NATIONAL AIR TOXICS INFORMATION
CLEARINGHOUSE NEWSLETTER 453N88006
*>EPA
Office of Air Quality Planning and Standards	Volume 6 Number 1
Research Triangle Park, North Carolina 27711	November 1988
/*\ r5)fD)A\ (j /AH	State and Territorial Air Pollution Program Administrators
U Zr-Alin/r-Au	Association of Local Air Pollution Control Officials
" ' ; ;1 j' A < v< V	
	' ;J A..' .IV;., V.vV 1	
IN THIS ISSUE	:i. v	-.ifAt. PROTECTION AGEWCT
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CLEARINGHOUSE EXPLORES NATICH/SARA LINK	1
STATE/LOCAL AGENCY SPOTLIGHT* OHIO COMPLETES AMBIENT AIR STUDY OF
DIOXINS, DIBENZOFURANS	2
IACP APPORTIONS MUTAGENIC POTENCY TO MOTOR VEHICLE AND WOOD SMOKE
EMISSIONS		
AIR RISK INFORMATION SUPPORT CENTER RESPONDS	4
NRDC ANALYZES SARA DATA FROM MARYLAND FACILITIES	6
TOXIC RELEASE INVENTORY DATA BASE AVAILABLE TO STATE AGENCIES	6
EPA RISK ASSESSMENT FORUM'S EXPERTS STUDY, REPORT ON ISSUES	7
STUDIES ADDRESS SUPERFUND AIR ANALYSES	8
CTC HOTLINE ACTIVE IN HANDLING STATE/LOCAL QUESTIONS	8
STAPPA/ALAPCO TO TRACK AIR TOXICS PROGRAM DEVELOPMENT PROGRESS	9
OAQPS ANNOUNCES NEW STUDY ON CANCER RISK FROM AIR TOXICS IN THE
UNITED STATES	9
NEW AIR TOXICS DOCUMENTS NOW AVAILABLE	9
PROPOSED REPRODUCTIVE RISK ASSESSMENT GUIDELINES APPEAR IN
FEDERAL REGISTER		
CLEARINGHOUSE EXPLORES
NATICH/SARA LINK
A feasibility study is currently underway to examine
the potential for linking the Superfund Amendments and
Reauthorization Act (SARA) Title III Toxic Release Inven-
tory (TRI) data base to NATICH. The TRI data base is
being developed to include emissions information from
air pollutant sources reporting to EPA under the require-
ments of SARA, Section 313. Should the TRI data base
link to NATICH appear feasible, current plans are to carry
out the work in the latter half of this fiscal year (1989).
More Point Source Risk Data Available
Results of additional risk analyses for point sources
performed by the EPA's Pollutant Assessment Branch
are now available through the NATICH data base. Risk
analysis information is now available on a total of 3,700
sources representing about 85 percent of the data
developed by PAB on point sources. Some values repre-
sent updates to last year's estimates; the majority are
new, expanding the previous number of sources. Over
40 pollutants are included. The Agency cautions that
varying levels of uncertainty are associated with the
data; this must be considered in any use made of the
data. For further details on these and other NATICH data
base activities, contact Tim Mohin at the Clearinghouse
number.
NATICH Demonstration Diskette Offered
Requests continue for copies of the diskette pro-
gram illustrating some of the types of data and retrieval
options in the NATICH data base. Announced initially in
the July 1988 issue, this program allows a potential user
to gain an appreciation for the NATICH data base
through a personal computer run sample of NATICH
capabilities. To obtain a copy of this program, please
send an unformatted double-sided, double density, 5.25
inch floppy diskette to Nancy Riley, U.S. EPA, MD-13,
Research Triangle Park, North Carolina 27711.
DEC 9 898'

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Mailing List Changes?
Readers needing to make any changes, additions,
or deletions to the National Air Toxics Information Clear-
inghouse mailing list should write Meredith Haley,
Radian Corporation, PO. Box 13000, Research Triangle
Park, North Carolina 27709.
Save Bibliography Volume 11
State and local agencies have recently received
the 1988 version of the Clearinghouse version of the
Clearinghouse document "Bibliography of Selected
Reports and Federal Register Notices Related to Air Tox-
ics." Readers should note that last year's Volume 1 of
the Bibliography remains current and existing copies
should be retained. Volume 1 contains document cita-
tions and abstracts for material published from 1974
through March 1987. The latest Volume 2 contains all
new document citations covering the period April 1987
through March 1988 and is designed to complement the
older Volume 1. The new index covers all citations found
in Volumes 1 and 2.
Volume 2 also contains an updated index of all
Newsletter articles (December 1983 through March
1988). The Newsletter index was previously included as
part of a Clearinghouse special report.
Recently published Clearinghouse reports are listed
below. These documents are distributed free of charge
to governmental and nonprofit organizations. If you are
not on the mailing list to receive these and other
documents but would like to be, call Nancy Riley at the
Clearinghouse number listed above.
The private sector may obtain copies from Radian
Corporation by sending a written request and advance
payment to Barbara Maxey, Radian Corporation, Post
Office Box 201088, Austin, Texas 78720-1088. Document
prices are listed below. Some of the reports are now
available through the National Technical Information
Service and NTIS numbers are given below. Others will
be available from NTIS later this fall.
