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ENVIRONMENTAL RISK; YOUR GUIDE TO
ANALYZING AND REDUCING RISK
People incur a certain amount of risk every
day. Whether they drive a car, cross a street,
use a knife, or varnish a piece of furniture,
they put themselves in a potentially risky
situation.
Risk is defined as the probability* of
injury, disease, or death under specific
circumstances. All human activities carry
some degree of risk.
Environmental risk is the risk associated
with the likelihood or probability that a
given chemical exposure or series of expo-
sures may damage human health. Environ-
mental risk takes two factors into
account: the amount of a chemical present
and its relation to the amount the exposed
person can tolerate. Each person reacts to
risk situations differently, both physically
and mentally.
*Words in bold are defined in the glossary
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HISTORY
Managing environmental risk is an endless and challenging
task of Government agencies, especially of the United States
Environmental Protection Agency (EPA). Government
agencies became heavily involved in risk management after
World War II, when production of industrial chemicals
surged without a complete understanding of their effects on
people and ecosystems. Two other important events con-
tributed to the growing awareness of risk: the focus of public
attention on specific chemicals, or classes of chemicals (such
as pesticides and asbestos) and the realization that people
were potentially exposed to them not only in one area but
worldwide. Epidemiologists (scientists who study the
spreading of diseases in a human population) also discovered
that some types of cancer were related to environmental
pollution.
It is very difficult to come up with the precise risk associ-
ated with toxic chemicals. With certain types of chemicals,
when someone is exposed to a high level, that person imme-
diately experiences some form of injury, perhaps even death.
This makes it easy for epidemiologists to determine the
cause. However, there are instances of everyday environ-
mental threats for which there are no immediate observable
forms of injury or disease. For example, a person who has
smoked heavily for 20 years may contract cancer only years
later. It is known that the more cigarettes you smoke, the
greater your chances or risk of developing lung or other forms
of cancer. The risk may not be obvious to smokers because
sometimes it takes years for cancer to develop.
The public seeks and deserves information on the safe
levels of toxicants in foods, water, or air. The term "safe" in
common usage means "without risk." However, scientifically
speaking, there is no definite way to determine the condi-
tions under which a given chemical exposure is likely to be
absolutely without risk. That is where the science of risk
assessment comes into play. It would be ideal if EPA could
guarantee "zero risk" for a certain chemial, but that is often
not possible to achieve without prohibiting all uses of the
chemical. Science can, however, describe the conditions un-
der which risks are so low that they are generally considered
to be of no practical consequence. Informing the public as to
which chemicals or technologies are hazardous is a realistic
goal of EPA.
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RISK CONCEPTS
Since the early 1970's, one of EPA's goals has been to re-
duce risks to human health and the environment caused by
toxic substances. Through risk assessment, EPAidentifies the
most serious risks by determining the size of the risk and the
number of people or wildlife exposed. EPA then develops
regulatory procedures to lower these risks to acceptable
levels. If chemical A poses 1,000 times more risk to people
than chemical B, chemical A will have greater priority for
regulatory action than chemical B. This does not mean that
EPA ignores chemical B — only that EPA believes it to be
more important to reduce risks from chemical A first.
You will often hear the words chronic v. acute associated
with risk. An acute health risk is a risk which is currently
dangerous and needs to be dealt with immediately, some-
times within hours or days. A chronic health risk may persist
for a long time without showing any significant effect. Take
suntanning. It poses an acute health risk when a person is out
in the sun all day and develops a painful sunburn. Remedies
applied in the short run may consist of a lotion or aloe to ease
the pain or heal the blisters. In contrast, suntanning can pose
a chronic health risk if a person sunbathes frequently over
many years. Such a person may never experience acute
sunburn, but may have an increased chronic risk of develop-
ing skin cancer later in life.
Dose and response are usually used together in deter-
mining risk. Dose refers to the amount of a certain chemical
to which someone is exposed. Response refers to a person's
reaction to that exposure.
