ITD180
1.U5
1976
United States
Environmental Protection
Agency
Office of Public Affairs (A 1071
Washington, D C 20460
May 1976
Pollution
and
Your Health
OOOK76004
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There is no way lor society to avoid paying for
pollution. If we do not pay for prevention,
we pay in other ways—in lost recreational
uses of rivers and beaches, in higher treatment
costs for drinking water, in damage to crops,
forests and buildings and, most importantly,
through higher medical bills, time lost because
of illness, human suffering and premature deaths.
The Department of Health, Education and
Welfare puts the total national health bill at about
$120 billion a year, most of it for cure rather
than prevention. Yet there is an increasing body
of evidence and an impressive array of expert
opinion that we may be approaching the whole
question of human health from the wrong side—
that, as a matter of national policy as well as
personal practice, an ounce of prevention may
well be worth a pound of cure.
In the United States the once-dreaded infectious
diseases are controlled through sanitation, immu-
nization and antibiotics. Today we are plagued
with chronic diseases that an increasing number
of health experts believe are largely caused
by environmental factors—where we work or
live, our habits, diets or lifestyles. The more
sophisticated and sensitive our monitoring devices
become; the more data we accumulate on the
health effects of pollutants and other agents in ^
the environment: the worse things look. ^
be fought, not simply in the hospitals and doctors'
offices, but in our streets, homes and workplaces; .o
in our air and water; in our food and products; cj CD
and in our habits and lifestyles. Such a shift in •*- .fc **.
emphasis will require a searching re-examination >• ^ O
and radical revision of our popular understanding __ E O
of, and our public approach to, health care and •£? >, _§ ^
disease. If environmental disease is becoming cu cu ro co
"the disease of the century," as it appears to be, g 5 Q ^
then environmental protection must become the £? "^ -c :£
most important ingredient in any national health > ^ 5 ~
program. uj c ^ J?
Russell E. Train, C/5 JW O .1-
Administrator ^ £} g> -C
U.S. Environmental Protection Agency ^ O
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Introduction
T^he principal reason for controlling
•*- pollution is to protect human
health and the ecological integrity of
man's life-support systems. Innumer-
able other benefits can result from
clean-up measures—financial savings,
more efficient productivity, and esthetic
pleasure. But fundamentally, the con-
cern about environmental pollution is
its threat to human health and life.
We have been slow to recognize the
damage brought about by our activi-
ties, almost as slow as the appearances
of some environmental after-effects.
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The impact of environmental deterio-
ration on health is often subtle, be-
coming apparent only when correction
is not always possible. Frequently
the results of environmental contami-
nation become known so belatedly
that few people are likely to associate
the effect with its cause.
The long-delayed beginnings of ill-
nesses caused by pollution makes it
difficult for many people to compre-
hend the full impact environmental
degradation has on their health.
The complexities of modern life and
the many forms of environmental
pollution combine to make the task
of protecting public health a major
challenge.
While much is already known about
the health effects of some pollutants,
pollution's total impact is difficult to
measure. What each pollutant does
to a human depends on the physical
and chemical properties of the pollut-
ant; the length, intensity and method
of exposure; and an individual's ability
to tolerate the pollutant.
Pollutants reach people through vari-
ous avenues, each taking its unique
toll. But virtually all forms of pollution
harm people somehow. Some people
are especially susceptible to attack,
notably the very young, the old and
those weakened by disease. Since
resistance to pollution is an individual
trait governed by such factors as age,
heredity, general health, climate, occu-
pation, residence, smoking and dietary
habits, it is extremely difficult to assess
precisely the general effects upon a
large population.
Effective and at times stern decisions
must be made to solve obvious prob-
lems, even though we may not know
the full extent of the health threat.
There is no way to ascertain abso-
lutely the chronic effects of environ-
mental pollution. We cannot, for
instance, state unequivocally that the
continued accumulation of tiny
amounts of pesticides in the fatty
tissue of humans or other organisms,
is a direct cause of disease. Neither
can we prove that life is not altered
at all as a result. The field of environ-
mental health effects is one of cer-
tainties mixed with uncertainties.
But we must not suspend all
judgment while we argue about proof.
