NATIONAL AIR TOXICS INFORMATION
CLEARINGHOUSE NEWSLETTER
<»EFV\
Office of Air Quality Planning and Standards Volume 5 Number 5
Research Triangle Park, North Carolina 27711 July 1988
~D)f\ fl A fl A FState and Territorial Air Pollution Program Administrators
rw u Association of Local Air Pollution Control Officials
IN THIS ISSUE
STATE AND LOCAL PARTICIPATION IN CLEARINGHOUSE CONTINUES TO GROW	1
STATE/LOCAL AGENCY SPOTLIGHTS PUGET SOUND AIR POLLUTION
CONTROL AGENCY	2
EPA INTRODUCES AIR RISC - SUPPORT ON HEALTH, EXPOSURE AND RISK ASSESSMENTS	4
CALIFORNIA IMPLEMENTS AIR TOXICS "HOT SPOTS" INFORMATION AND
ASSESSMENT PROGRAM	5
METHODOLOGY TO DERIVE INHALATION REFERENCE DOSES DESCRIBED	6
SARA SECTION 313 SUPPORT ACTIVITIES UNDERWAY	7
GENETIC ACTIVITY PROFILE METHODOLOGY AND DATA BASE DESCRIBED	8
NEW TECHNOLOGY AVAILABLE TO CONTROL ETHYLENE OXIDE EMISSIONS
FROM HOSPITAL STERILIZERS	10
ERA'S INTEGRATED RISK INFORMATION SYSTEM MADE AVAILABLE TO THE PUBLIC	10
STATE AND LOCAL PARTICIPATION IN
CLEARINGHOUSE CONTINUES TO GROW
This year, the number of State and local air quality
management agencies participating in the National Air
Toxics Information Clearinghouse activities has grown
to a record level. Currently, 128 agencies are submitting
information to the Clearinghouse. This includes 52 State
and territorial agencies and 76 local agencies.
Agencies Can Enter and
Edit Data Base Information
Since 1987, individuals from State and local agen-
cies who request authorization have been able to directly
enter and edit data contained in the NATICH data base
for their agencies. This allows for continuous updating
of the data base information through a set of user-
friendly data entry programs. To date, 63 agencies have
received authorization for direct data entry and editing.
This represents 49 percent of the agencies submitting
data to NATICH. For more information on direct data en-
try and editing contact the Clearinghouse staff at (919)
541-0850 or (FTS) 629-0850.
NATICH Demonstration Diskette Now Available
Some of the types of data and retrieval options
available through the NATICH data base are illustrated
by a computer-based floppy demonstration diskette. This
diskette contains only a subset of the NATICH data base
and is designed to encourage agencies to take steps to
access the mainframe computer. To obtain a copy of this
diskette, please send an unformatted double sided/dou-
ble density, 51/4 inch diskette to Nancy Riley, U.S. EPA,
MD-13, Research Triangle Park, NC 27711.
Clearinghouse Reports to Be Available Soon
The annual hardcopy report of information con-
tained in the NATICH data base will include information
submitted by State and local agencies through June 30.
It is scheduled for publication later this summer and will
be distributed in September. In addition, the annual up-
dates of the bibliography and ongoing research reports
will also be published and distributed later this summer.
This year, 283 citations for reports and Federal Register
notices and 196 ongoing research and regulatory
development projects have been added to the NATICH
data base. This represents a 20 percent increase in the
bibliographic file and an 83 percent increase in the ongo-
ing project file over last year's total.

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These documents will be 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 (919)
541-0850 or (FTS) 629-0850. Members of the private sec-
tor will be able to obtain copies through the National
Technical Information Service (NTIS), (703) 487-4650 or
by written request and advance payment through Bar-
bara Maxey, Radian Corporation, Post Office Box
201088, Austin, Texas, 78720-1088. Ms. Maxey should be
contacted for document prices, once they are available
at (512) 454-4797, extension 5224.
STATE/LOCAL AGENCY SP<
PUGET SOUND AIR POLLU
by Naydene Maykut, Air Toxics Coordinator, Put
The Puget Sound Air Pollution Control Agency
(PSAPCA) is a local agency charged with the air pollu-
tion control of sources in the Puget Sound area of
Washington. Several projects are underway to evaluate
and mitigate air pollution problems in this area. One proj-
ect is the development of a program to implement the
State of Washington's legislation and regulation for
controlling woodstove emissions* This legislation was
passed by the Washington legislature in the spring of
1987,	and the regulation became effective on January 15,
1988.	Provisions of the legislation include education, cur-
tailment of residential wood combustion on poor air
quality days, prohibited fuel types, opacity standards and
emission performance standards for wood burning
devices. Current PSAPCA activities on air toxics,
specifically the evaluation of wood combustion emis-
sions, are described below.
Toxic Prioritization Ranks Residential Wood
Combustion as Highest Risk Source
A simple methodology was used to rank the risks
due to exposure to the toxic chemicals contained in
PSAPCA's emissions inventory. This consisted of simp-
ly dividing the emissions of the chemicals by their
respective Acceptable Ambient Levels (AALs). The AALs
used were taken from the New Source Review
Guidelines proposed by the State of Washington. The
top four chemicals of risk that emerged from this screen-
ing exercise were the same four identified as the highest
risk in EPA's 1985 Five City Study: benzo(a)pyr0ne, for-
maldehyde, benzene and chromium. In addition, the top
12 chemicals identified were in close agreement with the
highest ranked toxic chemicals of concern in Oregon.
The PSAPCA's emissions inventory indicates that
within its jurisdiction the source responsible for 89 per-
cent of the top-ranked chemical of concern, benzo(a)-
pyrene, and 9 percent of the fourth-ranked chemical of
concern, formaldehyde, is residential wood combustion.