RECENT NATIONAL AIR TOXICS
INFORMATION CLEARINGHOUSE REPORTS
Report Title Price
Case Studies in Risk Communication $9.15
(EPA-450/5-88-03, NTIS PB89-104277/AS, June 1988)
Ongoing Research and Regulatory Developments $19.90
(EPA-450/5-88-004, NTIS PB89-103428/AS, July 1988)
Bibliography of Selected Reports and Federal Register $19.05
Notices Related to Air Toxics - Volume 2:
Citations - 1988
(EPA-450/5-88-005, NTIS PB89-103436/AS, July 1988)
Bibliography of Selected Reports and Federal Register $38 25
Notices Related to Air Toxics - Index - 1988
(EPA-450/5-88-006, NTIS PB89-103444/AS, July 1988)
Data Base Report on State, Local and EPA Air $47.70
Toxics Activities
(EPA-450/5-88-007, July 1988)
STATE/LOCAL AGENCY SPC
OHIO COMPLETES AMBIEP
DIOXINS, DIBENZOFURAN!
by Paul Koval, Division of Air Pollution Control,
The Ohio Air Quality Development Authority has
sponsored a study of the sources, occurrence and ef-
fects of dioxins and dibenzofurans in the State. The study
combined an ambient air sampling program with a
dispersion modeling and health risk assessment study
to describe and assess the potential occurrence of
adverse health effects from polychlorinated dibenzo-p-
dioxins (PCDD) and polychlorinated dibenzofurans
(PCDF) in the State's ambient air.
Airborne concentrations of PCDD and related com-
pounds, such as PCDF, have caused concern because
of the compounds' suspected high toxicity. Specifical-
ly, animal studies have demonstrated that
2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) and
perhaps other cogeners are potentially carcinogenic.
>TLIGHTi
JT AIR STUDY OF
I
Ohio EPA
Although results from human epidemiological studies
have been inconclusive, dioxins have been classified as
suspected human carcinogens.
Few ambient air measurements of PCDD and PCDF
exist because of the complex analytical methods re-
quired to measure such low concentrations. Recent
research has shown that possible contributors of
PCDD/PCDF to the atmosphere include municipal solid
waste and sewage sludge incinerators, commercial
boilers, hazardous waste incinerators, wire reclamation
incinerators, drum and barrel regeneration furnaces,
wood-fired boilers and stoves, and internal combustion
engines.
Previous studies of airborne dioxin levels exhibit
these trends in ambient air dioxin levels:
2

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•	the highest levels are detected in urban and
industrial areas;
•	urban levels can be up to 10 times suburban levels;
•	the actual amount of 2,3,7,8-TCDD jn t(-,e air jS
quite low; and
•	high levels of TCDD in automobile tunnels further
support the theory that automobile exhaust
contains TCDD/PCDD.
In Ohio's current study, six ambient air samples
were analyzed for PCDD/PCDF. Samplers were sta-
tioned near municipal waste incinerators in Columbus
and Akron. The Columbus site had sewage sludge in-
cinerators and other small industries nearby. Also, a site
was selected near a major highway in Columbus. A final
site was chosen in a rural area near Waldo, a town north
of Columbus and away from major combustion sources,
to determine background levels. The samples were col-
lected with a medium volume air sampler equipped with
a polyurethane foam (PUF) plug and filter. The samples
were analyzed using capillary column gas
chromatography/high resolution mass spectrometry.
The PCDD/PCDF levels found in the Ohio air
samples are similar to ambient air levels previously
reported in other studies. No 2,3,7,8-TCDD was detected
in any of the samples. The ambient concentrations of
PCDD/PCDF in the samples collected near the combus-
tion sources (Columbus and Akron) were found to be
slightly less than twice as great as those collected at the
background site (Waldo) but were much lower than the
average industrial airborne concentrations of dioxins in
Europe. Cogener profiles of the air samples demonstrate
that the Columbus and Akron samples match the pro-
files measured for municipal incineration in other
studies. The Waldo site also showed a cogener profile
similar to municipal incineration emission sources. At the
Columbus site, the ambient samples were found to com-
pose 70 to 80 percent of the PCDD/PCDF emissions
from municipal incineration and 20 to 30 percent
PCDD/PCDF emissions from municipal incineration and
20 to 30 percent PCDD/PCDF emissions from sewage
sludge incineration.
A dispersion model was used to estimate annual
average airborne dioxin concentrations in Columbus,
using data from previous studies, the present study, and
Columbus weather data for the past four years. The
average annual air concentrations predicted show the
airborne levels of dioxins in Columbus to be less than
60 femtograms (1015 gram) per cubic meter.
Sampling Results Used in Risk Assessment
The modeled air concentrations were used in a risk
assessment study to estimate the possibility of health ef-
fects caused by the concentrations of TCDD/PCDF in
Columbus. Most of the assumptions in a risk assess-
ment study are conservative, resulting in a calculated
risk which is not likely to be an underestimate and may
overstate the actual risk.
