How a little snooping can go a long way

Detective work can help ID cause of illness  

When an employee who works in a shop where strong chemical fumes are present comes to the company nurse complaining of respiratory problems, an exposure history that identifies the chemicals he works around is likely to uncover the source of the health complaint.

But when the symptoms don’t fit the job — and sometimes, even when they do, it takes a careful history and sometimes a bit of detective work to find out what’s making the employee sick or what caused an injury, and whether it was a work exposure.

"Sometimes it’s pretty straightforward, but other times, it’s not so obvious," says Rosemary Klein, MS, C-ANP, COHN-S, a nurse practitioner and occupational health nurse who acts as clinic coordinator at the Central New York Occupational Health Clinical Center and a faculty member in the Department of Family Medicine at the State University of New York Health Science Center at Syracuse.

Even when the cause of an injury or illness seems evident, Klein advises taking the time to complete an extensive history before ruling occupational exposure in or out. "Ask not only what is happening at this job, but ask about previous jobs, and what exposures there might be at home, or working on a hobby or other activity," she suggests.

When asking about the employee’s job, take time to find out what his or her work really entails, not just what the job title is. A worker’s job title might sound like it would be strictly office work, for example, when he or she actually might be moving throughout a worksite and in and out of potentially hazardous areas during the day.

"Sometimes job names are opaque," Klein says, meaning that the title doesn’t really reveal what the person does all day. "You should find out what the process is that is being accomplished at the job, and not only what kinds of chemicals the employee is using, but what chemicals are being used by other people who he might be in the vicinity of."

Another factor that can shed light on a possible occupational exposure is the ventilation — or lack of it — in the areas where the employee works. Important to note is not only whether the area is ventilated, but whether seasonal conditions affect the ventilation — are the doors and windows open in the summer, but closed tight during cold months?

Even if an employee has been doing the same job for years in the same way, with the same materials, and without complication, an occupational injury can’t be ruled out.

Klein explains that even a seemingly insignificant change can create symptoms where before there were none.

"I was working with a [patient] who has welded for 25 years with no problems, until he used a different welding rod on one job," she says. "It turns out his symptoms were consistent with manganism [manganese poisoning, also known as Parkinson’s syndrome’ because its symptoms closely resemble those of Parkinson’s disease], and his manganese level quite elevated. We’re trying to find out what was different about this rod or this situation that caused him to develop symptoms."

Granted, manganism symptoms in a welder are not unlikely — another name for manganism is "welder’s disease." Some complaints, however, may seem unlikely for people working in some jobs, but a thorough history and additional research can turn up surprising links, Klein says.

Occupational illnesses and injuries and hazardous exposures have long been part of the manufacturing, construction, and agricultural sectors, but in recent years have become more and more common in the service sector. A significant proportion of occupational illnesses are related to building conditions, such as inadequate fresh-air ventilation, low humidity, and the presence of cigarette smoke, volatile organic compounds and fibers, molds, or other microbiologic materials, says Klein.

An office employee might complain of upper airway and eye irritation, and possibly fatigue and difficulty concentrating. Could these be symptoms of asthma, or seasonal allergies brought on by being outdoors? Possibly — but if others in the office or building complain of similar symptoms, and they report clearing of the symptoms when they leave the workplace, the signs could point to poor indoor air quality, and further follow-up is indicated, according to Klein.

Furthermore, the workers report rapid clearing of the symptoms when they leave the workplace. Other illnesses, including asthma, hypersensitivity pneumonitis and respiratory infections, also have been linked to specific building-related exposures.

The timing of symptoms in relation to work often is crucial in the assessment of a potential occupational illness, Klein stresses. For example, a patient with asthma may report that her symptoms appear soon after she gets to work, and then go away when she leaves and on weekends. Establishing the timing of the symptoms may allow the nurse to pinpoint a specific substance, process, or recent change that could be causing the symptom flare-ups.

Klein notes that if a workplace illness progresses, it may be difficult to establish the temporality, because the symptoms may no longer abate after the patient leaves work.

"It’s easy to have your mind fixed on one idea and so miss another, so you have to try to not drop the ball by assuming something came from the workplace," she says. "The [patient’s] chart is a work in progress, so there’s a totality to it you’re building on, and sometimes missing something is just a matter of not thinking about it."

Klein says the initial interview with an employee who might have suffered an exposure needs to be a long one. "The first visit takes a while, and requires lots of follow-up after," she admits.

Every patient’s chart should include a self-administered occupational history form that the patient fills out. This should be a simple form on which the employee lists jobs he or she has held, the dates of employment, job title, specific duties, any exposures (e.g., dust, chemicals, noise, repetitive motion, stress, etc.), and protective equipment used.

