United States
Environmental Protection
Agency
Office of Exploratory
Research
Washington DC 20460
Research and Development
EPA-600/S6-84-005 Apr. 1984
&EPA Project Summary
Assessment for Future
Environmental Problems-
Agricultural Residues
M. T. McAdams, K. R. Meardon, D. P. Kent, and E. F. Darley
This assessment was undertaken to
determine whether agricultural burning
constitutes an environmental problem
in the United States. Preliminary indica-
tions are that agricultural burning is not
likely to become a national problem.
The report summarizes available in-
formation on location, types, and quan-
tities of residues burned; health effects;
nonhealth related concerns; policies,
regulations, and smoke management
plans affecting agricultural burning; and
alternative disposal practices. A qualita-
tive analysis discusses the future of
agricultural burning on a regional basis,
taking into account factors such as
agricultural production potential and
demographic changes. A trend analysis
computer model is used to examine the
potential future emissions of particu-
lates, hydrocarbons, and carbon mon-
oxide from agricultural burning in
California and in the Willamette Valley.
Oregon.
The report concludes by identifying
gaps in information, recommending
methods to gather the missing informa-
tion, and identifying and prioritizing
research efforts. An annotated bibliog-
raphy of over 100 references is pro-
vided.
This Project Summary was developed
by EPA's Office of Exploratory Re-
search, Washington. DC, to announce
key findings of the research project that
is fully documented in a separate report
of the same title (see Project Report
ordering information at back).
Introduction
In 1977, the Environmental Protection
Agency (EPA) published a report on
agricultural burning entitled "Source
Assessment: Agricultural Open Burning,
State of the Art." The objective of the
report was to "assess the environmental
impact of agricultural open burning and
to produce a state of the art report
summarizing available data on air emis-
sions from this source." Information in
the report included a process description
of the evolution of emissionsfrom agricul-
tural burning, factors affecting these
emissions, geographic distribution of
agricultural burning and its emissions,
emission estimates and characteristics,
and pollution control technology. The
current study was able to draw upon
some of the information developed in the
earlier report in addressing its primary
objective of determining whether agricul-
tural burning is a current or a potential
national problem, and, if so, identifying
research and policy alternatives available
to address the problem. However, most of
the information required expansions and
updating. Furthermore, the current study
attempts to assess the potential for
environmental problems to a greater
extent than did the previous study. The
report includes a qualitative trend analy-
sis for the nation based upon literature
and personal communications. Also, an
attempt was made to develop a quantita-
tive trend analysis. To this end, the
FUTURSCAN trend impact analysis model
was used to predict the status of the
practice in year 2002. The FUTURSCAN
analysis was conducted only for Califor-
nia and Oregon, as input data were insuf-
ficient for other states. Input data for
these two states also were limited. Con-
sequently, the usefulness of the
FUTURSCAN results, contained in an
appendix to the full report, is limited.
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Conclusions
From a review of the available informa-
tion, some conclusions can be drawn
about the practice of agricultural burning,
health effects, and the adequacy of the
data base available for this study.
Current and Future
Status of the Practice
Agricultural burning is an important
agronomic practice in certain areas of the
nation. Its use fs likely to continue, barring
discovery of major adverse health impacts
associated with exposure to its smoke.
Viable alternatives for certain crops or in
some areas are limited. Other major
factors that could influence the growth or
decline of the practice include increases
in agricultural production, continued
population shifts, and the development of
alternative disposal methods.
Agricultural burning is likely to de-
crease in California and Oregon due to
continued efforts to discover and imple-
ment viable alternatives and to limited
potential for increases in agricultural
production. Increased competition for
markets is likely to result in a decrease of
sugar cane production in Hawaii and,
hence, in a decrease in sugar cane burn-
ing. In the Southeast region, large acreage
available for agricultural production is
likely to result in more acres of residues
being burned. Population shifts toward
the West and Southwest are likely to
increase public exposure to the practice
and disagreements between farmers and
non-farmers. In the West, smoke manage-
ment programs are in effect. In the
Southeast, agricultural burning currently
is practiced with much less reliance on
smoke management techniques. If total
acres burned and populations increase as
expected, pressures to reduce emissions
and human exposure will likely result in
adoption of some form of regulation. As in
the West, Southeast states appear to
have mechanisms to manage emission
control programs.
