. This can lead to gene mutations, which can set in motion
a sequence of events leading to cancer, birth defects, developmental
or reproductive disorders. Chemicals that cause cancer are called
carcinogens. Chemicals that cause birth defects are called
teratogens. Chemicals that damage the normal development of the
fetus, infant, or child, or damage our reproductive tissues are
called developmental/reproductive toxicants. Some
chemicals can cause damage through their ability to interfere with
normal hormone function. These chemicals are called endocrine
Through these various mechanisms, toxic chemicals can cause a long
list of health problems. They include, for example, direct damage to
the lungs, liver, kidney, bones, blood, brain and other nerves, and
the reproductive systems. There are hundreds of adverse health
effects that can arise from exposures to chemicals or metals. These
potential effects include cancer; high blood pressure; asthma;
deficits in attention, memory, learning, and IQ; Parkinson's-like
diseases; infertility; shortened lactation; endometriosis; genital
malformation; peripheral nerve damage; and dysfunctional immune
systems. For example, dioxin is a carcinogen and fetal exposures to
dioxin interfere with normal development, including the immune
system. Fetal exposure to polychlorinated biphenyls (PCBs) is
related to behavioral and cognition problems. DDT exposure has been
related to women's inability to produce sufficient breast milk. The
immune systems of children in some areas of the far north are unable
to produce enough antibodies to make vaccinations effective. Since
these children and their mothers carry large chemical body burdens,
a chemical link to this problem is likely. Fetal exposure to mercury
causes attention, memory, and learning problems later in life. Brain
development is also impaired in fetuses and infants exposed to lead.
special health effects for children?
Developing or immature tissues are far more susceptible to chemical
exposures than adult tissues. Development is a time of special
vulnerability. It is a time of very rapid replication and
differentiation of cells - the latter being an incredibly complex
and vulnerable process.
means that the developing fetus, infant, or child may suffer harmful
impacts from relatively small exposures that have no measurable
impacts on adults. So, for example, fetal exposures to chemicals in
amounts that are safe for adults may result in birth defects or
abnormal brain development. For this reason, it is not only the
amount of the exposure that is important, but the timing of the
exposure. Unfortunately, few of the chemicals to which we are
regularly exposed to have undergone sufficient testing to fully
understand whether or not they might be harmful to a fetus or
Hormones play extremely important roles as they help to direct the
development of the fetus, infant, and child. Of course, hormones are
also important in adults, as they are crucial for normal functioning
of many bodily systems. What is amazing about hormones is that they
are present and active in only tiny amounts, yet these tiny amounts
produce major, major effects. Most importantly, exposure to an
endocrine disrupter at a low level during a critical time in
development can have lifelong impacts. For example, the developing
fetus may mistake a foreign chemical for a hormone, and this may, in
turn, cause an incorrect "signal" to be sent to developing tissues.
These early mistakes can permanently damage the baby's developing
immune, reproductive or nervous systems. Most of the confirmed
evidence of the importance of endocrine disrupters comes from
wildlife studies, but more recently, evidence for impacts in humans
has also emerged.
Can the links between body burden and illness be proven?
A: Of the more than 80,000 chemicals in commerce,
only a small percentage of them have ever been screened for even one
potential health effect, such as cancer, reproductive toxicity,
developmental toxicity, or impacts on the immune system. Among the
approximately 15,000 tested, few have been studied enough to
correctly estimate potential risks from exposure. Even when testing
is done, each chemical is tested individually rather than in the
combinations that one is exposed to in the real world. In reality,
no one is ever exposed to a single chemical, but to a chemical soup,
the ingredients of which may interact to cause unpredictable health
The amount of data on body burdens available in the U.S. and the
world is extremely limited, particularly compared to the voluminous
data we have for chemical levels in air, water, soil, food, and
wildlife. Most population-wide body burden data we do have covers
only a limited number of chemicals.
Concerning the chemicals that have been measured, there is good news
and bad news. The good news is that in several cases, public
interventions have resulted in primary prevention, the lowering of
the public's exposure, and the lowering of body burdens. For
example, the removal of lead from gasoline and the elimination of
lead from most kinds of paint have resulted in a marked decline in
the lead body burden of the general population in the United States.
Since lead causes lowered IQ in exposed children, this reduction in
body burdens is a hopeful sign.
bad news is that there are still groups of children who remain at
significant risk from impaired brain function because of elevated
lead levels. Many of them live in urban environments where they are
exposed to lead from numerous sources, including leaded paint in
houses, old industrial facilities, and contaminated soil. For PCBs,
current background levels cause neurodevelopmental deficits in
children. For dioxin, the general U.S. public carries a current body
burden near or above levels causing adverse effects in animal tests.