The current risk assessment shows a maximum in-
dividual risk for Columbus residents ranging from 1.3 x
10"6 to 9.9 x 10"6 (1.3 to 9.9 chances in 1 million of con-
tracting a health effect). Under a new unit risk factor EPA
has developed, which is less conservative (i.e., lower)
than the current risk factor, the maximum individual risk
is reduced to the 1.4 x 10 7 to 5.9 x 10"9 (1.4 in 10 million
to 5.9 in 1 billion) range. Calculations of individual risk
based upon measured amounts of dioxins in this study
yielded maximum individual risk values in the same
range as the values predicted by the dispersion model.
This study concludes that, given the current
knowledge of the health effects of exposure to
PCDD/PCDF in the ambient air, there is no appreciable
risk to public health from the concentrations of these
compounds found in Ohio's ambient air.
For more information on the study, contact Paul
Koval, Toxicologist, Division of Air Pollution Control, Ohio
EPA, 1800 WaterMark Drive, Columbus, Ohio 43215,
(614) 644-2270.
IACP APPORTIONS MUTAC
POTENCY TO MOTOR VEH
WOOD SMOKE EMISSIONS
The Integrated Air Cancer Project* (IACP) has
released results which apportion** the airborne
mutagenicity to its sources in Albuquerque, New Mex-
ico, and Raleigh, North Carolina. This study was con-
ducted during January, February, and March 1985. Table
1 summarizes these results.
The measurement site in both cities was a residen-
tial neighborhood in which a large amount of wood burn-
ing occurred, a principal reason for choosing each site.
Besides wood combustion, the only other important
SENIC
ICLE AND
source of particulate organic matter at these sites was
motor vehicles. The apportionments of both fine parti-
cle extractable organic matter (EOM) concentrations and
the mutagenicity concentrations associated with EOM
were performed with a multiple linear regression tech-
nique using fine particle concentrations of lead and soil-
corrected potassium as tracers of motor vehicle emis-
sions and wood smoke, respectively. These tracers were
validated through the simultaneous measurement of
carbon-14, a naturally occurring radioactive element pre-
3

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sent in wood smoke but not in motor vehicle emissions.
For the Raleigh results, the motor vehicle impact was so
small that its contribution had to be inferred by assum-
ing the measured lead concentration had the same rela-
tionship to motor vehicle EOM and mutagenicity in
Raleigh as it did in Albuquerque.
The dominance of the wood smoke contribution to
both ambient EOM and mutagenicity is apparent from
Table 1. However, when the results are expressed in
terms of potency (the ratio of the revertant concentration
to the EOM concentration for each source) a different
perspective emerges: the mutagenic potency of motor
vehicle emissions is approximately three times larger
than that of wood smoke.
For more information, call Barbara M. Andon, IACP
Program Coordinator, at (919) 541-7532 or (FTS)
629-7532.
*See related article in the June 1986 Newsletter.
"Unlike past efforts to identify airborne carcinogens
which relied on source inventories, emission rates and
production volumes of compounds which were potential-
ly hazardous, the IACP takes the approach of measur-
ing ambient mutagenicity (a surrogate for carcinogenici-
ty) directly and apportioning it to its sources through the
simultaneous measurement of particular chemical
species which are natural tracers for those sources. This
approach is a particular form of receptor modeling.
TABLE 1.
AVERAGE AMBIENT CONCENTRATIONS AND MUTAGENIC* POTENCIES
ATTRIBUTED TO WOOD SMOKE AND MOBILE SOURCES
Wood Smoke Mobile Sources Other Sources
Albuquerque Results
EOM, ug/m3
Mutagenicity,
revertants/m3
Potency,
revertants/ug
extractable organic
matter
15 + 1
19 + 2
1.3 + 0.3
3 ± 0.9
11 ±3
3.7 + 1.5
1 ± 0.9
3 + 3
Total
19
32
Raleigh Results**
EOM, ug/m3
Mutagenicity,
revertants/m3
Potency,
revertants/ug
extractable organic
matter
'Salmonella strain TA98 with an exogenous metabolizing system (+ S9).
**Pb coefficients were from Albuquerque results.
16 ± 0.5
12 ± 0.9
0.78 + 0.07
1 ± 0.3
4 + 1
3.7 + 1.5
0.1 ± 1
1 + 1
17
18
AIR RISK INFORMATION
SUPPORT CENTER RESPONDS
This is the first in a continuing series of articles
featuring questions and issues encountered which may
be of interest to others working in the air toxics field. The
Air Risk Information Support Center (Air RISC) is a new
EPA support program for State and local air pollution
control agencies to provide health, exposure and risk
assessment information on air toxics*
Urea Dust Raises Questions In Alaska
Information assistance was provided through Air
4

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RISC coordination to a question from an environmental
engineer working for the Alaska Department of En-
vironmental Conservation (ADEC). A large fertilizer plant
in this State emits urea dust particles from a prill tower
into air at an approximate rate of 100 Ib/hr. According to
the engineer, no employees filed health complaints, but
the surrounding trees were dead and automobile wind-
shield pitting occurred to the extent that the plant paid
for car washing. The Agency needed to know whether
there was any specific information on human or en-
vironmental toxicity of urea dust which could assist the
staff in making a regulatory decision.