Certain scientific terms of measurement are used to de-
scribe risk after it is assessed. Scientists may come up with
a figure like 1 x 10"5(0.00001) after they assess the risk of a
pesticide used on certain fruits and vegetables. It means that
one person in a 100,000 people who eat the food sprayed with
that pesticide may contract cancer. The use of these numbers
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represents a method that EPA uses to express the risk in
terms of human health.
Another common term the Government uses is parts per
million (ppm). For instance, there may be 1 ppm of a chemical
in a pesticide that is sprayed on crops. To put this unit of
measurement in perspective, one part per million is equiva-
lent to one facial tissue in a stack taller than the Empire State
Building.
NEED FOR RISK ASSESSMENT
Because "zero risk" does not exist in the environment, both
the EPA and the public need to manage the threats that
chemicals introduce. First, the risk to the community has to
be determined so that management decisions can be made.
Regulatory actions differ, depending upon the particular law
that Congress has passed. For example, the Federal Insecti-
cide, Fungicide, and Rodenticide Act (FIFRA), which governs
EPA's regulation of pesticides, is often called the balancing
statute because it requires EPA, when making regulatory
decisions, to weigh the risk of pesticides against their possible
economic and social benefits.
FIFRA offers EPA many risk management options to
reduce risks wherever possible — without doing away with
the benefits of a pesticide. For example, depending on the
nature of EPA concerns, such options might include: requir-
ing protective clothing or equipment to minimize risks to
pesticide applicators, reducing the rate or frequency of appli-
cation to lower pesticide residue levels on harvested crops, or
imposing national or regional restrictions against using a
pesticide in areas where it could contaminate ground
water.
FIFRA also gives EPA the authority to cancel a pesticide or
issue an emergency suspension. Strong evidence is needed
for such an action and it clearly represents a challenging risk
management situation. Making decisions on the regulation
of pesticides is just one example of the risk management
process at EPA. However, before any decision is made, EPA
needs to assess the risk involved. The next section describes
the risk assessment process.
RISK ASSESSMENT
According to the National Academy of Sciences, risk
assessment is a scientific activity that evaluates the toxic
properties of a chemical and the conditions of human expo-
sure to it. It determines the likelihood of harmful exposure
and characterizes the nature of the effects people may expe-
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rience. In essence, by assessing the risk of a chemical, EPA
can quantify the degree of hazard to which people might be
exposed.
There are four parts to every risk assessment:
Assess
Hazard Hazard identification is a process where potential toxic
Identification effects are determined. Scientists gather and evaluate data
on the types of injury or disease that may be caused by a
chemical. They also determine what happens to the chemical
once it enters the body.
Dose- Evaluating dose and response (amount and reaction) is the
Response second step. Scientists evaluate the relationship between the
Evaluation amount of exposure to a substance and the extent of toxic
injury or disease it causes. The information comes from
either animal data or, less frequently, from studies of human
exposure. In basic terms, it is the amount of a chemical taken
in and how the system reacts to it. The dose-response rela-
tionship needs to be put in numerical terms, such as one in a
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million (I x 106) or 0.000001, so that the risk associated with
a specific substance can he compared to other similar studies.
For instance, once the pollutant's hazards have been iden-
tified, the scientist looks at studies evaluating how much of
a chemical in drinking water people can ingest before it
produces an adverse response in their bodies. Scientists try
to come up with the dose-response relationship that is most
protective of human health.
Human In step three, scientists analyze the exposed population.
Exposure They determine the number of those exposed and their ages.
Evaluation They look at the amount and the length of exposure to a toxic
chemical. The evaluation could be based on past, present, or
future exposure.
In the example using drinking water, the population that
drinks the water would be evaluated, so that scientists could
have a clear picture of who was actually exposed to the
chemicals in the water. How much water do people drink each
day? Knowing such information makes it easier to assess the
risks. Sometimes, when no exposure data are available,
scientists must use assumptions to make estimates.
Risk Risk characterization is the final step of risk assessment.
Character- It brings together the results of the first three steps, then
ization determines the likelihood that people will experience any of
the various forms of toxicity associated with a substance.
In the drinking water example, to come up with a risk
characterization, the potential toxins in water are deter-
mined (hazard identification), the amount of water a person
can ingest without having adverse health effects is calculated
(dose-response), and the age and type of person involved is
examined (human exposure). An alternative to this process is
to perform health studies on exposed people.
