How to diagnose farmer’s lung

In this Article

  • Symptoms
  • Causes
  • Diagnosis
  • Treatment

Farmer’s lung is a disease caused by an allergy to the mold in certain crops. Farmers are most likely to get it because it’s usually caused by breathing in dust from hay, corn, grass for animal feed, grain, tobacco, or some pesticides.

Not everyone gets farmer’s lung after breathing in these things. It only happens if you have an allergic reaction.

Your doctor may use another name for your condition. It’s also called extrinsic allergic alveolitis, hypersensitivity alveolitis, or hypersensitivity pneumonitis. The “-itis” at the end of these names means it causes inflammation. With farmer’s lung, the inflammation, or swelling, is in your lungs.


Farmer’s lung can cause three kinds of allergic reactions.

An acute attack is an intense reaction that happens 4 to 8 hours after you breathe in mold. Symptoms include:

  • Dry irritating cough
  • Fever and chills
  • Rapid breathing
  • Rapid heart rate
  • Shortness of breath
  • Sudden feeling that you’re sick

A sub-acute attack is less intense and comes on more slowly than an acute attack. Symptoms include:

  • Achy muscles and joints
  • Coughing
  • Mild fever with some chills
  • No appetite
  • Shortness of breath

You may mistake acute or sub-acute farmer’s lung for the flu, because many of the symptoms are the same.

Chronic farmer’s lung happens after you’ve had many acute attacks and are around large amounts of moldy dust often. When you reach this point, your lungs may have permanent damage. Symptoms include:

  • Cough that won’t go away
  • Depression
  • General aches and pains
  • Night sweats
  • No appetite and gradual weight loss
  • Occasional fever
  • Shortness of breath that gets worse over time
  • Weakness and loss of energy
  • Weight loss

Most people with acute or subacute farmer’s lungВ get better; only a small percentage of peopleВ develop chronic farmer’s lung. Chronic farmer’s lung symptoms can be controlled/improved, but it can’t be cured.

Farmers may notice that their symptoms get worse in the winter. Storing animal feed like hay, grass, or grain inside makes mold more likely to grow. Plus, there’s no breeze or wind to clear it out of the air.


It’s common for farmers to get this disease from moldy hay and other crops. But you also can get it from dust in things like:

  • Animal dander
  • Bacteria
  • Bark
  • Bird droppings
  • Dried rat urine
  • Feathers
  • Fungi
  • Husks
  • Insects
  • Wood

These allergens have to be very small — around 5 millionths of a meter (5 microns) — to affect you. Because the particles are so tiny, the normal defenses in your nose and throat miss them, and they go straight to your lungs. Your lungs then try to get rid of the dust, and your symptoms start when your immune system reacts to that.


The most important questions your doctor will ask you will be about your environment. If you’re not a farmer, it may be harder to figure out that farmer’s lung is causing your symptoms.

It can also be hard to know what’s going on if you’re not having an acute attack. Your doctor can give you a blood test to look for certain things that trigger your immune system (called antigens) or order a chest X-ray to look for signs that you’ve had acute attacks.

Other things your doctor can do to find out if you have farmer’s lung include:

  • Pulmonary function test: This measures how much air you inhale and exhale.
  • Bronchoscopy: Your doctor uses a device called a bronchoscope to look at your airways and lungs and collect a sample of fluid for testing. You’ll be given medicine to make you sleep through this.
  • Lung biopsy: If your doctor thinks you might have farmer’s lung but can’t be sure, theyВ may want to take a sample of your lung tissue and send it to a lab for tests. You’ll probably be given medicine to sleep through this as well.


There’s no cure for farmer’s lung, but you can control it by staying away from the allergen that causes your symptoms. You might:

  • Work outside as much as possible
  • Avoid dusty work
  • Wear a mask or other protective equipment
  • Use fans, filters, or exhaust blowers wherever you can

Steroid drugs like prednisone (Deltasone, Orasone, Meticorten) can help with your symptoms because they can slow down your immune system and help with inflammation. Your doctor may only prescribe these if you have a chronic case, though.

If steroids don’t work, your doctor may want to prescribe and immune suppressantВ such as a drug calledВ azathrioprine (Azasan).

In addition to recommending that you avoid your triggers, your doctor may also recommend bed rest or oxygen therapy, which involves getting extra oxygen through tubes in your nose or a mask, to help you feel better.


