905R88113
ŁEPA
United States
Environmental Protection
Agency
Office of Public Affairs
Region 5
230 S. Dearborn
Chicago, IL 60604
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MICHIGAN DIOXIN STUDIES
Incinerator Exhaust and
Ambient Air Study Fact Sheet
Midland, Michigan
April 1988
INTRODUCTION
At the request of the Michigan
Department of Natural Resources
(MDNR), the U.S. Environmental
Protection Agency (U.S. EPA) has
conducted a series of studies in and
around the Dow Chemical Company
plant hi Midland, Michigan. These
studies were designed to determine the
concentrations of dioxins and other tone
pollutants present at and near the Dow
Chemical Midland plant in air, soil, fish,
drinking water, and wastewater. Results
of these studies were released in 1985
and 1986.
This fact sheet summarizes the results of
an incinerator exhaust and ambient air
study conducted by the U.S. EPA in fall
1984, and compares those results with
similar testing at other sites from
U.S. EPA's National Dioxin Study.
Incinerator emissions samples for these
studies were collected at the Dow
Chemical Company Midland plant
Building 703 incinerator. Samples of
ambient air also were collected at the
plant fence line and in the city of
Midland.
Using the results from all of these
studies, U.S. EPA has evaluated the risks
of dioxins to Midland area residents and
presented the findings in a risk
assessment report. The U.S. EPA has
also developed a set of proposed risk
management actions to reduce and
manage exposures to dioxins hi the
environment. These reports are
summarized in another fact sheet. 40
2,3,7,8 -Tetrachloro
dibenzo-p-dioxin (TCDD)
Molecular Model
ABOUT DIOXINS
The word dioxin is a generic name for a
group of 75 related chemicals known as
chlorinated dibenzo-p-dioxins (CDDs).
2378-TCDD or 23,7,8-
tetrachlorodibenzo-p-dioxin, is believed
to be the most toxic of the dioxin group,
and is very persistent in the environment.
Once dioxins are released to the air,
water, and soil, they are not easily
broken down into less harmful
substances. Dioxins have been formed
as unwanted by-products during the
manufacture of certain pesticides, during
combustion of waste materials, and
through other reactions involving
chlorine and organic chemicals.
U.S. EPA has developed a procedure to
estimate the toxicity of mixtures of
dioxins and related compounds
compared to 2378-TCDD. For purposes
of this fact sheet, all dioxin
measurements have been converted to
2378-TCDD equivalents, or TEQs,
unless otherwise noted.
Experimental studies with 2378-TCDD
in laboratory animals have shown a
variety of toxic effects. These include
cancer, reproductive effects, liver
damage, effects on the skin and thyroid,
and effects on unborn offspring.
U.S. EPA has determined that the
critical concerns associated with
exposure to dioxins in the Midland area
are cancer, reproductive and teratogenic
effects, and liver damage. A teratogen is
a substance which has adverse effects on
an unborn child, when the mother is
exposed.
Continued on next page
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About Dioxins Continued
The evidence for the cancer-causing
effects of 2378-TCDD comes mainly
from several long-term studies of
laboratory animals exposed to the
substance. Based on these studies and
other factors, U.S. EPA has concluded
that 2378-TCDD causes cancer in
animals and should be regarded as a
probable human carcinogen. U.S. EPA
used the experimental animal data to
develop dose levels at which various
health effects may occur. U.S. EPA is
currently re-evaluating its estimates of
the cancer potency of 2378-TCDD.
U.S. EPA has not adopted an ambient
air standard for dioxins. When dioxins
are found, the Agency assesses risk on a
site-specific basis to determine whether
a public health concern is present. V
AIR MONITORING STUDY
Project Approach
The purpose of this study was to
determine the levels of dioxins and other
toxic compounds in ambient air near the
Dow Chemical Midland plant. Air
samples were taken at three locations
near the plant fence line and one
location hi the city (Midland Community
Center at George and Jefferson Streets).
Sampling was conducted on 18 days
between September 7 and September 27,
1984. Over 300 samples were gathered.
Based on wind conditions during the
study, selected samples were analyzed
for dioxins and other pollutants.
Air Study Conclusions
Low levels of dioxins were found at air
monitoring sites near the plant fence line
and at the site located in the city, ranging
up to 0.0004 ug/m3 for the less toxic
forms. 2378-TCDD, the most toxic form
of dioxin, was found on one day at a site
near the Dow Chemical fence line at a
level of 0.000005 ug/m3.
The proportions of various dioxin
compounds found in this study were
similar to those found in previous studies
of air in incinerator areas and soils
sampled by U.S. EPA in 1984. Also,
U.S. EPA determined that the levels of
dioxin found in air around the plant are
higher than can be accounted for by the
current incinerator emissions. This
suggests that some dioxins found in air
outside the plant may have come from
past incinerator emissions, windblown
dusts from the plant, or past process
emissions. The possible health risks
associated with the air data are
described in the risk assessment.
INCINERATOR
EXHAUST STUDY
Project Approach
The purpose of this study was to
determine the levels of dioxin and other
chemicals in the Building 703 incinerator
exhaust gas, wastewater, and ash, under
normal operating conditions. The
discharged compounds detected were
then compared to the liquid and solid
wastes incinerated at those times. Based
on previous Dow Chemical studies, the
Building 703 incinerator is believed to be
a principal source of dioxin
contamination at the Dow/Midland
plant.
