453N90010
NATICH
NEWSLETTER
&ERfc
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
i
State and Territorial Air Pollution Program Administrators
Association of Local Air Pollution Control Officials
Produced by the National Air Tbxics Information Clearinghouse March 1990
How the Public Interprets Small Risks
The following short piece is
drawn from an article, "Communi-
cating Risk Under Title III of
SARA: Strategies for Explaining
Very Small Risks in a Community
Context," by Ann Fisher* Gary H.
McClelland and William D. Schulze
that appeared in the March 1989
issue of The Journal of the Air &
Waste Management Association
(formerly JAPCA, Vol. 39, No. 3,
pp. 271 - 76).**
Even before Title III of the
Superfund Amendments and Re-
authorization Act of 1986 (known
as SARA or the Emergency Plan-
ning and Community Right-to-
Know Act) became effective in
1987, research had shown that
people have problems evaluating
small probabilities. As shown in
Figure 1, people tend either to
dismiss the risk as being too small
to worry about, or to feel that it is
fairly serious. Some community
groups may tend toward the first
response while others tend toward
Figure 1
Is the Risk Worth Considering?
Dismiss Risk
If
No Concern
Evaluate Risk
I
Anchor on
Consequences
I
Adjust Concern
Down
I
Express
Concern
North Carolina Adopts
New Air Regulations
North Carolina's new air toxics
regulations were adopted at the
February 8, 1990, meeting of the
State's Environmental Manage-
ment Commission. Prior to the
meeting, the N.C. Department of
Environment, Health, and Natural
Resources (NC DEHNR) had
presented the regulations at public
hearings in August and had received
more than 100 written comments
from industry and other groups.
Five years in the making, the
new regulations cover hotfwiAw
and existing sources of air toxics,
establishing guideline acceptable
ambient levels for 105 pollutants.
The regulations become effective
May 1,1990, for 84 of the pollu-
tants, and May 1,1991, for the
remaining 21. Four types of
pollutants are covered:
carcinogens;
chronic toxicants;
acute systemic toxicants; and
acute irritants.
(continued on page 2)
the second response. Thus, reac-
tions to information on chemical
risks made available under SARA
Title III may range from apathy to
extreme concern.
If, as shown on the left half of
Figure 1, the community weighing
the possible risk perceives the
risks from, say, a nearby chemical
manufacturing plant to be below
some threshold they interpret as
negligible, then reaction will be
"no concern."
*Ann Fisher is with EPA's Office of
Policy Analysis in Washington, DC;
Gary H. McClelland and William
D. Schulze are with the University
of Colorado in Boulder.
* *Included here with permission of
Ann Fisher and the Journal.
(continued on page 8)
CARB Supports Air Hades
"Hot Spott" Act with
Regulation 2
AirPraewra $,
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Emission R«port II
-------
North Carolina (continued from page 1)
Permits are required for both
new and existing sources for
pollutants emitted in greater than
threshold amounts. Except for
boilers burning only unadulterated
fossil fuels or wood, new sources
will be required to demonstrate
compliance with the guidelines or
demonstrate that their emissions
would not adversely affect human
health. Existing sources have to
make these demonstrations, sub-
mit a compliance schedule, or
show that complying with the
guidelines would be technically in-
feasible or result in significant
economic hardship. If either a
technically infeasible or significant
economic hardship demonstration
is made, the source nevertheless
has to install maximum feasible
control. Technical infeasibility and
serious economic hardship will be
determined by the Commission on
a case-by-case basis.
An existing source will not be
required to have a permit to emit
air toxics until it receives an of-
ficial notice from the Division of
Environmental Management re-
questing that it apply for a permit.
Notification will be made on the
basis of Standard Industrial
Classification codes. Gasoline
dispensing facilities and service
stations are exempt from the per-
mit requirements because they will
be required to install Stage I vapor
controls. Reporting, recordkeeping,
and dispersion modeling require-
ments are also spelled out in the
new regulations.
For further information, call
Earl McCune, Assistant Chief for
Technical Services, Air Quality
Section, NC DEHNR, Division of
Environmental Management, at
(919) 733-3340.
CARB Supports Air Toxics
"Hot Spots" Act with Regulation
by M. Beth Schwehc, Technical Support Division, California Air Resources Board
As a result of the Air Toxics
"Hot Spot" Information and
Assessment Act (AB 2588) passed
in 1987,* CARB will eventually
have expanded information to set
priorities for the identification and
control of air toxics under its Toxic
Air Contaminant Identification and
Control Program. AB 2588 requires
California facilities to prepare air
toxics emission inventory plans and
reports, and in some cases prepare
health risk assessments and notify
the public. Under AB 2588, CARB
is responsible for:
compiling and maintaining the
list of air toxics;
adopting a fee schedule;
providing guidance to districts
and facilities on emission inven-
tory preparation;
managing the resulting data;
developing inventories for
mobile, area, and natural
sources;
examining whether smaller
facilities should be included in
the reporting requirements; and
developing procedures for bi-
ennial updates of the emission
inventories.
The list of substances was ap-
proved by CARB in July 1988 and
amended in September 1989. The
list includes over 400 substances
compiled from other lists referenced
in AB 2588.
The act requires CARB to
adopt an annual fee schedule,
assessing every facility subject to
the act in order to cover State and
district agency administrative
costs.
