Fw: ARTICLE: Do you have a cluster? (workplace diseases)

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From Flanders at IAQ List:

>Do you have a cluster? (workplace diseases)

>( Occupational Hazards )

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> Odds are if you are an occupational health professional, you will be asked

>to determine if disease or symptoms in a group of workers is due to work or

>the environment. Fortunately, most companies have reduced chemical

exposures

>to levels that meet or better recommended levels. Still, workers,

especially

>in small companies, can develop work-related illnesses. Certain remediation

>activities, such as refurbishing steel highway overpasses, have produced

>excessive lead levels and workers have complained of symptoms potentially

>related to lead toxicity.

>

>The term " cluster " refers to a group of complaints or diseases with

something

>in common, such as similar exposure or place of work. Examples of clusters

>include a group of individuals with cancer or complaints from individuals

in

>an office of irritation due to poor air quality. Clusters are usually

>identified by individuals comparing notes and realizing " Gee, four people

in

>our office have come down with cancer in the past three years. I wonder if

>it's something in the workplace. "

>Approaching a cluster requires management commitment as well as a solid,

>objective scientific approach. It is very easy to dismiss workers'

complaints

>as the product of a few disgruntled employees. While the vast majority of

> " clusters " are not confirmed, it is critical not to miss real work-related

>adverse health effects. Moreover, with " chemicalphobia " rampant, a prompt

>caring response will help allay unwarranted fears and assure all parties

that

>a real health concern does not exist.

>

>Investigating the Cluster

>

>Critical to cluster investigation is the proper identification and

>classification of the complaints. Alleged cancer clusters have consisted of

>many different types of cancers in workers of various ages, different

>employment duration and even varied past exposures. Frequently, common

cancer

>types such as breast, lung and colon are manifested. With the exception of

>specific workplace exposures of a long-term, high-level nature such as for

>asbestos, the causes of the other cancers (and most lung cancer) are rarely

>work-related. Remember that one in four Americans will develop cancer

during

>their lifetime.

>

>Clusters are frequently just what the term means, a group of events. To

>qualify as a related group of events, work-related cancers should meet

these

>scientific criteria: (1) adequate latency period, (2) pathological

>confirmation of the same organ and cell type, (3) lack of recognizable

>alternative etiologies, and (4) demonstrated related exposure(s).

>

>Two difficult problems often surface during the investigation. First, the

>number of events is usually small. Only two or three cancers, for example,

>may be in question. What makes them stand out is that the individuals

>involved may occupy a small lab or common area and to the occupants, they

>feel that " 50 percent of our group are ill. " If one applies the appropriate

>epidemiologic approach, the basis for the presence, or lack thereof, of the

>cluster and any relevance to the workplace can be determined.

>

>

>

>Communication of the investigation process and of the results as they are

>developed to all interested parties is essential. It may require a

>presentation to the entire work force, along with an opportunity for

>questions and answers, before concerned parties' fears can be allayed.

>

>

>

>When investigating cluster reports, be sure to speak to concerned parties.

>Frequently, there are other workplace issues such as labor- management

>problems. Lack of communication and/or mistrust can easily elevate a

>curiosity into " another example of management toying with us. " Thus, the

>cluster issue may not be put to rest until other employee problems are

>identified and handled.

>

>

>

>The second problem is that a chemical " culprit " will rarely be identified.

>When you attempt to explain this, the response often is to reaffirm that

>there is in fact something in the air or water which has caused the

problem.

>Performing air monitoring of the work environment may reassure employees by

>demonstrating that there are presently no readily identifiable

carcinogen(s)

>in the workplace. However, sufficient sampling at various times must occur

to

>assure that sampling was performed under all appropriate conditions.

Further

>objections may be derived from the fact that the current sampling does not

>reflect past exposure. Given the latency issue (time from first exposure to

>expression of disease), appropriate exposure modeling may be helpful.

>

>

>

>Noncancer Clusters

>

>

>

>Other types of reported clusters can include reproductive effects, indoor

air

>complaints or " chemical sensitivities. " Reproductive effects can run the

>gamut from infertility to spontaneous abortions to birth defects.

Situations

>may also arise where breast lumps, menstrual difficulties and other issues

>such as decreased libido may be lumped together as part of the

" reproductive "

>cluster. The larger the group, the less likely there is to be a single

>explanation.

>

>

>

>Although not as serious, probably more daunting is the " symptom " cluster.

>Indoor air complaints and other complaints such as Multiple Chemical

>Sensitivity are frequently associated with a wide range of symptoms. It is

>difficult to determine where to begin with such complaints. Many times,

these

>ill-defined entities are not a single diagnosable disorder but simply a

>constellation of disparate symptoms.

>

>

>

>Symptoms may range significantly over the group and be the resulting

>combination of: real workplace exposures, exacerbations of pre-existing

>disorders, somatic expressions of work and individual psychosocial

stressors,

>disgruntled employees, and other factors.

>

>

>

>Even choosing a case definition to attempt classification is problematic.