Calculations of relative risk for the highest risk area
sources show that residential wood combustion presents
the highest relative risk. These calculations were made
by dividing the emissions by the corresponding AALs for
each chemical, for each high risk area source and ad-
ding the relative risks for each chemical to obtain a total
yrLiGHit
TION CONTROL AGENCY
let Sound Air Pollution Control Agency
relative risk. This relative risk methodology depends on
the assumptions that relative risk is linearly proportional
to emissions, inversely proportional to the AAL, and that
the total relative risk can be obtained by adding the
relative risks for each chemical.
If such a simplistic methodology which takes into
account both potency (AAL) and potential exposure
(emissions) can be legitimately used to rank high risk
sources of concern then, clearly, residential wood com-
bustion presents the highest risk of all these sources.
This conclusion agrees with a recent ranking exercise
undertaken by the State of Oregon in which residential
wood combustion was ranked as the highest risk source
both for carcinogens and noncarcinogens. Additional
sources of concern identified in the emissions inventory
were chrome plating facilities (hexavalent chromium)
and motor vehicles, gasoline handling and automotive
refinishing (benzene).
Urban Mitigation Study Conducted to
Collect Ambient Air Data
A study focusing on identifying air toxics in the Seat-
tle urban ambient air was initiated by the University of
Washington in the fall of 1986." A residential high
impact site was identified by screening night-time air
quality values in north Seattle with a mobile integrating
nephelometer. Results of the initial screening phase
showed significant differences in ambient levels of par-
ticulates between ridge and valley locations. One of the
highest impacted valley locations was chosen as the
final residential site.
Air samples were taken at both the selected residen-
tial valley location (Lake Forest Park) and an industrial
site (Duwamish) in January and February 1988. Con-
tinuous monitoring was performed using integrating
nephelometers. Harvard Samplers were used for par-
ticulate measurements. Both Teflon™ and quartz fiber
filters were used in the Harvard Samplers and subse-
quently analyzed by X-ray fluorescence (XRF) and gas
chromatography/mass spectrometry (GC/MS)
methodologies. Results from the analyses were used for
source contribution analysis by the chemical mass
balance equations using both the metals detected by
XRF and the organics measured by GC/MS.

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Results Showed High Levels of
Particulates and Toxics
A high correlation exists between particulates
measured by the integrating nephelometer and the
Harvard Sampler at Lake Forest Park (R2 = 0.98). The
Harvard Sampler was used in this study to measure par-
ticulate mass concentrations less than 10 microns
(PM10). Although the Harvard Sampler is not a reference
or equivalent PM10 method, there was a high correlation
between co-located EPA approved PM^ sampler and
Harvard Samplers (R2 = 0.96) in this study. The period
of sampling for the integrating nephelometer was
October 24,1987, through March 12,1988, while the Har-
vard sampling period was January 8 through March 3,
1988. The highest 24-hour mass concentrations
measured by the Harvard sampler were: Jan 27:133, Jan
25:108, Jan 24:150, and Jan 23:96 ug/m3. However,
using the correlation between the nephelometer and the
Harvard Sampler to extend the data set, four values ex-
ceeding 150 ug/m3 were predicted for the 1987-1988
heating season. The four highest 24-hour Harvard
Sampler mass concentrations were predicted to have oc-
curred in December 1987: Dec 19(204), Dec 25(187), Dec
24(172), and Dec 26(155) ug/m3. Chemical Mass
Balance (CMB) model results for the Lake Forest Park
station apportioned the mass as presented in Table 1.
Metal and organic data from 20 filters were analyzed for
this source apportionment. Clearly, residential wood
combustion was the major source of particulates in the
Lake Forest Park area during this period.
TABLE 1.
CHEMICAL MASS BALANCE RESULTS,
LAKE FOREST PARK

Marina
Road
Dust
MoMla
Wood-
burning
Daytime
(7 a.m. - 7 p.m.)
4.0%
7.2%
44.0%
44.7%
Night-time
(7 p.m. - 7 a.m.)
0.9%
0.2%
20.6%
78.7%
Mass weighted
1.8%
2.0%
27.7%
68.4%
average of all filters
In addition to source apportionment, the concentra-
tions of particulates and of various chemical species
were measured during this study. Frequency distribu-
tions of the benzo(a)pyrene concentrations measured
during the study at both the Lake Forest Park and
Duwamish sites are shown in Figure 1. Benzo(a)pyrene
concentrations at the residential site (Lake Forest Park)
were higher than at the industrial site (Duwamish). The
Washington State Guideline AAL for benzo(a)pyrene, 0.6
nanograms per cubic meter (ng/m3) (24-hour average),
is shown for reference.
Measured values of benzo(a)pyrene at both sites
were much higher than the guideline AAL. Measured
concentrations in the residential neighborhood (Lake
Forest Park) were 3.5 to 50 times higher than the AAL.
Study Has Serious Implications for
Residential Area Exposure
Residential wood combustion has been shown to
be a major source of particulates and toxics in residen-
tial areas. In this study, residential wood combustion
contributed the highest percentage of the mass to ex-
ceedingly high concentrations of benzo(a)pyrene, a
known carcinogen. Study results also show a high pro-
bability of ambient exposure in excess of particulate
standard levels and benzo(a)pyrene guideline values in-
dicating the possibility of excess public health risk. The
high residential levels have serious implications in terms
of excess risk since most people spend more time (16
versus 8 hours) in residential areas, while sensitive sub-
populations - children, the elderly and the sick - spend
even higher percentages of their time in residential
areas. The excess risk suggested by these measured
and predicted values agrees with ranking procedures
identifying residential wood combustion as a high risk
source.
FIGURE 1.