The study of disease rates and causes in humans is called
epidemiology, the study of patterns of illness among groups of
people. Because epidemiology is such a blunt instrument, it will
almost never be able to tell us if a specific chemical causes a
particular human disease or health effect. Since we regulate, and
thereby reduce exposures, on a chemical-by-chemical basis,
epidemiological studies will almost never succeed in producing
primary prevention - the lowering of human exposures to
environmental chemicals - because epidemiology cannot identify the
specific chemical that is causing the disease.
definitive proof for a linkage between a specific disease and a
specific toxic chemical is almost always lacking. Absent this, we
can use data from laboratory and wildlife studies to make useful
predictions about human health, and these predications are often
borne out by current statistics about human birth defects,
infertility, developmental delays, and increasing rates of certain
Q: How do I
find out about my own body burden?
A: In general, there is no readily accessible way
to know. Even if you could learn about your own body burden, you may
not find the information useful. Your doctor in general cannot
prescribe treatments that will lower the level of chemicals in your
body. Finding out about your community body burden, however, is
useful, and can lead you and your neighbors to take actions to lower
your chemical exposures.
agencies, health care facilities, or other laboratories do not
routinely offer body burden measurements. Most of what we know
about body burdens of contaminants comes from limited studies of a
few contaminants, conducted by government agencies on selected
groups of people. These studies often break down the analysis by
sex, age, and race, which provides useful information about
population-wide averages. But population-wide averages cannot
predict body burdens for individual people. Moreover, these
population studies are usually limited to just a few of the
contaminants to which people are regularly exposed.
In general, you can find out more about the chemicals in the fish
you eat than you can discover about the chemicals stored in your
body. In other countries, Sweden for example, body burden monitoring
is more extensive, and the government tracks how well it is doing in
reducing people?s exposures to environmental chemicals by watching
the body burdens go down. Body burden monitoring gives them a
report card on their primary prevention activities. Body burden
monitoring also can serve as an early warning system that identifies
new chemicals that are increasing in people, and that the government
should pay attention to.
we have the right to know about what chemicals are in our air,
water, soil, food and products we use daily, it makes sense that we
should have the right to know about the chemicals we carry in our
bodies. We should take a lesson from the Swedes and establish
extensive community-based body burden monitoring programs around the
What does a body burden test tell me about my own health?
A: Body burden testing tells us something about
what chemicals we have been exposed to. It usually tells us almost
nothing about whether those exposures are responsible for any health
problems. However a single body burden test, or, better yet,
community-based monitoring, may indicate a great deal about the
overall state of our environment and public health.
How can I get these chemicals out of my body?
A: At this time there is no general agreement about
useful or safe methods for reducing body burdens. The best course is
long-term prevention. Contamination of future generations by toxic
chemicals can be prevented by working together to: 1) eliminate the
most dangerous persistent chemicals that bioaccumulate (concentrate
more as they get higher in the food chain); 2) develop alternative
production methods that use non-toxic materials, and 3) ensure that
communities, national governments and international agencies take a
precautionary approach when it comes to chemicals released into our
air, water, and soil. Please look at the
Learn More section on this website that lists organizations you
can contact to learn how to participate in campaigns based on these
Changes in lifestyles may prevent some exposures. Recent studies of
chemical body burdens in the state of Washington have found that
children who ate organic food and who were not exposed to pesticides
in their homes had significantly lower body burdens.
limited research shows that body burdens of some contaminants stored
in fat can be lowered by a combination of special diets, exercise,
and saunas. But data are very limited and preliminary. When some
metals, like lead or mercury, are present in the body at fairly high
levels, "chelating agents" are sometimes used to lower the total
body burden of that particular metal. However, "chelation"
treatments are somewhat controversial with potential side effects
and have not been proven to consistently reduce toxic impacts of
exposure. For example, one study showed that a chelating agent used
in children with moderately elevated lead levels did not improve
Don't government regulations protect my family and me?
A: Current regulations were developed well in
advance of the new science that shows that small exposures to
chemicals - once considered harmless - are indeed capable of subtle
cellular changes. New evidence shows that these subtle changes can
raise the risk for birth defects, cancer and other health problems.
In addition, the regulations now in place are not designed to look
at exposures in the context of the full burden of chemicals we
carry. No one is looking at the health effects of the cumulative
regulations are the result of long, involved political processes in
which special interests exert considerable influence. Industries
with significant financial interest in the continued use of a
particular product or chemical have historically been quite
successful in limiting regulatory controls. More information about
the chemical body burdens of individuals, particularly exposed
communities, and national populations could help us make better
decisions about which products we want to use, which food we want to
consume and what laws need to be in place to protect us.