Regulation Provides Criteria
for Emission Inventories
In providing guidance to af-
fected facilities on preparing emis-
sion inventories, CARB was to
adopt a criteria and guidelines
regulation. AB 2588 outlines mini-
mum components of the guidelines
and identifies the classes of facil-
ities that must prepare inventories.
In response, CARB developed the
regulation in consultation with the
air pollution control districts, air
quality management districts, and
the California Department of
Health Services. CARB approved
the regulation as an emergency
measure at a public hearing on
April 13 - 14, 1989. The emer-
gency regulation became effective
on June 1, 1989, and the final
regulation became effective on
October 30, 1989. The resulting
Emission Inventory Criteria and
Guidelines Regulation sets forth
the components that a facility
operator must include in the emis-
sion inventory plan. It also
specifies the criteria and guide-
lines for districts to determine
whether these documents are
acceptable.
The criteria and guidelines
regulation divides the list of air
toxic substances into two groups
that differ in their requirements
for emission inventory reporting
based on suspected potential for
public exposure. The two groups
are: (1) substances for which emis-
sions must be quantified (to a
degree of accuracy specified in the
regulation), and (2) substances for
which the production, use, or other
presence in an operation must be
reported but no emissions informa-
tion supplied. Information gathered
2
-------
(continued from page 2)
on the second group of substances
will be used to redesignate sub-
stances from the second to the first
group, if appropriate.
The criteria and guidelines
regulation specifies which emis-
sions must be quantified by source
testing and which emissions may
be quantified by estimation
methods. In specifying source test
procedures, consideration was
given to the availability of testing
methods, the appropriateness of
testing, the potential public health
risks of the sources, and the cost to
facilities to perform the required
testing. Alternatives are included
for small businesses where
appropriate.
"Pooled Source Testing"
an Option Under Regulation
The regulation includes an op-
tion for "pooled source testing,"
whereby operators of a group of
substantially similar facilities may
propose to meet the source testing
requirement by pooling resources
to test a representative sample of
the sources of interest and to apply
the results to the group. A proposal
for pooled source testing must be
submitted for review by the district
and CARB prior to its implementa-
tion. The regulation also establishes
a process as well as criteria for ap-
proval of alternatives to the re-
quired source testing if the testing
is not feasible due to site-specific
factors or if the alternative can be
demonstrated to result in an equal
or better characterization of emis-
sions. A proposal for alternatives
must be submitted for review by
the district and CARB.
*See related article in the July 1988
NATICH Newsletter.
(continued on page 10)
NESCAUM Pursues California Auto Standards
In August 1989, the eight en-
vironmental commissioners in the
NESCAUM* States signed a
Memorandum of Understanding
(MOU) stating their intention to
"propose regulations to adopt
motor vehicle emission standards
equivalent to California's." Each of
the Northeast States will propose
California emission standards on
new vehicles beginning as early as
model year 1993. In addition, each
State will evaluate and select,
through its respective State plan-
ning process, elements of Califor-
nia's more stringent enforcement
program that will provide the
greatest benefits. Implementing
State regulations will, in some
cases, require legislative concur-
rence.
In stating their reasons for
pursuing this strategy, NESCAUM
pointed out that the Northeast ex-
periences frequent and widespread
violations of the national air quality
standards for ozone and carbon
monoxide (CO). Exposure to un-
healthy levels of ozone is one of
the most serious and widespread
public health problems in the
Northeast; each year, more than 35
million people in the area are ex-
posed to unhealthy levels of ozone.
In fact, in 1988 ozone levels in
the Northeast were the highest in
more than five years. Ozone con-
centrations exceeding Federal
standards occurred on 56 days in
one or more Northeast States,
resulting in unhealthy air every
other summer day, on average.
Peak ozone concentrations in the
Northeast were about twice the
Federal standards, prompting
public health officials to warn sen-
sitive individuals to remain indoors
and to avoid heavy exercise and
exposure during peak ozone hours.
Ozone episodes in 1988 were
exacerbated by an unusually warm,
dry summer. Typical summer
weather in the Northeast usually
leads to about 40 unhealthful sum-
mer days each ozone season (viola-
tions about every third day).
Preliminary ozone data for 1989
show fewer ozone violation days,
primarily due to the small number
of very hot days in 1989 and, to a
lesser degree, to strict gasoline
volatility rules adopted by seven
Northeast States in the last year.
How Motor Vehicles Contribute
Motor vehicles are the largest
source of emissions of CO, hydro-
carbons (HC), and nitrogen oxides
(NOx). The percentage of total
emissions due to mobile sources,
both nationally and in the North-
east, is as follows.
National
Northeast
HC
35%
60% (higher on
hot summer days)
NOx
45%
55%
CO
70%
70%
While Federal emission stan-
dards for automobiles have reduced
emissions per vehicle in recent
years, the growth in vehicle miles
traveled (VMT) and the short life
of federally certified emission con-
trols have tended to offset much of
the gain from new car emission
standards. Growth in VMT is pro-
jected to continue at 2 to 3 percent
per year for the region and at even
higher rates in some cities. In addi-
tion, EPA test data show that even
properly maintained cars (which do
not include the effects of tamper-
ing, misfueling, poor maintenance,
or lack of maintenance) usually ex-
ceed the 50,000-mile standards by
the time they reach 30,000 miles,
and over their lifetimes emit pollu-
tants well in excess of tailpipe
standards.