CONCENTRATIONS OF AIRBORNE BENZO(A|PYRENE*
100
ST 10
li
(L
sr 1
0.1
Lake Forest Pk
Duwamish (KSS)
0.6
' ¦
""Washington ITtate "SuideiTne
(24 hour average)
-I	III
5 10 25 50 75
Percent of data less
than stated value
90 95
99
12 hour averages
Study Recommendations Highlighted
Since this and numerous other studies have indi-
cated that residential wood combustion*** is a high risk
toxic source, a strong control program must be imple-
mented in those areas where the problem exists. By
definition, an effective program would need to go beyond
existing programs. The study recommends that massive
education efforts be initiated at all governmental levels
stressing the risks from residential wood combustion and
its potential health effects. In addition, effective enforce-
ment is needed to protect the public during high risk
days.
PSAPCA Experience Described
The PSAPCA has been involved in the past two
3

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years in the local and State of Washington efforts to
educate the public about the pollution problems and the
health effects associated with residential wood combus-
tion. This has involved working with the media, presen-
ting a conference titled "Woodsmoke, Health and
Washington," making numerous public presentations
and working with local governments to develop educa-
tion programs. The State of Washington woodsmoke
regulation makes it unlawful to use a woodstove,
woodstove insert or fireplace (unless it is a sole source
of heat) on days the State declares an "episode" or on
days when the State or any local agency declares
"impaired air quality." (Certified stoves are exempted
from impaired air quality curtailment until 1990.) The
PSAPCA has developed a system for declaring "im-
paired air quality" whenever the particulate Pollutant
Standards Index (PSI) is predicted to exceed 70, unless
meteorological conditions are forecast to improve within
12 hours. The PSAPCA enforcement personnel are in-
structed to enforce mandatory curtailment, focusing on
nonattainment and known problem areas. Currently, an
evaluation of PSAPCA's woodstove program is underway
and recommendations for the next heating season are
being developed.
For more information on air toxics activities in Puget
Sound, contact Naydene Maykut, Air Toxics Coordinator,
(206) 344-7335.
*See related article in June 1987 issue.
"University of Washington researchers were Drs. Tim
Larson and Dave Kalman and doctoral candidate Shi
Zoom Wang.
***See related article in other Newsletter issues,
especially June 1986 and September 1987.
EPA INTRODUCES AIR RISC - SUPPORT ON HEALTH
EXPOSURE AND RISK ASSESSMENTS
The EPA recently began operating its newest tech-
nology transfer center, the Air Risk Information Support
Center (Air RISC). The Air RISC provides technical
assistance to State and local air pollution control agen-
cies and EPA Regional Offices with health, exposure
and risk assessment questions pertaining to toxic (i.e.,
noncriteria) air pollutants. The Air RISC is patterned after
the Control Technology Center (CTC)* and, like the CTC,
provides assistance in three categories: (1) a hotline, (2)
technical assistance and (3) technical guidance, as ex-
plained below.
First, the hotline refers the caller quickly to EPA ex-
perts "in the know" on a certain subject area. These
contacts have access to recent EPA documents and will
make every attempt possible to provide additional infor-
mation as requested. Depending on the nature and
immediacy of the request and availability of resources,
responses to questions via the hotline will be given in
a timeframe ranging from within minutes to within days.
Where more time and resources are involved in respon-
ding to a request than can be reasonably accomplished
within a week or two, and if this is consistent with the re-
questor's needs, the second category, technical
assistance, can be used. For requests handled as
technical assistance projects, reports generally will be
issued after several months of technical effort. Finally,
for questions likely to have broad national interest, the
Air RISC can produce technical guidance documents.
Other methods of technical guidance may be used as
well - such as workshops and videotapes.
It is important to note what Air RISC will not do. First,
it will not answer risk management questions, such as
whether a permit should be issued in a given cir-
cumstance, or whether a population exposure to a
specific pollutant concentration is acceptable. The Air
RISC is a "technology transfer" center, not a policy
development center or a place to issue risk management
decisions for State or local governments. The Air RISC
will not entertain questions from the general public, the
private sector or public interest groups. Questions from
contractors will be answered only if the contractor is
working for a State or local air pollution control agency
and the State or local agency project manager calls first.
Although the Air RISC is a cooperative effort among
several groups within the Office of Air and Radiation
(OAR) and the Office of Research and Development
(ORD), the leads for this project are the Pollutant Assess-
ment Branch (PAB) within the Office of Air Quality Plan-
ning and Standards (OAQPS) and the Environmental
Criteria and Assessment Office (ECAO) within the Office
of Health and Environmental Assessment (OHEA), both
located in Research Triangle Park, North Carolina. Other
groups providing assistance and expertise are the Center
for Environmental Research Information, the Environ-
mental Criteria and Assessment Office (Cincinnati), the
Carcinogen Assessment Group, the Exposure Assess-
ment Group, the Reproductive Effects Assessment
Group, the Health Effects Research Laboratory and the
EPA Library (RTP).
During the planning stages for the Air RISC, EPA met
with representatives of State and Territorial Air Pollution
Program Administrators (STAPPA) and the Association of
Local Air Pollution Control Officials (ALAPCO). The STA-
PPA and ALAPCO representatives included managers,
scientists and engineers. The purposes of these meet-
ings were to discuss the planned scope of services and to
ensure that the services EPA is developing will in fact
meet the State and local air programs' wants and needs.

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The Air RISC hotline telephone number is (919)
541-0888 or (FTS) 629-0888 and operates between the
hours of 8:00 a.m. and 5:00 p.m. (Eastern Standard
Time), Monday through Thursday, and from 8:00 a.m.
to 4:00 p.m. on Fridays. Even though there has been
limited publicity of the Air RISC to date, the staff has
been responding to approximately two calls per day over
the last two months. Questions have spanned a broad
spectrum from very technical and specific to very broad
and general in the areas of health assessment, risk
assessment, risk characterization and risk communica-
tion. An upcoming issue of the Newsletter will present
several example questions and responses that Air RISC
staff have fielded. For general questions about the Air
RISC, call Karen Blanchard, U.S. EPA, OAQPS, PAB,
(919) 541-5503, (FTS) 629-5503 or Winona Victory, U.S.