Canadian Centre for Occupational Health & Safety: “Farmer’s Lung,” “Hypersensitivity Pneumonitis (Extrinsic Allergic Alveolitis).”

Farm Safety Association: “Farmer’s Lung: It Takes Your Breath Away!”

Canadian Lung Association: “Farmer’s Lung.”

Medscape: “Farmer’s Lung.”

Virginia Tech Virginia Cooperative Extension: “Farmer’s Lung: Causes and Symptoms of Mold and Dust Induced Respiratory Illness.”

What Is Farmer’s Lung?

Farmer’s Lung is a disease which is caused by chronic inhalation of spores from moldy hay. It is usually seen in people who work with hay. As the time progresses, some people may become allergic to this mold present in the hay thus causing symptoms. As the exposure to this moldy hay becomes chronic, symptoms of respiratory illness start to surface. Once an individual starts having symptoms, there is a high likelihood that he or she will always be at risk for having symptoms whenever being exposed to hay mold.

How to diagnose farmer's lung

What Are The Causes Of Farmer’s Lung?

Farmer’s Lung as stated is caused due to exposure to spores of hay mold, especially in places which does not have good ventilation like a barn.

What Are Some Of The Symptoms Of Farmer’s Lung?

After being exposed to moldy hay for a significant amount of time, the individual will start to notice following symptoms:

  • Increased coughing with abnormal production of phlegm
  • Fever with at times chills
  • Shortness of breath
  • A tightness sensation in the chest.

How Is Farmer’s Lung Diagnosed?

To diagnose Farmer’s Lung, the treating physician will first take a detailed history, especially the occupational history to look for exposure to moldy hay. After that, a blood draw may be performed along with a chest x-ray and pulmonary function test to look at the functioning of the lungs. At times, there may be other tests that may be required for a confirmatory diagnosis of Farmer’s Lung.

What Are The Treatments For Farmer’s Lung?

The gold standard for treatment for Farmer’ Lung is to stay away from moldy hay. Apart from this, medications may be given for control of symptoms but use of medications may not prove effective until exposure to hay is completely stopped. Administering corticosteroids is one of the main treatments for this condition.

Have you heard of a disease called Farmer’s lung? Farmer’s lung is so-called because the disease is commonly found to affect the lungs of the farmer. Farmer’s, when they are attacked by various allergens like mold spores, dust, straw, or grain can cause severe allergic reactions leading to serious respiratory hazards.

What is Farmer’s lung?

Farmer’s lung disease is a non-infectious allergic lung disease and is a type of hypersensitivity pneumonitis that is caused by inhaling mold spores present in the air from moldy hay, straw, or grain. The disease is found to disrupt the normal functioning of the lungs which involves inhalation of oxygen and exhalation of carbon dioxide.


  • Sudden shortness of breath
  • Chronic cough and lung congestion.
  • A general feeling of tiredness.
  • Tightness in the chest

The symptoms are similar to acute bronchitis, which is classified as J20 under ICD-10 code for acute bronchitis. The code is a medical classification of the diseases of the respiratory system.

Read Also: Five Most Common Types Of Nutritional Deficiencies In The World

What Causes Farmer’s Lung disease?

Farmer’s lung is an allergic reaction to tiny particles that are suspended in the air. These small particles when inhaled can give rise to farmer’s lungs. Some of these particles include:

  • Animal dander
  • Pollen grains
  • Moldy hay or straws
  • Bird droppings
  • Feathers
  • Fungal spores
  • Husks
  • Insects
  • Wood particles


Diagnosing a farmer’s lung disease is most of the time mistaken with flu and asthma. In such a case it’s important for the person to explain to the doctor that you are a farmer and have come in contact with moldy hay. Other diagnostic tests your doctor may recommend to find out if you have farmer’s lung include:

  • Pulmonary function test: This test measures how well your lungs function. The test reveals how much air you inhale and exhale.
  • Bronchoscopy: This is a technique used to look at the airways and lungs. The doctor may also sample fluid for testing. You will be under the influence of anesthesia throughout the whole process.
  • Lung Biopsy: A tissue sample may be collected from your lungs for further lab tests.


Farmer’s lung disease has no cure and there is only prevention for this disease. You can control the disease by

  • Avoiding tasks that involve too much exposure to dust.
  • Wear a piece of protective equipment or mask.
  • Use filters, exhaust, blowers, and fans wherever you can.

Your doctor may prescribe you some medications that can help with your symptoms. These medications include steroid drugs like prednisone which helps with inflammation by slowing down your immune system.

