Introduction

The physician should ask about previous occurrences of similar symptoms. If a temporal association between symptoms and exposure to certain products is suspected, the physician should try to identify the specific chemical ingredients involved. If the product label does not list the chemical ingredients, the regional poison control center may maintain a list of ingredients in consumer and proprietary products.

In occupational exposures, the employer or manufacturer is required by law to provide pertinent Material Safety Data Sheets (MSDS). The MSDS for a chemical product lists its ingredients, describes their potential toxicity, and suggests precautions for safe use.

Patient History

Determine whether other family members or co-workers may have similar symptoms. Note the time of the patient's last exposure to a suspected chemical, because a temporal relationship between onset of symptoms and work or other activity may provide important diagnostic clues. The physician should also evaluate the patient's general health and question the patient about alcohol and drug use.

Physical Examination

Record the patient's vital signs, especially abnormalities of heart rate or rhythm. Carefully examine eyes, nose, throat, and skin for inflammation or irritation. The conjunctiva may be injected. Nasal mucosa may be injected and swollen. Repeated inhalation exposures to tetrachloroethylene can cause defatting of nasal mucosa, leading to a friable condition with drying, cracking, or bleeding. Skin contact may cause dermatitis by irritation and defatting.

Examine the patient for hepatomegaly and costovertebral angle tenderness. Also note any urinary abnormalities, such as hematuria (Ellenhorn MJ 1988).

A complete neurological evaluation should be performed, with special attention to memory, gait, and balance. Short-term memory loss, if associated with tetrachloroethylene exposure, is generally transient. Patients with acute exposures have been tested positive on the Romberg balance test (Ellenhorn 1997).

Signs and Symptoms

Acute exposure

Background levels of tetrachloroethylene in air, water, and food have not been associated with symptoms. People can first smell tetrachloro­ethylene at about 1 ppm; but symptoms typically do not occur until concentrations reach approximately 50 ppm. Odor warning is not always reliable, however, because some people have a higher threshold of detection and may become acclimatize to the smell of tetrachloroethylene.

The principal symptoms of acute inhalation exposure are eye and upper airway irritation (about 100 - 200 ppm) and CNS depression (at 50 - 300 ppm). Splash exposures of the eye can cause corneal burns and conjunctivitis. Skin contact may produce inflammation or chemical burns (Ellenhorn 1997).

The onset, intensity, and duration of symptoms can vary among identically exposed persons. The variability of toxicity is influenced by many factors, including respiratory rate, target organ sensitivity, body fat content, and general health. CNS symptoms can be similar to those of ethanol inebriation. Pulmonary edema due to accidental exposure was reported in a single worker, but this lesion may have been a secondary finding rather than a direct pulmonary effect of tetrachloroethylene itself.

Symptoms associated with acute high-level tetrachloroethylene exposure may include

• Nervous system
  • confusion,
  • dizziness,
  • euphoria,
  • forgetfulness,
  • headache,
  • irritability,
  • light-headedness,
  • loss of consciousness,
  • loss of coordination,
  • sleepiness, and
  • slurred speech.
• Gastrointestinal
  • Nausea
• Ear, nose, and throat
  • Cough,
  • eye and nose irritation, and
  • upper airway irritation.
• Cardiac
  • dysrhythmia (noted in one worker exposed occupationally to tetrachloroethylene, but no exposure-related cases of sudden cardiac deaths have been reported).

Chronic exposure

Mild CNS symptoms have been reported to result from exposure to tetrachloroethylene-containing household products in confined spaces, and after exposure in industrial settings. Reported symptoms have included

• ataxia
• disorientation
• irritability
• persistent headache
• short-term memory deficits
• sleep disturbances(Agency for Toxic Substances and Disease Registry 1997.)

Observation of experimental volunteers and exposed workers indicates that if the blood concentration of tetrachloroethylene does not exceed 1 mg/l, 16 h after the end of exposure, the time-weighted average exposure is likely to have been below 50 ppm. Exposure to such level for six years on the average does not seem to exert any adverse effect on the central nervous system, the liver and the kidney (Lauwerys, Herbrand et al. 1983).

The liver is the primary target organ in animals exposed chronically to tetrachloroethylene. In humans, chronic exposure has led to hepatitis and elevated transaminase levels (serum glutamic-oxaloacetic transaminase [SGOT] or aspartate aminotransferase [AST] and serum glutamic-pyruvic transaminase [SGPT] or alanine aminotransferase [ALT]).

Dysrhythmia was noted in one worker exposed occupationally to tetrachloroethylene, but no exposure-related cases of sudden cardiac deaths have been reported (Agency for Toxic Substances and Disease Registry 1997).

Tetrachloroethylene's defatting action on skin may cause dermatitis, thereby predisposing the skin to infection (HSDB 2005).

Progress Check