Who is at Risk for Exposure to Trichloroethylene?

CHAPTER 1. EXPOSURE BASICS - Section 1.4

Course: SS4561
CE Original Date: 08/05/2022
CE Expiration Date: 08/05/2024
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Learning Objective 2 (cont.)

After completing this section, you will be able to identify the populations with potentially high exposures to trichloroethylene.

Overview

The Environmental Protection Agency (EPA) recently finalized its risk assessment of TCE, which identified health risks to

  • workers when TCE is used as a degreaser in small commercial shops and as a stain removing agent in dry cleaning
  • consumers who use spray aerosol degreasers and spray fixatives
General Populations

The general population can be exposed to TCE via inhalation of ambient air, ingestion of food and drinking water contaminated with TCE, or skin contact with TCE contaminated water. Water and air become contaminated by releases of TCE from active industries or from hazardous waste sites. A survey conducted by the National Health and Nutrition Examination Survey (NHANES) from 1988 to 1994 tested 677 whole-blood samples for TCE. The results suggested that approximately 10% of the U.S. population had detectable levels of TCE in their blood. More recently, NHANES tested 3,178 samples from 2005–2006 and 2,952 samples from 2007–2008. Those results detected TCE in the blood of less than 5% of people in all age groups, genders, and races or ethnicities studied in the surveys (CDC, 2011, 2016).

Workers

An estimated 300,000 workers are exposed in dry cleaning facilities that use TCE to remove spots from garments before or after dry cleaning. An estimated 30,000 additional workers are potentially exposed to TCE at small commercial degreasing operations (EPA 2014; NTP 2016).

The Occupational Safety and Health Administration (OSHA) Chemical Exposure Health Database (which includes results for 3,600 air samples from 1984 to 2011) reported that from 2000 to 2010, 92 samples exceeded the OSHA permissible exposure limit of 100 ppm. Among those samples, two exceeded the National Institute for Occupational Safety and Health “immediately dangerous to life or health” level of 1,000 ppm (NTP 2016).

Consumers

An EPA risk assessment (EPA, 2014) reported that TCE constituted 80% to 100% of three aerosol spray fixative products for arts and crafts uses and other products intended for use as cleaners or degreasers in automobile or home maintenance. However, EPA was not able to estimate the numbers of consumers or bystanders exposed to TCE from arts and crafts spray products or degreasers (NTP, 2016).

Others

Because TCE can cross the placenta as well as accumulate in breast tissue, the fetus and nursing newborn of women at risk for exposure might be exposed to TCE.

Key Points
  • The general population can be exposed to TCE by inhaling contaminated air, eating food and drinking water contaminated with TCE, or skin contact with TCE-contaminated water.
  • A recent NHANES survey shows an overall decrease in TCE exposure in the general population.
  • Workers in metal-degreasing and dry-cleaning operations have the greatest likelihood of exposure to high concentrations of TCE.
  • The numbers of consumers exposed to TCE are not known.
Section 1.3: Question #1

To review relevant content, see Section 1.4.