Health Effects
Little research has been conducted to
document health effects from agricultural
burning, and the findings from these
studies are inconclusive. Therefore, con-
clusions are limited in scope and reliabil-
ity.
Common observation indicates that
short-term eye and respiratory irritations
may occur as a result of exposure to the
smoke. Long-term impacts of exposure
are unknown; however, the smoke is
composed primarily of particulates, car-
bon monoxide, and hydrocarbons. Much
of the particulate burden is submicron in
size and is easily deposited deep in the
lungs. Known and suspected carcinogens
and some trace metals have been identi-
fied in the smoke emitted from some
residues. The presence of these materials
suggests a potential for adverse health
impacts.
Health effects data in general are insuf-
ficient to determine long-term impacts
associated with exposure to airborne
carcinogens. While agricultural smoke
can be a source of materials to which the
local population could be exposed, it is
only one among many potential sources
on a nationwide scale. Research programs
are underway to identify health impacts
of criteria pollutants and airborne carcino-
gens, and the identification of agricultural
fire smoke as a source of potentially
harmful pollutants underscores the need
to continue these research efforts. Health
effects information specific to agricultural
burning should be used to supplement
ongoing research.
Information Base
Significant gaps in available informa-
tion have made it impossible to drawfinal
conclusions about the importance of
agricultural burning as a nationwide
source of air pollution. Analysis showed
that most available and reliable informa-
tion pertained to agricultural burning in
California, Oregon, and Hawaii. However,
sources with nationwide information
about crops, location, and quantities
burned contained numerous inconsis-
tencies.
A more reliable analysis of the impor-
tance of agricultural burning as an agro-
nomic practice and a source of air pollu-
tion could be completed if a new data
base were created or even if the reliability
of the existing data bases could be
verified. A uniform approach to collecting
specific information would provide a data
base suitable for developing a clear
picture of agricultural burning and other
residue disposal methods. The U.S.
Department of Agriculture annually con-
ducts a census of agricultural statistics. A
section added to this census could provide
the desired data base. Alternatively, a
nationwide survey of agricultural exten-
sion agents or agriculture department
officials in county offices could provide a
reasonably accurate description of the
practice.
Little information was available con-
cerning health and socio-economic ef-
fects associated with agricultural burning.
The initial literature search produced
reports concerning energy production
from burning or agricultural residues;
however, little of this information could
be obtained or analyzed under the scope
of the present study.
FUTURSCAN
Insufficient historical data and the
difficulty in determining the technical
relationship between events and their
impacts limit the usefulness of the results.
Also, the results give little information
that is not already apparent from a careful
study of the input data and event param-
eters. Furthermore, the probabilities of
events vary among states and the impacts
of events vary among crops and states.
Thus, it is only feasible, at best, to use a
futures model of agricultural burning for
small geographic areas, such as the
Willamette Valley in Oregon. These re-
sults are not applicable to other parts of
the country for several reasons, including
the absence of an event concerning
increased agricultural production. That
particular parameter was not considered
for this study because increased produc-
tion in the two study areas (California and
Oregon) is questionable.
Recommendations
Agricultural burning is primarily an air
pollution problem. The Clean Air Act
defines air pollution problems that befit
federal action, and it describes appropri-
ate actions that the federal government
should take with respect to air pollution
problems. The act specifies protection of
public health as EPA's top priority with
regard to air programs. Thus, EPA's top
research priorities should include filling
data gaps relating to health effects associ-
ated with agricultural burning. Secondary
priority should be given to research that
would assist EPA or the states in develop-
ing appropriate regulatory responses.
Such research priorities are further sug-
gested by the gaps that exist in the health
effects information.
