Agency for Toxic Substances and Disease Registry 
Case Studies in Environmental Medicine (CSEM) 

Taking an Exposure History
What Role Can Primary Care Clinicians Play in Detecting, Treating, and Preventing Disease Resulting from Toxic Exposures?

Learning Objectives

Upon completion of this section, you will be able to

• explain why primary care clinicians should be knowledgeable about the exposure history process.

What Happens in the Clinical Setting

Most people with illness caused or exacerbated by exposure to hazardous substances obtain their medical care from clinicians who are not specialists in either environmental or occupational medicine.

Consideration of environmental factors rarely enters into the clinician’s history taking or diagnosis (Marshall, Weir et al. 2002).

In a study of a primary care practice in an academic setting, only 24% of 625 charts reviewed included any mention of the patient’s occupation; only 2% included information about toxic exposure, duration of present employment, and former occupations (Anonymous 1993).

A chart review of 2922 histories taken by 137 third-year medical students showed that smoking status was documented in 91% of cases, occupation in 70% and specific occupational exposures in 8.4%. Patients less than 40 years of age and women were significantly less likely than older patients or men to have their occupation and industry noted (McCurdy, Morrin et al. 1998; Marshall, Weir et al. 2002).

Findings from another recent study showed that work-related issues might not be adequately addressed or documented in the provider’s clinical notes and that opportunities for preventive care relating to work-related injuries and illnesses may not be realized in the primary care setting (Thompson, Brodkin et al. 2000).

What Clinicians Need to Do

The single most important aspect of the approach to patients with potential occupational or environmental disease is to have a high index of suspicion and to follow through on that suspicion (Frank 2000).

Although many clinicians recognize the importance of taking a work and exposure history to evaluate certain problems, most have had little training or practice in doing so (Becker 1982; Pope AM and Rall DP 1995; Merritt 1999; Frank AL 2000; Kilpatrick, Frumkin et al. 2002).

There are numerous resources available to the practitioners willing to spend the time and effort needed to better understand certain environmental health dilemmas.

Extensive knowledge of toxicology is not needed to diagnose environmental and occupational disease. The same criteria are employed as those used in diagnosing other medical problems—history, including onset and temporal pattern of symptoms and palliative and provocative factors; physical examination; and laboratory results.

If necessary, consultation with other health professionals such as industrial hygienists or environmental and occupational physicians may facilitate the gathering of helpful information concerning exposures.

In addition to current exposures, the clinician must consider the long-term or latent effects of past exposures to agents such as asbestos, radiation, and chemical carcinogens.

Exposure History Form

The exposure history form, (see Appendix I) which can be completed by the clinician or by the patient (to save staff time), will guide the clinician through various aspects of this process.

The form elicits many important points of an exposure history, including job descriptions and categories associated with hazardous substances, physical, and biologic agents; and temporal and activity patterns related to environmental and occupational disease.

The form explores past and current exposures.

Process Takes Just a Few Minutes

Taking an exposure history requires only a few minutes of the clinician’s time and can be abbreviated, expanded, or focused according to the patient’s signs and symptoms.

The exposure history form is designed for quick scanning of important details and can be copied and used for a permanent database as well as for the investigation of current problems.

An exposure history should be taken on every patient. It is of particular importance if the patient’s illness occurs at an atypical age or is unresponsive to treatment.

Use Sound Judgment

The diagnosis of environmental or occupational disease cannot always be made with certainty. Sound clinical judgment must be used, and common etiologies should be considered. The multi-factorial nature of many conditions, particularly chronic diseases, must not be overlooked.

The clinician must also keep in mind that many organ systems are affected by toxic exposure (Table 1). Exposure and effects can be acute or chronic. The latency period from exposure to manifestation of disease can vary, ranging from immediate to delayed (hours or days) to prolonged (decades).

Conclusion

With practice using the exposure history form and a network of referrals, the primary care clinician can play an important role in detecting, treating, and preventing disease resulting from toxic exposures.

Key Points

• An exposure history should be taken on every patient.
• With practice using the exposure history form and a network of referrals, the primary care clinician can play an important role in detecting, treating, and preventing disease resulting from toxic exposures.

Progress Check