Responses were provided by scientists in EPA's En-
vironmental Criteria and Assessment Office (ECAO),
Research Triangle Park, North Carolina, as well as the
Environmental Effects Branch, Office of Toxic
Substances. There were only limited data available
(either through EPA's Health Assessment Documents or
chemical data bases searched) on direct human, animal
or plant toxicity from urea.
The primary effect of acute exposure to urea is ir-
ritation of mucous membranes (including the eyes, nose,
and throat) and skin. Urea is hydrolyzed in the at-
mosphere to ammonia and carbon dioxide. Inhaled am-
monia is efficiently absorbed by mucous membranes in
the upper respiratory tract which could cause irritation.
The occupational standard for an 8-hour exposure to am-
monia is 50 ppm (35 mg/m3) time-weighted average
(TWA), as set by OSHA in 1983. The TWA is the exposure
level considered safe for workers in an 8-hour workday
and a 40-hour workweek. If exposure is chronic, this level
may be irritating to the upper respiratory tract and eyes.
The threshold limit value (TLV) set by the American Con-
gress of Governmental and Industrial Hygienists
(ACGIH) in 1984 is 25 ppm (18 mg/m3) and the 15-minute
short term exposure limit (STEL) is 35 ppm (27 mg/m3).
These are threshold levels not to be exceeded in occupa-
tional exposure. It is possible that especially sensitive
people may experience these effects at lower
concentrations.
Information on the toxicity of ammonia, as reviewed
in a draft Health Effects Review, was provided. The ex-
act level of exposure that causes toxicity in humans is
not well documented. The primary effects of acute am-
monia exposure are burns of the eyes, skin and
respiratory tract. This is due to high water solubility of
ammonia resulting in formation of ammonium hydrox-
ide. If it had been possible to determine the levels of am-
monia present near the fertilizer plant such information
would have been helpful to determine the possible con-
tribution of this chemical to any health problems.
The atmospheric and environmental chemistry of
ammonia depends on what other pollutants are present.
This is discussed in a newly prepared EPA Issue Paper
on Health Effects of Acid Aerosols. For example, am-
monia will react with sulfuric acid or HS04 ion to form
ammonium sulfate (ammonia neutralization). By
neutralizing acidity in aerosols, cloud droplets, fog or
dew, ammonia would allow more SO2 to react but would
not increase the acidity. When ammonia was in excess
of SO2, it would reduce the acidity. Urea particles might
serve as centers to collect water and S02 might react to
form sulfate in the droplets. This might lead to pitting of
paint or increased rusting of metals. Whether or not this
would pit windshields is not known.
Damage to the trees in the area could have resulted
from the excess fertilization from either urea or am-
monia. The biological utilization of nitrogen in urea or
ammonia is thought to produce acidity and therefore
deposition of urea could lead to acidification of soil. An
article on this topic was sent with the suggestion that a
forestry or agricultural extension person could probably
assess the probable cause with more expertise.
Vermont Concerned with Talc Dust
The Vermont Air Pollution Control Agency received
a citizen complaint regarding the fugitive emissions of
dust from a talc quarry. The question was whether this
talc dust (probably in a size range less than 2.5 microns
and therefore respirable) was more toxic than the
broader class of fine particulates. The citizen had heard
of a medical article linking talc with ovarian cancer. It
turned out that the specific medical article discussed
possible ovarian cancer increases in women exposed
via topical application of talc to the genital area, rather
than exposure from an industrial source via inhalation.
More pertinent information on potential health ef-
fects associated with talc inhalation was provided by
scientists from ECAO/RTP and the Human Health
Assessment Group of EPA's Office of Health and En-
vironmental Assessment (OHEA). A summary of the EPA
Document of Health Effects Associated with Mineral
Fibers Other than Asbestos was forwarded. The Mineral
Fibers Document stated that "available animal and
epidemiology data suggest that pure talc is not car-
cinogenic" and also that there are no determined NOEL
(no observed effects level) or LOAEL (lowest observed
adverse effects level) at present. The project officer for
preparation of this document added that one would need
to know concentration levels and composition of the talc
exposure mixture in order to make interpretations of
possible health risks relative to U.S. EPA National Am-
bient Air Quality Standards for particles and/or NIOSH
workplace standards.
For assistance with health, exposure, or risk assess-
ment questions, State and local agencies can contact
the Air RISC Hotline at (919) 541-0888 or (FTS) 629-0888.
Readers interested in receiving documents mentioned
in this article can contact ECAO, (919) 541-4828 or (FTS)
629-4828.
"See related article in the July 1988 Newsletter, pages
4-8.
5

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NRDC ANALYZES SARA DATA FROM
MARYLAND FACILITIES
by Deborah A. Sheiman, Resource Specialist, Natural Resources Defense Council
Industries in Maryland released 19 million pounds
of 100 different toxic chemicals into the air last year,
according to a Statewide analysis of Section 313 Toxic
Release Reports * The analysis was issued in August by
the Natural Resources Defense Council (NRDC), Sierra
Club's Potomac Chapter, the Maryland Waste Coalition,
and the American Lung Association of Maryland.
The report catalogues Maryland's largest producers
of toxic and carcinogenic air pollution, based on more
than 600 reports filed with the State in July by more than
140 Maryland companies under the Superfund law's
"Right-to-Know" provisions. Eighty percent of the com-
panies reported toxic releases to the air. Industries did
not report any pollution controls for 75 percent of the
large releases to the air.
