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It is only in the last 50 years that diseases linked to environmental
contamination have been recognized in pediatrics. Most environmental
exposures now understood to be harmful to children were initially identified
as a result of acute epidemics of illness affecting groups of people.
For example, polluted outdoor air was not well understood to be unhealthy
until the London Smog of 1952.1 An estimated 4000
people died from exposures to the very heavy air pollution; deaths
were unusually high among the very young and the elderly. This led
to the development of the first laws to regulate air pollution. Mercury
was not understood to be harmful until an epidemic of cerebral palsy
occurred among infants living near Minamata Bay, Japan, in the 1950s
(Minamata disease).2 Between 1959 and 1972 in Iraq,
seed grain treated with a mercury fungicide was accidentally eaten
by humans instead of being planted in the fields, and thousands
of Iraqi people developed mercury poisoning.3,4
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The harmful effects of polychlorinated biphenyls came to light
in 1968 when an epidemic of acne occurred among people in Japan;
the disease was traced to the use of cooking oil inadvertently mixed
with polychlorinated biphenyls (PCBs). About 2000 Japanese people
exposed to the oil were diagnosed with Yusho (oil
disease).5-7 Dioxin’s health effects were
not well known until 1975 when a chemical plant explosion in Seveso,
Italy, released large amounts of dioxin, and children in the area
near the explosion developed chloracne, especially on areas of the body
unprotected by clothing.8-10 Drinking water contamination
became well recognized in 1986 when a cluster of childhood leukemia was
uncovered in Woburn, Massachusetts, and was epidemiologically linked
to drinking water supplied from 2 municipal wells contaminated with
seepage of the animal carcinogens trichloroethylene, tetrachloroethylene, and
chloroform from area chemical disposal pits that had been in use
for several decades.11 Natural toxins began being
recognized as potentially important indoor contaminants when, in
1994, a cluster of cases of acute pulmonary hemorrhage among infants
was linked to inhalation exposures to natural toxins produced by molds
that grow in chronically water-damaged environments.12
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One of the most important themes that emerged from these acute
epidemics of environmental diseases was that, unlike some other
specialty areas of pediatrics, in environmental pediatrics, treatment
of the individual patient is not sufficient; it is critical to identify
and eliminate the sources of exposure so that disease does not recur
in the known patients and so that additional cases do not occur.
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Most signs and symptoms of illnesses linked to environmental
contaminants are nonspecific and may occur only in association with
fairly high-level exposures. The signs and symptoms of high-level,
acute poisoning are relatively well-characterized for most chemicals.
In contrast, the effects of low-level, chronic, and mixed exposures
are poorly studied, particularly in infants and children. Establishing
the environmental cause of a given illness is further complicated
by the similarity of pollutant ...