We know that environmental pollution
has significant adverse effects on the
physical and emotional health of
Americans.
The U.S. Environmental Protection
Agency (EPA) was created in De-
cember 1970 to consolidate, strength-
en and coordinate Federal efforts
to enhance human health and well-
being through environmental reha-
bilitation and protection. Since 1970
existing laws have been strengthened
and new laws enacted which give
EPA the mandate and the means
to accomplish these national goals.
Much has been accomplished in
recent years, but much more remains
to be done. As the costs of pollu-
tion control become more apparent,
it is important to remember that
the primary benefit—-good health—
is priceless.
This booklet is a general discussion
of possible threats to human health
posed by environmental pollution.
It presents some of the background
that must be considered as we try
to solve the problems of environ-
mental health risks.
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Air
Thirty air makes eyes water, burns
throats and stifles lungs. Fumes
of sulfur and nitrogen oxides, sulfuric
acid and photochemical oxidants
irritate the respiratory system
causing coughing, chest discomfort
and impaired breathing. When small
particles are breathed in along with
these fumes, the irritation—and
injury—may increase substantially.
Carbon monoxide interferes with the
ability of blood cells to carry oxygen.
Heart and nerve tissues are parti-
cularly susceptible to oxygen defi-
ciency, so that carbon monoxide
pollution can seriously impair coro-
nary and central nervous system
functions.
On Friday, December 5, 1952,
static weather conditions turned the
air of London, England, into a
deadly menace. A prolonged temper-
ature inversion held the city's air
close to the ground and an anti-
cyclonic high pressure system pre-
vented the formation of winds which
would have dispersed the pollutants
that were accumulating heavily at
ground level.
For five days the Greater London
area was blanketed in airborne muck.
Few realized it at the time, but there
were 4,000 more deaths than normal
for a five-day period, hospital ad-
missions were 48 percent higher and
sickness claims to the national health
insurance system were 108 percent
above average. Eighty-four percent
of those who died had pre-existing
heart or lung diseases. Hospital
admissions for respiratory illness in-
creased threefold and deaths due to
chronic respiratory disease increased
tenfold.
The same static atmospheric condi-
tions had caused a similar incident
in Donora, Pennsylvania, in 1948.
A town of only 14,000, it had 15
to 20 more deaths than normal
during the episode. More than 6,000
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of its residents were adversely af-
fected, 10 percent of them seriously.
Among those with pre-existing illnes-
ses, 88 percent of the asthmatics,
77 percent of those with heart
disease, and 79 percent of those with
chronic bronchitis and emphysema
were adversely affected. Allowing
for the great difference in population,
Donora paid a much higher price
for air pollution than London.
New York City has experienced
similar periods of atmospheric stag-
nation on numerous occasions
during the last 50 years. During one
such episode, in 1953, the city
reported more than 200 deaths above
normal. Birmingham, Alabama, is
another high-exposure area where
residents frequently have exhibited
a greater-than-avcrage incidence of
respiratory irritation symptoms, such
as coughing, burning throats or
lungs, and shortness of breath. EPA
monitoring studies indicated that
non-smokers in these two cities de-
veloped respiratory symptoms two
or three times more frequently than
non-smokers in cleaner communities.
Unfortunately, the climatic condi-
tions and human activities that
combine to form critical build-ups
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of pollutants are by no means un-
common in the United States. They
occur periodically in various parts
of the country and will continue to
threaten public health as long as air
pollutants are emitted into the at-
mosphere in amounts sufficient to
accumulate to dangerous levels.
Air pollution disasters such as these
are alarming. However, many people
are even more concerned about the
health effects of long-term exposure
to air pollution. While we have
learned a great deal in recent years
about the effects of air pollution,
we are still very far from being able
to assess accurately what low but
persistent levels of air pollution do
to human beings.
Emphysema and chronic bronchitis—•
the chronic obstructive lung diseases
—are two of the more significant
causes of disability compensated
by Social Security. Since these two
diseases are commonly responsible
for workdays lost to illness, chronic
disabilities and premature retire-
ments or deaths, they hurt the
Nation's physical health and its eco-
nomic well-being.