EPA, ECAO, (919) 541-4828, (FTS) 629-4828. For
technical questions on health, exposure or risk assess-
ment on air toxics, EPA Regional Office, State and local
air programs staff should call the Air RISC hotline at (919)
541-0888 or (FTS) 629-0888.
*See related Newsletter articles, December 1986, June
1987, January 1988 and March 1988.
CALIFORNIA IMPLEMENTS
INFORMATION AND ASSE!
by Janette Brooks; California Air Resources Boai
Bill and Program Explained
In September 1987, Governor Deukmejian signed
into law Assembly Bill (AB) 2588, the Air Toxics "Hot
Spots" Information and Assessment Act. Under AB
2588, stationary sources are required to report the type
and quantity of certain substances their facilities routine-
ly release into the air. The goals of the AB 2588 program
are to identify facilities that create air toxics "hot spots,"
to collect emissions data, to ascertain health risks, and
to notify nearby residents, when appropriate, of signifi-
cant risks. Air toxics hot spots are areas of exposure with
elevated risks of adverse health effects resulting from
routine emissions of toxic air pollutants.
The process established by AB 2588 requires facili-
ty owners or operators to prepare and submit to their air
pollution control districts an air toxics emissions inven-
tory plan, a subsequent emissions inventory, and - for
high priority facilities - a risk assessment. The risk
assessment must be reviewed by the California Depart-
ment of Health Services and approved by the local air
pollution control district. If the district judges that signifi-
cant health risks are associated with facility emissions,
operators must notify all exposed individuals in the
vicinity.
The California Air Resources Board (CARB) is re-
quired to develop a program to make the emissions data
collected under AB 2588 available to the public, and, if
requested, districts must make health risk assessments
available for public review. Districts must also publish an-
nual reports summarizing the results and progress of the
health risk assessment program.
The AB 2588 program will complement CARB's ex-
isting air toxics control program by providing exposure
and risk information necessary to establish priorities and
regulatory action.
How the AB 2588 Process Works
Assembly Bill 2588 requires CARB to compile and
AIR TOXICS "HOT SPOTS"
SSMENT PROGRAM
rd. Stationary Source Division
maintain a list of substances posing a chronic or acute
health threat when they are present in the air. The bill
identifies, by reference, about 310 substances to be in-
cluded initially in the list. The list will be used in deter-
mining which facilities are covered by the AB 2588 re-
quirements and will be used by CARB to develop report-
ing guidelines for various types of facilities. The Board
may make changes to the list based on criteria outlined
in the law; however, about 75 substances required by law
to be on the list may not be removed.
A facility is subject to AB 2588 if it (1) manufactures,
formulates, uses, or releases a listed substance (or
substance which reacts to form a listed substance), and
(2) emits 10 tons or more per year of total organic gases,
particulate matter, nitrogen oxides or sulfur oxides. Also
covered are facilities listed in any existing toxics use or
toxics air emission survey, inventory, or report released
or compiled by an air pollution control district.
Assembly Bill 2588 requires facilities subject to the
law to prepare air toxics emissions inventories. Facility
operators must first submit to the local air pollution con-
trol district a proposed emission inventory plan showing
how emissions will be measured or calculated. The
district must approve, modify, or return the inventory plan
to the operator for revision within 120 days. Guidelines
for preparing emission inventory plans are to be
developed by CARB in consultation with local air pollu-
tion control districts by May 1,1989.
Once a district approves a plan, the operator will
have to implement the plan and submit the emissions
data to the district within 180 days. Emissions inventories
will have to be updated biennially according to pro-
cedures developed by CARB. For certain classes of
facilities, districts will have to prepare industrywide in-
ventories; individual facility reports will not be required.
Districts will determine which facilities will be covered
by industrywide inventories based on conditions such
as emission of a single hazardous material, economic
5

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hardship, and small business status. Facilities emitting
25 tons per year or more of total organic gases, par-
ticulates, nitrogen oxides, or sulfur oxides must submit
inventory plans by August 1,1989, and facilities emitting
10 to 25 tons per year must submit their plans by August
1,1990.
To place industrial facility air toxic emissions into
perspective, CARB is required to compile emissions in-
ventory data for mobile, natural, and area sources not
subject to district permit requirements.
After reviewing the data, districts must then rank
facilities for purposes of risk assessment into high, in-
termediate, and low priority categories. Those facilities
that the districts designate as high priority must submit
a risk assessment to the district for approval. Risk
assessments will be reviewed by districts and by the
California Department of Health Services. Facility
operators will then have to notify all exposed persons of
the risk assessment results if the district determines that
there is a significant health risk associated with emis-
sions from the facility.
Assembly Bill 2588 prescribes stiff penalties for
failure to comply with or for knowingly submitting false
information. Depending on the violation, civil penalties
range from $500 to $25,000 for each day the infraction
remains uncorrected.
To recover costs of the program, CARB will adopt
a fee schedule to assess a fee upon the operator of every
facility subject to AB 2588 requirements. The fees will
cover program costs incurred by the air pollution con-
trol districts, CARB, and the Department of Health Ser-
vices. Districts must notify each person subject to the fee
and assess an administrative penalty if the fee is not paid
within 60 days of receipt of the notice. The CARB will
adopt the fee schedule by August 1, 1988.
In summary, AB 2588 establishes a formal air tox-
ics emissions inventory and risk quantification program
for districts to manage. The goal of AB 2588 is to iden-
tify high risk point sources, to collect emissions data in-
dicative of routine predictable releases of toxic
substances to air, to evaluate health risks from exposure
to these emissions and to notify nearby residents of
significant risks. Information gathered from this program
complements the GARB's existing toxic air contaminants
program by locating sources of substances not current-
ly under evaluation and by providing exposure data
needed to develop regulations for control of toxic
pollutants.
