Air Emissions More Than Odor
Robert E. Graves
Penn State Extension
Agricultural, Biological, and Engineering
Air quality, especially as it relates to odors and
nearby surroundings is of great interest in many
communities. Many equate air pollution and air
quality with our nose. We see it as an aesthetic or
nuisance problem, a “quality of life” issue. “If it
doesn’t smell, we are OK.”
A quick review of a recent publication from the
National Research Council of the National Acade
mies “Air Emissions From Animal Feeding Opera
tions: Current Knowledge, Future Needs”
(www.nap.edu) helps one realize that air emission
from animal agriculture are much more than just
what our neighbor can smell. The committee has
classified the issue into 13 major findings with ac
companying recommendations.
Of interest to me is a table in the executive sum
mary “Committee’s Scientific Evaluation of the Po
tential Importance of AFO Emissions at Different
Spatial Scales.” The table lists nine emissions from
animal feedings operations (AFO) and rates them
by potential importance in two categories: Global,
National, and Regional; and Local-Property Line or
Nearest Dwelling. These nine emissions include
chemical forms of nitrogen, hydrogen sulfide, meth
ane, particulates, and odors. Odor is rated the major
“local” concern but is considered insignificant on a
“global” basis. It is a quality of human life issue for
those living nearby the source. However, ammonia
is considered of minor “local” concern but is rated
as major on a “global” basis. This explains why sci
entists at Penn State and many other institutions
are working to quantify the amount of ammonia re
leased to the atmosphere from animal housing
units.
Manure and how it is managed is the primary
source of ammonia from most animal units. In the
future it may not be acceptable to just turn up the
fans and blow away ammonia that results from,
wet, manure soaked bedding, sloppy freestall alleys,
or manure storages. It may be necessary to manage
moisture levels, cleaning schedules, pH, or other
conditions to minimize loss of ammonia to the at
mosphere in the barn, in storage, and during land
application.
Let’s hope that answers to some of the questions
that have been raised by this report concerning
these nine different emissions areas will be helpful.