Aside from the question of whether
or not air pollution causes chronic
lung diseases, it certainly aggravates
their symptoms and increases the
frequency and severity of asthma
attacks. It also caused changes in
the heart and lung functions of
healthy people. Early childhood ex-
posure to heavy pollution is believed
to contribute significantly to a lowered
pulmonary reserve capacity in adults.
Children from high exposure areas
suffer a greater risk of developing
lung disease as adults than children
raised in cleaner communities. Statis-
tics also show that residents of com-
munities with persistently high
pollution levels have higher death
rates than residents of other com-
munities. Particulates and sulfur
oxides are not the only major classes
of pervasive pollutants. All kinds of
combustion produce nitrogen oxides
which have been associated with
increases in acute respiratory disease.
Carbon monoxide is still a problem
in today's heavy traffic. Inhalation of
carbon monoxide can impair a
driver's judgment and his ability to
respond rapidly in traffic. Further-
more, it can also impair vision,
produce headache, and exert a strain
on the heart.
There arc other air pollutants that
in minute amounts can cause severe
health effects. Each has its parti-
cular adverse characteristics which
place unique stress on human beings.
The total number of such pollutants
commonly found throughout the
country is not known but every year
thousands of new chemicals are intro-
duced into manufacturing processes
alone. It is impossible to discuss the
potential health effects of all likely
pollutants, so here are four examples
that suggest the kinds of health ef-
fect that may be involved.
Inhalation of asbestos fibers has
been related to asbestosis, broncho-
genie cancer, mesothelioma, and
other malignant diseases. Symptoms
of mesothelioma, for instance, de-
velop about 30 years after the initial
exposure to asbestos, and some phy-
sicians expect an increase in the
disease among persons who worked
in or near American shipyards during
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World War II. Asbestos is used in
many products and industrial opera-
tions.
Beryllium is a metal commonly used
in rocket fuels, missile guidance
systems, nuclear reactors and atomic
weapons. The most deleterious effect
of inhaled beryllium is a progressive
lung disease.
Mercury is commonly used in bat-
teries, mildew-proofing and the
manufacture of paint, pulp, and
paper. Airborne mercury can affect
the central nervous system and can
lead to weight loss, insomnia, tremors
and psychological disturbances.
Lead absorption is often prevalent
among preschool children in urban
areas. In the past, we attributed most
of the poisoning to eating lead-based
paint chipped from the walls of
older dwellings, but recent evidence
indicates that other environmental
lead sources are also contributing to
the problem. High concentrations
of lead in dust, soil and vegetation
near streets and highways clearly
can be attributed to lead emissions
from motor vehicles. Precipitation
samples from locations throughout the
United States show a positive corre-
lation between gasoline consumption
and the lead content of rain. People
who ingest excessive amounts of
lead may show neurological impair-
ment such as seizures, mental re-
tardation and behavioral disorders.
Ordinarily we all accumulate lead in
our bodies, but urban residents
usually have higher average blood
levels of lead than rural residents.
Children and the newborn may be
particularly susceptible to lead damage
of the central nervous system.
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Water
"pifty years ago, the United States
was plagued by massive outbreaks
of typhoid, cholera, dysentery and
other water-borne diseases. Better
treatment of sewage and drinking
water have largely eliminated these
epidemics. As a result, Americans
have long considered safe drinking
water as a natural heritage. We have
accepted it much as we regarded
the air we breathe—unlimited, free
and clean. But, like air, water is
not limitless, nor free, nor some-
how immune to the pollution which
affects other aspects of our environ-
ment.
Between 1961 and 1973, there were
more than 200 known or reported
outbreaks of disease or poisoning
caused by contaminated drinking
water. Twenty-two people died and
nearly 55,000 became ill, many of
them seriously. And some EPA water
supply experts believe that perhaps
ten times as many such incidents
occur but go unreported for a variety
of reasons and that countless indi-
vidual sufferers—and their doctors
—fail to associate ailments with
contaminated water.
A 1970 survey of 969 public water
supply systems disclosed that 56 per-
cent had facility deficiencies relating
to equipment design, construction
or plant condition; 77 percent of the
plant operators were inadequately
trained in microbiology and 46
percent were deficient in the chem-
istry relating to their assignments;
and 79 percent of the systems had
not been inspected by State or county
authorities during the preceding
year.