RISK MANAGEMENT
Once a risk has been characterized, it must be properly
managed. First, EPA must decide if a situation is risky enough
to present a public-health concern. If it is, the risk has to be
controlled. In the drinking-water example, determining
whether the risk is acute or chronic will determine whether
the community will be advised to start using bottled water
instead of tap water, or to keep watching health advisories for
further directions. Several factors are considered in deciding
how to best manage a previously assessed risk:
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Magnitude The magnitude, or size, of the risk has a direct bearing on
of the risk how rapidly the risk will be managed. Lifetime cancer risks
greater than one in a hundred thousand (10"s), or one in ten
thousand (10~4) are generally unacceptable. In most cases,
when risks exceed these levels, EPA will take action to reduce
these risks unless severe technical or economic constraints
are present.
Social EPA must often determine how a risk management deci-
Concerns si°n will affect society. Will people lose jobs or be required to
move? Will the decision disrupt personal lifestyles and com-
munity life? The EPA, as a protective agency, considers
societal concerns and, particularly, impacts to communities
before it takes action on risk assessment information.
Technical EPA must assess whether it is technically and economi-
and cally possible to reduce risks. Can industry keep up with the
Economic innovations needed to continually manage a risky situation?
Constraints Does such technology exist, to begin with?
RISK COMMUNICATION
The third part of dealing with risk is risk communication.
Once the risk has been assessed and the methods to manage
it have been chosen, EPA must communicate the findings in
a way that everyone involved will understand.
The key to communicating any risk situation successfully
is realizing that each person reacts to the situation differ-
ently. In fact, different publics even define the word "risk"
differently. In a community, "publics" include parents, chil-
dren, politicians, economic experts, scientists, and even
employees who work at a plant that may be causing environ-
mental problems in the community.
An employee may look at the risk of being unemployed as
greater than the risk of chemical exposure. A parent may
view any risk to children, no matter how small, with out-
rage. EPA tries to take into account these different risk
perceptions. To the Government scientist, risk means haz-
ards presented by a chemical or a situation. Some social
scientists have defined risk perception as hazard plus out-
rage.
Scholars who study the way people understand risk have
focused on how the public reacts to risk situations. They can
then guide experts and Government decision-makers in the
process of making risk management and communication
decisions.
Studies have shown that a voluntary risk is much more
acceptable to people than an involuntary risk. People are
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willing to engage in voluntary risks. People feel safer when
they are in control of a situation. Most people view driving a
car as a safer activity than being a passenger in a plane, even
though the risk of dying in a car crash is 1 in 100 in a
lifetime...and less than 1 in a 1,000,000 in an airplane.
REDUCING ENVIRONMENTAL RISKS
We are all concerned about reducing our risks. EPA and other
organizations have evaluated environmental risks and have
ranked them on the basis of magnitude.
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Since cancer is of great concern to people, shown below are
various cancer risks from environmental agents:
Cancer-Causing Approximate Lifetime
Agents or Situations Risk of Cancer
, jt;. Exposure to the wat ,'.: /;. '
'.' '\ {skiix cancer); •; '- '.. •••-••
-' +• •On^szttcikii£gacpack 0^ •
' * ; ' .nioi*e 'pfeit day/ + +. <• \ ' '
B, ; Natural radon in in^qor
;-:. : airaihoitte ^ -;•"•.:••'. /'
4. : Oiitside f aeaaiten (radon
6< . jftersffltts, in twad with ft . .
6. Human-made chemicals
,. in indoor air at home
;;. •' industrialized areas - ,
-^, Human-made chemicals ,
;!;'•*• in drinking water*: '. , •"
0. Hwman'-niadie chemicals
..: r. * ; (a) ^QZ; of pi^antitbutter ,
/ ;',per,weefe (n?i|iKPally .,-;•*
*' ', 'pVesent);;. -.'-. t .<' "j';-.*'
. ', (3&) oiie meal per yeaiof
'..".- small Lake Michigan
'•-':;•;"; trout'.-" . ••'• ,:' .* .: • .,"
10. Chemical exposure at ,.•
! most uncontrolled , . '
• 1- .: hazardous waste sites :
£fe;S^$;
;• rin'100- '_,'". . "' • t': ,
i:«il,QOO ;
,; 7 in 10,000 , / .; „
2inlO,000 !
