United States
Environmental Protection
Agency
Atmospheric Sciences
Research Laboratory
Research Triangle Park NC 27711
Research and Development
EPA/600/S3-85/024 May 1985
Project Summary
S02 Concentration Estimates for
New York City, 1880-1980
R. B. Husar and D. E. Patterson
The purpose of this investigation
was to estimate the yearly ambient
concentration of SO, and SO4 wet
deposition from 1880 to 1980 for the
greater New York City area. This in-
formation was used to reconstruct
ambient concentrations at two New
York Veterans Administration ceme-
teries. Cypress Hills and Long Island,
for studying marble deterioration. This
study, which involved a determination
of marble loss rate as a function of
SOi concentrations, is the subject of
another report. The methodology for
developing the retrospective model to
estimate yearly ambient concentra-
tions since the turn of the century for
the greater New York City area is
presented in this report. The retro-
spective estimation of sulfur concen-
tration and deposition required
estimation of both local and regional
emission trends since the turn of the
century, along with suitable choice of
a local and a regional dispersion
model to relate emissions to ambient
concentrations and deposition. The
retrospective estimates are compared
to observed SO, concentrations. It
needs no elaboration that the estima-
tion of local and regional emissions
pertinent to a given receptor, the
quantification of the local and
regional contributions to SO2 and to
the wet deposition, and reconciliation
with existing observations are for-
midable tasks. Lacking data for the
historical trends, many of the assump-
tions are based on "best available
science," and they should be revised
with the availability of new
knowledge.
This Project Summary was devel-
oped by EPA's Atmospheric Sciences
Research Laboratory, Research Tri-
angle Park, NC, to announce key find-
ings of the research project that is ful-
ly documented in a separate report of
the same title (see Project Report
ordering information at back).
Introduction
Weathering rates of marble tombstones
, in Veterans Administration (VA) ceme-
teries have been determined by New York
University through a program with Task
Group G, Effects on Materials and
Cultural Resources, within the National
Acid Precipitation Assessment Program.
The cause of the marble loss nor the ap-
portionment of the loss rate between
natural and man-induced causes was not
revealed in that study. In order to in-
vestigate this cause, estimates of the en-
vironmental history of the exposed marble
are necessary. Standard meteorological
parameters, but more importantly, for the
estimation of the man-induced damage,
the concentration history of air pollutants,
particularly S02, that span this century
are required.
The purpose of this investigation was to
estimate the yearly ambient concentration
of S02 and S04 wet deposition from 1880
to 1980 for the greater New York City
area. The study to determine the effects
of SO2 concentration on marble deteriora-
tion at two Veterans Administration cem-
eteries located in New York is the subject
of another report. The methodology for
developing the retrospective model to
reconstruct ambient concentrations since
the turn of the century for the greater
New York City area is presented in this
report.
Discussion
The reconstruction of sulfur oxide con-
centrations over the past century for the
-------
New York City area involved five distinct
steps:
(1) Gathering of data on pollutant con-
centration. Although pollutant concentra-
tion data are generally sparse in time and
space, a 15-year trend for S02 concentra-
tion between 1958 and 1972 was assem-
bled from report measurements for New
York City Central Park. These data pro-
vided significant anchor points for
reconstruction.
(2) Reconstruction of emission trends.
The reconstruction of the sulfur emission
trends for the New York City metropolitan
area were based on the fuel consumption
data and on the estimate of the sulfur
content of anthracite, bituminous coal,
and residual fuel oil. In order to estimate
the contribution of regional sources to the
New York City area, consideration was
given to the emission trends over eastern
North America.
(3) Regional background concentration
and deposition. The contribution of
sources to the regional background was
determined by using a long range trans-
port model. A Monte Carlo or direct
simulation scheme for the dispersion,
transformation, and deposition of in-
dividual puffs of pollutants was used to
estimate the regional background.
(4) Local concentrations. The sulfur
dioxide concentration in New York City
was strongly influenced by sources on the
local scale (100 km), which required a
local emission inventory and a local scale
dispersion model. The maximum concen-
trations were estimated from the local
model to be three times higher than the
surface concentration given by the
regional model.
(5) Reconciliation of monitoring data
with model estimates. The 15-year trend
data for S02 concentration was higher
than that predicted from the regional
model but lower than the upper estimate
because of local sources. In order to in-
corporate this observation, a "short
stack" factor, which takes into account
changing stack height over the last cen-
tury, was applied to the regional model
predictions to produce the "best
estimate" of yearly S02 concentration for
the New York City area over the last cen-
tury.
The regional model was also used to
estimate the wet deposition trend for New
York City. Comparison of the wet deposi-
tion and S02 concentration trends show a
similar pattern until the mid 1960's. At
that time the wet deposition was evidently
rising and leveled off in the 1970's, while
the S02 concentration has sharply de-
clined because of the "tall stack" effects.
Conclusion
The estimation of local and regional
emissions pertinent to the New York area
and the quantification of the local and
regional contributions to S02 and to S04
wet deposition are formidable tasks. Many
of the assumptions that were made in
reconstruction of the yearly S02 concen-
tration of the New York City area are
based on "best available science" and are
to be revised with the availability of new
knowledge. Uncertainties associated with
retrospective concentration estimates are
identified and discussed in the report.
Rudolf B. Husar and David E. Patterson are with Center for Air Pollution Impact
and Trend Analysis, Washington University, St. Louis, MO 63130.
John W. Spence is the EPA Project Officer (see below).
The complete report, entitled "SOa Concentration Estimates for New York City,
1880-1890," (Order No. PB 85-181 840/AS; Cost: $8.50, subject to change)
wilt be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield. VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Atmospheric Sciences Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
ft U.S. GOVERNMENT PRINTING OFFICE: 1985-559-016/27065
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
OCOC329 FS
U S ENVIR PROTECTION flGENCY
CHICAGO
------- |