For more information, call Robert D. Barham, Chief,
Toxic Air Contaminants Identification Branch, California
Air Resources Board, at (916) 322-7072.
METHODOLOGY TO DERIV
REFERENCE DOSES DESCRI
The Office of Health and Environmental Assess-
ment within EPA's Office of Research and Development
has developed an interim methodology for estimating in-
halation reference doses (RfDs). An RfD is defined as
an estimate (with uncertainty spanning perhaps an order
of magnitude) of a daily exposure to the human popula-
tion (including sensitive subpopulations) that is likely to
be without appreciable risk of deleterious effects during
a lifetime. In the past, RfDs have been developed to
evaluate chronic oral exposures to environmental
pollutants - for example, pollutants in drinking water. An
RfD is developed for a systemic toxicant where there is
an identifiable exposure threshold (for both the individual
and for the population) below which adverse health ef-
fects are not observed. Similar to the concept of "accep-
table daily intake" levels (ADIs), RfDs are based upon
a rigorously defined methodology and an Agencywide
review and verification process.
Inhalation RfDs are derived in generally the same
way as the oral RfDs. The data on health effects are
reviewed, a critical effect is selected, and the appropriate
no-observed-adverse-effect level (NOAEL) or lowest-
observed-adverse-effect level (LOAEL) is selected.
Order of magnitude uncertainty factors are applied to the
NOAEL or LOAEL to derive the RfD. Uncertainty factors
are used to account for inter- and intraspecies variability,
'E INHALATION
BED
subchronic versus chronic exposure data, and use of a
LOAEL versus a NOAEL. An additional modifying fac-
tor that is greater than zero and less than or equal to ten
is incorporated to account for scientific uncertainty in the
toxicological data base not explicitly treated with stan-
dard uncertainty factors.
To address issues that are specific to inhalation, the
interim methodology document provides a detailed
discussion of factors that determine inhaled dose, in-
cluding respiratory anatomy and physiology, physico-
chemical properties of the inhaled pollutant, and
clearance mechanisms. Discussions of these areas
include currently available information on interspecies
variability. The interim methodology document also
discusses the exposure technology used in experi-
mental inhalation toxicology and the issues related to
evaluating study design that are specific for inhalation
exposures - such as mode of inhalation (oral versus
nasal), characterization of the inhaled pollutant, etc.
On the premise that interspecies extrapolation of
dose can be better defined for inhalation exposure than
for oral exposure, the methodology for deriving inhala-
tion RfDs includes consideration of the factors that con-
trol inhaled dose and the significant mechanisms by
which inhaled pollutants are deposited or taken up by
the lung. For example, for insoluble, nonhygroscopic
6

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aerosols, regional deposited dose ratios (RDDRs) can
be calculated in order to adjust the exposure effect level
for dosimetric differences between the experimental
species and humans. The regional deposited dose is the
dose of an exposure aerosol deposited in a given region
of the respiratory tract for the experimental species be-
ing evaluated. Work is underway to incorporate
clearance components into these ratios to estimate
regional retained doses, a more appropriate measure for
chronic exposure conditions.
Tabulated RDDRs for species commonly used in
risk assessment will be available in the fall of 1988.
Tabulated regional retained dose ratios (RRDRs), a
detailed description of their derivation, and limitations
on their application will be provided in a technical sup-
port document scheduled to be available in June 1988.
A similar technical support document with adjustment
factors for other types of inhaled pollutants such as
gases and vapors is also under development.
The interim methodology document also addresses
the development of multiple, duration-specific RfDs for
short-term exposures. These short-term RfDs would be
derived in the same way and use the same uncertainty
factors as chronic RfDs. Current unresolved issues
regarding short-term RfD development include the
equivalence of exposure durations between humans and
animals and the validity of extrapolation between ex-
posure durations.
For more information on the methodology to derive
inhalation RfDs, contact Annie Jarabek, U.S. EPA, En-
vironmental Criteria and Assessment Office, Research
Triangle Park, North Carolina, (919) 541-4847, (FTS)
629-4847 or Dan Guth, U.S. EPA, Office of Air Quality
Planning and Standards, Research Triangle Park, NC,
(919) 541-5340, (FTS) 629-5340.
SARA SECTION 313 SUPPOI
By the first of July 1988, approximately 30,000
chemical manufacturers, processors and users were re-
quired to submit information to EPA and State agencies
on their emissions to the environment of over 300
chemicals and categories of compounds. This data sub-
mission, which was mandated by Section 313 of the
Superfund Amendments and Reauthorization Act of
1986 (commonly referred to as SARA), represents a new
and challenging source of information for evaluation by
the public and governmental agencies. To help meet this
challenge, the EPA has taken steps to support State and
local governments in their activities to understand, evalu-
ate and use the data, and in their efforts to respond to
inquiries from the public regarding the Section 313 data.
Coordinated Activities Described
As a first step, a major emphasis has been placed
by EPA on coordination of activities by the many EPA
offices affected by the SARA statutes. With respect to
Section 313, roles have been defined for the various
headquarters and regional offices of EPA. The Office of
Toxic Substances (OTS) has overall lead in development
of support materials (described below) and in coordina-
tion with groups such as the State Emergency Response
Commissions (SERCs) and Local Emergency Planning
Committees (LEPCs). The Office of Air Quality Planning
and Standards (OAQPS), in consultation with OTS, has
taken the lead in coordinating with the EPA regional air
offices and State and local air agencies. The OAQPS has
managed, for the air offices, the distribution of support
materials and the development of a network for respon-
ding to public inquiries.
With many groups involved in the SARA activities,
it is very important that lines of communication be estab-
lished at all levels of government between the various
RT ACTIVITIES UNDERWAY
environmental media offices, the SERCs, LEPCs, and
the State recipient of the SARA 313 data. Through these
lines of communication, each level of government will
be in the best position to understand and use the data
and respond to any questions raised by the public.