Sources of water pollution are
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innumerable. Major sources can be
found in nearly every kind of in-
dustrial, municipal or agricultural
operation. There arc thousands of
toxic chemical compounds in use
today and new chemicals are being
developed every year. Chemical con-
taminants, such as phosphates, ni-
trates, pesticides, detergents, trace
amounts of metals, acid from mine
drainage, cyanide, phenols, radioactive
substances, solvents, and hydro-
carbons, are all products of our
technological society and potential
threats to our water sources.
A 1975 EPA survey of drinking
water supplies in 80 cities found that
small quantities of organic chemicals
were present in public water supply
systems throughout the country. Some
of these were suspected cancer-
causing chemicals, if taken in large
amounts. Although the survey found
very low concentrations of them in
the water, their presence is cause
for concern.
Water supply intakes are also
jeopardized from time to time by
spills of oil and hazardous materials.
Such spills in estuaries often make
fish and shellfish unsuitable for food.
Oil in water is known to concentrate
fat-soluble poisons, such as insecti-
cides and certain chemicals, many
times higher than would normally
occur in water alone. In this way,
oil spilled into water can permit
highly destructive amounts of pol-
lutants to be ingested by organisms
in man's food chain.
The widespread use of high-nitrate
fertilizers and extensive feedlot
operations have resulted in an in-
creased contamination of both sur-
face and ground waters with nitrates.
As a result, the nitrate content of
much of our ground water now
exceeds the drinking water standard.
This is highly significant because
once an underground water supply
source becomes contaminated, it is
virtually impossible to purify. In-
fants up to three months old run the
principal risk of damage from
drinking water having a high nitrate
content—damage that includes a
blood disease that is fatal if not
properly treated.
Sodium levels also have been rising
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Solid Wastes
in American waters. Increased sodium
intake from polluted water, for those
who are susceptible, can put a strain
on the heart and aggravate
cardiovascular (heart and blood
vessel) disease. The corrosiveness of
water is also linked, statistically, with
deaths due to cardiovascular diseases.
Water that corrodes pipes causes
metals to be swallowed by people
drinking the water. Comparatively
little is known about the effect on
human health of ingesting these
metals.
Sewage discharges can also
contaminate surface waters with
harmful bacteria and viruses. Water-
borne viruses still cause infectious
hepatitis in this country and may be
causing some gastroenteritis and
salmonellosis. Most hepatitis
outbreaks from public supplies occur
after the water is purified, and result
from contamination of the distribution
system due to mechanical
inadequacies. Many of our recreational
waters, too, are unsafe because of
high bacteria counts from sewage
discharges.
Mismanaged water resources can
deteriorate into swamps and stagnant
areas that foster the growth of
mosquitoes and insects. In the United
States, mosquitoes still transmit
disease. Encephalitis has occurred in
epidemic form, reaching a median of
1,340 reported cases a week during
the years 1969-73.
"C nvironmental health cannot be
compartmentalized. Nowhere is
this more evident than in the area of
solid waste management. There are
only three places to put our wastes:
the Earth, its waters, or its atmosphere.
The use or misuse of any one is
inextricably bound up with the other
two. Restrictions on using one medium
almost invariably lead to increased
burdens on—and frequently to abuse
of—others. Certainly, improper
management of solid wastes on land
creates health hazards from both air
and water pollution. For example,
water picks up foreign matters as it
trickles down through open dumps or
improperly designed landfills and
pollutes ground or surface waters;
open burning of solid wastes and
faulty incineration contribute to air
pollution.
Conversely and somewhat
paradoxically, what may be counted
as successes for air and water
pollution control programs may
actually aggravate the public health
problems of solid waste management.
For example, effective waste water
treatment plants produce solid
sludges, which must be disposed of.
A ban on home incinerators or open
burning of yard debris immediately
results in a greater burden on the
solid waste collection, processing, and
disposal system. And as land disposal
activities are upgraded, some coastal
communities look to the sea for
ultimate disposal of their solid wastes.
Management of solid wastes, clearly,
is a root environmental issue with
profound public health implications.
