Occupational Asthma
Note: This site addresses a limited range of issues in Occupational Asthma,
and should not be used as the sole source of diagnosing yourself.
Asthma can be quite complex with many issues involved in its diagnosis.
The problem especially with Occupational Asthma is proving that there is
an explicit link between the place of work and the developing symptoms. Even
after a link is established, how much responsibility should the employer
take? How much exposure is will it take to cause occupational asthma and
what if anything can be done to prevent it? First we will try to answer the
basic questions and then examine the role of September 11th.There are many
issues involved in occupational asthma and few answers to be found.
I. What is occupational asthma?
IV. Who gets occupational Asthma?
V. What causes Occupational Asthma?
VI. Is Occupational Asthma preventable
VII. Correlating Sept. 11 and Occupational Asthma
WHAT IS OCCUPATIONAL ASTHMA?
Occupational asthma, one form of asthma, is a
lung disease in which the airways overreact to dusts, vapors, gases, or fumes
that exist in the workplace. When these irritants are inhaled:
-
Airway inflammation begins
-
Muscles in the airways tighten.
-
The airway tissue swells.
-
Too much mucus is produced.
These changes all make breathing difficult.
Occupational
asthma is usually reversible, but permanent lung damage can occur if exposure
to the substance that causes the disease continues. In highly sensitive
persons, even very low levels of exposure may provoke an episode.
The key issue in Occupational Asthma (OA)
is establishing a causational link between workplace and symptoms. This becomes
difficult because there is no one set of guidelines in diagnosing OA. In fact
diagnosis differs from country to country and physician to physician. The
Occupation of Safety and Health department has established some basic guidelines,
but these are by no means universal. Six guidelines have been proposed:
1.
Clinically demonstrable variable airways obstruction.
2.
A known Proving agent in the workplace.
3.
There must be exposure to this agent for sufficient time.
4.
Tests of pulmonary function show airway obstruction to a specific agent.
5.
The asthmatic condition usually develops when inhaling low concentration
of the
specific agent.
6.
Symptomatic improvements occurs in may cases when the patient is away from
work, and symptoms are
aggravated during the week day or week.
In
the early stages of the disease
, symptoms usually decrease or disappear during weekends or vacations, only
to recur upon return to work. In later stages of the disease, symptoms may
occur away from work after exposure to common lung irritants.
Once
the airways have a pattern of overreacting
, many common substances such as cigarette smoke,
house dust, or cold air may produce asthma-like symptoms.
The most important step diagnosis is careful listing of places
of works, length of time and conditions. It would also be valuable to examine
others in the same work environment to see if others are reacting in the same
manner. Yet another factor to keep in mind is threshold. Everyone has a different
threshold and what irritates one may not necessarily irritate another. Therefore
people in the same conditions will or will not develop the same problems.
It is necessary to understand why someone who may experience
the symptoms may be reluctant to report them. Chances are employers will not
take the extra step and invest in extra safety equipment. Complaining may
mean loss of job, which many cannot afford. However OA is not limited to
the lower classes, any variety of peoples can develop it.
Legal Issues
Many insurance companies are becoming increasingly aware
of OA in light of recent litigations. Still, a long road ahead lies ahead.
If more awareness existed about OA, employers would be scared to action and
be more compliant to workers needs.
The
concept of protecting workers from the consequences of occupational diseases
is a relatively recent development among industrial countries, compared with
protection from occupational injuries. Moreover, there are no official European
or American guidelines for the assessment of impairment/disability and for
compensation of OA. Because the symptoms of asthma seem so flimsy and occupational
asthma is difficult to correlate among a large population, it is not designated
the same amount of damages. The seriousness of the problem is often underestimated.
Workers in hundreds of occupations
are exposed to substances in the air that may cause occupational asthma in
susceptible people. Many of these substances are very common and not ordinarily
considered hazardous.
Only a small proportion of exposed workers develop occupational asthma.
Workers most likely to develop the disease are those
with a personal or family history of allergies or asthma and frequent exposure
to highly sensitizing substances. But the disease also can develop in persons
with no known allergies.
[see Genetics and asthma]
Occupational asthma may be suspected whenever a worker
begins to develop respiratory symptoms. It may take several years to develop.
The reason that such a disparity exits between the confirmed
and questionable cases goes back to
A) proving that there is relationship between work and symptoms
B) varying diagnosis
WHAT CAUSES OCCUPATIONAL ASTHMA?
Two
types of asthma have been identified in medical textbooks.
