United States
                            Environmental Protection
Office of
Public Affairs (A-107)
Washington DC 20460
July 1984
v>EPA          Dioxin   Facts
 Answers to Commonly Asked Questions
 What is dioxin?
 The word dioxin is a generic term for a group of 75 related
 compounds known as polychlonnated dibenzo-p-dioxms
 (PCDDs), but m popular use it usually refers to the most toxic
 and carefully studied of these compounds  2,3,7,8-
 tetrachlorodibenzo-p-dioxm, or 2,3,7,8-TCDD. or simply TCDD

 Where  does dioxin come from?
 Nobody produces dioxin (TCDD) on purpose. It is an
 unwanted but almost unavoidable by-product that comes
 from manufacturing several commercial substances, chiefly
 the pesticide 2,4,5-tnchlorophenol (2,4.5-TCP). This  pesticide
 is then  used as a  basic ingredient in the manufacture of
 several  other pesticides, including the herbicides 2,4,5-T and
 silvex, and the bactencide hexachlorophene. (Pesticide is a
 general  term for chemical products used to destroy or control
 unwanted insects, plants,  fungi, mites, rodents, bacteria, or
 other organisms-)

 How does dioxin get into the environment?
 TCDD can enter the environment in several ways; through
 chemical products contaminated with dioxin; as a component
 of the wastes that are produced in manufacturing these
 products; and through the widespread use of contaminated
 products. Combustion is another possible source of dioxin
   Dioxin can enter waterways and soil in stormwater runoff,
 through industrial discharges, or by seeping from landfills that
 contain  dioxm-contammated wastes. Dioxm's solubility in
 water is quite low. but it attaches itself to soil particles, thus
 making  it more likely to be found  in the sediment than in the
 water itself.
   Once in the environment, dioxin can be very persistent. Its
 half-life  in soil is on the order of 5-10 years. Under special
 circumstances, however, the ultraviolet radiation in  sunlight
 can degrade it over a shorter amount of time

 How does dioxin affect people?
 Although scientists disagree on the long-term health effects
 of exposure to 2,3,7.8-TCDD, tests on laboratory animals
 indicate that it is one of the most toxic man-made chemicals
 known.  Because information on effects to humans  has come
 mostly  from accidental exposures, the data are not definitive
 Scientists do agree,  however, that exposure to TCDD can
 cause a persistent skin rash called chloracne, as experienced
 by some workers exposed to dioxin in the work place  or
 through industrial accidents. Tests on laboratory animals also
 indicate that exposure may result m a rare form of cancer
 called soft tissue  sarcoma, liver dysfunction, elevated blood
 cholesterol, nervousness,  and other problems.
   Much controversy still exists over the use of Agent
 Orange, a dioxm-contammated defoliant used during the
 Vietnam War, and whether some veterans and their children
 may be suffering  from delayed effects of the chemical

 How do people generally come in contact with dioxin?
 There are two exposure routes that present the greatest
 possibilities for health risks  One $ through contact with
dioxm-contammated soil and the other is through eating
contaminated fish. Dioxm-contammated soil presents a
particular risk to children who  ingest it.

At what levels is dioxin a danger to people?
The Centers for Disease Control (CDC) considers 1 part per
billion (ppb) of dioxin in soil to be a level of concern in
residential areas  (CDC is the federal agency EPA relies on to
conduct site-specific exposure and risk assessments
whenever hazardous pollutants are found m soil at  high
levels.) The Food and Drug Administration recommends
limiting consumption of fish with 25 parts per trillion (ppt) or
greater of dioxin to no more than one  meal  per week and not
eating any fish  with greater than 50 ppt of dioxin.
  EPA, m coniunction with these federal agencies and State
and local health agencies, will  issue health advisories and
alert people to  any precautions they need to take whenever
dioxin is detected at these levels. They will  also decide what
further actions  are necessary

Is it safe to swim or boat in  water that contains dioxin?
Local health agencies post signs to alert people when they
should not be using a particular body of water for recreational
purposes Since dioxin does not readily dissolve .n  water, but
instead attaches to particles and eventually settles  to the
bottom, it is not likely to pose a threat to human health
unless you disturb any sediment in which diox;n has settled.
However, if you have any concerns whatsoever about the
safety of the water, for any reason,  ask the advice  of your
local health officials before swimming  or boating.

