Farmer's Lung?So what is the difference between farmers and us?

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Causes and Symptoms of Mold and Dust Induced Respiratory Illness

http://www.cdc.gov/nasd/docs/d001201-d001300/d001270/d001270.html

Glen H. Hetzel, J.

Virginia ative Extension

Table of Contents

Introduction

What is

What Are These Mold Spores and Why Are They So Dangerous?

Symptoms of Lung Disease and State of Illness

How to Tell If You Have Farmer's Lung

Medical Treatment

Measures Farmers Can Take

More Information About Farmer's Lung

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Introduction

Who Needs to Know About Respiratory Illnesses?

those working in dusty fields or buildings

those handling moldy hay

those working in silos

those feeding or working with feedstuffs

those working in corn silage

those uncapping silos

those cleaning grain bins

those exposed to bird droppings or feather, hair, or fur dust

those exposed to fish meal

Farmers account for more than 30% of adults disabled by respiratory

illness, yet a large percentage of farmers are nonsmokers. If you

work in any one of these situations, then you need to be aware of

Farmer's Lung as well as other respiratory hazards.

Farmer's Lung is only one of the respiratory hazards for farmers,

but it is a serious one. The number of farmers affected has also

been increasing in recent years. This results from a growing

awareness among farmers and that they have been seeing their

physicians more frequently. The larger size of silos accounts for

much of the increase.

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What is Farmer's Lung?

Farmer's Lung is a noninfectious allergic disease caused by inhaling

dust from moldy hay, straw or grain. It is a disease because the

body reacts to the invading contaminants (mold spores) which the

body's immune system cannot counteract.

The lungs allow oxygen to enter the bloodstream and carbon dioxide

to exit the bloodstream. They are the location for a vital process

for good health; but they are also the quickest and most direct

route for hazardous contaminants to enter the body and the

bloodstream. The results from exposure to mold spores can be so

debilitating that some farmers are even forced to leave the

occupation completely.

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What are These Mold Spores and Why are They so Dangerous?

Mold spores are tiny bacteria less than 4 microns in size -- so

small that as many as 250,000 spores can fit on a pin head and a

farmer can inhale as many as 750,000 of these spores per minute!

They are produced by microorganisms which grow in moist hay and

stored grain silage where the moisture content is high (30%) and the

area is poorly ventilated.

When farmers move or work with hay and silage materials in which

mold spores have grown, the mold spores attach themselves to

airborne dust particles. The farmer not only inhales dust particles

which may not be extremely hazardous, but he also inhales mold

spores which are a serious hazard. Heavy concentrations of mold

spores appear as dry, white or grey powder or clouds.

The body has natural defense filtering systems (such as mucous

lining, coughing and sneezing) against dusty air which helps remove

some contaminants, BUT most contaminants overpower and pass through

these defenses. Mold spores not only bypass defenses because of

their number, but also because they are so small.

Very fine particles, like mold spores, move into, accumulate and

settle into the lower lungs. There they produce toxins. Remember

that the lungs transfer oxygen to the bloodstream, and most of the

actual exchange of carbon dioxide and oxygen takes place in the

lower lungs. Now the lungs become a roadway for toxic materials to

travel through the bloodstream with the oxygen. The body's reaction

to the toxins permanently affects the lungs' ability to transfer

oxygen into the bloodstream. The lung tissue becomes permanently

scared and each exposure to mold spores increases the damage.

The body's last defense against these tiny invaders is to develop an

allergy producing cold or pneumonia-like symptoms.

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Symptoms of Lung Disease and State of Illness

The farmer will develop specific symptoms based upon the intensity

of dust and spores to which he has been exposed or the intensity of

his body's reaction to the dust and spores. He is also likely to

develop an increased sensitivity to mold exposure, having more

severe reactions with fewer exposures. In all cases, each exposure

aggravates the problem.

Acute State This is the most noticeable condition which typically

begins 4 - 8 hours after exposure. Most farmers ignore the symptoms

because they are so similar to a common summer cold.

Typical Symptoms:

fatigue

chills

shortness of breath

tightness in the chest

Subacute State This is a more serious condition because symptoms

will be stronger and remain longer even with no further exposure to

moldy dust particles.

Typical Symptoms:

severe shortness of breath with any exertion

headache

irritating cough

Chronic State This is the most serious condition because of its

gradual onset and its long-lasting debilitation. At the chronic

state, the disease becomes irreversible.

Typical Symptoms:

chronic coughing

progressively increasing and severe shortness of breath with even

the slightest exertion

physical weakness

occasional fever and sweating at night

appetite depression

general aches and pains

Typically farmers develop chronic Farmer's Lung slowly over time

after repeated exposure to mold spores because they continue to

ignore the symptoms of acute attacks. However, it is possible to

develop Chronic Farmer's Lung even after one acute attack.