The following are research recommen-
dations listed in order of priority:
1. Improve data base concerning
health impacts of agricultural burn-
ing. To accomplish this, the federal
government should support air pol-
lutant risk assessments, according
to the steps itemized below:
conduct smoke assays and deter-
mine specific hazardous com-
pounds in smoke for crops the
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residues of which typically are
burned in the largest quantities or
in areas appearing to have the
highest probability for human
exposure to smoke;
for use in estimating ambient air
concentrations and population
exposures, develop air pollution
dispersion models applicable to
agricultural burning area sources;
conduct source characterization
studies for crops selected as
described above. These studies
should contribute to the develop-
ment of a uniform national data
base for all crops burned. The
studies could be undertaken as
part of the annual census con-
ducted by the U.S. Department of
Agriculture, or they could consist
of surveys of agricultural exten-
sion agents and local agricultural
department officials. The studies
should provide information, in-
cluding the location of sources
(given in latitudinal and longitu-
dinal coordinates), areas of spe-
cific types of crops grown and
harvested per source, tons per
acre of residue generated, annual
burn periods, and descriptions of
physical characteristics of agricul-
tural burning sources, including
burning technique, fuel heating
value, heat loss, moisture content
of residue, flame height, temper-
ature and wind speed, and fire
propagation rate;
conduct lexicological, or, where
feasible, epidemiological studies
to verify suspected short-term
impacts of intrusions (e.g., eye
and respiratory irritation), and to
develop risk factors (if not already
developed with regard to other
sources of the same pollutant) for
hazardous components of agricul-
tural burning smoke. Synergistic
effects also should be investiga-
ted; and
use risk factors, pollutant disper-
sion, and population exposure
(population information should be
available) models to determine
annual health effect incidence
and maximum lifetime risk for
specific hazardous compounds in
smoke for crops selected as de-
scribed above.
2. Actively encourage the development
and implementation of smoke man-
agement techniques. Smoke man-
agement techniques appear to be
the best available techniques for
limiting emissions where agricul-
tural residues are burned. These
techniques have been implemented
successfully in California, Hawaii,
Oregon, and Washington and could
be adapted for use elsewhere,
especially in the Southeast.
To promote smoke management
techniques, the federal government
should direct efforts toward:
a. Development of a guidance docu-
ment for state air pollution con-
trol and agriculture department
personnel explaining smoke
management techniques. Specif-
ically, these reports should con-
tain the following types of
information:
description of smoke manage-
ment techniques and alterna-
tive methods (both tried and
untried);
description of regions and
crops where methods are used
or may be appropriate for use;
critical factors that affect the
feasibility of implementation
or transferability to other
areas;
instruction for adapting tech-
niques to accommodate local
or regional needs;
the kinds of impacts the meth-
ods have on emissions, safety,
cost to the farmer, agronomic
and other benefits, other envi-
ronmental and economic
factors, and smoke plume
characteristics;
critical factors that affect the
above impacts;
instructions for developing a
smoke management plan and
incorporating the plan into the
state's body of regulations; and
contacts for further informa-
tion.
b. Development of a guideline docu-
ment to introduce smoke man-
agement techniques to farmers,
including information listed
above that would assist farmers
in implementing the technqiues.
c. Implementation of outreach pro-
grams to farmers to explain and
encourage the use of smoke
management techniques. Work-
shops, provided through agricul-
tural extension agencies and
using guideline documents de-
scribed above should be provided
to farmers.
Support research into alternative
methods of residue disposal. Re-
search already is underway in cer-
tain areas. One particularly promis-
ing alternative is the substitution of
meadow foam grass for ryegrass in
Oregon. Further market assess-
ments and breeding experiments
are necessary to establish the value
of meadow foam and increase its
agronomic suitability to Oregon
soils. Further research is also
needed in Oregon and elsewhere
into alternative disease, pest, and
weed control; research efforts in
these areas have been slow due to
high costs and the long-term nature
of the experiments.
Energy production from residues
in California has already been suc-
cessful. Further research is required
to determine the energy-producing
value of other promising residues,
particularly those from prunings,
rice, and field crops.
Whole cane stalk cleaners have
shown promise in Louisiana; how-
ever, more study is needed to
demonstrate their value under field
conditions and for different condi-
tions of cane stalk.
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M. T. McAdams, K. R. Meardon. and D. P. Kent are with Pacific Environmental
Services. Inc., Durham, NC 27707; E. F. Darley is at 108 Aldous Street,
Cashmere, WA 98815.
Robert Barles is the EPA Project Officer (see below).
The complete report, entitled "Assessment for Future Environmental Problems
Agricultural Residues," (Order No. PB 84-161 371; Cost: $17.50, subject to
change) will 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:
Office of Exploratory Research
U.S. Environmental Protection Agency
Washington, DC 20460
*tt U.S. GOVERNMENT PRINTING OFFICE; 1984 759-015/7664
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