Is it safe to drink water that contains dioxin?
Any drinking water that is suspected of being contaminated
with dioxin or any other hazardous chemical should  not be
consumed.  You should contact your local health department
to find out the  facts, or heed any advice they have given you
They will also advise you on whether or not you should be
using an alternative drinking water source. Most water
treatment plants can eliminate dioxin during the water
treatment process by removing the  sediment in which it

Does dioxin affect animals?
The only known incident in the U.S. occurred in Missouri in
1971 when horse arenas were sprayed with high levels of
dioxm-contammated oil Hundreds of horses became sick and
65 of them died

What federal agencies are involved in dioxin detection
and cleanup?
EPA regulates dioxin under the Toxic Substances Control Act
and the Federal Insecticide, Fungicide, and Rodenticide Act
and is developing regulations to control it m wastes under
the  Resource Conservation and Recovery Act. The  Food and
Drug Administration issues health advisories for dioxin in
products for human consumption. The Occupational Safety
and Health Administration has  jurisdiction over dioxin
exposure in the workplace  Issues associated with  dioxin in

Agent Orange involving military personnel are handled by the
Veterans Administration (VA) and the Department of
Defense, although the  VA has relinquished control of  a
project to investigate a link between dioxin and Vietnam
veterans to the  Centers for Disease Control.

What has  industry done about the dioxin problem?
By 1965, some  companies had changed their production
processes  and increased quality control practices in an
attempt to reduce the levels of TCDD in the pesticide
2,4,5-T. As the controversy over dioxin increased, these
companies instituted practices to further lower dioxin  levels,
and some companies ceased manufacturing the controversial
product altogether. Today there is no domestic manufacturer
of the pesticide 2,4,5-T.

What has the federal  government done about the  dioxin
In 1970, the Department of Health, Education, and Welfare
(now the Department of Health and Human Services), the
Department of Agriculture, and the Department of Interior
suspended many  uses  of the herbicide 2,4,5-T as a result of
a report by the National Institute for Environmental Health
Services that is  caused birth defects in laboratory mice.
  In 1970.  the Department of Defense halted the spraying of
Agent Orange in Vietnam and in  1978,  the Veterans
Administration created  the Agent Orange Registry to identify
veterans who are  concerned about possible exposure to
Agent Orange.
  In 1979,  on the  basis of controversial evidence that linked
forest spraying of  2,4,5-T with an increase in  miscarriages
among some Oregon women, EPA suspended use of silvex
and 2,4,5-T on forests,  rights-of-way and pastures,  but still
allowed spraying on rice fields, fence rows, vacant lots and
  In 1981,  the Centers for Disease Control began a study to
determine  if Vietnam veterans are at a  greater risk of  having
children with birth defects.
  In 1981,  the Food and Drug Administration  banned  the use
of hexachiorophene in nonprescription soaps  and deodorants.
  In 1981,  the Food and Drug Administration  recommended
that people not  eat fish with dioxin levels greater than 50 ppt,
and limit their consumption of fish with 25-50 ppt of dioxin.
Fish with dioxin below  the 25 ppt level are considered safe
to eat.
                                         In 1982, EPA required some industries to certify that they
                                       were no longer using chlorophenol-type compounds as slime
                                       control agents.
                                         In 1983, EPA proposed cancellation of all remaining 2.4.5-T
                                       and silvex products. This action was appealed at a hearing by
                                       a number of pesticide registrants and  users. Until the
                                       hearings are completed, as required by law, limited use of
                                       2,4,5-T and silvex may continue.
                                         In 1983, EPA initiated a National Dioxin Strategy to look for
                                       areas throughout the country where 2,3,7,8-TCDD may be
                                       present in the environment. The strategy provides a
                                       systematic framework under which the agency will study the
                                       nature of dioxin contamination throughout the U.S. and the
                                       risks to  people and the environment; clean up dioxin-
                                       contaminated sites that  threaten public health; find ways to
                                       prevent future contamination; and find ways to destroy or
                                       dispose of existing dioxin. A National Dioxin Study to
                                       investigate the nature and extent of dioxin contamination in
                                       the environment will begin  this summer and take from 12-15
                                       months. Air, water, soil, and fish sampling will take place in
                                       over 1,000 locations across the country.
                                         In 1984, EPA issued a water quality criteria document for

