" (Murphy, 2009) This is held by Murphy to be what is wanted since high carbon dioxide levels help to maintain high quality silage." (2009) Simultaneously, the gas that is "odorless and colorless" is stated to be that which is dangerous. The gas is stated to replace the oxygen in the silo and since this gas is present in high concentrations the individual receives very little in the way of warning that the gas is about to overcome them. This gas is stated to be characterized by "…a strong bleach-like odor and low lying yellow, red, or dark brown fumes. Unlike carbon dioxide, nitrogen dioxide levels reach a peak about three days after harvesting and rapidly begin to decrease thereafter particularly is the silo is ventilated." (Murphy, 2009)

Sealed silos are specifically designed so that there is no necessity to enter them however, there are various gases present in convention silos and in open-top silos however the largest presence is that of nitrogen dioxide and this gas is stated to be "highly toxic…[and]…characterized by a strong bleach-like odor and low lying yellow, red, or dark brown fumes." (Murphy, 2009) Nitrogen dioxide levels are stated to peak at approximately three days following harvest and to begin a rapid decline and this is especially true in vented silos.

A. Harms

Harm caused by nitrogen dioxide include: (1) severe irritation to nose and throat; and (2) inflammation of the lungs. (Murphy, 2009) Since there is little in the way or pain or discomfort following exposure, this gas is particularly dangerous because it may be inhaled without the individual realizing it due to lack of serious effects. This is sometimes fatal as individuals are known to die in their sleep following exposure due to fluid collection in the lungs.

B. Safety Practices

Recommended safety practices include: (1) provide good ventilation whenever possible in and around the silo when silage is fermenting; (2) keep door...

(Murphy, 2009) if one must enter the silo it is suggested that they use a "self-contained breathing apparatus." (Murphy, 2009) it is additionally stated that one should never under any circumstances enter the silo when no one else is present.
Summary and Conclusion

Agriculture is clearly a necessary profession for the world-at-large as agriculture provides food for both human beings and animals however, there are significant respiratory dangers present on farming operations. Farmers and their families and those who labor on farms should be educated about the various respiratory dangers that exist on farming operations. This work has identified two of these respiratory dangers including: (1) toxic mold and dust; and (2) gases that are present in silos. This work has also explained the information available in the state of Pennsylvania to farmers to assist them in safe agricultural initiatives in order that they have enough knowledge to protect themselves, their families and those who work on the farming operation.

Bibliography

Murphy, Dennis J. (2009) Silo Gases the Hidden Danger. College of Agricultural Sciences -- Cooperative Extension. Agricultural and Biological Engineering. Penn State E-16. Online available at: http://www.age.psu.edu/extension/factsheets/e/E16%20.pdf

Murphy, Dennis J. (2009) Farm Respiratory Hazards. College of Agricultural Sciences -- Cooperative Extension. Agricultural and Biological Engineering. Safety 26. PennState. Online available at: http://www.age.psu.edu/extension/factsheets/e/E26.pdf

The Dirt on Pennsylvania Agriculture (2004) Trends in Rural Pennsylvania. March/April 2004. Online available at: http://www.ruralpa.org/dirtonpaag.pdf