The OAQPS philosophy has been to rely on the ex-
isting lines of communication and support within the air
programs that have served us well for many years. The
EPA, the State and Territorial Air Pollution Program
Administrators (STAPPA) and the Association of Local Air
Pollution Control Officials (ALAPCO) view State and
local agencies as the primary recipients and responders
to public inquiries. The EPA will support the State and
local agencies through development of informational
materials and through our existing response programs.
In June, prior to the deadline for facility submissions, the
EPA distributed an information package to the State and
major local air agencies. The package, which was
developed by OTS in consultation with the other EPA pro-
gram offices, included:
•	a background information brochure for distribu-
tion to citizens;
•	a question and answer booklet to aid agency
personnel in their understanding of the SARA
313 data, and to use in responding to questions
from the public;
•	a list of State contact names to aid communica-
tion efforts;
•	an overview document on the regulatory status
of the chemicals included in SARA 313;
•	a description of existing support programs for air
agencies, such as the National Air Toxics Infor-
mation Clearinghouse and the Control
Technology Center; and
•	a checklist to order additional support materials.
7

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In addition, over 150 fact sheets on the specific
chemicals included in the SARA 313 chemical list have
been developed and will be distributed shortly. These
fact sheets, developed by the State of New Jersey, pro-
vide an overview of health effects data on the chemicals.
Additional fact sheets are currently under development.
These materials provide a foundation upon which air
management agencies, as well as SERCs and LEPCs,
can build in developing procedures for understanding
and responding to the data submitted by industry under
the SARA 313 provisions.
Toxic Release Inventory System Data Base
Under Development
At present, the EPA is building a data base for stor-
ing and retrieving the SARA 313 data. This data base,
referred to as the Toxic Release Inventory System (TRIS),
is located on the EPA's mainframe computer in Research
Triangle Park, North Carolina. The tentative plan is for
governmental agencies to have direct access to TRIS
reporting programs on the mainframe computer. The
public will have access to a copy of TRIS placed on the
computer system of the National Library of Medicine. It
currently appears that the TRIS information will be
available in the spring of 1989.
In summary, the data submitted by industry on
releases to the environment of over 300 pollutants will
provide a significant challenge to EPA and other govern-
mental agencies. The challenge is not only in the need
for agencies to manage the collection and classification
of information, but also in the interpretation and use of
the data in keeping with the spirit of the Superfund
amendments. The information will also present a
challenge to agencies faced with responding to ques-
tions from the public regarding perceived public health
risks and the actions that agencies and industry are tak-
ing to minimize these risks. For further information on
OAQPS activities underway in support of State and local
air management agencies, call Robert Schell, U S EPA
OAQPS, at (919) 541-5519 or (FTS) 629-5519.
GENETIC ACTIVITY PROFI
AND DATA BASE DESCRIBE
A methodology has been developed to display and
evaluate quantitative information on genetic toxicants
generated from multiple test systems for purposes of
hazard/risk assessment. The EPA's Health Effects
Research Laboratory, Genetic Toxicology Division,
developed the genetic activity profiles which were used
by the International Agency for Research on Cancer
(IARC) Working Group in the preparation of IARC
Monographs Supplement 6, "Chemicals, Industrial Pro-
cesses and Industries Associated with Cancer in
Humans." These profiles constitute a quantitative data
base on the genetic and related effects of nearly 200
chemicals for which some data are available on car-
cinogenicity in humans. This information should be
useful for purposes of comparative chemical hazard
assessment. Together with information derived from
animal carcinogenicity studies and human
epidemiological studies, assessments may be made
regarding potential human health risks associated with
exposure to these chemical substances.
What Is a Genetic Activity Profile?
A genetic activity profile is a bar graph representing
short-term assays and doses of a specific chemical
required to produce responses in those assays. The con-
cept of presenting graphically the results from short-term
tests originated from the need to represent the available
qualitative and quantitative data in a standardized for-
mat.
An example of a genetic activity profile for
dibromochloropropane is given in Figure 1. Accompa-
nying each profile is a profile listing. A subset of the
LE METHODOLOGY
sD
profile listing for dibromochloropropane is given in Table
1. Each entry summarizes the test results and identifies
the source of that information. In the figure, the x-axis
respresents the assays plotted in a phylogenetic se-
quence. Values on the y-axis are the logarithmically
TABLE 1.
A SUBSET FOT THE GENETIC ACTIVITY
PROFILE LISTING FOR DIBROMOCHLOROPROPANE
Don
1M End RaSUltl fLEO
Coda Point No Act* Act' or HID) Short Citation
1	BSDd D® - - 300 Shiau, Huff, Wells 169,
1980
2	SAO1 Gg - + 118 Stolzenberg and Hine
59, 1980
3	SAO G + 500 Moriya, Ohta,
Watanabe 185,1983
4	SAO G + 59 Stolzenberg and Hine
1149, 1979
5	SAO G 0 + 50 Blum and Ames 17,
1977
6	SA5h G + 25 Biles, Connor, Trieff
301, 1978
a0 « not tested.
- « negative.
+ » positive.
bNo act - no exogenous metabolic system employed.
°Act - an exogenous metabolic system employed.
dBSD - Bacillus subtilis rec strains, differential toxicity.
eD » DNA damage.
*SA0 - Salmonella typhimurium TA100, reverse mutation.
flG » Gene mutation.
SA5 - Salmonella typhimurium TA1535, reverse mutation.
8

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FIGURE 1.