(continued on page 4)
3
-------
(continued from page 3)
Two Years of Investigation
Preceded the MOD
In 1987, in response to persis-
tent violations of Federal air quality
standards for ozone and CO despite
increasingly more stringent con-
trols imposed on stationary sources,
NESCAUM commissioned an in-
dependent study to assess the ef-
fectiveness of the Federal Motor
Vehicle Control Program in meet-
ing the requirements of the 1970
Clean Air Act. The resulting
report concluded that although
substantial progress has been
made in reducing in-use auto emis-
sions per mile, overall improve-
ments have fallen far short of the
reduction goal established by Con-
gress. The report offered a series
of recommendations to improve the
effectiveness of the program, in-
cluding improved vehicle testing
by EPA; more stringent emission
standards for HC, CO, and NOx;
emission control requirements for
the full useful life of the vehicle;
more aggressive vehicle recall; and
specific organizational and funding
changes within EPA.
After studying this report, the
Environmental Commissioners of
the Northeast States signed an
agreement in February 1989 to co-
operatively evaluate the feasibility,
air quality benefits, and associated
costs of adopting the more strin-
gent California Motor Vehicle Con-
trol Program in the Northeast.
NESCAUM also commissioned
outside assistance for the evalua-
tion. At the same time, NESCAUM
began a series of discussions with
motor vehicle manufacturers to ex-
plore options for further reducing
motor vehicle emissions.
The independent evaluation
found that the Northeast could
significantly reduce emissions by
adopting the California motor vehi-
cle program. In addition, the cost
effectiveness of the California pro-
gram was found to be favorable
compared to the current cost of
VOC and NOx controls for many
stationary sources. According to
these estimates, the Northeast
could reduce emissions of HC by
16%, NOx by 27%, and CO by
39% by the year 2010, as com-
pared to emissions under current
Federal standards. The cost of
these reductions would be about
$150 per vehicle or about $600 per
ton of VOC and NOx removed.
The full benefit of California-
type new vehicle standards in the
Northeast would not be felt until
about 2010 when the current
generation of higher emitting
vehicles is replaced by lower emit-
ting vehicles. These reductions,
while significant and cost-effective,
will not be adequate to ensure
achievement of Federal clean air
standards without additional emis-
sion reduction measures for sta-
tionary and mobile sources. Accord-
ingly, States have undertaken re-
newed planning efforts to explore
and, in some cases to test, new
emission control approaches for
stationary sources and for other
mobile sources. These measures
include innovative new control
technologies and alternative fuels
for both stationary and mobile
sources.
The key elements that make
the California vehicle standards ef-
fective are:
Lower N0X limits
California limits automobile NOx
to 0.4 g/mi as compared to 1.0
g/mi for federally certified autos,
and CARB staff has proposed
NOx limits as low as 0.2 g/mi.
California NOx standards for
trucks are also more stringent
than the corresponding Federal
standards.
Lower HC limits
Beginning with the 1993 model
year, California regulations limit
automobile emissions of non-
methane hydrocarbons (NMHC)
to 0.25 g/mi. The Federal stan-
dard for HC is 0.41 g/mi (the
Federal standard for total HC is
equivalent to a standard of
about 0.35 g/mi for NMHC).
Full useful life provisions
Beginning in 1993, California re-
quires that automobiles be cer-
tified to 100,000-mile emission
standards as well as 50,000-mile
standards, while Federal stan-
dards only apply for 50,000
miles.
On-board diagnostics
Advanced on-board diagnostic
(OBD) systems, as proposed by
California for model year 1993
and later light duty vehicles,
could detect engine and emis-
sion control system malfunc-
tions, alert the operator and
store in the on-board computer
specific "fault codes" to assist in
diagnosis and repair. This capa-
bility, along with more extensive
warranty and recall provisions of
the California program, will en-
sure that emission controls on
California type vehicles continue
to outperform controls on other
vehicles throughout the vehicle's
useful life. They also help en-
sure that California vehicles will
have lower lifetime CO emis-
sions than federally certified
vehicles which meet the same
50,000 certification limit.
For further information on
each State's motor vehicle pro-
gram, contact the appropriate per-
son as listed below or call
NESCAUM at (617) 367-8540.
CT
Len Bruckman
(203) 566-4030
ME Ron Severance
(207) 289-2437
MA
Laurel Carlson
(617) 292-5630
NH
Stephanie DeMeis
(603) 271-1370
NJ
Dave West
(609) 530-4036
NY
Tfed Davis
(518) 457-6379
RI
Steve Majkut
(401) 277-2808
VT
Harold Garabedian
(802) 244-8731
4
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Proposed Revisions
to CAA Outlined
The current National Air Tox-
ics Strategy relies on a strong part-
nership between the EPA and State
and local (S/L) air pollution control
agencies to comprehensively ad-
dress the air toxics problem. This
partnership envisions a strong na-
tional regulatory program com-
bined with financial and technical
assistance to S/L agencies to sup-
port program development and
source-oriented rulemaking. Since
the drafting of the National Air
Toxics Strategy in 1985, S/L agen-
cies have made significant pro-
gress in designing, developing, and
implementing their own programs.
State and local agencies have been
successful in the high risk point
source program; they are begin-
ning to assess urban air toxics, and
many have developed regulatory
programs aimed specifically at air
toxics.
The federal regulatory pro-
gram, however, has been slowed
by the controversial and time-
consuming process of evaluating
and setting national emission stan-
dards for hazardous air pollutants
(NESHAP). Determining an emis-
sion standard that represents "an
ample margin of safety to protect
public health" has been the issue
of wide debate and disagreement.
