Children's Unique Vulnerability to Environmental
Children are uniquely vulnerable to environmental toxins.
This heightened susceptibility stems from several sources.
Children have greater exposures to environmental toxins than adults.
Pound for pound of body weight, children drink more water, eat more
food, and breathe more air than do adults. For example, children
ages one through five years eat three to four times more food per
pound than the average adult American. The air intake of a resting
infant is twice that of an adult per pound of body weight. These
patterns of increased consumption reflect the rapid metabolism of
children. The implication for environmental health is that children
will have substantially heavier exposures pound for pound than adults
to any toxins that are present in water, food, or air. This has
been demonstrated clearly in the case of children's exposures to
pesticides in the diet. Two additional characteristics of children
further magnify their exposure to toxins in the environment: their
hand-to-mouth behaviour, which increases their ingestion of any
toxins in dust or soil, and their likelihood of playing close to
the ground, which increases their exposure to toxins in dust, soil,
and carpets as well as to any toxins that form low-lying layers
in the air, such as certain pesticide vapors. Children are undergoing
rapid growth and development, and their developmental processes
are easily disrupted.
Many organ systems in young children-the nervous system, the reproductive
organs, the immune system-undergo very rapid growth and development
in the first months and years of life. During this period, structures
are developed and vital connections are established. Indeed, development
of the nervous system continues all through childhood, as is evidenced
by the fact that children continue to acquire new skills progressively
as they grow and develop, crawling, walking, talking, reading, and
writing. The nervous system is not well able to repair any structural
damage that is caused by environmental toxins. Thus, if cells in
the developing brain are destroyed by chemicals such as lead, mercury,
or solvents, or if vital connections between nerve cells fail to
form, there is high risk that the resulting neuro-behavioral dysfunction
will be permanent and irreversible. The consequences can be loss
of intelligence and alteration of normal behavior.
children have more future years of life than do most adults, they
have more time to develop chronic diseases that may be triggered
by early environmental exposures.
Many diseases that are triggered by toxins in the environment require
decades to develop. Examples include mesothelioma caused by exposure
to asbestos, leukemia caused by benzene, breast cancer that may
be caused by DDT, and possibly some chronic neurologic diseases
such as Parkinson's disease that may be caused by exposure to environmental
neurotoxins. Many of those diseases are now thought to be the products
of multistage processes within the body's cells that require many
years to evolve from earliest initiation to actual manifestation
of illness. Consequently, certain carcinogenic and toxic exposures
sustained early in life appear more likely to lead to disease than
do the same exposure encountered later in life.
This summary was prepared by the Center for Children's Health and
the Environment of the Mount Sinai School of Medicine. CCHE's mission
is to promote the health of children by conducting environmental
health and policy research. CCHE was established in 1998 with the
support of The Pew Charitable Trusts. CCHE's director is Philip
J. Landrigan M.D., M.Sc., a pediatrician who chairs the Department
of Community and Preventive Medicine at Mount Sinai.
National Academy of Sciences: Pesticides in the Diets of Infants
and Children. Washington, DC: National Academy Press, 1993.
Landrigan, PJ, Carlson JE: Environmental policy and children's
health. The Future of Children 1995;5:34-52.
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