Section 1.2. Where Is Tetrachloroethylene Found?
After completing this section, you will be able to identify sources of tetrachloroethylene exposure.
People can be exposed to tetrachloroethylene from environmental and occupational sources and from consumer products. Tetrachloroethylene can be released into air, water, and soil at places where it is produced or used.
Numerous studies have detected tetrachloroethylene in the air in rural, urban, and industrial areas in the United States. Although background levels are generally a fraction of a part per billion (ppb) in rural and remote areas, values in the parts per million (ppm) range are found in dry cleaning facilities [ATSDR 2015; NTP 2014]. Ambient air concentrations of tetrachloroethylene vary from source to source and with distance from the source. Near points of use, such as dry cleaners or industrial facilities, indoor exposure to tetrachloroethylene is more significant than outdoor exposure [EPA 2012a]. For instances, indoor air concentrations in apartments above a dry cleaning shop have been measured at up to 4.9 mg/m3 [Verberk and Scheffers 1980]. People living in New York City apartment buildings that also housed dry cleaners were exposed to higher levels of tetrachloroethylene (indoor air level of 27.5 μg/m3) than were residents of buildings without a dry cleaner (2.3 μg/m3) [Storm et al. 2013].
Tetrachloroethylene has been detected in
- drinking water,
- ground water, and
- surface water.
Some industries and building supplies can release tetrachloroethylene. In areas near sources of contamination, ground water and surface water concentrations can be considerably higher than in general areas [EPA 2012a].
Contamination of soil can occur when tetrachloroethylene seeps from waste at disposal sites [ATSDR 2015].
Tetrachloroethylene has been detected in a variety of food items, including dairy products, meats, oils and fats, beverages, fruits, vegetables, fresh bread, fish, shellfish, and marine mammals [EPA 2012a; Gold LS et al. 2008; NTP 2014], but usually at low levels [ATSDR 2015]. Among about 280 food items periodically sampled as part of the U.S. Food and Drug Administration’s Total Diet Study, tetrachloroethylene has been detected in 67 items (such as milk, cheese, meats, etc.) [FDA 2006].
Tetrachloroethylene is a widely used solvent produced commercially for use in
- dry cleaning,
- textile processing, and
- metal cleaning [Guyton et al. 2014].
Occupational exposure has been decreasing over the past several decades. For example, typical tetrachloroethylene concentrations in workplace air at dry-cleaning facilities were 350–700 mg/m3 (about 50–100 ppm) in the 1970s and 70–350 mg/m3 (about 10–50 ppm) in the 1980s. In 2003, the mean concentration of tetrachloroethylene at U.S. dry-cleaning facilities was 3.8 ppm [NTP 2014].
Tetrachloroethylene is found as an ingredient in a number of consumer products such as
- stain removers, and
- auto care products [U.S. National Library of Medicine 2015].
Tetrachloroethylene is likely to enter the environment by fugitive air emissions from dry cleaning and metal degreasing industries and by spills or accidental releases to air, soil, or water [Howard 1990]. Tetrachloroethylene has relatively low solubility in water and has medium-to-high mobility in soil; thus, its residence time in surface environments is not expected to be more than a few days. However, it persists in the atmosphere for several months and can last for decades in the groundwater. Tetrachloroethylene can migrate through groundwater (or soil) up into the air of homes and buildings through vapor intrusion [ATSDR 2015].
- People can be exposed to tetrachloroethylene from environmental sources, occupational sources, and consumer products.
- Tetrachloroethylene can last for decades in the groundwater and can migrate through groundwater (or soil) up into the air of homes and buildings through vapor intrusion