Azathioprine is also prescribed as an immunosuppressant in case steroids won’t work.

  • Share
  • Email
  • Print
  • Feedback

Approach Considerations

Systemic corticosteroid administration and avoidance measures constitute the primary treatment for farmer’s lung. Patients may decrease activity because of cough and dyspnea on exertion. In a patient with acute farmer’s lung, pulmonary function improves once antigen exposure is eliminated. Between episodes of acute disease, activity may be unlimited.

In patients who develop progressive fibrosis, lung transplantation should be considered. [20]

Long-Term Monitoring

Follow-up care should include routine spirometry with lung volumes and diffusion capacity, arterial PO2 and arterial-alveolar gradient assessment, and chest radiographs. Consider high-resolution CT scans of the chest to seek resolution of infiltrates or presence of ground-glass opacities that may indicate a need for further treatment with corticosteroids and/or continued insult to the lungs by antigen exposure.


Zergham AS, Heller D. Farmers Lung. StatPearls [Internet]. 2020 Jan. [Medline]. [Full Text].

[Guideline] Raghu G, Remy-Jardin M, Ryerson CJ, et al. Diagnosis of hypersensitivity pneumonitis in adults. An official ATS/JRS/ALAT clinical practice guideline. Am J Respir Crit Care Med. 2020 Aug 1. 202(3):e36-e69. [Medline]. [Full Text].

Lehrer SB, Turer E, Weill H, Salvaggio JE. Elimination of bagassosis in Louisiana paper manufacturing plant workers. Clin Allergy. 1978 Jan. 8(1):15-20. [Medline].

Liu S, Chen D, Fu S, et al. Prevalence and risk factors for farmer’s lung in greenhouse farmers: an epidemiological study of 5,880 farmers from Northeast China. Cell Biochem Biophys. 2015 Mar. 71(2):1051-7. [Medline].

Barrera C, Millon L, Rognon B, et al. Immunoreactive proteins of Saccharopolyspora rectivirgula for farmer’s lung serodiagnosis. Proteomics Clin Appl. 2014 Dec. 8(11-12):971-81. [Medline].

Ashitani J, Kyoraku Y, Yanagi S, Matsumoto N, Nakazato M. Elevated levels of beta-D-glucan in bronchoalveolar lavage fluid in patients with farmer’s lung in Miyazaki, Japan. Respiration. 2008. 75(2):182-8. [Medline].

Deschenes D, Provencher S, Cormier Y. Farmer’s lung-induced hypersensitivity pneumonitis complicated by shock. Respir Care. 2012 Mar. 57(3):464-6. [Medline].

Bellanger AP, Reboux G, Botterel F, et al. New evidence of the involvement of Lichtheimia corymbifera in farmer’s lung disease. Med Mycol. 2010 Nov. 48(7):981-7. [Medline].

Barrera C, Valot B, Rognon B, Zaugg C, Monod M, Millon L. Draft genome sequence of the principal etiological agent of farmer’s lung disease, Saccharopolyspora rectivirgula. Genome Announc. 2014 Dec 18. 2(6):[Medline]. [Full Text].

[Guideline] Dobashi K, Akiyama K, Usami A, et al, for the Committee for Japanese Guideline for Diagnosis and Management of Occupational Allergic Disease, The Japanese Society of Allergology. Japanese guidelines for occupational allergic diseases 2017. Allergol Int. 2017 Apr. 66(2):265-80. [Medline]. [Full Text].

Cardoso J, Carvalho I. The value of family history in the diagnosis of hypersensitivity pneumonitis in children. J Bras Pneumol. 2014 Mar-Apr. 40(2):183-7. [Medline]. [Full Text].

Hanak V, Golbin JM, Ryu JH. Causes and presenting features in 85 consecutive patients with hypersensitivity pneumonitis. Mayo Clin Proc. 2007 Jul. 82(7):812-6. [Medline].

Barber CM, Wiggans RE, Carder M, Agius R. Epidemiology of occupational hypersensitivity pneumonitis; reports from the SWORD scheme in the UK from 1996 to 2015. Occup Environ Med. 2017 Jul. 74(7):528-30. [Medline]. [Full Text].

Liu S, Chen D, Fu S, et al. Prevalence and risk factors for farmer’s lung in greenhouse farmers: an epidemiological study of 5,880 farmers from Northeast China. Cell Biochem Biophys. 2015 Mar. 71(2):1051-7. [Medline].