Perhaps the most obvious health
aspect of waste management is the
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adverse effect of hazardous wastes—
that is, wastes that are toxic, corrosive,
flammable, or explosive. These wastes,
whether solid, liquid, or sludge, have
a unique potential for affecting public
health and the environment. Some are
hazardous to human health; others
adversely affect desirable plants and
animals, and, indirectly, man. They
require special care in all aspects of
their storage, collection, processing,
and disposal.
Less obvious, though nonetheless
important, are the adverse health
impacts associated with seemingly
"nonhazardous" wastes. The
relationship between public health
and improper storage and disposal of
solid wastes has long been recognized.
Rats, flics, and other disease carriers
breed in open dumps and in
residential areas where food and
shelter are available. Many fires begin
or are spread by improperly stored
trash. Drinking water sources can be
contaminated by leaching from dumps
and poorly designed landfills. Among
the diseases that have been directly
or indirectly associated with the open
dump are typhoid fever, cholera,
dysentery, anthrax, trachoma, and
trichinosis. And there are still
thousands of open dumps operating
in various parts of the country.
Modern food-production and
marketing techniques have created
new potential health hazards.
Livestock and poultry production in
the United States is commonly
concentrated in large-scale,
confinement-type operations. These
large concentrations of animals have
greatly magnified the problem of
managing wastes in a way that will
minimize health hazards. Among the
serious health-related effects possible
in feedlot operations are the wholesale
reproduction of flies and the
contamination of water.
The basic health and environmental
problems associated with solid waste
management are exacerbated by a
number of factors related to our social
and economic structures, institutions,
and attitudes. One result is the
incquitability of health impacts on
different population groups in the
United States. The poor are most
likely to suffer ill effects from
unsanitary storage and inadequate
waste collection.
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Noise
"VToisc is perhaps the most overlooked
and underestimated form of
environmental pollution. This is partly
true because noise has long been
regarded as an inevitable
accompaniment to modern life. The
clamor of machinery and tools, the
roar of aircraft and automobiles, the
racket of appliances—all have been
considered to be the sounds of
progress. We have accepted the noise
and adjusted to it, without fully
recognizing its health effects.
It is known that continued exposure
to high noise levels results in hearing
loss. Some 16 million Americans, in
fact, suffer some hearing loss because
of noise. Studies show that high noise
levels detrimentally affect work
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performance, cause accidents and
foster absenteeism in industry.
Perhaps the most serious concern of
noise pollution is that it diminishes the
quality of life. People, especially
urban dwellers, are bombarded daily
by the clamor of construction
equipment and the roar of traffic. The
home is no longer a silent refuge. It
reverberates with the cacophony of
kitchen appliances, vacuum cleaners,
power mowers, radios and television
sets. At the very least such noise
disturbs sleep, interrupts concentration
and conversation, and jangles the
nerves. More serious, though, is a
buildup of stress which can lead to
ulcers, gastrointestinal problems and
heart disease.
Pollution on the job
Pollution: a spreading pall of black
smoke; scum-coated water; blue-grey
smog- These are familiar pollution
images. But the environment is more
than the sky, a river or a forest. It
is also the places where people work.
And too many Americans today work
in environments which are not
healthy. The National Institute for
Occupational Safety and Health esti-
mates that as many as 100,000
American workers may die each year
from conditions they are exposed to
in their jobs. Environmental standards
for workplaces are being developed
and enforced by the Department of
Labor.
As of June 1975, the National Cancer
Institute had confirmed 27 cases of
liver angiosarcoma among workers
with a history of exposure to vinyl
chloride, a major compound used in
making plastics. Angiosarcoma of the
liver is a rare form of cancer. An
American Cancer Society survey re-
corded only one case per 78,000
deaths. This indicates that workers
exposed to vinyl chloride are 3,000
times more likely to develop this
disease than the general public. The
Department of Labor has adopted
vinyl chloride exposure standards to
protect workers within a plant and
EPA has proposed standards to pro-
tect the general public from atmos-
pheric exposures that result from
vapors being released by these plants.