ACTIVITY PROFILE OF SHORT-TERM TESTS ON DIBROMOCHLOROPROPANE IN PHYLOGENETIC SEQUENCE
Test I
Codes
-2 ->
-3-
Test f
Codes I
DiBnomncHLunupncjpnnF
96- '2- a
S S SS B
A A AA S
0 5 9S M
D D 0 00
MMMMI
G X H NA
A-
transformed lowest effect doses (LED) and highest in-
effective doses (HID) tested. All doses are first converted
to common units (i.e., ug/ml, or mg/kg body weight/day),
then to log dose units for plotting. Figure 2 shows this
conversion. The term "dose," as used here, does not
take into consideration length of treatment or exposure
and therefore may be considered synonymous with con-
centration. Profile-line height (the length of each bar) is
a function of the LED or HID for a given bioassay.
Positive results are projected upwards, negative results
are projected downwards. Levels of log dose units be-
tween 1 and -1 define a "zone of uncertainty" in which
positive results are reported at very high doses (10,000
to 100,000 ug/ml or mg/kg body weight), and negative
results are reported at relatively low dose levels (1 to 10
ug/ml or mg/kg body weight).
Genetic Activity Data Base Available
Data on short-term tests for 187 chemicals (approx-
imately 7000 entries from 4000 references) have been
compiled in the EPA/IARC Supplement 6 data base. A
complementary carcinogen data base was established
by an IARC Working Group that met in March 1987 to
evaluate the data on the carcinogenicity of these
chemicals to humans and to animals. In addition to pro-
viding concise data on known or suspected human car-
cinogens, these data bases can be used to examine
retrospectively the usefulness of short-term tests for the
prediction of carcinogenicity and the relationship be-
tween specific endpoints or assays and carcinogenicity.
The EPA/IARC Supplement 6 data base is available in
a personal computer format and represents a ready
source of internationally peer-reviewed data on chemical
agents of known or suspected hazard to human health.
For a copy of the EPA/IARC Supplement 6 data
base, please send a written request to Dr. Michael
Waters, U.S. EPA, Genetic Toxicology Division, MD-68,
Research Triangle Park, North Carolina 27711. Ques-
tions on the data base and the use of the genetic activi-
ty profiles should be directed to Dr. Waters at (919)
541-2537 or (FTS) 629-2537.
FIGURE 2.
SCALE OF LOG DOSE UNITS USED ON THE YAXIS
OF ACTIVITY PROFILES
LED
|ug/ml or mg/kg bw|	Log Dom Units
0.001	8
0.01	7
0.1	6
1.0	5
10	4
100	3
1000 	2
10000	1
100000	1	0
10	-1
100	-2
1000	-3
10000	-4
100000	-5
HID
|ug/ml or mg/kg bw)

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NEW TECHNOLOGY AVAII
ETHYLENE OXIDE EMISSIC
HOSPITAL STERILIZERS
Several Michigan hospitals are currently installing
a new control technology system to limit ethylene oxide
(EtO) emissions from hospital sterilizers. Ethylene oxide
and EtO-containing gas mixtures continue to be used to
sterilize equipment or instruments for which neither
steam nor gamma radiation sterilization is feasible or
practical. Technologies previously assessed for control-
ling EtO emissions from hospital sterilizers include acid
scrubbing and catalytic oxidation*
The new technology, designed specifically to ad-
dress EtO emissions from hospital sterilizers, uses either
a one- or a two-step process to destroy EtO. The single-
stage system (or the second stage of the two-stage
system) is a proprietary reactor containing a solid
catalyst. Ethylene oxide, even at dilute concentrations,
reacts quickly in the presence of the catalyst. The unit
.ABLE TO CONTROL
>NS FROM
operates at room temperatures, requires no chemical
feed, heating, or cooling, and produces no waste.
Ethylene oxide discharges are reduced to levels below
the detection limit. Not only can the concentrated
sterilizer off-gases be treated, but the more dilute con-
taminated room air, contaminated sewer gases, and all
sterilizer air washes can also be cleaned. Where ap-
propriate, a two-stage system can be used in which the
proprietary reactor is preceded by a catalyst scrub-
ber/reactor similar to the older acid scrubbing systems.
For more information on this new technology, call David
Hammer, Michigan Science and Engineering
Associates, (313) 994-0280.
*See related article in the May 1988 Newsletter.
EPA S INTEGRATED RISK If
MADE AVAILABLE TO THE
The EPA's Integrated Risk Information System
(IRIS) is now available to those outside EPA. A June 2
Federal Register notice announced the release of the
system. IRIS is an on-line data base of chemical-specific
risk information produced by EPA* The IRIS data base
is a primary source of EPA health hazard assessment
and related information on chemicals of environmental
concern.
Most of the health assessment information con-
tained in IRIS has been reviewed and agreed upon by
two interdisciplinary review groups of EPA scientists who
have extensive experience in risk assessment. Thus, this
information represents an expert Agency consensus.
This Agencywide agreement is one of the most valuable
aspects of IRIS. Some chemicals are undergoing the
review process; these are identified by checking the
status for each chemical of interest. In the March 1987
Newsletter, IRIS was described as having information
sections called service codes. Changes have been
made to the service codes listed then and two new codes
added. Eight service codes are now available to access
the following information:
1.	Chemical files which summarize data on each
chemical,
2.	Alphabetical and Chemical Abstract Service
(CAS) number listings of chemicals in IRIS,
3.	List of revisions made to existing chemical files,
4.	Introduction that provides general information
about the system,
5.	Background documents on methodologies,
^FORMATION SYSTEM
PUBLIC
6.	User's guide and instructional case study,
7.	Glossary of terms and acronyms used in IRIS,
and
8.	Status of chemicals scheduled for the IRIS
review process.
The primary focus of IRIS, the chemical files, con-
tain the following information:
—	Oral reference doses,
—	Inhalation reference doses,
—	Oral slope factor for carcinogens,
—	Inhalation slope factor for carcinogens,
—	Summaries of EPA regulations,
—	Summaries of Drinking Water Health Advisories,
and
—	Supplementary information.