Barbee RA, Callies Q, Dickie HA, Rankin J. The long-term prognosis in farmer’s lung. Am Rev Respir Dis. 1968 Feb. 97(2):223-31. [Medline].

Ohtsuka Y, Munakata M, Tanimura K, et al. Smoking promotes insidious and chronic farmer’s lung disease, and deteriorates the clinical outcome. Intern Med. 1995 Oct. 34(10):966-71. [Medline].

Soumagne T, Chardon ML, Dournes G, et al. Emphysema in active farmer’s lung disease. PLoS One. 2017. 12(6):e0178263. [Medline]. [Full Text].

Roussel S, Reboux G, Dalphin JC, Laplante JJ, Piarroux R. Evaluation of salting as a hay preservative against farmer’s lung disease agents. Ann Agric Environ Med. 2005. 12(2):217-21. [Medline].

Cormier Y, Belanger J. The fluctuant nature of precipitating antibodies in dairy farmers. Thorax. 1989 Jun. 44(6):469-73. [Medline].

Kern RM, Singer JP, Koth L, et ak. Lung transplantation for hypersensitivity pneumonitis. Chest. 2015 Jun. 147(6):1558-65. [Medline]. [Full Text].

Hypersensitivity Pneumonitis

What Are the Symptoms of Hypersensitivity Pneumonitis?

Hypersensitivity pneumonitis is typically divided into two types based on how long you have been affected and how severe your symptoms are.

An attack of acute hypersensitivity pneumonitis usually occurs four to six hours after a short period of intense exposure to the substance you are allergic to. You may feel as if you have caught the flu when an acute attack occurs. Common symptoms include fever, chills, muscle aches, headache and cough. These symptoms may last for as little as 12 hours to a few days and will resolve if further exposure is avoided.

Chronic hypersensitivity pneumonitis develops after numerous or continuous exposures to small amounts of the allergen. Symptoms may include shortness of breath, tiredness, coughing that lasts weeks or months and weight loss that gets progressively worse. Over time, some people with chronic hypersensitivity pneumonitis develop clubbing of fingers and toes and irreversible pulmonary fibrosis.

How Hypersensitivity Pneumonitis Is Diagnosed

If you suspect your symptoms are hypersensitivity pneumonitis, schedule an appointment with your doctor. Because of the risk of progressive chronic disease, it is important to get a prompt diagnosis. Your doctor will ask about your exposures, perform a physical examination and listen to your lungs with a stethoscope. Individuals with hypersensitivity pneumonitis may have abnormal lung sounds or crackles. Your doctor may also use a small instrument called a pulse oximeter that is placed on the finger to check the oxygen levels in your blood.

Some specific questions that your doctor may ask are:
  • Have you been exposed to any water damage in your house or at work, especially from humidifiers, heating systems or air conditioners?
  • What types of substances are you regularly exposed to in your work?
  • Do you have a hot tub at home?
  • Have you have been exposed to bird droppings/do you have any birds as pets/do you have any feather cushions or down pillows?

If your physician is unsure of your diagnosis, they may order additional tests. These include:

  • Chest X-ray and CT scan which may be able to show early stages of the disease and if there is any scarring.
  • Lung function tests to measure how well you breathe to see if your lungs are working correctly.
  • Blood tests to find out if you have developed antibodies to any substances that might be causing an allergic reaction.
  • Bronchoscopy, which is when a bronchoscope (small flexible tube about the size of a pencil with a video camera attached at its end) is passed either through your nose or mouth. The scope is then passed into your vocal cords, windpipe and the air passages. This tool can be used to collect tissue samples from your lung for further testing.

Surgical lung biopsy, which is performed by a cardiothoracic surgeon under general anesthesia. It is another way to get lung tissue for further testing.

Hypersensitivity pneumonitis (HP) happens if your lungs develop an immune response – hypersensitivity – to something you breathe in which results in inflammation of the lung tissue – pneumonitis. It used to be called extrinsic allergic alveolitis (EAA).

One example is farmer’s lung. This is caused by breathing in mould that grows on hay, straw and grain. Another is bird fancier’s lung, caused by breathing in particles from feathers or bird droppings. Many other substances can cause similar disease patterns. In many cases it can be very difficult to find the exact cause.