At a small plant manufacturing the
pesticide Kepone, about 70 employees,
out of a total workforce of 150
during 16 months of operation, were
sickened with tremors, memory loss,
nerve damage, blurred vision, erratic
eye movements, chest pains and, in
some cases, at least temporary ster-
ility.
Among the pollutants that attack
workers are coal dust, asbestos fibers,
lead particles, uranium radiation,
chemical fumes, deafening noise,
pesticides, and glass fibers. There is
usually a long latency period—per-
haps as much as 30 years—between
the first exposure to dangerous en-
vironmental pollutants and the oc-
curence of disease. So it may be
decades before we will know how
much harm pollutants in the work-
place are doing to the Nation's
health.
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Pesticides
Tn contrast to most other contami-
•*• nants, pesticides are deliberately
introduced into the environment as a
killing agent to perform various
beneficial functions. Improved
agricultural production, control of
dangerous insect-borne diseases such
as malaria, and greater sanitation in
homes and recreation areas are only a
few of the many ways pesticides
benefit human health.
Widespread pesticide use has,
however, also been accompanied by
serious problems for man and his
environment. It is presently known
that many pesticides at various
exposure levels will cause illness.
Some highly toxic chemicals, such as
parathion, can cause serious illness or
even death if only one drop of the
concentrated substances touches the
skin.
Reactions to pesticide exposure vary
greatly. They include damage to the
central nervous system, respiratory
and digestive tracts, skin, eyes,
mucous membranes, visceral organs,
and the mind. Every year a number of
persons are killed and still more are
made seriously ill by pesticides.
Improper application because of
failure to follow instructions on
pesticide labels or ignorance of
pesticide hazards causes most of these
incidents.
While we are well aware of the
immediate hazards, we do not know
enough about the long-range effects
on human health resulting from our
increasingly widespread exposure to
pesticides. Among the pesticide
characteristics which contribute to this
diffuse exposure are mobility,
persistence, and bioaccumulation.
Pesticides can be transported great
distances by air and water.
Measurable levels of DDT, for
example, have been found in
Antarctic penguins, although the
animals have never been directly
exposed to the compound. Some
pesticides do not break down readily.
Thus, they remain in the environment
for very long periods and can move
up the food chain through the process
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Radiation
of bioaccumulation. In other words,
minute quantities of chemicals
absorbed by plankton and insects arc
transferred, in constantly increasing
concentrations, up the food chain to
fish, birds, other higher animals and
man. These chemicals are stored in
body fat and tissues where they may
remain for many years.
Scientific experiments indicate that
some pesticides have caused
malformations in the developing
embryos of test animals and that other
pesticides may cause cancer in certain
species. While there is no direct
evidence linking pesticide residue to
similar health effects in man, the
potential for long-term effects on large
numbers of people cannot be
discounted.
The nervous system —
is it affected?
Beyond the physical waste, environ-
mental pollution may have a more
profound effect on man: on mental
health, for example. Most lead poison-
ing causes behavioral difficulties, per-
ceptual disabilities, and emotional
instability. Mercury poisoning causes
emotional instability, tremors, fatigue,
dizziness, memory and speech diffi-
culties, and headaches. Carbon mo-
noxide poisoning causes apathy,
psychological tiredness, headaches,
temporal-spatial disonentation, re-
tardation, and psychosis. Psychologi-
cal impairment following exposure to
pesticides has been discussed else-
where, and a number of studies have
linked excessive noise to higher mental
hospital admissions as well as to
other psychological disturbances.
Tncrcasing man-made radiation also
poses a danger to our health. The
principal adverse effects that radiation
can have on human health are genetic
disturbances and cancer. Apparently,
some body tissues are particularly
vulnerable to irradiation, notably the
blood-forming organs, thyroid, bone
marrow, breast, lung and reproductive
organs. The young, particularly, the
unborn, are most susceptible to
radiation damage.
We all receive radiation from natural
sources over which we have little
control. Our remaining exposure comes
from medical and dental X-ray
machines; fallout from nuclear
weapons testing; uranium mines, mills
and fabrication plants; nuclear power
generating and fuel-reprocessing
installations; and various electronic
devices. Many hospitals and
laboratories commonly use radioactive
isotopes in basic research and patient
diagnosis and treatment. And
construction materials with radioactive
properties have been used for homes,
schools, factories and other structures.