This issue has been further com-
plicated by varying interpretations
of the role of cost and economic
impacts in decisions under Section
112. Within the current statutory
framework, the emissions
standards-setting process is likely
to remain slow, contentious, and
conducted under the constant
threat of additional litigation.
The amendments to the air
toxics provisions of the Clean Air
Act (CAA) proposed by President
Bush are designed to remove a
number of legal and procedural
difficulties that have hampered
EPA's progress in setting national
emission standards. The air toxics
provisions (Title III) are contained
in a more comprehensive bill ad-
dressing air toxics, nonattainment,
acid rain, and mobile sources.
These provisions represent a ma-
jor redirection of the current
federal regulatory program, with
emphasis on reducing emissions
from a broad range of pollutants
and source categories based
primarily on technology rather
than risk. The amendments em-
phasize initial early development
of stringent technology-based
emission standards for major
source categories, and defer the
evaluation of residual risks until
the standards are in place.
The proposed amendments
also require certain research ac-
tivities, as well as the continuation
of EPA's technical assistance
centers including NATICH, CTC,
Air RISC, AMTIC, and EMTIC.
The major provisions of the Ad-
ministration's proposal are dis-
cussed below and are outlined in
Figure 1.
Pollutant Listing
The bill lists 191 chemicals or
chemical classes as hazardous air
pollutants. The list is used as the
basis for identifying source cate-
gories for possible regulation. The
public may petition the Admini-
strator to add or delete chemicals
from the list. The pollutant listing
removes principal roadblocks that
have hampered EPA's regulatory
efforts under Section 112-the
need to develop a health-based
justification (i.e., demonstration or
reasonable anticipation of mortal-
ity or serious illness), publish a for-
mal listing notice for each pollu-
tant to be regulated, and publish
within 180 days a proposed
NESHAP for the listed pollutant.
Source Category Listing
Within 12 months of enact-
ment, EPA will publish a list of all
source categories and subcate-
gories of major sources and area
sources of listed pollutants. A
major source is defined as a sta-
tionary source that emits, or has
the potential to emit, 10 metric
tons or more of a single listed
pollutant, or 25 metric tons or
more of a pollutant mix per year.
(continued on page 10)
Figure 1
5
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Puget Sound Evaluates Air Program
by Margaret Corbin, Puget Sound Air Pollution Control Agency
The Puget Sound Air Pollution
Control Agency (PSAPCA) in
Seattle, Washington, has developed
a program to evaluate the effective-
ness of its air toxics program. The
evaluation:
estimates reductions from the
new source review (Notice of
Construction) program,
examines effectiveness in enforc-
ing existing VOC, PMio, and
toxic regulations, and
evaluates the results of working
directly with specific facilities
on emission reductions.
Notice of Construction Program Is
Most Important Tool
The Notice of Construction
(NC) program has been and con-
tinues to be one of the most effec-
tive tools at reducing toxic air con-
taminants released to the atmo-
sphere. A first step in evaluating
this part of the air toxics program
involves reviewing the NC permits
that went through a screening pro-
cess. The engineers use EPA's
SCREEN model for potential
sources of toxic contaminants. The
model is used to determine if there
is a residual risk after the installa-
tion of BACT. In all cases, there
has not been residual risk after the
installation of BACT.
The quantity of toxic air con-
taminants prevented from release
to the atmosphere through the NC
program was estimated for one
year (June 1988 to June 1989 - see
Table 1). This calculation was
made by comparing the estimated
controlled emissions to the esti-
mated uncontrolled emissions.
This simplistic approach probably
overestimates the quantity of tox-
ics prevented from release to the
atmosphere because it is impossi-
ble to determine what the toxic
emissions would have been if
PSAPCA's toxic NC program were
not in place.
The difference between con-
trolled and uncontrolled emissions
for all the toxic compounds eval-
uated was 1220 tons for one year.
At present, the evaluation looks
only at quantity and not toxicity. It
will be important in the future to
consider toxicity as well, because
the impact on human health is
related to both. Because of the vast
difference in toxicity, the reduction
of 738 pounds of hexavalent chro-
mium was at least as important
from a human health risk perspec-
tive as the 701,873 pound reduc-
tion of acetone.
Table 1.
Estimated Effectiveness of
Air Toxic Program
Reduction
Program
(tons /year)
Notice of
1220
Construction
Reg II
25,915
Woodsmoke
90/189
Facility
5
TOTAL
27,230/27,329
Regulation Enforcement -
How Effective?
The second stage of the
evaluation program is to estimate
the amount of toxic reduction due
to regulation enforcement. VOC
reductions resulting from the en-
forcement of PSAPCA's Regula-
tion II* were estimated to be
25,915 tons/year in the Puget
Sound region. Gasoline marketing
losses from gasoline bulk plants
and service station loading opera-
tions are controlled through Stage
I vapor recovery. Reductions esti-
mated due to the enforcement of
this regulation amounted to 4,599
tons/year. This is an important and
particularly toxic subset of the
125,915 tons/year VOC reduction
discussed above.
Article 13 of Regulation I**
was enacted to reduce woodstove
emissions in the Puget Sound area.
The most effective strategy con-
tained in Article 13 is mandatory
curtailment. Curtailment was man-
dated on 22 days and 15 nights
during the last heating season.
The reduction of toxic air con-
taminants was calculated using
estimated numbers of woodstoves
and the results of a mobile moni-
toring field study conducted by the
University of Washington.