How to Access IRIS
IRIS is housed in EPA's electronic mail system,
which State staff can access through some 138 EPA-
sponsored E-mail accounts in 47 States. To obtain a list
of the accounts and the name of the State contact for
each, call IRIS User Support at (513) 569-7254 or (FTS)
684-7254.
Dialcom, Inc., supports the E-mail system. If you are
not on the aforementioned list and wish to obtain an IRIS
account call Dialcom directly. The contact is: Mike
McLaughlin, Dialcom, Inc, 600 Maryland Avenue SW,
Suite 307, Washington, D.C. 20024, (202) 488-0550.
Those outside EPA who access IRIS through
10

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Dialcom, Inc., pay only for the cost of accessing IRIS.
Users will be billed by Dialcom. There is a $25.00 month-
ly minimum which is applied against a usage fee of
$25.00 per hour. In addition to the usage fee, there is a
$.05 charge per computer screen accessed. There is no
EPA charge for using IRIS.
IRIS is also available to local, State and Federal
health officials through the Public Health Foundation's
Public Health Network (PHN). For information on access
and cost call Paul Johnson at (202) 898-5600.
Later this summer, IRIS will also be made available
through the National Library of Medicine's TOXNET.
TOXNET is a widely used network of systems, which in-
cludes the Hazardous Substances Data Base (HSDB)
and the Registry of Toxic Effects (RTECS).
New Developments Described
The EPA has placed a priority on scientifically veri-
fying and adding IRIS chemical files for the SARA Title
III, Section 313, Community-Right-to-Know chemicals.
The Community-Right-to-Know legislation requires com-
panies producing or storing the more than 300
chemicals listed in Section 313 to report the total amount
of these chemicals they have released during the past
year. Currently IRIS contains information on 280
chemicals, 80 of which are on the Section 313 list. EPA
hopes to add another 50 of these chemicals to IRIS by
the end of this year.
Although no inhalation reference doses currently
exist on IRIS, an interim methodology for deriving inhala-
tion reference doses was recently finalized** and an In-
halation Reference Dose Work Group formed. As this in-
'jrdisciplinary panel of EPA scientists begins to verify in-
halation reference doses, they will be added to IRIS.
For more information on IRIS, call IRIS User Sup-
port at (513) 569-7254 or (FTS) 684-7254.
*See related articles in the March and September 1987
issues.
**See related article elsewhere in this issue.
COPIES OF 1986 RISK ASSE
GUIDELINES AVAILABLE
On September 24, 1986, the EPA issued risk
assessment guidelines relating to five areas: carcino-
genicity, mutagenicity, chemical mixtures, suspect
developmental toxicants, and exposure assessments (51
FR 33992). The guidelines were developed to promote
high technical quality and Agency consistency in the risk
assessment process.
A document entitled "Ri?k Assessment Guidelines
of 1986" presents the five guidelines as they originally
appeared in the Federal Register but in a format that is
easier to read. Single copies of this document are
SSMENT
available from the Office of Research and Development
at the following address:
ORD Publications Office
Center for Environmental Research Information
U.S. Environmental Protection Agency
26 W. Martin Luther King Drive
Cincinnati, Ohio 45268
Requesters should request the document by its EPA
number, EPA-600/8-87-045.
INFORMATION NEEDED -
SARA TITLE III DATA BASE
The Kansas City-Wyandotte County Health Depart-
ment is interested in State and local agency experiences
in compiling Superfund Amendments and Reauthoriza-
tion Act (SARA) Title Ill-related data. Example data in-
clude facility names and addresses, facility coordinator
names and telephone numbers, emergency telephone
numbers, Material Safety Data Sheets, and Tier I and II
reports. The EPA Toxic Release Inventory System con-
tains only SARA Section 313 material and, therefore,
does not contain many of these data types. The Kansas
City-Wyandotte County Health Department anticipates
the development of data handling problems that could
hinder eventual sharing of SARA Title III data among
State Emergency Response Commissions (SERCs),
Local Emergency Planning Committees (LEPCs), EPA,
and State and local agencies - incompatible data base
systems being a major handicap.
If you are preparing a data base to handle the SARA
Title III data using commercial microcomputer data base
software such as dBase III to run on IBM-compatible
microcomputers and are willing to share your ex-
perience, please contact Richard S. Michael, Director,
Air Pollution Control Center, Kansas City-Wyandotte
County Department of Health, (913) 321-4803.
11

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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
or local agencies who have such information will be able
to contact you with assistance. In addition, the Clearing-
house 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 Susan Buchanan, Radian
Corporation, (919) 541-9100.
The National Air Toxics Information Clearinghouse Newsletter is published by the National Air Toxics Informa-
tion Clearinghouse to assist State and local agencies making decisions on noncriteria pollutant emissions. The Clear-
inghouse is being implemented by the U.S. Environmental Protection Agency, Strategies and Air Standards Division,
Pollutant Assessment Branch as part of a joint effort with the State and Local Air Pollution Control Officials (ALAPCO).
The National Air Toxics Information Clearinghouse Newsletter is prepared by Radian Corporation under EPA Con-
tract Number 68-02-4330, Work Assignment 34. The EPA Project Officer is Robert Schell, EPA Office of Air Quality
Planning and Standards, Research Triangle Park, North Carolina 27711, Telephone: (919)541-5519. The Radian Proj-
ect 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 po by contacting Nancy Riley, EPA OAQPS (919)541-0850.
Please contact the Project Officer either with any comments yotHnight have pertaining to this newsletter or with sug-
gestions for future newsletters. Articles in the newsletter are written »y 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.
Beth Hassett
Pollutant Assessment Branch
U.S. Environmental Protection Agency
MD-13
Research Triangle Park, NC 2i /11
FIRST CLASS MAIL
U.S. Postage Paid
E.P.A.
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