The symptoms include cough, shortness of breath and sometimes fever and joint pains. They can come on suddenly after you’ve been exposed. This is called acute HP. It goes away – without leading to fibrosis of the lung – if you can recognise and completely avoid the substance that caused the attack.

Other people may get symptoms of breathlessness and cough more gradually, perhaps over many years, because their lungs are permanently scarred. This is called chronic, or long-term, HP. Often a specific cause cannot be found.


HP is regarded as a more treatable cause of pulmonary fibrosis, but it can cause progressive symptoms and become hard to treat.

If a specific cause is identified, it’s really important to completely avoid exposure to it.

You may need to take anti-inflammatory medication called steroids for a few weeks or months. If you need steroids to control the condition for longer, your doctor may recommend more drugs to reduce the risk of side effects associated with steroids.

“I may never know what’s causing my condition”

Jane, 61, was first diagnosed with hypersensitivity pneumonitis 10 years ago

When I moved to London, I developed a cough. It got so bad I ended up in hospital and was diagnosed with hypersensitivity pneumonitis. I took high dose steroids – and my symptoms disappeared! For seven years I had no symptoms at all.

But when the symptoms came back they didn’t go away. So now my hypersensitivity pneumonitis is long-term. Tests showed I have a hypersensitivity to pigeon and budgie droppings, but my doctor says there are thousands of other things that I could be reacting to. I may never know what’s causing my condition.

I get unpleasant bouts of coughing. And a small things makes me tired – like carrying shopping home.

I found my work as a lawyer more and more difficult. My employers suggested I claim on their permanent health insurance policy. My claim was accepted and I’m now on long-term sick leave.

I take steroids and immune-suppressing drugs every day. I’ll probably take drugs for the rest of my life.

Last medically reviewed: August 2019. Due for review: August 2022

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.

Join the Community

How to diagnose farmer's lung

Farmer’s lung, formally known as extrinsic allergic alveolitis, is a type of allergic pneumonia. The disease is caused by inhaling dust that is carrying certain types of mold or bacteria. This disease is mostly found among farmers, but it may also inflict those who have no connection to the agricultural industry.

Analyzing the formal name of this disease can provide a bit of insight on the disease. Extrinsic denotes something from outside. Alveolitis refers to inflammation of the alveoli. The alveoli are small sac-like structures on the lungs that allow carbon dioxide to exit the bloodstream and oxygen to enter it.

Farmer’s lung is caused when a person has an allergic reaction to particles he inhales. That allergic reaction causes swelling of alveoli. As a result, the person is likely to experience breathing difficulty. The more severe the case, the more severe the associated symptoms can be. Symptoms include chronic coughing, tightness of the chest, and feelings of general illness.

For agricultural workers, the disease is commonly caused by exposure to contaminated hay. It is highly unlikely a person will develop farmer’s lung from a single exposure or from brief exposures. The disease generally develops as a result of excessive and prolonged exposure.

Although farmer’s lung is noted to be most common among agricultural workers, it is not restricted to such individuals. Anyone who is exposed to intense or repeated inhalation of contaminated dust can be inflicted with the disease. The organisms that cause farmer’s lung can be found in ventilation systems. This explains how an office worker, for example, could be found with the disease.

It has been noted that people are most likely to contract farmer’s lung in cold, damp conditions. Those with the disease may find it worsens in winter. There are two likely reasons for this. One, the allergens that cause the condition tend to like damp environments. Two, there is usually poorer ventilation during cold periods.

The disease can often be treated by changing environments. If a person can avoid inhaling further allergens, there is a possibility of recovery. When this is not possible, however, a person with farmer’s lung faces serious risks. For example, it has been noted that there is an increased risk of mortality if a person suffers with symptoms of the disease for more than a year before being diagnosed. In more severe cases, medication may be necessary to facilitate breathing and alleviate other symptoms.

How to diagnose farmer's lung

Use the following format to cite this article:

Respiratory illnesses associated with agriculture. (2012) Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from

A farmer’s or rancher’s life is not always associated with the great outdoors and fresh air. In production agriculture, farmers and ranchers can be exposed to toxic gases and contaminated particulate matter that can cause short- and long-term health problems. The three main respiratory illnesses associated with production agriculture are:

  • farmer’s lung,
  • silo filler’s disease, and
  • organic dust toxicity syndrome.