A delay in seeking medical help damages the farmer most. Often, by

the time a farmer sees a physician, there is already serious,

permanent damage. And in some cases scar tissue (pulmonary fibrosis)

develops, further interfering with the normal functions of the

lungs.

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How to Tell if You Have Farmer's Lung

Self diagnosis is not recommended. Always check with your physician

to confirm your suspicions. However, here are some ways to

tentatively diagnose yourself:

Have you experienced a sudden illness that developed a few hours

after you handled moldy crop material?

Do you have a chronic cough?

Do you have a general feeling of tiredness or depression?

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Medical Treatment

It is not enough to look at the list of symptoms and think that you

may have Farmer's Lung. You need to see your family physician. The

list only helps you recognize symptoms that might match and it is

important not to ignore them.

When you see your doctor, there are several things you can do to

help him/her diagnose you correctly. A doctor who is unfamiliar with

farmers' illnesses or does not know you are a farmer can mistake the

symptoms of Farmer's Lung for a cold, asthma, flu or even pneumonia,

and incorrectly diagnose your illness.

Tell your doctor:

you are a farmer and the type of farming you do

if you have been exposed to moldy crop material

what chemicals and/or dusts you work with

Then your doctor can do several things to confirm or disprove a

tentative diagnosis.

take a blood test

take a chest x-ray

administer a breathing capacity test

examine lung tissue

administer an inhalation challenge

perform an immunological investigation

perform lung function testing

review clinical history

Farmer's Lung can be controlled in many ways. One way for your

doctor to help control it is to give you symptomatic relief. But

Farmer's Lung cannot be cured. Unfortunately, there is no way to

determine in advance if you are immune.

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Measures Farmers Can Take Farmers can control or even minimize the

possibility of getting Farmer's Lung by several preventative

measures:

Preventative Measures

identify contaminants and hazards in the work environment

minimize the amount and type of contaminants in the work environment

avoid exposure to contaminants and mold spores and dust from decayed

grains and forages

limit exposure to all contaminants

operate within a controlled environment whenever possible (e.g.,

cab, control room, etc.)

depend upon mechanical controls to remove air contaminants (e.g.,

fans, exhaust blowers, filters, etc.)

have as much ventilation as possible in dusty areas

move work outside whenever possible

avoid dusty work in confined areas

wear respirators, masks or other protective equipment

Management to Prevent Mold Spore Growth

use mold inhibitors

bale hay, ensile crops, harvest and store grain at recommended

moisture contents

dry grain properly before storage

properly ventilate storage buildings

crops should be adequately ventilated to cool them down.

always use a plastic sheet to cap open silos (not plant material)

holding down the edges with heavy weight (e.g. tires)

When You Must Work With Moldy Materials

wet down feed before transferring to minimize dust

convert to mechanical or automated feeding or feed handling systems

wet down the top of the silo before uncapping ensiled material

use some wetting techniques when cleaning out grain bins or other

dusty areas

use respiratory protection when handling moldy or dusty materials.

If you decide to use some form of respiratory protection, then make

sure you use the appropriate device for the work task. Most farmers

wear dust masks to protect themselves from Farmer's Lung. This is

the best and most cost-efficient protection unless you know you will

be exposed to extremely high levels of moldy dusts or you already

have developed Farmer's Lung.

Those who have Farmer's Lung should talk to their doctor about the

type of equipment that will offer the most protection because every

exposure increases the risk of serious permanent damage.

Also, for any device you choose, make sure it fits well and is

properly maintained.

For more information about respiratory equipment, see your local

extension office or the publication on " Respiratory Protection. "

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More Information About Farmer's Lung

The chances of acquiring the disease are the greatest in late winter

and early spring. This is mainly because farmers feed the hay and

grain materials which have had a longer time to develop mold. Also,

during those colder months, farmers are likely to feed baled hay

inside, and mold spores stay in the air inside a barn much longer.

The amounts of mold spores a farmer will breathe in such a confined

space are much more concentrated. Unrolling large round hay bales

also may release mold spores.

Other times to be more careful about dusts that may contain higher

levels of mold spores are:

In late summer - while cleaning out grain bins before filling with

new grain

In early winter- opening new silos may release mold spores from the

top layer of silage.

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Disclaimer and Reproduction Information: Information in NASD does

not represent NIOSH policy. Information included in NASD appears by

permission of the author and/or copyright holder. More

NASD Review: 04/2002

This publication was developed with funds form the Center for

Disease Control/National Institute for Occupational Safety and

Health, Project UCS/CCU 306075-03-1.

October 1996

Authors: Glen H. Hetzel and J. , Agricultural Engineering

Department, Virginia Tech

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