This report is the first Statewide analysis of the new
emissions data. With a computer tape of the emissions
reports scheduled to be made available to States by EPA
in the spring of 1989, State and local air pollution con-
trol agencies will have the opportunity to analyze the new
information and issue reports to make air toxics emis-
sions information available to the public.
State or local agencies that are planning or have
already undertaken analysis of the Toxic Release Inven-
tory data may call Deborah Sheiman, NRDC, at (202)
783-7800 to share information.
Copies of the 80-page report on Toxic Air Pollution
in Maryland are available for $20.00, prepaid, from:
NRDC, 1350 New York Avenue N.W., Washington, D.C.
20005.
"These reports are filed pursuant to the toxic chemicals
emission inventory reporting requirements of Section
313 of the Superfund Amendments and Reauthorization
Act (SARA). See related article in the September 1987
issue, pages 11-12.
TOXIC RELEASE INVENTORY DATA BASE
AVAILABLE TO STATE AGENCIES
Title III, Section 313 of the Superfund Amend-
ments and Reauthorization Act of 1986 (SARA), also
known as the Emergency Planning and Community
Right-to-Know Law* requires EPA to establish a toxic
release inventory and to make the toxic emissions data
available to the public through a National Toxic Chemical
Release Inventory (TRI) data base and by "other
means." All of the submission forms for the first annual
reporting year were due to EPA by July 1,1988. To date,
EPA has received more than 73,000 TRI forms and is cur-
rently processing them into the internal EPA data base,
which is the precursor to the National Library of
Medicine's TRI (public) data base and access by other
means.
The TRI data base became available on the IBM
3090 computer at the National Computer Center (NCC)
in Research Triangle Park (RTP), North Carolina, on
September 1, 1988. At this time, user accounts were
established for each of the EPA Regions and timeshare
dollars were made available to permit the Regions and
the States to access the TRI data.
Persons in EPA Regional offices and the States who
desire access to the TRI data base should contact the
Regional TRI Account Manager listed below for a user
i.d. and instructions on how to access the data base.
Since users are being permitted to access the TRI
data base before the scheduled completion of all data
entry and quality assurance/error correction activities,
a message screen appears after log-on. The screen pro-
vides a status on data entry activities, giving the number
of partial TRI submission forms (submissions for which
only the facility identification information has been
entered), the number of complete submission forms
(submissions for which all the form's data have been
entered), and the total number of submissions on the TRI
data base.
ALL USERS SHOULD BE ADVISED THAT THE
TRI DATA WILL BE SOMEWHAT QUESTIONABLE AND
SHOULD BE USED WITH EXTREME CAUTION UNTIL
ALL DATA ENTRY AND QA ACTIVITIES ARE COM-
PLETE. These activities are scheduled for completion
annually in February.
Anyone with questions about the data base or who
needs additional assistance gaining access to the data
base should call Ruby N. Boyd, (202) 475-8387, (FTS)
475-8387, or E-MAIL EPA7590.
*See related article in this issue and in the September
1987 issue, pages 11-12.

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TOXIC CHEMICAL RELEASE INVENTORY
TRI DATA BASE REGIONAL ACCOUNT MANAGERS
REGION I
Mike Mac Dougall
US EPA Region I
JFK Federal Building
Boston, MA 02203
(617) 565-3377
REGION II
Bob Messina
US EPA Region II
Woodbridge Avenue,
Bldg 209
Edison, NJ 08837
(913) 236-2806
REGION III
Wendy A. Bartel
US EPA Region III
841 Chestnut Street
Philadelphia, PA 19107
(215) 597-3532
REGION IV
Jesse Dooley
US EPA Region IV
345 Courtland Street, NE
Atlanta, GA 30308
(404) 347-2316
REGION V
Stan Hutchens
US EPA Region V
536 S. Clark Street
Chicago, IL 60605
(312) 353-0623
REGION VI
Dave White
US EPA Region VI
1445 Ross Avenue
Dallas, TX 75202
(241) 655-6540
REGION VII
Dale Parke
US EPA Region VII
726 Minnesota Avenue
Kansas City, KS 66101
(913) 236-2827
REGION VIII
Diane Broh
US EPA Region VIII
999 18th Street
Denver, CO 80202
(303) 293-1730
REGION IX
Mario Pineda
US EPA Region IX
215 Fremont Street
San Francisco, CA 94105
(415) 974-7733
REGION X
Gus Parlier
US EPA Region X
12000 Sixth Avenue
Seattle, WA 98101
(202) 442-2988
EPA HEADQUARTERS
Carolyn Thronton
US EPA OTS/IMD TS-793
401 "M" Street, SW
Washington, DC 20460
(202) 475-8620
EPA RISK ASSESSMENT FORUM S EXPERTS STUDY,
REPORT ON ISSUES
Established several years ago by EPA, the Risk
Assessment Forum promotes Agency consensus on risk
assessment issues and consistency in risk assessment
guidance.
How the Forum Works
Generally, the Forum focuses on issues fundamen-
tal to the risk assessment process, analysis of data
used in risk assessment, and Agency consensus in ap-
proaches to risk assessment. New issues may be pro-
posed for study at any time. The Forum has worked with
program offices at EPA Headquarters and with the
Regional offices and laboratories to develop project pro-
posals of common interest.