>Usually, the result is so broad as to be meaningless clinically. Any group

of

>people will have a high percentage of symptoms such as headache, fatigue,

>pain or GI upset at a given point in time. Also, studies have demonstrated

>that when there is a health concern or question of potentially hazardous

>exposure, the symptom rate climbs significantly. Bodily sensations or long

>standing symptoms, e.g. sore throat from pre-existing allergies, now

receive

>focused attention by the individuals and frequently become significantly

>enhanced.

>

>

>

>Approaching the Noncancer Cluster

>

>

>

>By the time the " symptom " cluster is reported to management or other

>authorities for investigation, there is frequently a conviction within the

>affected group that the problem is real and something must be done - right

>away. Dismissing complaints as mass hysteria or intentional will in many

>instances just escalate the problem. An OSHA inspection, NIOSH health

hazard

>evaluation and/or a lawsuit may result.

>

>

>

>Performing a symptoms survey is a good place to start. While this can help

>you target where, if at all, to explore potential exposures, most surveys

are

>not sufficiently focused to truly determine likely sources of concern. A

>better approach may be focused, detailed medical interviews by health

>providers. Accurate information surrounding time frames, frequency and

range

>of symptoms, symptom intensity and consistency, pre-existing disease, etc.

is

>essential and may only be gained in this manner.

>

>

>

>In many instances, the gold standard for assurance is to perform exposure

>sampling. Evaluation of air, water and other sources for potential

toxicants

>may help identify the culprit or help to demonstrate the lack of a toxic

>basis for the complaints.

>

>

>

>Communication of the results of the investigation is critical. It should be

>done by a combination of management, health care professionals and possibly

a

>few members of the affected group. This will demonstrate the commitment and

>concern of all parties and assist in assuring a consensus as to the

potential

>work-relatedness of the complaints.

>

>

>

>Single-Event Clusters

>

>

>

>A leak, spill or other event may also trigger complaints. Cleaning of an

HVAC

>system, laying down new carpeting, applying pesticides and other activities

>which were formerly considered routine and benign often produce complaints

>and sometimes result in emergency room visits and hospitalizations. Not too

>long ago, there was a tendency to dismiss these complaints as mass

hysteria.

>However, there is frequently a basis for the complaints, although

significant

>toxic effects may not be evident.

>

>

>

>Turning on an HVAC system after maintenance may send odors of the cleaners

>through the building. Off-gassing of formaldehyde from new building

materials

>may temporarily cause minor, but noticeable, irritation.

>

>

>

>The odor issue in many instances appears to be the common link. Odors, like

>beauty, are highly dependent on individual response. In some instances,

odors

>can create nausea and other temporary symptoms.

>

>Odors also can serve as a trigger mechanism. Many individuals will

>automatically assume that because they smell something, they are being

>exposed. While technically that is correct, many odor thresholds are so low

>that toxic manifestations will not arise.

>

>In cluster situations, the odor can serve as an anxiety trigger. Many of

the

>symptoms reported in these incidents are consistent with those produced by

>anxiety. Such symptoms can affect the skin, breathing and GI tract, and

>produce unpleasant sensations. Hyperventilation may not be recognized by

the

>individual; however, its symptoms can be very distressing.

>

>

>

>Just as in any hazmat response, you should have a detailed plan to approach

>these incidents, including: (1) rapid exposure testing, (2) symptom/

>complaint survey and analysis, (3) documentation of all on- site

>investigations, (4) results interpretation, and (5) communication.

Following

>such a plan will go a long way to assure a logical and objective

explanation

>of the " cluster. "

>

>

>

>Hazardous leaks and spills, along with real health effects, do occur. The

> " single incident " can also bring its own set of problems such as the

>development of reactive airways dysfunction syndrome (RADS) following an

>acute, high-level irritant exposure.

>

>

>

>Emergency response procedures must include a detailed medical plan. Some

>individuals are highly suggestive or may be suffering from somatic

>manifestations of the stressful event. Early and detailed documentation is

>critical in these situations to ascertain the extent of health problems and

>prevent false claims of injury.

>

>Summary

>

>Clusters of health problems and complaints come in all shapes and sizes.

Each

>one merits careful attention, investigation and scrutiny to determine the

>presence and underlying causes. Just as important is the communication of

>what you are doing and how you are doing it. Media and governmental

attention

>are quickly focused on such " problems. " Having a well-constructed approach

>for each " cluster " type will contain the situation and provide for

>appropriate health care and investigation.

>

>Contributing Editor M. Sandler, M.D., is president of Sandler

>Occupational Medicine Associates Inc., a Melville, N.Y., occupational and

>environmental consulting firm. Dr. Sandler is a former medical officer with

>NIOSH and has consulted for EPA, OSHA and the Consumer Product Safety

>Commission.

>

>Sandler, M., Do you have a cluster? (workplace diseases). Vol. 58,

>Occupational Hazards, 07-01-1996, pp 49(2).