Intrinsic
Extrinsic
Occurs chronically and continuously
Sudden
attacks triggered by exposure
in prolonged periods for no
to airborne contaminants
apparent reason
New
processes and substances that can cause occupational asthma are being identified
continually. The following list includes some of the airborne substances
and some related occupations known to be associated with the disease:
Chemicals Occupations
|
Acrylate |
Adhesive handlers |
|
Amines |
Shellac and lacquer handlers |
|
Anhydrides |
Users of plastics |
|
Animal proteins |
Animal handlers, veterinarians |
|
Cereal grains |
Bakers, millers |
|
Chloramine-T |
Janitors, cleaning staff |
|
Drugs/medicines |
Pharmaceutical workers, health care people |
|
Dyes |
Textile workers |
|
Enzymes |
Detergent workers, pharmaceutical workers |
|
Fluxes |
Electronic workers |
|
Formaldehyde, glutaraldehyde |
Hospital staff |
|
Gums |
Carpet makers, pharmaceutical workers |
|
Isocyanates |
Spray painters, insulation installers |
|
plastics, foam and rubber |
industry workers |
|
Latex |
Health care professionals |
|
Metals |
Solderers, refiners |
|
Persulfate |
Hairdressers |
|
Seafood |
Seafood processing workers |
|
Wood dust |
Forest workers, carpenters, cabinetmakers |
In addition Chemical dusts or vapors from plasticizers, polyurethane paints,
insulation, foam mattresses and upholstery, and packaging materials used in
manufacturing and processing operations. Among specific chemicals known to
cause asthma are the isocyanates, trimellitic anhydride, and phthalic anhydride.
Animal substances
such as hair, dander, mites, small insects, bacterial or protein dusts.
Exposed workers at special risk include farmers, animal handlers, shepherds,
grooms, jockeys, veterinarians, and kennel workers.
Organic dusts
such as flour, cereals, grains, coffee and tea dust, papain dust from meat
tenderizer. These substances can cause asthma in millers, bakers, and other
food processors.
Cotton,
flax, and hemp dust inhaled by workers in cotton processing and textile industries.
Metals such as platinum, chromium, nickel sulfate, and soldering fumes.
Workers are exposed in refining and manufacturing operations.
IS OCCUPATIONAL ASTHMA PREVENTABLE?
In trades and industries in which there is a known risk to workers, steps
can be taken to eliminate or at least reduce the number of workers who will
be affected.
-
Protective gear should be worn
-
Persons at increased risk because of a family or personal history of
allergy or asthma should be aware of the potential problems involved
in entering trades with obvious hazards and seek advice.
-
Periodic medical surveillance may allow early identification of affected
workers before they have any permanent lung damage.
If a worker begins to have asthma symptoms due to occupational exposure,
the disease usually can be reversed and permanent lung damage prevented by
changing jobs. Sometimes, a transfer to a different location within the same
plant is helpful.
Because changing jobs may cause a severe financial hardship, such a recommendation should be made only after careful medical evaluation.
Now that we have analyzed some of the basic components of occupational asthma, let us
examine the issues of September 11th and see how many occupational health issues were at play.
Correlating September 11th and Occupational Asthma
Lecture
given at The New York Academy of Medicine
Given
Oct 29th 2002 (6:00- 8:00 pm)
http://www.nyam.org/
It is impossible to speak of occupational asthma without speaking of September 11th. A tragedy on multiple levels, it left physical and emotional scars on millions around the world. One year after the incident, a convention of doctors and learned peoples gathered for conference to asses the way the medical community responded to Sept 11th as well as to inform medical students of the different aspects of treating people who have been exposed. A host of doctors that included a leading pediatrician, a specialist of lung diseases and an authority on Post Traumatic Stress disorder (PTS) gave presentations.
Adult Workers
(Metal cutters, Firefighters,
rescue workers, etc)
Thousands of workers at ground zero were a exposed to a host of chemicals including smoke, fumes, dust, combustion gases, acid mists, metal fumes, volatile organic compounds, and concrete dust (which is highly alkaline and leaves corrosive burns on the lungs). People who were exposed to these toxins for some extended period of time have devolved some serous difficulties including asthma and other breathing disorders. Persons who had never been diagnosed with asthma before working at ground zero, suddenly began reporting incidences of asthma attacks. The experts speculated that the effects of exposure would be long lasting.
Many health organizations had a difficult time estimating just how many people were physically effected by the September 11, and many reasons are to blame. Many of the men that that worked as iron cutters or on construction crews at the site were Òmacho.Ó Many felt that there was no need to consult a physician. Unfortunately, this tough guy attitude has caused some serious difficulties. Some firefighters have developed not just occupational asthma but severe infections that will cause permanent impairment of their lifestyles, as they are no longer able to continue their services as firefighters.
Statistics
The first 24 hours
:
240
FDNY rescue workers--firefighters and paramedics are included in the term
"rescue workers"--sought emergency medical treatment.
63
% suffered eye injuries, of which the vast majority were eye irritations
due to exposure to fine particulate airborne matter.
20
% suffered respiratory tract irritation requiring hospital evaluation.
Eight had chest pain, with subsequent evaluation not revealing any evidence
for myocardial infarction.
1
had a severe inhalation injury with both upper and lower airway damage,
severe swelling of the upper airway requiring an emergency tracheostomy, and
then developed adult respiratory distress syndrome requiring prolonged mechanical
ventilation. We are happy to report that that firefighter had fully recovered
from his respiratory injuries.