The estimated reduction of
total suspended particulate matter
(TSPM) due to woodstove use cur-
tailment was 39 to 82 tons/day.
The total annual reduction was
between 585 and 1225 tons/year.
Estimates of the reductions in ben-
zo(a)pyrene, formaldehyde, phenol,
acetaldehyde, and manganese were
also made. An estimated total of 90
to 189 tons/year of these toxic
chemicals are prevented from
release into the air by the curtail-
ment program.
Facility-Specific Reduction
Program to Reduce Ethylene
Dichloride Emissions
Another facet of the toxic pro-
gram is work on reduction of toxic
emissions from major sources.
PSAPCA and Boeing have been
holding regular quarterly meetings
to identify major toxic emissions
and develop strategies to minimize
the use or emissions of these tox-
ics. For example, at the most re-
cent quarterly meeting, Boeing an-
nounced that it would be phasing
out the use of ethylene dichloride.
Boeing will instead substitute
tetrahydrofuran. (An estimated 4.7
tons, of ethylene dichloride were
used by Boeing in 1988.) Other
toxics of concern PSAPCA is ad-
dressing with Boeing include: hex-
avalent chromium, trichloroethy-
(continued on page 7)
6
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Air Pollution Contributes Toxics to Lake Erie
by Paul Koval, Ohio EPA, Division of Air Pollution Control
The Ohio EPA, Division of Air
Pollution Control has recently com-
pleted a study entitled "Input of
Toxic Substances from the Atmo-
sphere to Lake Erie." This project,
conducted by a contractor and
funded by the Ohio Air Quality
Development Authority evaluated
the relative contributions of six
pathways by which toxic chemicals
enter Lake Erie. The study was
conducted in support of the Great
Lakes States Air Permitting
Agreement signed in 1988 by the
eight States bordering the Great
Lakes System.
This study produced two main
conclusions: (1) estimates of the
absolute amounts of each toxic
substance entering Lake Erie an-
nually by each of the input path-
ways, and (2) the relative contribu-
tion of the atmospheric pathways
to the total Lake Erie input. Suffi-
cient data were available for a
complete evaluation of all or nearly
all pathways for 13 species. Table
1 summarizes the results of those
13 species in terms of the total
amount of material entering Lake
Erie each year by all pathways
combined and the percentage of
that total contributed by atmo-
spheric pathways.
The table shows that for most
of the substances, atmospheric in-
put to Lake Erie is a minor but
significant fraction of the total in-
put. The two exceptions are benzo-
a-pyrene and cadmium, for which
the atmospheric pathways appear
to contribute a majority of the total
input. Considering the individual
pathways, this study found that
the Detroit River was the largest
single input pathway for most of
the species considered. This study
also found that for some volatile
organic species the vapor phase
flux of material was out of, rather
than into, the lake. For example,
the calculations indicate volatiliza-
tion of PCBs and PAHs from Lake
Erie in the amounts of 1,150
kg/year and 11,500 kg/year,
respectively.
The pathways considered in
this evaluation were inflow from
the Detroit River, inflow from
Canadian and U.S. tributaries,
deposition in precipitation, dry
deposition of airborne particles,
and dry deposition of vapor-phase
materials. The study was not a
mass-balance study; it focused on
the input pathways only. How-
ever, outflow from Lake Erie was
considered in calculating deposi-
tion of vapors to the lake because
the overall vapor flux may by out
of the lake (i.e., volatilization) in-
stead of into the lake (i.e.,
deposition).
The chemical compounds con-
sidered included:
metals (mercury, lead, cad-
mium, chromium, arsenic),
pesticides (e.g., DDT,
toxaphene),
(continued on page 8)
Table 1.
Substance
Total Input to Lake Erie
to all pathways (kg/year)
Total from Atmospheric
Pathways (%)
PCBs
1,014
27
PAHs
50,800
19
Benzo-a-pyrene
1,234
66
Hexachlorobenzene
121
9
2,3,7,8-TCDD
0.16
11
2,3,7,8-TCDF
0.32
37
Lead
673,000
37
Mercury
3,310
22
Cadmium
21,000
59
Chromium
142,000
17
Arsenic
128,000
8
Dieldrin
115
34
DDT
123
25
PSAPCA (continued from page 6)
lene, and methylene chloride. For
more information contact Margaret
Corbin, PSAPCA, 200 W. Mercer
St., Room 205, Seattle WA
98119-3958, or call (206) 296-7446.
* Regulation II provides for control of
photochemically reactive volatile
organic compounds.
* *Regulation I is used to control the
emissions of air contaminants from
all sources within PSAPCA's
jurisdiction. It also provides for
uniform administration and enforce-
ment of this regulation.
7.
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Lake Erie
(continued from page 7)
polynuclear aromatic hydro-
carbons (total PCBs,
hexachlorobenzene),
total polychlorinated dibenzo-p-
dioxins and dibenzofurans
(PCDDs and PCDFs), and
individual tetrachlorinated
dibenzo-p-dioxins and diben-
zofurans (2,3,7,8-TCDD and
-TCDF).
The evaluation of metals in-
cluded only the total amount of
each element rather than any of
the chemical forms or oxidation
states. Organic compound classes
(e.g., PCBs, PAHs) were generally
considered using physical and
chemical parameters characteristic
of each compound class.
Input from the Detroit River
and smaller tributaries was
calculated using long-term average
stream flow rates and represen-
tative aqueous concentration
values based upon published data.