                                       Are there ways to safely dispose of or destroy dioxin?
                                       EPA is currently evaluating  methods of disposing of or
                                       destroying dioxin-contaminated soils and wastes. Established
                                       technologies include incineration, chemical degradation, and
                                       biological treatment measures, but EPA is working to find
                                       other methods of disposal as well. One  promising technique
                                       is to treat soil with a chemical compound and sunlight. This
                                       method holds  promise for actually detoxifying the dioxin
                                       molecule. Another alternative that is being investigated
                                       involves the use of solvents to change dioxin  into a soluble
                                       form capable of destruction.
                                         Some temporary methods to limit exposure include:
                                       excavating highly contaminated soil and  removing it to a
                                       secure landfill or concrete vault;  securing and capping the
                                       contaminated area; and  using high efficiency vacuums and
                                       liquid dust suppressants.

                                       Who can I contact if I have more questions about dioxin?
                                       Each of  EPA's 10 regional offices has  a community involvement
                                       contact  who can answer your questions about dioxin. Following
                                       are their names, addresses, and telephone  numbers.
Debra Prybla
Office of Public Affairs
U.S. EPA Region 1
JFK Federal Building
Boston, MA 02203

Richard Cahill
Office of Public Affairs
U.S. EPA Region 2
26 Federal  Plaza
New York,  NY I0007

Joe Donovan
Office of Public Affairs
U.S. EPA Region 3
6th and Walnut Sts.
Phila., PA I9I06

Hagan Thompson
Office of Public Affairs
U.S. EPA Region 4
345 Courtland St., NE
Atlanta, GA 30308

Vanessa Musgrave
Office of Public Affairs
U.S. EPA Region 5
230 S. Dearborn
Chicago, IL 60604
(6I7) 223-4906
(2I2) 264-25I5
(2I5) 597-9370
(404) 88I-3004
(3I2) 886-6I28
Connecticut, Maine,
Massachusetts, New
Hampshire, Rhode
Island, Vermont
New Jersey, New York,
Puerto Rico, Virgin
Delaware, Maryland,
Pennsylvania, Virginia,
West Virginia. District
of Columbia
Alabama, Georgia.
Florida, Mississippi,
North Carolina, South
Carolina, Tennessee.

Illinois, Indiana. Ohio,
Michigan, Wisconsin,
Betty Williamson
Office of Public Affairs
U.S EPA Region 6
I20I Elm St.
Dallas, TX 75270

Steven Wurtz
Office of Public Affairs
U.S. EPA Region 7
324 E. llth St.
Kansas City,  MO 64I06

Nola Cook
Office of Public Affairs
U.S. EPA Region 8
Suite 900
I860 Lincoln St.
Denver, CO 80295

Deanna Wieman
Office of External Affairs
U.S. EPA Region 9
2I5 Fremont St.
San Francisco, CA 94I05

Bob Jacobson
Office of Public Affairs
U.S. EPA Region 10
1200 Sixth Ave.
Seattle. WA 98IOI
                                                            2I4) 767-9986
                                                            (8I6) 374-5894
(303) 837-5927
                                                            (4I5) 974-8083
                                                            (206) 442-I203
               Arkansas, Louisiana,
               Oklahoma. Texas, New
               Iowa, Kansas, Missouri.
Colorado, Utah,
Wyoming, Montana,
North Dakota. South
               Arizona, California.
               Nevada, Hawaii,
               American Samoa,
               Alaska, Idaho. Oregon,