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2008 National AgrAbility Workshop
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Promoting Success in Agriculture for People with Disabilities and Their Families
Focus & Assistive Technology Notes – Respiratory Issues: Confinement Housing HazardsA primary chronic health condition affecting farmers is respiratory disease. 1 Terry Strine developed his permanent respiratory damage from a gaseous chemical inhaled in the milk house on his family’s dairy farm, but many of his symptoms and complications parallel those seen in animal confinement workers. While respiratory disease can be found in most types of confinement livestock production (e.g., cattle, swine, poultry, etc.), this article will focus on swine. Within modern swine confinement housing, dust and other gases can easily rise to levels harmful for both the animals and their human handlers. DustWhile the acceptable levels of airborne contaminants such as dust and harmful gases are legally controlled in many industries, this isn’t the case in production agriculture. In the United States, an estimated 700,000 people work in livestock confinement operations; in Iowa alone, 80,000 people work in swine confinement buildings.2 In fact, the group of farmers/ranchers and farm workers with the most frequent and severe health problems are those associated with swine confinement housing.2 The primary contaminant encountered in swine confinement barns is related to the very fine organic airborne dust the workers breathe. This fine dust is a chemical soup containing swine dander, swine feed and feces, insects, rodent and bird feces, and bacterial or fungal toxins.1 Since these fine dust particles are small enough to enter the human respiratory system, the body’s natural reaction to a “foreign” material is to defend against it. This could take the form of an inflammatory response or perhaps even a toxic response. Immediate symptoms may be eye irritation, nasal stuffiness, or itchy throat. Delayed responses could include headaches, dizziness, shortness-of-breath, vomiting, and/or a fever. Inhaling this very fine dust could cause temporary, insidious, or permanent lung damage. The respiratory system should recover when the damage is temporary and the person is no longer exposed to the dust. When one suffers insidious damage, reducing exposure helps, but the person’s respiratory system may not fully recover. Permanent lung damage indicates that parts of the lung tissue are irreversibly damaged. Below are some of the more serious respiratory conditions one may experience when exposed to these airborne contaminants. Sinus Conditions: Occurring in up to 25% of swine confinement workers.1 Treatment involves decreasing exposure. Chronic Bronchitis: Is defined as a daily productive cough for three months a year, over a two-year period. Of the various animal and grain production workers, those working in swine confinement have the highest prevalence of chronic bronchitis. Prevention involves respiratory protection to decrease exposure to dusts and gases, and to stop smoking, which increases the risk.1 Asthma-like Syndrome: Asthma-like symptoms may disappear with time away from the contaminant but may reappear upon returning to the environment. This disease has been identified in up to 25% of swine confinement workers.1 Treatment is similar to chronic bronchitis. Asthma a , Occupational Asthma: Whether asthmatic, or experiencing an increase in airway reactivity such as wheezing, cough or dyspnea (air hunger), occupational asthma occurs because a particular antigen b is present.1 While not common, continued exposure can lead to progressively worsening symptoms. Treatment follows a stepwise approach and prevention may require appropriate personal respirators and measuring/controlling airborne dust levels. Organic Dust Toxic Syndrome (ODTS): ODTS is an inflammatory pulmonary reaction caused by exposure to massive amounts of organic dust containing molds and endotoxin c levels and is particularly common in swine confinement workers.1,3 Treatment and prevention vary depending on severity and situation.
Farmer’s Hypersensitivity Pneumonitis (FHP) [formerly referred to as Farmer’s Lung Disease or FLD]: FHP is a form of hypersensitive pneumonitis d specific to actinomycete e spores found in organic dust. It is more common among dairy than swine confinement operations, since the source mold or spore filled contaminant are directly connected to feeding/handling moldy silage, grains, feed, hay, or straw bedding.1, 3 Again, treatment and prevention vary depending on severity and situation. GasesThe two primary gases of concern to workers health in and around swine confinement housing include ammonia (NH3) from the animals’ urine/feces, and hydrogen sulfide (H2S) from stored manure in pits.1 Ammonia has a low odor threshold that is lighter than air. Ammonia compounds the negative effects of dust, and can be carried deeper into the lungs via respiratory dust, thus causing inflammation, cough, and chest pain. Hydrogen sulfide also has a low odor threshold, sometimes described as smelling like “rotten eggs”, while being both colorless and heavier than air. Hydrogen sulfide is much more serious than NH3 . Hydrogen sulfide can cause paralysis of the respiratory center, and is considered a very toxic asphyxiant. Whenever manure pits are agitated in preparation for manure removal, lethal levels of hydrogen sulfide can easily be present. Together, these “dust and gases” form the primary airborne contaminants and while there are exposure risks associated with all types of livestock raised in confinement housing, human health responses seem to be the greatest when dealing with swine (see table 1).2
Assistive TechnologyUnfortunately, as stated above, acceptable levels of airborne contaminants such as dust and harmful gases are not legally controlled in most livestock confinement buildings. The first line of defense should be designing agriculture housing with proper ventilation to provide a safe and healthy environment for the animals and the workers. Engineers have determined the proper ventilation for all types of livestock confinement housing. These building ventilation plans can be viewed at the Midwest Plan Service (MWPS).6 If required to work in a livestock confinement housing building, there are simple ways to help reduce the amount of airborne dust contaminants that can sometimes be helpful. For example, when breaking/spreading bales for animal bedding, pouring some water into the bale prior to spreading it may reduce the amount of dust. If the confinement housing is equipped with misting sprayers for controlling the environment heat and animal stress, a short mist of water prior to entering the building will reduce the airborne dust. Even with the best ventilation, however, people who work in a swine confinement house should understand the dangers involved and take personal responsibility for their safety. An air-purifying respirator would offer additional personal protection. There are essentially two types of air-purifying respirators, disposable and reusable7 that protect the user in two basic ways. They remove contaminants from the air (e.g., particulate respirators); or they supply clean respirable air. The most common disposable respirator is the dust mask. The dust mask must be properly fitted, preferably with two straps rather than one. The common disposable dust mask cannot protect against gases, chemical vapors, or lack of oxygen. Another kind of disposable respirator looks like the dust mask, but contains a non-replaceable cartridge, designed for a specific hazard. Reusable air-purifying respirators have cartridges that are replaceable, and may look like a dust mask, or have a full-face shield. Reusable respirator cartridges can be changed to match the particular hazard (i.e., selected for a particular gas or vapor). Full-face versions are light weight, easy to wear and usually also have a battery powered fan. When there is a lack of oxygen, or the contaminants are unknown and/or toxic, neither a disposable nor a reusable air-purifying respirator should be used. For example, if you need to enter a manure pit, which contains toxic H2S gas, only someone who is properly trained and wearing a self-contained breathing apparatus should be allowed to enter.
The National Institute for Occupational Safety and Health (NIOSH) provides ratings for disposable respirators, and approved respirators are marked with the manufacturer’s name, part number, and the protection provided. For example, an N-95 would filter at least 95% of airborne particulates, but is not resistant to oils.8 Many of the local farm supply stores and industry/farm suppliers, such as Gempler’s9 or Great Plains,10 offer safety and security equipment ranging from safety glasses, hearing protection, to NIOSH rated respirators. 8, 11 These items may also be listed under the category of personal protective equipment (PPE).
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