Wet deposition of toxic substances
in precipitation was calculated
using published data on concentra-
tions in precipitation and an aver-
age precipitation depth of 0.85
meters per year falling onto the
lake surface area of 2.57 x 1010
square meters. Particle dry deposi-
tion was calculated using ambient
air concentration data and apply-
ing long-term average particle
deposition velocities. For a few of
the toxic substances considered,
deposition velocity values were ob-
tained from previous studies on
those specific substances. How-
ever, for most substances it was
necessary to adopt deposition
velocity values estimated for small
particles from studies on sulfate
aerosol deposition. Transfer of
vapors between the atmosphere
and the water of Lake Erie was
calculated using the two-film diffu-
sion model, which assumes
equilibrium between static air and
water layers at the lake surface.
The overall rate of vapor transfer
was calculated using the dissolved
concentrations of volatile species
and values of liquid- and gas-phase
mass transfer coefficients recom-
mended in previous studies.
An additional activity in the
present study was an evaluation of
the geographic scale over which
atmospheric transport may con-
tribute toxic substances to Lake
Erie. This evaluation was carried
out using air mass trajectories
calculated in a previous study for
movement of acid rain precursors
to Holland, New York, near the
eastern end of Lake Erie. Based
upon these trajectories, it is con-
cluded that over a 24-hour interval
atmospheric transport can bring
toxic substances to Lake Erie
from distances of up to 500 miles.
The primary directions of at-
mospheric flow to Lake Erie are
from the west and southwest, im-
plying that sources in those direc-
tions have much greater impact on
the atmospheric contribution of
toxic substances to Lake Erie than
do sources in other directions.
A summary of the report is
available. Write Paul Koval, Ohio
EPA, Division of Air Pollution
Control, 1800 Watermark Drive,
Columbus, Ohio 43216, or call
(614) 644-2280.
Small Risks (continued I
However, if on evaluating the
risk, a group of citizens concludes
that there is cause for concern, two
cognitive processes may figure in
their final decision. Either they
will dismiss the risk out of hand or
they will focus (or anchor) on the
magnitude of the potential loss of
feeling safe in the community and
then adjust that concern because
they recognize that the loss will oc-
cur only some of the time. It turns
out, however, that the adjustment
process usually is incomplete for
small probabilities. This means
that their degree of concern may
be stronger than scientists would
predict on the basis of expected
value of the loss.
page 1)
How People Evaluate Risk
Among the factors that in-
fluence whether people dismiss or
evaluate a risk are these:
framing of gains and losses - a
perceived increase in risk (that
is, a loss) will have a greater
psychological impact than the
same size reduction in risk (a
gain). This factor may be impor-
tant since much of the informa-
tion now available under SARA
Title III is new to the public.
Therefore, expressing risk in
negative terms ("there will not
be an accident" or "there will
not be adverse health effects"
would be a more effective way
of helping the public dismiss
truly small risks. Expressing the
same risk in terms of the pro-
bability that "there will be an
accident" or "there will be
adverse health effects" will be
more effective if the Local
Emergency Planning Committee
judges that the community
should show more concern.
quantitative expression of risk -
expressing risk as an aggregate
across several time periods seems
to help people in adjusting their
perceived risk so that it is closer
to the scientists' estimates of
that risk. Therefore, it may be
helpful to express risk in a long
time frame such as lifetime risk
- at least for annual risks in the
8
-------
Small Risks
(continued from page 8)
range of 10'2 to 103. If the risk
is extremely small, communi-
cating risk in terms of a com-
munity rather than one indivi-
dual may help. For example, an
individual lifetime risk estimate
of 1(M could be explained as
one expected death over 70
years in a community of 10,000
people.
experience - familiar risks that
are understood or with which
people have had prior benign ex-
perience are more likely to be
dismissed.
characteristics of the risk - the
more serious and dramatic the
consequences of a risk, the
higher will be the anchor in the
anchoring and adjustment pro-
cess, so the final level of concern
will be higher.
personal characteristics - the
more education or experience
people have in asking questions
or reading about health issues,
the less concern people are like-
ly to have about risk. However,
families with children, relatively
young people, and women all
tend to be more fearful of Super-
fund sites; such concern may ex-
tend to Title III.
media attention - media coverage
is likely to focus on factors that
encourage evaluation and lead to
concern.
physical reminders - the more
people are reminded of risk, the
more likely they are to be con-
cerned. In a study of attitudes of
citizens living near a Superfund
site, 45 percent of residents
living near a Superfund site per-
ceived a dramatic decline in risk
after the site was closed.
How to Communicate Risk
For those who interpret Title
III data, the following recommen-
dations may help in communicating
small risk to the public:
identify and address community
concerns.
establish and protect credibility.
account for typical reactions to
low-level risks.
recognize that characteristics of
risk matter.
use comparable risks - those
with similar characteristics - to
help people put a particular risk
in perspective.
treat the media as legitimate
partners.
account for individuals'
characteristics.
See the following documents
for additional information: "The
Emergency Planning and Com-
munity Right-to-Know Act of 1986:
Questions and Answers,: U.S. En-
vironmental Protection Agency
Emergency Planning and Com-
munity Right-to-Know Information
Hotline, Washington, DC, 1988;
"The Hazardous Materials
Emergency Planning Guide," Na-
tional Response Team, NRT-1,
Washington, DC, 1987; "Risk
Screening Guide - interim final,
Appendix F and Appendix G,"
U.S. Environmental Protection
Agency Office of Toxic Substances,
Washington, DC, 1988; P. M.