Two weeks after the attack
,
1
additional New York City firefighter suffered severe respiratory complaints
requiring NEER intubation, and he was subsequently found to have acute eosinophilic
pneumonia, which has fully recovered with corticosteroid treatment, is now
of steroids, and has returned to work.
13 firefighters
reported the incidence of pneumonia with lobar consolidation, but this
is not an increased incidence from our previous numbers.
6 months- 1year later
Over 332
firefighters had noted severe respiratory-related cough and symptomatology.
We call this the WTC-related cough, and we have a unique definition for this.
Because so many of our firefighters have reported coughing, over 90 percent
of the exposed workforce has reported an acute new or increased cough after
exposure to WTC.
52
percent have shown only partial improvement and remain on either medical
leave, light duty, or are filing for retirement injury/disability evaluations.
Over 500
firefighters will ultimately file and probably qualify for retirement injury/disability
on the basis of WTC cough and other respiratory-related problems. This is
a dramatic increase from our prior numbers.
Respirators
The lecturer presented us with dozens of photographs in which those workers most exposed to corrosive chemicals often went out without any physical protection. No masks, no gloves, no breathing devices were enforced. Iron workers continued to blaze their torches even as the asbestos piled up to their knees. Their reasoning was such; ÒWe are here to save lives.Ó Another reason was that the protective equipment interfered with communication. Thirdly they were taking their cues from the firefighters who were mainly concerned with finding people.
ÒThe New York City Fire Department has the best respirator on the
Planet Earth, and it's called the Self-Contained Breathing Apparatus(SCBA).Ó
It's designed, however, to fight fires. So in that environment, you need total
protection. You strap on an air tank so that you don't have any exposure to
the external environment.
The unfortunate thing, however, is because it's designed for fires,
-
It lasts only 8 to 15 minutes
-
It's incredibly heavy.
-
Once the WTC collapsed, this became a rescue operation and no one had enough
time for its use, only 8 to 15 minutes
So that many firefighters went in with the best respirator and the best
intention for protection, but then did not have any respirator because of
the resulting lack of ability to use the SCBA.
Conclusions based on evidence gathered from Center for Disease Control (CDC)
MMWR Examines Health Effects Related to World Trade Center Terrorist Attacks
http://www.cdc.gov/od/oc/media/transcripts/t020905.htm
The
following are the results of a telephone survey conducted 5-9 weeks after
Sept 11.th
Manhattan
Residents were given a host of questions and the survey was performed by
NYAM. Here are the results:
1,008 people participated in the survey.
13 % of those participants had
prior diagnosed asthma
27 % reported more severe asthma in the weeks after September 11th
It should be note here that
-
Asthma attacks usually increase in the fall, so some increase in asthma
severity was not unexpected
.
-
Life stressors increase the likelihood of an attack
-
Study relied on self-report of symptoms and exposure.
-
Study had a cross-sectional design. This means asthma symptoms, exposures,
psychological distress, these were all measured at the same point in
time.
-
Similar surveys that have not been done in similar places at that exact
time of the year to say how many other asthmatics would report that their
asthma was more severe.
Conclusion:
Because of these
limitations the study can't prove or quantify a causal link of the September
11th attacks to worsening asthma. But despite these limitations, the survey
results suggest that both environmental and psychological impacts of the
September 11th attacks contributed to an increase in symptoms that some asthmatics
in Manhattan experienced last fall.
To sum it up, Occupational asthma, is asthma developed
at work. The case for OA is often difficult to make and relies on a host of
variables. Because it is often difficult to prove, it is difficult to make
a legal case against it. However, OA maybe prevented by early intervention
or by utilizing proper equipment. The case of September 11th is
interesting because even though the exposure of workers was relatively short,
for many there were long term consequences involved.
Bibliography
CDC Telebriefing
September 5, 2002
The Following People were speakers
1. Dr. Thomas Matte
CDC Physician/Environmental Epidemiologist
2. Dr. Joanne Fagan
Epidemiologist/Consultant New York Academy of Medicine
3. Dr. Wayne Giles
CDC Physician/Cardiovascular Epidemiologist and
Occupational Health Expert
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http://www.healthsquare.com/ana/occasth.html
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http://www.haz-map.com/OA.htm
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http://www.lungusa.org/asthma/astoccasthm.html
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http://www.nycosh.org/wtc-catastrophe-factsheet.html
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http://www.healthscout.com/static/news/509135.html
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http://www.cdc.gov/od/oc/media/transcripts/t020909.htm
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http://www.cdc.gov/od/oc/media/transcripts/t020905.htm
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http://www.envirobay.com/spotlight.asp?deptid=14&spotlightid=19
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http://www.aaaai.org/scripts/search/searchresults.asp?qu=occupational+asthma&FreeText=&sc=%2F&RankBase=680&pg=3&submit2=Next+5+documents