Incinerator exhaust samples were
collected by U.S. EPA on three separati
days in August and September 1984.
Over two hundred samples of wastes fei
into the incinerator, exhaust gas,
wastewater, and ash were gathered. Th
samples were analyzed for dioxins,
volatile organic compounds (VOCs), an
semi-volatile compounds.
Incinerator Exhaust Study
Conclusions
Various forms of dioxin were found on
all three sampling days in the incineratoi
exhaust gases at concentrations between
0.005 and 0.125 ug/m .
The study concluded there were no
readily observable relationships between
the incinerator temperature, pressure,
air pollution control device and flow
rates, and the levels of certain dioxins
found in the exhaust during the three
days of testing. However, there may be
a relationship between the levels of
dioxin being drawn into the incinerator
and the levels of dioxin begin discharged
after burning has taken place.
Dow Chemical Company
X Midland Plant Site Map
Midland, Michigan
V I I I I I I t I X' ' ' ' M I II M I
X
Oow
Chemical
X \pompany
Air Monitoring
Locations
Consumers Power Company
Cooling Ponds
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Comparison With Other Sites
The following table compares the
amount of dioxins discharged from Dow
Chemical's waste incinerator in 1983,
1984, and 1987, with the amounts coming
from other sources studied by U.S. EPA
in the National Dioxin Study. Data from
the Dow incinerator were developed by
Dow Chemical in 1983 and 1987, and by
U.S. EPA in 1984. These results show
two things:
1. The Dow Chemical incinerator
emits less dioxins into the air
than some other types of
sources; and
2. The amounts of dioxins emitted
by Dow Chemical have been
reduced by more than 95
percent from levels measured in
1983. (Levels emitted by Dow
prior to 1983 are believed to be
higher than those measured in
1983.)
* COMPARISON OF DOW CHEMICAL
INCINERATOR EMISSIONS
WITH NATIONAL DIOXIN STUDY RESULTS
2378-TCDD
Equivalent Emissions
(qrams/veart
Secondary Copper Smelter
Municipal Waste Combustor
Municipal Waste Combustor
Municipal Waste Combustor
Municipal Waste Combustor
DOW CHEMICAL -1983
Sewage Sludge Incinerator
Hazardous Waste Incinerator
Industrial Waste Incinerator
Wood-fired Boiler
:800
500
140
95
80
2
2
0.7
0.6
0.3
0.3
0.2
0.04
0.03
0.02
0.02
>0.01
0.009
0.00004
0.00001
NOTE: > means greater than. For the Dow Chemical tests in 1983,
not all forms of dioxin were analyzed.
GLOSSARY
Ambient Air - The air in a given
location people breathe, usually
referred to as outdoor air outside of
industrial facilities.
Concentrations -- The amount of a
chemicaTin a given unit of measure.
For air measurements, concen-
trations are usually expressed in
terms of the weight of the
compound in one cubic meter of air,
which is about 35 cubic feet. One
microgram of a chemical per cubic
meter (ug/m ) is equivalent to
0.00000000006 Ibs. of that chemical
in one cubic foot of air.
Incinerator — A furnace or other
apparatus used for burning waste.
Incinerator exhaust is made up of
fumes, gases and particles left over
from the burning process, and may
or may not contain toxic chemicals.
Particulate Matter - Dust and
small particles of material blown by
the wind. Particulates may float in
the air for some time; chemicals can
become attached to them and be
transported some distance from
their original site.
Pesticide -- A general term for
chemicals used to destroy or control
unwanted insects, plants, fungi,
mites, rodents, bacteria, or other
organisms.
Potentially Responsible Party
(PRP) - Any individual(s) or
company(s) potentially responsible
for, or contributing to, the
contamination problems at a
Superfund site. Whenever possible,
U.S. EPA requires the PRPs,
through administrative and legal
actions, to clean up hazardous waste
sites they have contaminated.
Toxic Pollutant or Compound -
Any of a number of chemicals under
special regulation by U.S. EPA
because of the harmful effects these
compounds can have on humans,
animal life, or the environment.
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FOR MORE INFORMATION
INFORMATION
REPOSITORIES
For more information about U.S. EPA's
dioxin studies in the Midland area, you
may review site related documents at the
following locations:
Grace A. Dow Memorial Public Library
Emilia Parker
1710 West St. Andrews Drive
Midland, Michigan 48640
(517) 835-7157
Ingersoll Township Hall
Kurt Shaffner, Supervisor
4400 Brooks Road
Midland, Michigan 48640
(517) 835-5289
Midland Health Department
Dr. Winifred Oyen, Director
125 West Main Street
Midland, Michigan 48640
(517) 832-6655
U.S. EPA CONTACTS
The following U.S. EPA personnel are
available to answer any further questions
you may have about the studies, this fact
sheet, and future activities planned for
the site.
John Perrecone
U.S. EPA Office of Public Affairs
230 South Dearborn Street
Chicago, Illinois 60604
(312) 886-1660 or call
Toll Free: 1-800-621-8431
Gary Amendola
U.S. EPA Project Manager
Michigan Dioxin Studies
25089 Center Ridge Road
Westlake, OH 44145
(216) 835-5200
v-xEPA
U. S. Environmental Protection Agency
Region 5
Office of Public Affairs
230 South Dearborn Street
Chicago, IL 60604
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