Sandman, "Explaining Environ-
mental Risk," U.S. Environmental
Protection Agency, Washington,
DC, 1986; V. T. Covello, F. W.
Allen, "Seven Cardinal Rules of
Risk Communication," OPA-87-020,
U.S. Environmental Protection
Agency, Office of Policy Analysis,
Washington, DC, 1988; "Toxic and
Hazardous Chemicals, Title III and
Communities: An Outreach Manual
for Community Groups," U.S. EPA,
Office of Pesticides and Tbxic Sub-
stances, EPA/56/1-89/002, Wash-
ington, DC, September 1989; and
"Risk Communication About
Chemicals in Your Community: A
Manual for Local Officials," U.S.
EPA, Washington, DC, EPA/230/
09-89/066, December 1989.
OAQPS Revises Air Speciation Manual
OAQPS has completed a major
revision to the "Air Emissions
Species Manual," EPA-450/2-88-
003a and b. This two-volume docu-
ment contains species profiles for
both VOCs and particulate matter.
By applying species profiles to
either total VOC or particulate
matter emissions estimates, the
weight percentage of specific
VOCs or the elemental composi-
tion of particulate matter can be
estimated for the source categories
covered in the manual. In the
revised document, more than 250
VOC profiles and more than 300
particulate matter profiles are
presented. The species profiles are
available in three specific products:
Users who have the April 1988
version of the "Air Emissions
Species Manual," EPA-450/2-88-
003a and b, NTIS No. PB88-
225792 and PB 88-225800,
should obtain the document
"Addendum to the Air Emis-
sions Species Manual,"
EPA-450/2-88-003c, NTIS No.
PB90-146416, October 1989.
New users should obtain the
revised two-volume set. The
titles are: "Air Emissions
Species Manual. Volume I.
Volatile Organic Compound
Species Profiles, Second Edi-
tion," EPA-450/2-90-00la, and
"Air Emissions Species Manual.
Volume II. Particulate Matter
Species Profiles, Second
Edition," EPA-450/2-90-001b,
January 1990. No NTIS
numbers have yet been assigned.
(continued on page 10)
9,
-------
(continued from page 9)
In addition to the above hard
copy versions, the Air Emissions
Species Manual is available on
diskettes. This version requires
a personal computer with DOS
3.0 or higher and a hard drive
with 5 megabytes of space
available. A user's manual is fur-
nished. The system will soon be
available through NTIS.
Government agencies can
obtain items 1 and 2 from the
EPA library at Research Triangle
Park by writing the EPA library
at MD-35, Research Triangle
Park, NC27711 orby calling
(919) 541-2777 or (FTS)
629-2777. Other organizations
should order these documents
from the National Technical
\jlIAD (continued from page 3)
To assist facility operations in
selecting emission estimation
methods, CARB staff published a
technical guidance document in
August 1989. The document in-
cludes a compilation of available
emission factors for air toxics and
a number of emission estimation
techniques for particular source
types.
Reporting Requirements Designed
to Dovetail with SARA
The criteria and guidelines
regulation includes instructions for
recordkeeping, and for reporting
mixtures and trade name products,
giving guidance in the form of a
"Facility Look-Up Table" for iden-
tifying emission points as well as
likely substances emitted. To
facilitate the reporting require-
ments, the reporting period, which
began in 1989, coincides with that
of EPA's Superfund Amendments
and Reauthorization Act (SARA)
Title III, Section 313. Similarly,
the exempted uses of chemicals
have been closely correlated with
those of SARA, such as personal
and office products, which are not
expected to contribute significantly
to hot spot risk.
CARB is currently preparing
the inventories for mobile, area,
and natural sources, and the report
on classes of smaller facilities to be
included in the program. AB 2588
establishes deadlines for these of
March 1990 and July 1990, respec-
tively. CARB staff is also develop-
ing procedures for the biennial up-
dates of the emission inventories.
Periodic updates are anticipated to
the list of air toxics, criteria and
guidelines regulation, and the
VjJ\1I (continued from page 5)
An area source is defined as any
source that is not major but that is
a member of a source category on
the list, based on aggregate emis-
sions in an area. The EPA has the
discretion to establish a lesser
quantity than 10 tons of one pollu-
tant or 25 tons of a mixture for
emissions to establish the defini-
tion of a major source based on
potency or other characteristics,
and to designate area source
categories for inclusion on the list
of major source categories.
Emission standards will be
established for this designated list
of source categories according to
the schedule discussed below. In
determining priorities for promul-
gating standards, consideration will
be given to quantity and location of
emissions, public health impacts,
and efficiency of grouping categories
according to pollutants emitted or
processes or technologies used.
Information Service (NTIS) for
a fee. Item 3 is available to
government agencies through
Bill Kuykendal. Other organiza-
tions should order item 3 from
NTIS. For additional informa-
tion, contact Bill Kuykendal at
(919) 541-5372.
associated technical document.
CARB is also involved with the
California Air Pollution Control
Officers Association and the De-
partment of Health Services who
are developing approaches that
districts can use to prioritize facili-
ties based on health risk assess-
ments and guidelines for the
preparation of the required risk
assessments.
For further information re-
garding the emission inventory
component of the Air Tbxics "Hot
Spots" program, write to Beth
Schwehr at P.O. Box 2815,
Sacramento, CA 95812 or call
(916) 322-3807.