Forum activities may include: developing scientific
analyses, preparing risk assessment guidance and risk
assessment methodology for use in ongoing and pro-
spective Agency actions, and using scientific and
technical analysis to propose risk assessment positions.
Forum activities are referred to the Agency's Risk
Assessment Council for consideration of policy and pro-
cedural issues, and Forum scientific analyses become
Agency policy upon recommendation by the Risk
Assessment Council and concurrence by the Ad-
ministrator.
Forum Membership Reflects Balance of
Disciplines, Experience
Selection of the 13 Forum members is based on ex-
perience and expertise in risk assessment and underly-
ing disciplines such as toxicology, chemistry, exposure,
ecology, epidemiology, and statistics, and not on office
affiliation. The overall composition of the Forum attempts
to reflect a balance of scientific disciplines and Agency
experience.
What the Forum Does
The Forum has published final reports on "Pro-
liferative Hepatocellular Lesions of the Rat: Review and
Future Use in Risk Assessment" and "Interim Pro-
cedures for Estimating Risks Associated with Exposures
to Mixtures of Chlorinated Dibenzo-p-Dioxins and -
Dibenzofurans (CDDs and CDFs)," and another
"Special Report on Ingested Inorganic Arsenic: Skin
Cancer; Nutritional Essentiality," will soon be published.
When the Forum completes work on a report, a
notice of availability is published in the Federal Register
announcing that interested parties may obtain a copy of
the report through the Office of Research and Develop-
ment's Publication Center in Cincinnati, Ohio.
In addition, a large portion of the Forum's work in-
7

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volves coordinating the development of risk assessment
guidelines. In 1986, EPA published final risk assessment
guidelines in five areas: carcinogenicity, mutagenicity,
chemical mixtures, suspect developmental toxicants and
estimating exposures. New guidelines are in various
development stages in areas such as male and female
reproductive risk (see related article in this issue) and
exposure measurement.
For further information, call Linda Tuxen, Technical
Liaison for EPA's Risk Assessment Forum, at (202)
475-6743 or (FTS) 475-6743.
STUDIES ADDRESS SUPERF
AIR ANALYSES
The EPA's Office of Air Quality Planning and Stan-
dards (OAQPS), the Regional Air/Superfund Coordina-
tors,* and the Superfund program have joined forces to
produce a series of four national technical guidance
manuals covering the procedures and protocols used in
conducting air pathway analyses at Superfund hazar-
dous waste sites. Limited information was available on
how to conduct the analyses before these groups
developed the procedures and protocols, and prepared
the studies.
Volume I, prepared under the direction of Mark Gar-
rison of EPA Region III, discusses the overall applica-
tion of air pathway analyses for Superfund activities, in-
cluding a description of air pathway analyses and an ex-
planation of why they are important. It also identifies the
air emission sources at Superfund sites and explains
why they should be evaluated. Further, it identifies where
to find additional information with respect to implemen-
ting a selected air pathway analysis approach.
Volume II, prepared under the direction of Margaret
McDonough of Region I, provides guidance on develop-
ing baseline air emission estimates from hazardous
waste sites. It offers a protocol for determining if baseline
emission estimates are required and how to develop site-
specific baseline emission estimates. It also gives case
studies illustrating how to use the techniques and pro-
cedures presented in the manual.
UND
Volume III, prepared under the direction of John
Summerhays of Region V, describes the development
of air emissions from remedial activities at hazardous
waste sites. This volume discusses air emissions dur-
ing site cleanup and outlines a protocol for estimating
emissions. It discusses the data needed to calculate the
air emissions and provides case studies to illustrate how
to use the techniques and procedures presented in the
manual.
Volume IV, prepared under the direction of Mark
Garrison of Region III, recommends appropriate disper-
sion modeling protocols and procedures, and air moni-
toring protocols and procedures for conducting air
pathway analyses at Superfund sites. Field support pro-
cedures during remedial/removal activities are also
covered.
Volumes II and III currently are undergoing review.
Interim drafts of these manuals are scheduled for
distribution in December. Volumes I and IV are still in
preparation and will follow the same process.
For further information on the National Technical
Guidance Studies and the four manuals, call Joe
Padgett at (919) 541-5589 or (FTS) 629-5589.
*See related article in the May 1988 Newsletter.
CTC HOTLINE ACTIVE IN H
STATE/LOCAL QUESTIONS
State and local agencies have been making good
use of the Control Technology Center's Hotline in seek-
ing technical assistance on control questions. During a
recent 9-month period, the Hotline received 522 calls.
Questions came in from 47 States, with 85 percent com-
ing from State and local agencies and the remainder
from EPA regional offices, other government agencies,
and universities.
The process of most concern to Hotline callers was
incineration including hospital and municipal waste in-
cineration. Painting and coating, hospital sterilizers,
chrome/electroplating, and fiberglass manufacturing
were also of concern. Of the 522 calls, slightly over half
ANDLING
were asking questions about criteria pollutants, while the
remainder were concerned with air toxics, especially for-
maldehyde, chromium, styrene, and metals.