Farmer’s Lung

Farmer’s lung, or farmer’s hypersensitivity pneumonitis (FHP), is a noninfectious allergic disease that affects normal lung function. It results from the inhalation of mold spores from moldy hay, straw, or grain. The mold spores that cause farmer’s lung are microorganisms that grow in baled hay, stored grain, or silage with high moisture content (30%). Exposure to mold spores is greater in late winter and early spring.

Mold spores, which are not always visible, are so tiny that 250,000 spores can fit on the head of a pin. Because the spores are so small, it is easy for a farmer or rancher to breathe in millions of spores in a few minutes. Due to their size, the mold spores easily move into and settle in the lower part of the lungs.

Symptoms usually begin four to six hours after exposure to mold spores and can include increased coughing, coughs that bring up mucus, fever, chills, shortness of breath, discomfort in the lungs, and a tightness and/or pain in the chest. Symptoms may become most severe from 12 to 48 hours after exposure.

Allergic reaction to mold spores can be acute or chronic. An acute attack typically resembles the flu or pneumonia. Chronic reactions can resemble a nagging chest cold. A producer who has been diagnosed with farmer’s lung should avoid additional exposure to mold spores; otherwise, the producer’s condition could worsen and render him or her inactive. In some cases, farmer’s lung can be fatal.

If you think that you may have farmer’s lung, contact your physician and explain your symptoms and occupation. If your physician is not familiar with farmer’s lung, you may need to request a referral to a specialist for testing, diagnosis, and treatment.

To reduce the risk of contracting farmer’s lung, take the following steps:

  • Identify and minimize contaminants in your work environment.
  • Avoid exposure to contaminants and mold spores.
  • Limit the growth of mold spores by using mold inhibitors.
  • Harvest, bale, store, and ensile grains at the recommended moisture level to reduce mold growth.
  • Convert from a manual to a mechanical or automated feeding or feed-handling system to reduce the release of airborne mold spores.
  • Move work outside and avoid dusty work in confined areas whenever possible.
  • Mechanically remove air contaminants through ventilation with fans, exhaust blowers, and so on.
  • Wear appropriate respirators, dust masks, or other personal protective equipment (PPE). Click here to learn more about respiratory PPE.

Silo Filler’s Disease

Silo filler’s disease results from inhaling nitrogen dioxide, a silo gas produced during the silage fermentation process. Although a producer who has been exposed to silo gases may not experience symptoms, damage to the lungs may still have occurred. Fluid can build up in a person’s lungs 12 hours after exposure to nitrogen dioxide. Cough, hemoptysis (coughing up blood from the respiratory tract), dyspnea (shortness of breath), and chest pain can occur after an exposure to 20 ppm, a moderate level of nitrogen dioxide. This concentration has been designated by the National Institute for Occupational Safety and Health (NIOSH) as immediately dangerous to life and health (IDLH). Exposure to higher concentrations (greater than 100 ppm) can result in pulmonary edema (fluid accumulation in the lungs) and in swelling in the lungs, leading to long-term respiratory problems or death. Lower concentrations of 15 to 20 ppm are considered dangerous and can cause respiratory impairment.

If you have been exposed to silo gases, even a small amount, seek immediate medical attention.

To reduce exposure to nitrogen dioxide in silo gases, refrain from entering a silo for ten days to three weeks after filling is complete. If entry is necessary after the three-week period, run the silo blower for a minimum of 30 minutes prior to and during entry, and use a portable gas monitor to continually monitor the gas and oxygen levels in the silo. Click here to learn more about silo gases and how to reduce the risk of exposure.

Organic Dust Toxicity Syndrome

Organic Dust Toxicity Syndrome (ODTS), also called grain fever, toxic alveolitis, or pulmonary mycotoxicosis, is caused by exposure to very large amounts of organic dust. Certain agricultural areas may have large amounts of organic dust: grain storage, hog barns, poultry barns, and cotton-processing areas.

The onset of ODTS can occur four to six hours after exposure, and symptoms can be similar to those of acute farmer’s lung and may include cough, fever, chills, fatigue, muscle pain, and loss of appetite. People who have experienced ODTS and who experience additional exposures to organic dust have an increased risk for respiratory problems and the potential for developing chronic bronchitis. Producers can become very sick from ODTS, but most people completely recover. Occurrences of ODTS are underreported because symptoms often resemble the flu or other mild illnesses.

You can reduce your risk of contracting ODTS by using a respirator to decrease exposure to organic dust. Click here to learn about the different types of respirators used in production agriculture. Implement best management practices to maintain good air quality in confinement buildings for swine and poultry.