In Tennessee, cement blocks arc
often made of Conasauga shale, which
contains high concentrations of
thorium and in Florida blocks are
sometimes made of phosphate rock,
which contains high concentrations of
radium. In buildings constructed of
these materials, radioactive gases seep
out of the blocks and accumulate in
the ambient air. Granite, too,
frequently emits gamma radiation.
Despite this variety of sources, man's
exposure to radiation thus far has
been quite low. Nevertheless we know
very little about the long-term effects
of repeated exposure to radiation at
low levels. One major hazard is
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damage to or alteration of human
genes, since natural background
radiation is believed to be one of the
causes of natural mutation. It is
generally accepted that any amount
of radiation, however small, can
cause damage to genetic cells and
hence cause an indeterminate number
of undesirable mutations. Such genetic
damage is believed to be cumulative.
Also, it is generally accepted that any
increase in radiation exposure can
cause increases in the frequency of
many cancers.
nvironmenta! Protection Agilicy
V, Library
outh Dearborn Street
go, Illinois 60604
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Carginogens,
Teratogens,
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Carginogens,
Teratogens,
Mutagens
These three terms have become more
familiar to many Americans as we
have become more aware of the
perils of environmental pollution.
Carcinogens arc substances that
cause cancer. Teratogens cause birth
defects. Mutagens cause hereditary
changes thai may be passed from one
generation to another
Carcinogens
The effect of carcinogens on human
tissue (if exposure is sufficient) is
generally irreversible. Incidences of
cancer today may reflect an exposure
many years ago. Similarly, carcino-
genic contaminants added to the
environment today may not reveal
their damage until many years from
now.
Cancer is not one disease. It is at
least one hundred diseases that in-
volve derangement in body cells.
Many cancers are self-inflicted by
habits such as smoking, overeating,
overdrinking and sunbathing.
Carcinogens that produce cancer in
experimental animals are found in
low concentrations in food. Others,
such as some air and water pollutants,
certain pesticides and food additives,
are everywhere. Not only are we
ignorant of the carcinogenic potential
of many substances repeatedly intro-
duced into the environment, but we
also do not know much about the
synergistic effects of two or more
carcinogens or even a single carcino-
gen in combination with various pro-
moting agents or other chemicals. It
is not widely appreciated that a com-
bination of pollutants can be more
damaging than the sum of their
separate effects. Many substances,
which are not carcinogenic by them-
selves, interact with other substances
to promote the development of cancer.
Cancer has been a major cause of
death in the United States since 1900.
In this century there has been an
absolute increase in cancer deaths
which cannot be explained as a re-
sult of either the increase or aging of
the population. On the average,
cancer deaths have increased by about
one percent per year since 1933.
Cancer of the respiratory tract has
shown the most rapid increase ever re-
corded for a non-infectious disease,1800
percent during the past 40 years. And
the death rate from lung cancer for
urban residents is twice the rural
rate, even after allowing for smoking
habits. In the vast majority of cases,
pollution in urban areas exceeds the
levels in less populated regions.
Numerous environmental pollutants
are not only carcinogenic but tera-
togenic and mutagenic as well. Tera-
togens may cause monstrous deformi-
ties. Congenital defects account for
14 percent of all infant deaths and
are the third most common explana-
tion for deaths in the newborn. Many
substances induce abnormalties in a
fetus at levels below those needed to
make the mother ill. Methylmercury,
for example, affects prenatal develop-
ment; children born to mothers who
have eaten food contaminated by it
frequently exhibit a disorder resem-
bling cerebral palsy. One of the most
disquieting aspects of teratogens is
that their potential for destruction has
rarely been known in advance. X-rays,
German measles, mercury, thalido-
mide—all extracted costly tolls before
their teratogenic features were recog-
nized.
Mutagens
Mutagens result in transmissible
changes that affect potential offspring.
If a pollutant damages a cell while
its capacity for division remains un-
impaired, the result may be defects
among future generations.
Many chemicals which pollute the en-
vironment are mutagenic in large
doses. But we do not know whether
these chemicals are mutagenic haz-
ards at the levels they presently
appear in the environment.
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