Concerns regarding airborne emissions from Ohio livestock facilities are being addressed by ongoing research to assess farm air quality and farm worker exposure as well to provide preliminary data for government agencies, producers and researchers. Considering the fact that the air emission data is not easily transferable from other states or country due to variations in geographical regions, climate conditions, management practices, animal growth cycle, building types and ventilation systems, it is very meaningful to have air emission data collected from Ohio farms. The study uses a variety of instruments to measure weather conditions, indoor environment (air velocity, temperature, humidity, static pressure), gasses (ammonia, hydrogen sulfide, carbon dioxide), dust (concentration, size distribution, toxicity), and odor in typical Ohio farms in three seasons. In March 2003, measurements were made at three sites: 1) high-rise chicken layer farm; 2) swine finishing farm with deep pit; and 3) free-stall dairy farm with natural ventilation. Although more data are needed and continuous measurement is ideal, preliminary measurements indicate that, gas, dust and odor levels are very low in farms in early Spring. However, dust in the poultry house and odors in the swine barn are relatively higher than that in the other facilities. In 2004, three different animal facilities will be added to the study.
Discussion:
Harold Keener (OSU) asked if
the data presented was based on single measurements or replications. Zhao
responded that they were one time measurement taken in March 2003. For
each facility, measurements were made at fourteen different locations both
inside and outside the building. She plans to take measurements at each
facility during each season to identify seasonal variations.
Keener asked if dust measurements outside the poultry facility were made before
or after those inside (Note: Zhao had reported that entering the building caused
high activity, increasing dust levels). Zhao replied that in all
cases, the first measurements made were where the lowest results were expected
so as not to affect the equipment.
Jon Rausch (OSU) asked whether the particle size of the dust had been measured.
Zhao noted that the data were collected but need to be summarized. The
measurements are being made to reflect human breathing.
Rausch questioned whether bacteria associated with the dust are being cultured
to determine what species are present. Zhao responded that it is work that
is just beginning.
Rausch asked if there are other studies available across the country that would
provide a benchmark. Lingying confirmed that Purdue, Illinois and
Minnesota had conducted some farm studies; however, data can vary significantly
in different locations. Therefore, findings in other states are often not
applicable in Ohio.
Rausch asked if the differences are due to different feeding practices.
Zhao agreed that feeding is one parameter that may have an impact and indicated
that the difference is true for gases and odors as well as dust. There are
many European studies but the findings are not transferable to the U.S.
Keener questioned which facilities could pose the greatest risk from a health
standpoint. Zhao noted that, of the gases measured, carbon dioxide is
generally not a health risk but is an indicator of freshness of air and
effectiveness of the ventilation system. The health risks from dust is
that it can carry pathogens and odors, which may be an irritant or cause
psychological impairment, and the size of the particulate matter may cause or
exacerbate respiratory illnesses. For hydrogen sulfide, OSHA standards are
10 ppm for 10 minutes but more clarification on long term exposure at lower
levels is needed. Zhao stressed that the risks vary with both
concentration levels and length of exposure and that additional studies are
needed before setting standards.
Notes
by Mary Wicks
The
OCAMM (Ohio Composting and Manure Management) Program is funded by OARDC/OSU.