! iinlO.OOO .
1 in 100,000 dr less , i
,8 in 100,000 /;
1 in 10,000 W ,
-^:^000^;^:-;-::\-;.
* Some chlorinated waters may have slightly higher
risks. Chlorination is used to destroy disease-causing
organisms often found in drinking water.
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As you can see from the chart, the greatest risk of contracting
cancer is from exposure to the sun. Although most skin
cancers are not fatal, one type of skin cancer, called mela-
noma, yields a high risk of 2 in 1,000. This means that if
1,000 people are exposed, 2 may die of skin cancer over their
lifetime. Doctors now strongly recommend using protective
clothing and sunblocking agents to reduce the risk of skin
cancer. It is most important to avoid a sunburn because even
a single sunburn in one's lifetime may cause serious, and
often fatal, forms of skin cancer.
Smoking cigarettes over a lifetime yields a voluntary risk
of 8 in 100 of contracting cancer. The most common form of
cancer from cigarettes, lung cancer, is not readily curable. It
is important to note that nonsmokers, in the presence of
smokers, also experience a very high risk of cancer — 7 in
1,000, or only about 10 times less than the smoker. Quitting
smoking not only reduces the risks to smokers, but also to
those around them.
An extremely high risk of cancer (an average of 1 in 100)
results from naturally occuring radiation, in the form of
10
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radon in the home. It is estimated that 4,000- 5,000 deaths per
year occur in the Great Lakes Region (Illinois, Indiana,
Michigan, Minnesota, Ohio, and Wisconsin) due to radon
exposure in homes. EPA has frequently recommended that
people test their homes for radon, but less than 5 percent
have done so nationally. Yet exposure to radon, like smoking
cigarettes, is known to cause lung cancer.
Studies show that people are less concerned about natural
risks, such as radon, than they are about unfamiliar risks,
such as living near an uncontrolled hazardous waste site.
Most hazardous waste sites before cleanup pose cancer risks
ranging from one in a million to one in ten thousand—or 100
to 10,000 times less than posed by radon in homes. But people
are far more concerned about getting cancer from hazardous
waste sites, even if cancer risks are as small as one in a
million. The hazardous waste site is human-made, less un-
derstood, and is therefore perceived to be more threatening
than radon in homes. However, radon in homes presents afar
greater danger than most hazardous waste sites. Fortu-
nately, simple measures exist to reduce radon. EPA encour-
ages homeowners to test their homes and, if necessary, take
steps to reduce radon. (For more information write to:
Radon Publication Coordinator, EPA Region 5, 77 West
Jackson Blvd., Chicago, IL 60604).
Researchers have shown that the indoor air in homes has
chemicals other than radon with the potential to cause
cancer. Some of these human-made chemicals found include
solvents in paints, cleaning agents, and pesticides. EPA has
found that indoor air cancer risks from these chemicals (2 in
10,000) generally are greater than risks from cancer-causing
agents found outdoors in heavily industrialized areas (1 in
10,000). This was an unexpected finding.
You can reduce your exposure to cancer-causing agents in
the home by minimizing your use of solvents, cleaning prod-
ucts, or deodorizers containing chloroform, trichlorethylene,
tetrachloroethylene, benzene, and dichlorobenzene.
If you are using chemicals to strip wood, you should use
protective gloves, good ventilation or a carbon respirator to
protect yourself from these chemicals. If you use pesticides
in and around your home, or have them applied profession-
ally, ask if they cause cancer or have other serious toxic
effects. As a general rule, pesticides should be used only if
absolutely needed.
Homes may also contain formaldehyde as a component of
glue in wood paneling or in insulation (urea-formaldehyde
foam). Find out if wood paneling contains formaldehyde,
particularly if you plan to use a great deal of paneling in your
home. Also, before you buy or sell a home, find out if urea-
formaldehyde insulation foam is present. If so, you may wish
to test the air for formaldehyde.