Note: the opinions, findings, and
conclusions expressed in this article
are those of the author and not
necessarily those of the California
Air Resources Board.
Technology-Based Standards and
Residual Risk
A two-step basis for regulating
air toxics has been incorporated in-
to the amendments. Initial regula-
tions will require maximum achiev-
able control technology (MACT)
for new and existing sources. The
standards will be based on the
most stringent control that is
achieved in practice, considering
energy, environmental, and
economic impacts. Following
(continued on page 11)
10
-------
CAA (continued from page 10)
the application of MACT, but
within 7 years, EPA must evaluate
if the residual risks remaining for
a source category present an
unreasonable risk to public health.
Standards are to be promulgated
within 2 years to adequately pro-
tect against such risk, considering
cost, technical feasibility, and
health risks of the prescribed stan-
dard. This approach is in marked
contrast to the current Section 112
process that requires the demon-
stration or reasonable anticipation
of mortality or serious illness as
the primary basis of regulation.
Schedule
The MACT standards will be
promulgated according to the
following schedule:
10 source categories within 2
years of enactment,
25 percent of the source cate-
gories within 4 years of
enactment,
50 percent of the source
categories within 7 years of
enactment, and
decisions on all remaining
categories within 10 years.
Alternative Compliance
On a case-by-case basis, States
may authorize emission limitations
for individual sources in lieu of the
federal standards if:
the source poses a negligible
risk to public health, or
the source has voluntarily re-
duced emissions of listed
organic pollutants by 90 per-
cent, and listed particulate
pollutants by 95 percent (con-
sidering a base year of 1987).
The EPA will be publishing
guidance that will instruct the
State how to make these
determinations.
Compliance Schedules
Schedules for sources to comply
with emission standards are as
follows:
For MACT standards, new
sources must comply imme-
diately and existing sources on a
date required by the Admini-
strator within 3 years of the ef-
fective date of the standard.
Extensions of up to 2 years may
be granted to an existing source
by a State with an approved
permit program under Title IV
for compliance with MACT
standards if an additional period
is needed for the installation of
- controls.
Where the source has installed
controls required by certain
other CAA provisions within 5
years prior to MACT proposal,
compliance with MACT stan-
dards can be extended 5 years.
State and local air pollution
control agencies will have an
enhanced role in implementing the
new federal requirements. Specifi-
cally, in Title IV of the proposed
amendments, a renewable operat-
ing permits program is required
that implements and enforces any
federally promulgated air toxics
standard and standards pursuant
to other provisions (e.g., nonattain-
ment, acid rain, and mobile
sources). This process is also to be
relied upon to collect appropriate
fees to support the program. The
operating permit program repre-
sents a significant new legal and
procedural requirement for most
State and local agencies, and will
be discussed in a future issue of
the NATICH newsletter.
OAQPS Publishes Toxic Aif Emission Report
... o^;iahle data) and does not :iWo
^
The EPA's Office of Air Quality
Planning and Standards (OAQPS)
has published a report that pro-
vides information on identifying
the types of toxic compounds that
may potentially be emitted from a
source category. The report is en-
titled "Tbxic Air Pollutant/Source
Crosswalk - A Screening Tbol for
Locating Possible Sources Emit-
ting Toxic Air Pollutants, Second
Edition" (EPA-450/2-89-017). This
document updates a previous report
of the same title, EPA-450/4-87-
023a. The crosswalk indicates the
potential for a pollutant/source
association (based on literature in-
formation, existing inventories, and
other available data) and does not
include emission factors. The se-
cond edition of Crosswalk includes
associations for more than 1100
substances and contains pollutant
names, CAS numbers, Standard
Industrial Classification (SIC)
codes, emitting Source Classifica-
tion Codes (SCC's), and references
for each association. The cross-
walk tables are sorted by pollutant,
SIC codes, and SCC. A data base
management system for use on
IBM-compatible personal com-
puters has been developed that
contains all crosswalk data and air
toxic emission factors. The system,
XATEF, will be available soon.
Single copies of this report are
available by writing the EPA
library at MD-35, Research
Triangle Park, NC 27711 or by
calling (919) 541-2777 or (FTS)
629-2777. The process to make the
reports available through the Na-
tional Technical Information Ser-
vices (NTIS) for a fee has been in-
itiated. No NTIS order number
has yet been assigned to the
report. For further information on
the report and data base, contact
Anne Pope, EPA, OAQPS, Non-
criteria Pollutant Programs Branch
(NPPB), MD-15, Research Triangle
Park, NC 27711, (919) 541-5373 or
(FTS) 629-5373.
11
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The NATICHNewsletter is published six times a year by the National Air Toxics Information Clearinghouse.
The Newsletter is prepared by Radian Corporation under EPA Contract Number 68-D8-0065, Work Assign-
ment 21. 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
Caroline Brickley, P. 0. Box 13000, Research Triangle Park, North Carolina 27709, (919)541-9100.
The Newsletter is distributed free of charge. To report address changes, write Meredith Haley, Radian Cor-
poration, P. O. Box 13000, Research Triangle Park, North Carolina 27709.
The views expressed in the NATICH 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.
Printed on recycled papet
Scott Voorhees
Pollutant Assessment Branch
U.S. Environmental Protection Agency
MD-13
Research Triangle Park, NC 27711
FIRST CLASS MAIL
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E.P.A.
Permit No. G-35
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