Health Concerns

Tetrachloroethylene

One way tetrachloroethylene (perc) may enter the body is by inhalation of contaminated air into the lungs. Although this compound is rapidly absorbed by the lungs, the amount that is absorbed from the lungs into the bloodstream is influenced by how quickly a person is breathing (inhalation rate), the amount of chemical in the air, how long the person is exposed, the person's body mass and degree of physical activity while being exposed (NYS 1996; ATSDR, 1996b).

Studies with human volunteers indicate that absorption of tetrachloroethylene vapors from the air across the lungs may be greatest during the first few minutes of exposure. Perc absorbed into the blood stream is transported throughout the body and may be temporarily stored (accumulated) in fat tissue and slowly re-released to the blood stream over a period of several days. Absorbed perc can cross the blood-brain and placental-fetus barriers and has been found in fat rich tissues such as the brain, liver and breast milk (NYS, 1996).

The majority of perc absorbed from the lungs into the blood stream leaves the body unchanged in air exhaled from the lungs (EM, 1995). A small percentage of perc that is absorbed into the blood stream is broken down into other compounds (metabolites) in the liver (EM, 1995; ATSDR, 1996b). One metabolite in particular, trichloroacetic acid, is thought to be associated with some of the adverse health effects noted with prolonged inhalation of elevated levels of perc (ATSDR, 1996b). These metabolites leave the body in the urine. Experimental studies indicate that, once exposure has stopped, total elimination from the body may take a few days to a few weeks, depending on the amount of perc that has accumulated in body tissues.

Brief inhalation of large amounts of tetrachloroethylene can adversely effect the central nervous system and result in dizziness, headache, sleepiness, confusion, nausea, difficulty in speaking and walking, unconsciousness and, in extreme instances, death (ATSDR, 1996b). The mucous lining of the eyes, nose and throat may also become irritated (EM, 1995).

Recovery from the adverse central nervous system effects associated with inhalation exposure to perc vapors, in some cases even moderate term exposures, is possible once exposure has stopped (EM, 1995). However, the potential effects of long-term inhalation of relatively low levels of perc vapors are not currently known (ATSDR, 1996b).

Some liver and kidney effects may be associated with inhalation of elevated levels of perc. One instance of a reversible adverse cardiac effect associated with inhalation of tetrachloroethylene vapors is noted in the literature.

Limited studies of women exposed to elevated levels of perc in the work place, in a mix of other volatile chemicals, indicate that such exposure may effect the reproductive system and perhaps be related to an increased risk of spontaneous abortion (miscarriage) (ATSDR, 1996b). Because exposure was to more than one chemical at a time, it is not known which chemical or combination of chemicals may be responsible for the health effects noted.

Repeated or prolonged dermal contact with perc can cause skin irritation (ATSDR, 1996b). Potential health effects that may be associated with long term consumption of food and/or drink containing low levels of tetrachloroethylene are not known (ATSDR, 1996b).

Long term experimental studies with laboratory animals exposed to very high levels of perc vapors have noted skin, liver, kidney, cardiac effects and in some cases liver and kidney cancer. Not all such effects have been noted in people who have been exposed to tetrachloroethylene at much lower levels.

Tetrachloroethylene has been classified as Group 2A: Probably Carcinogenic to Humans by the International Agency for Research on Cancer and is generally considered to be an animal carcinogen and probable human carcinogen by the United States Environmental Agency.

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Last Updated: 1/31/03