11
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home. Also, before you buy or sell a home, find out if urea-
formaldehyde insulation foam is present. If so, you may wish
to test the air for formaldehyde.
Asbestos is also a known human lung carcinogen and you
should know if your home contains asbestos. Asbestos in
homes is most often found in insulation for hot water pipes or
furnaces. Asbestos poses a danger when the fibers are loose
or crumbling. To determine if material contains asbestos,
send a bulk sample to a laboratory. But be careful not to
disturb the suspected material when collecting a sample. Do
not try to remove asbestos yourself; there are licensed asbes-
tos contractors for that. A list of approved laboratories and
contractors is available from your EPA office at the address
for radon publications on page 11. Cancer risks from human-
made chemicals in drinking water and in foods are generally
low. You can reduce both human-made and natural cancer-
causing chemicals in your diet by eating foods low in fat. A
diet high in fiber reduces the chances of colon cancer, a
leading form of cancer. Washing or peeling fruits and vege-
tables will help remove traces of pesticides.
There are also significant noncancer environmental risks
that we often do not think about. The risk of death from a fall
in your lifetime is 4 in 1,000; from drowning, 3 in 1,000; from
fire, 2 in 1,000; and, electrocution 4 in 10,000. Numerous
safety measures exist which, if used, will reduce these other
risks, too.
RISKS TO ECOSYSTEMS
EPA is also concerned about risks to wildlife and to the many
complex and diverse ecosystems. Recently, in an EPA Region
5 project comparing these risks to the environment, several
problems were found to cause significant risks to ecosystems.
For example, physical destruction of terrestrial and aquatic
ecosystems caused by certain types of agriculture, forestry,
and urbanization is a major stress on the environment.
Pesticides and other chemicals were also found to have
undesirable risks to wildlife. In addition, very significant
potential risks to animal and plant life, including agricul-
ture, may result from global warming, stratospheric ozone
depletion, and accidents involving chemical or nuclear mate-
rials.
To prevent present and future damage to ecosystems to
which we are directly dependent, EPA believes additional
environmental protection measures are needed. Similar con-
clusions regardingthe need to protect ecosystems were reached
in September 1990, by the Science Advisory Board, an in-
dependent advisory group to EPA.
12
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RISK COMPARISONS
dependent advisory group to EPA.
If you wish to obtain more information on comparative
human health and ecological risks, you can contact the EPA
and ask for the following reports:
"A Risk Analysis of Twenty-six Environmental Problems,"
U.S. EPA Region 5,1991.
Reducing Risk: "Setting Priorities and Strategies for En-
vironmental Protection," U.S. EPA, Science Advisory Board,
Washington, DC, September 1990.
WHAT EPA IS DOING...
In addition to the pollution control activities of EPA's air,
water, and land programs, EPA Region 5 has created a new,
centralized office for handling risk assessment activities —
the Office of Health and Environmental Assessment (OHEA).
Its main functions are:
• to communicate environmental and human health risks
to the public and the media;
• to establish priorities for assessing and reducing risk to
human health;
• to provide other EPA staff with technical assistance,
advice, and direction on health and environmental matters;
and,
• to expand and enhance risk assessment and communi-
cation expertise within the Region by conducting risk-train-
ing courses.
WHAT YOU CAN DO
• Reduce personal risk through some of the suggestions in
this brochure.
• Take an active role in community meetings that involve
environmental activities.
• Work with local environmental agencies on issues that
may pose environmental risk.
• Make an effort to learn more about the risk assessment
and risk management process by requesting EPA employees
to come and speak to your community.
• Contact EPA Region 5 at:
77 West Jackson Blvd.
Chicago, IL 60604
(312) 353-2072
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In Illinois 1-800-572-2515
In Indiana, Minnesota, Michigan, Ohio, Wisconsin
1-800-621-8431
The social activism of the 1960's and the 1970's has left a
legacy that is evident in today's public debates about the
environment. People demand to be more involved in the
decision-making process. To be more effective, EPA seeks a
more open dialogue with the public. The more we work
together and understand each other's concerns, the closer we
will be to reaching our goals — protecting public health and
the environment for generations to follow.