During this 9-month period, some of the calls led the
CTC to initiate 24 projects of broad interest to the CTC
users. Most of these projects involve emissions and con-
trol while others include software assistance, determina-
tion of emissions, and presentation of workshops.
For help from the CTC Hotline, call (919) 541-0800
or (FTS) 629-0800. Written requests should be sent to
Fred Dimmick, CTC, Emission Standards Division
(MD-13), U.S. EPA, Research Triangle Park, North
Carolina 27711.
8

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STAPPA/ALAPCO TO TRAC
PROGRAM DEVELOPMEIM1
Information is being solicited from State and local
agencies through a questionnaire developed by
STAPPA/ALAPCO and EPA. The questionnaire, which
was scheduled to be distributed in October, will be used
to update the STAPPA/ALAPCO 1984 survey report en-
titled "Toxic Air Pollutants: State and Local Regulatory
Strategies." The questionnaire asks for information on
enabling legislation and regulations, control program
scope and approach, implementation, mechanisms, use
of quantitative risk assessment, level of agency effort
devoted to air toxics, and suggestions for EPA
K AIR TOXICS
r PROGRESS
assistance. Agencies are urged to return completed
questionnaires to STAPPA/ALAPCO by December 1988.
EPA's air toxics program section of OAQPS is develop-
ing a computerized data base to help evaluate the results
of the questionnaire and the progress in building and im-
plementing State and local air toxics programs. A sum-
mary of survey results will be published later.
For more information on the questionnaire, call Bill
Becker, STAPPA/ALAPCO, (202) 624-7864. For more in-
formation on EPA's support, call Martha Keating, EPA,
NPPB, (919) 541-5376 or (FTS) 629-5376.
OAQPS ANNOUNCES NEW
CANCER RISK FROM AIR TO
The Office of Air Quality Planning and Standards
(OAQPS) is undertaking a new study on the air toxics
problems in the United States. In May 1985, EPA
published a report entitled "The Air Toxics Problem in
the United States: An Analysis of Cancer Risks for
Selected Pollutants." A goal of that report, known as the
Six-Month Study, was to define the size and nature of the
air toxics problem in the United States.
The objectives of the current study are to reevaluate
the size and nature of the cancer problem associated
with air toxics in the United States and to determine
whether the conclusions reached in the Six-Month Study
are still valid. This study will not include a revaluation
of EPA's air toxics control strategy, but it will attempt to
identify any obvious impact which the new results may
have on EPA toxics activities. The final product also will
be used as a resource for an anticipated subsequent
review of EPA's current air toxics control strategy.
STUDY ON
XICS IN THE UNITED STATES
The current study will draw upon information and
results contained in some ten existing studies and from
approximately 15 more limited risk assessments that
have been completed for a variety of individual pollutants
and source categories. Among the major studies to be
used are four integrated environmental management
reports; updates on the National Emission Standards for
Hazardous Air Pollutants (NESHAPs), 35-county, and
ambient air quality studies originally prepared for the
1985 report; a study on air toxics emissions from mobile
vehicles; and an ambient air toxics report on the South
Coast Air Basin. A draft external review report is ex-
pected to be complete by the end of January 1989.
Joe Padgett, OAQPS, is the project manager on the
current study. Assisting him in providing an overview of
the work are Dr. Ila Cote, Pollutant Assessment Branch;
Bob Faoro, Monitoring and Reports Branch; and Tom
Lahre, Noncriteria Pollutant Branch. For more informa-
tion, contact Joe Padgett, (919) 541-5589 or (FTS)
629-5589.
NEW AIR TOXICS
DOCUMENTS NOW AVAIL/
Air Species Manual Accompanied by Data Base
Copies of EPA's "Air Emissions Species Manual"
(EPA-450/2-88-002a and b) are ready for distribution.
The two-volume document contains speciation factors
for both volatile organic compounds (VOC) and par-
ticulate matter (PM), enabling the user to determine
compound-specific emissions from a large number of
source categories.
Document users may also obtain both the PM and
IBLE
VOC data bases in a user-friendly personal computer
version. An IBM PC compatible machine with disk drive
and an available 3 megabytes of disk storage are
necessary to support this version.
Further, using the manual has identified a number
of errors in the VOC data base. Some corrections have
been made and an errata sheet is also available.
The manual and errata sheet are available from the
9

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EPA Library, Mail Drop 35, Research Triangle Park, North
Carolina 27711, (919) 541-2777, (FTS) 629-2777. For
details on obtaining the data bases, call Bill Kuykendal
at (919) 541-5372, (FTS) 629-5372.
OAQPS Publishes Organic Liquid
Storage Tank Document
The EPA's Office of Air Quality and Planning Stan-
dards has published "Estimating Air Toxics Emissions
from Organic Liquid Storage Tanks" (EPA-450/4-88-004).
The report is designed to help air pollution control agen-
cies and others in estimating air toxics emissions from
storage tanks.
Single copies are available by writing or calling the
EPA library at the address and telephone number given
above. The process to make this report available for a
fee through the National Technical Information Service
(NTIS) has been initiated. For further information, call
Anne Pope at (919) 541-5373, (FTS) 629-5373.
