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

Taking an Exposure History
What Is the Purpose of Taking an Exposure History?

Learning Objectives

Upon completion of this section, you will be able to

• explain the importance of taking an exposure history.

Purpose

Most environmental and occupational diseases either manifest as common medical problems or have nonspecific symptoms. Yet environmental factors rarely enter into the clinician’s differential diagnosis. As a result, clinicians miss the opportunity to make correct diagnoses that might influence the course of disease in some afflicted individuals (by stopping exposure) and that might prevent disease in others (by avoiding exposure) (Goldman and Peters 1981).

What can a clinician do to improve recognition of disease related to current or past exposures? First, one must be suspicious and think about the possibility of environmental factors of disease. Next, one needs to incorporate an exposure history questionnaire into the practice.

The purpose of this case study is not to demonstrate all exposure possibilities but rather to illustrate the principles and process of investigating the etiology.

Exposure Factors vs. Etiology

The preceding case study describes a patient with angina. He has new, nonspecific symptoms of headache and nausea.

Suppose this patient lived near a hazardous waste site.

• Would your differential diagnosis change?
• If the patient refinished furniture as a hobby, would you consider this important?
• Is there a connection between his headaches and cardiac symptoms?
• How would you investigate the possible correlation?
• Could he be exposed to chemicals in his workplace?

Each of these factors could play a role in the etiology of this patient’s illness; each exposure could cause disease.

Three Scenarios

The patient described in the case study—a 52-year-old male with angina—is portrayed in three scenarios throughout this document. An exposure history provides clues that prompt the clinician to investigate the possibility of toxic exposure.

• Scenario 1: This patient is an accountant who has had the same job and the same residence for many years.
• Scenario 2: This patient owns a commercial cleaning service and uses cleaning products at various industrial and commercial sites.
• Scenario 3: This patient is a retired advertising copywriter who lives in the vicinity of an abandoned industrial complex.

Etiologic Diagnosis

Most environmental and occupational diseases either manifest as common medical problems or have nonspecific symptoms (e.g., headache, difficulty concentrating, behavioral problems, rashes, asthma, angina, myalgia, difficulty conceiving, spontaneous abortion) (Amdur MO 1991; Wigle D 2000; Marshall, Weir et al. 2002).

Etiology distinguishes a disorder as an environmental illness.

Unless an exposure history is pursued by the clinician, the etiologic diagnosis might be missed, treatment may be inappropriate, and exposure can continue.

dermatoses (allergic or irritant)

metals (chromium, nickel), fibrous glass, solvents, caustic alkali, soaps

electroplating, metal cleaning, plastics, machining, leather tanning, housekeeping

headache

carbon monoxide, solvents

firefighting, automobile exhaust, wood finishing, dry cleaning

acute psychoses

lead, mercury, carbon disulfide

removing paint from old houses, fungicide, wood preserving, viscose rayon industry

asthma or dry cough

formaldehyde, toluene diisocyanate, animal dander

textiles, plastics, polyurethane kits, lacquer, animal handler

pulmonary edema, pneumonitis

nitrogen oxides, phosgene, halogen gases, cadmium

welding, farming, chemical operations, smelting

cardiac arrhythmias

solvents, fluorocarbons

metal cleaning, solvents use, refrigerator maintenance

angina

carbon monoxide, methylene chloride

car repair, traffic exhaust, foundry, wood finishing

abdominal pain

lead

battery making, enameling, smelting, painting, welding, ceramics, plumbing

hepatitis (may become a long-term effect)

halogenated hydrocarbons (e.g., carbon tetrachloride)

solvents use, lacquer use, hospital workers

chronic dyspnea, pulmonary fibrosis

asbestos, silica, beryllium, coal, aluminum

mining, insulation, pipefitting, sandblasting, quarrying, metal alloy work, aircraft or electrical parts

chronic bronchitis, emphysema

cotton dust, cadmium, coal dust, organic solvents, cigarettes

textile industry, battery production, soldering, mining, solvent use

lung cancer

asbestos, arsenic, nickel, uranium, coke-oven emissions

insulation, pipefitting, smelting, coke-ovens, shipyard workers, nickel refining, uranium mining

bladder cancer

β-naphthylamine, benzidine dyes

dye industry, leather, rubber-workers, chemists

peripheral neuropathy

lead, arsenic, hexane, methyl butyl ketone, acrylamide

battery production, plumbing, smelting, painting, shoemaking, solvent use, insecticides

behavioral changes

lead, carbon disulfide, solvents, mercury, manganese

battery makers, smelting, viscose rayon industry, degreasing, manufacture/repair of scientific instruments, dental amalgam workers

extrapyramidal syndrome

carbon disulfide, manganese

viscose rayon industry, steel production, battery production, foundry

aplastic anemia, leukemia

benzene, ionizing radiation

chemists, furniture refinishing, cleaning, degreasing, radiation workers

Key Points

• Unless an exposure history is pursued by the clinician, the etiologic diagnosis might be missed, treatment may be inappropriate, and exposure can continue.

Progress Check