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BIBLIOGRAPHY
Bean, Martha C., "Effective Risk Communication: Foundation for Making Difficult Choices."
Paper Presented to the American Society of Public Administrators, Boston,
MA, March 1987.
Covello, Vincent T., Peter M. Sandman, and Paul Slovic, "Risk Communication, Risk Statistics
and Risk Comparisons: A Manual for Plant Managers." Chemical Manufac-
turers Association Workshop, 1988.
Covello, Vincent T., Detlof von Winterfeldt and Paul Slovic, "Communicating
Scientific Information About Health and Environmental Risks: Problems
and Opportunities from a Social and Behavioral Perspective." Risk
Communication. The Conservation Foundation: Washington, DC, January
1986.
Crouch, EA.C. and R. Wilson, 1984. "Inter-Risk Comparisons." Assessment and Management
of Chemical Risks, ed. J. Rodricks and R. Tardiff, Washington, DC:
American Chemical Society, pp. 97-112.
Ruckelshaus, William D., "Risk, Science and Democracy: Part 1." Chemteeh.
November 1987, pp. 658-662.
Ruckelshaus, William D., "Risk, Science and Democracy: Part 2," Chemteeh.
December 1987, pp. 738-741.
Sandman, Peter M., "Explaining Environmental Risk." TSCA Assistance Office, U.S. Environ-
mental Protection Agency, November 1986.
U.S. Department of Health and Human Services. U.S.Environmental Protection Agency, A,
Citizen's Guide to Radon. What It Is and What To Do About It. Washington,
DC, August, 1986.
U.S. Environmental Protection Agency, "A Risk Analysis of Twenty-six Environmental Prob-
lems," U.S. EPA, Region 5, Chicago, Illinois, 1990.
U.S. Environmental Protection Agency, "Environmental Risk." EPA Journal. Office of Public
Affairs, U.S. EPA, Washington, DC, Volume 13, Number 9, November 1987.
U.S. Environmental Protection Agency, "Guidelines for Risk Assessment." Federal Register,
Washington, DC, 51(185): 33991-34053.
U.S. Environmental Protection Agency. "Lawn Care For Your Home." Office of Public Affairs,
U.S. EPA Region 5, Chicago, Illinois, February, 1988.
U.S. Environmental Protection Agency, Science Advisory Board, Reducing
Risk: Setting Priorities and Strategies for Environmental Protection.
Washington, DC, September, 1990.
U.S. Environmental Protection Agency, Seven Cardinal Rules of Risk Communication. Wash-
ington, DC, April, 1988.
U.S. Environmental Protection Agency, Wood Preservatives for Consumers. Office of Public
Affairs, U.S. EPA Region 5, Chicago, IL, 1987.
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GLOSSARY
acute: having a sudden onset, sharp rise, and short course
(in respect to a disease)
aflatoxin: any of several toxins produced by fungi that can
cause cancer
asbestos: a noncombustible, nonconducting, or chemically
resistant mineral
assessed: determined in terms of importance, size, or value
chronic: marked by long duration or frequent recurrence
contract: to acquire, usually involuntarily
dose: a measured quantity of a substance
ecosystem: community and its environment functioning as
a unit in nature (i.e.: a forest ecosystem, a lake ecosystem,
etc.)
exposure: a condition or instance of being subject to an
influence (in this case to chemicals)
formaldehyde: a colorless, pungent, irritating gas, chiefly
used as a disinfectant, preservative, and synthesizer of other
compounds.
ground water: water beneath the surface of the earth
\
ingest: to take in, as if for digestion
pesticide: an agent used to destroy pests
probability: a chance that something will occur
quantify: to put in terms of amount or number
regulatory: governing actions controlled by the law
response: the activity or inhibition of previous activity of an
organism or any of its parts resulting from stimulation
statute: a law enacted by the legislative branch of
Government
toxic; of, relating to, or caused by a poison
voluntary: proceeding from one's own choice or consent
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•a US. GOVERNMENT PRINTING OFFICE 1991—545-607 + Printed on Recycled Paper +
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