PROPOSED REPRODUCTIV
ASSESSMENT GUIDELINES
FEDERAL REGISTER
On June 30,1988, proposed guidelines for assess-
ing female and male reproductive risk appeared in the
Federal Register (53 FR 24834 and 24850).* The
guidelines were prepared to help EPA scientists con-
ducting Agency risk assessments and to inform Agency
decision makers and the public about these procedures.
According to the proposed guidelines, risk
assessments will be conducted on a case-by-case basis,
giving full consideration to all relevant scientific informa-
tion. Further, this information will be fully presented in
Agency risk assessment documents. Each assessment
will be evaluated by Agency scientists in terms of uncer-
tainties, assumptions, and limitations as well as scien-
tific basis and rationale.
The guidelines were formulated in part to bridge
gaps in risk assessment methodology and data. EPA
hopes that by identifying these gaps and stressing the
importance of the missing information to the risk assess-
rE RISK
APPEAR IN
ment process it will encourage research and analysis
leading to new risk assessment methods and data.
As with EPA's guidelines for cancer risk assess-
ment" the reproductive assessment guidelines are
based on four steps: (1) hazard identification (both ani-
mal and human studies, as well as pharmacokinetics),
(2) dose-response assessment, (3) exposure assess-
ment, and (4) risk characterization. However, hazard
identification is the primary focus of the reproductive
guidelines.
The guidelines were developed as part of an interoffice
guidelines development program under the auspices of
OHEA and ORD. Work on the proposed guidelines
began in 1985.
""Guidelines for Carcinogenic Risk Assessment,"
September 24, 1986, 51 FR 33992.
URBAN AIR TOXICS WORK
TO BEGIN IN FEBRUARY
EPA and STAPPA/ALAPCO will offer workshops on
Urban Air Toxics in Southern California (February 15-17,
1989), Denver (March 8-10,1989), and Baltimore (April
19-21,1989). These are two-and-a-half-day, information
exchange workshops to share information and promote
discussion on urban air toxics, including evidence
assembled to date and air quality planning and manage-
ment activities by State and local agencies. The
workshops are being co-hosted by State and local
agencies that have recently completed major urban air
SHOPS
toxics studies. State and local experiences in assessing
and mitigating urban air toxics as well as the latest EPA
information will be presented and discussed.
Registration is reserved for government agency per-
sonnel until one month prior to workshops. The cost is
$40. Names of interested nongovernment personnel will
be placed on a waiting list for registration. Contact Bill
Lamason, Noncriteria Pollutant Programs Branch,
MD-15, U.S. EPA, Research Triangle Park, North
Carolina 27711, (919) 541-5374 or (FTS) 629-5374.
NEED HELP?
If your agency needs help in finding information on
a specific air toxics question, you can announce that
need in the National Air Toxics Information Clear-
inghouse Newsletter. Your colleagues from other State
10

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or local agencies who have such information will be able
to contact you with assistance. In addition, the Clear-
inghouse staff would like to receive your ideas for future
Newsletter articles. To list an information need in the next
issue or to submit an article or a suggestion for a future
Newsletter article, please call Alice Pelland, Radian Cor-
poration, (919) 541-9100.
CTC AND AIR RISC HOTLINES
ARE READY TO ASSIST
STATE AND LOCAL AGENCIES
For answers to control technology questions, State
and local air agencies can call EPA's Control Technology
Center (CTC) Hotline at (919) 541-0800.
Help with questions on health effects, exposure, or
risk assessment associated with air toxics is available
from EPA's Risk Information Support Center (Air RISC)
Hotline at (919) 541-0888.
The National Air Toxics Information Clearinghouse Newsletter is published by the National Air Toxics In-
formation Clearinghouse to assist State and local agencies making decisions on noncriteria pollutant emissions.
The Clearinghouse is being implemented by the U.S. Environmental Protection Agency, Emission Standards
Division, Pollutant Assessment Branch as part of a joint effort with the State and Local Air Pollution Control Of-
ficials (ALAPCO). The National Air Toxics Information Clearinghouse Newsletter is prepared by Radian Cor-
poration under EPA Contract Number 68-08-0065, Work Assignment 1. The EPA Project Officer is Scott Voorhees,
EPA Office of Air Quality Planning and Standards, Research Triangle Park, North Carolina 27711, Telephone:
(919)541-5348. The Radian Project Director is Alice Pelland, P.O. Box 13000, Research Triangle Park, North
Carolina 27709, (919)541-9100.
The Newsletter is prepared primarily for State and local air pollution control agencies and is distributed
free of charge. Those wishing to report address changes may do so by writing Meredith Haley, Radian Cor-
poration, P.O. Box 13000, Research Triangle Park, North Carolina 27709. Please contact the Project Officer either
with any comments you might have pertaining to this newsletter or with suggestions for future newsletters. Ar-
ticles in the newsletter are written by Radian Corporation or EPA staff unless otherwise indicated.
The views expressed in the National Air Toxics Information Clearinghouse Newsletter do not necessarily
reflect the views and policies of the Environmental Protection Agency. Mention of trade names or commercial
products does not constitute any endorsement or recommendation for use by EPA.
11

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Scott Voorhees
Pollutant Assessment Branch
U.S. Environmental Protection Agency
MD-13
Research Triangle Park, NC 27711
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