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),
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
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 this problem?
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
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
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 disrupters.
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.
there 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
This 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 child.
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 effects.
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.
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.
Thus, 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 cancers.
I find out about my own body burden?
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 peopleÔs 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
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 world.
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
How can I get these chemicals out of my body?
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
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.
Some 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 neuralgic performance.
Don't government regulations protect my family and me?
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
U.S. 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
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