The history taken by the occupational health nurse should include a standardized set of questions asked of every patient — Klein says this is the single most important method of recognizing the link between illness and occupation. Besides aiding in the establishment or exclusion of an occupational exposure in the patient being seen, a standard questionnaire will point out similarities among symptoms seen in more than one employee, should other complaints arise.

The key screening questions include:

• What type of work do you do?

• Do you think your health problems might be related to your work?

• Are your symptoms different at work and at home?

• Are you currently exposed to chemicals, dusts, metals, radiation, noise, or repetitive work? Have you been exposed to chemicals, dusts, metals, radiation, noise, or repetitive work in the past?

• Are any of your co-workers experiencing similar symptoms?

Answers to these questions that suggest the employee’s symptoms might be job-related or the result of a hazardous exposure should trigger a comprehensive occupational history, Klein says.

HHS’ Agency for Toxic Substances and Disease Registry (ATSDR) offers a thorough exposure history form, and provides it on-line at www.atsdr.cdc.gov/HEC/CSEM/exphistory/pdffiles/exposure_form.pdf.

An early step, if an employee reports an exposure, is getting his or her permission to request the employer submit material safety data sheets (MSDS), required by OSHA for identifying hazardous ingredients and health risks of the substances. This gives the nurse full information about the substances the employee works with, including materials the employee might not be aware he or she works with.

"We try to get those, but sometimes it’s difficult to find them, because not all employers are as up to date as they are supposed to be," she says. "Sometimes they’re wary about turning those over, but we just tell them that we are not an enforcement agency — we’re just looking for information."

Asking for the right MSDS can hinge on getting an accurate job description from the employee. "I had one fellow who said his job required him to work in one area, but when we got him to explain in detail where he was, we found he was all over the place, and was exposed to all sorts of things," she recalls.

Once the MSDS is in hand, the employee’s symptoms can be compared against the known effects of the material to see if there is a match.

According to the ATSDR, the numbers of toxins and how they can affect different organ systems are countless. For example:

• More than 100 toxicants cause asthma, and many more can exacerbate it.

• Symptoms of liver disease due to toxic exposure can mimic viral hepatitis.

• Organic solvents and heavy metals are known to adversely affect renal function.

• Many chemicals cause mild central nervous system depression that may be misdiagnosed as intoxication and, if undetected, can progress to psychoses or dementia.

• Cardiovascular changes, as well as exacerbation of preexisting cardiovascular conditions, can result from exposure to noise and to chemicals such as carbon monoxide and tobacco smoke.

• Benzene can cause bone marrow changes leading to aplastic anemia, acute leukemia, and chronic myelogenous leukemia.

Effects can be long-lasting, leading to symptoms that don’t match up with the employee’s current working or living environment.

"I saw one man who was four years removed from a job in a foundry, where he’d handled lead as part of a brass process," Klein recalls. "He worked there for 50 years, retired, but four years later had elevated lead levels. We very carefully tried to determine whether he had other sources of lead contamination — in his home, in dietary supplements, eating off pottery with a lead glaze. We couldn’t find anything, so we sent the typical letter to the employer [seeking MSDS information], and instead of sending us the information, the employer replied that they hadn’t used lead in their processes for a very long time."

Off-work activities may also contribute to illness, and should be assessed as part of the comprehensive history, she says. Smoking and excessive alcohol use contribute to a variety of diseases and may interact with occupational exposures to increase the risk of adverse health effects. Recreational activities, hobbies, and drug use are other potential sources of hazardous exposure. For example, a miner may be exposed to noise both at work and at home, or a construction painter may be exposed to lead during bridgework and while scraping and repainting his own house. A complete history allows the evaluation of the relative contribution of on- and off-job exposures to an illness.

Klein and her colleagues use the team approach when working on exposure cases, calling in industrial hygienists, occupational medicine physicians and nurses, nurse practitioners, and social workers to discuss cases and make sure stones aren’t left unturned.

The Internet has revolutionized the research component, and Klein says as a result, her network’s traditional library is beginning to age.

The ATSDR, one of the resources Klein says has proven very useful to her practice, notes at its Web site (www.atsdr.cdc.gov) that the introduction of new chemicals and other materials has far outpaced general knowledge of their potential toxicity. The MSDS often is limited, however. Since many substances remain unstudied and their toxic effects are unknown, they have not been deemed harmful by OSHA. As a result, they are not covered in MSDS materials.

[For more information, contact:

  • Rosemary Klein, MS, C-ANP, COHN-S, Nurse Practitioner, Central New York Occupational Health Clinical Center, State University of New York Health Science Center at Syracuse. E-mail: kleinr@upstate.edu.
  • Agency for Toxic Substances and Disease Registry. Web site: www.atsdr.cdc.gov. Phone: (888) 422-8737.]