Trichloroethylene is a colourless liquid at room temperature with an odour similar to ether or chloroform. It is a man-made chemical, mainly used as a solvent to remove grease from metal parts and for dry cleaning of fabrics. It can enter the body when a person breathes air, drinks water containing it or through skin contact.
The two main sources of human exposure to trichloroethylene are the environment and the workplace. An important source of environmental release of trichloroethylene is evaporation to the atmosphere from work done to remove grease from metal. In addition, at places where wastes are disposed, trichloroethylene is released to the air by evaporation and to underground water when it passes through the soil. Trichloroethylene can also be released into the environment through: (1) Evaporation from adhesive glues, paints, coatings, and other chemicals; (2) Release of trichloroethylene and chemicals containing it, when it is made; (3) Air-cleaning processes at publicly owned waste treatment plants that receive wastewater containing trichloroethylene; and (4) Burning of community and hazardous waste. Some consumer products that may contain trichloroethylene are typewriter correction fluids, paint removers and paint strippers, adhesive glues, spot removers, cleaning fluids for rugs and metal cleaners.
Early symptoms (often years in advance) are loss of smell and constipation. Dizziness, headache, slowed reaction time, sleepiness, and facial numbness have occurred in workers breathing trichloroethylene or in people who use trichloroethylene-containing products in small, poorly ventilated areas. More severe effects on the central nervous system, such as unconsciousness and possibly death, can occur from drinking or breathing higher levels of trichloroethylene. Some health effects may persist in persons following long-term exposure to trichloroethylene. Drinking alcohol can make people more susceptible to liver and kidney injury from trichloroethylene. At present, information is not sufficient to determine whether cancer or the effects on the unborn seen in animals following exposure to trichloroethylene may also occur in humans. The International Agency for Research on Cancer has determined that trichloroethylene is not classifiable as to its carcinogenicity to humans. Medical tests for exposure to trichloroethylene are not routine, nor are they specific to the chemical.
During the period 1953-1957, numerous US Marines were exposed to trichloroethylene at Marine Corps Base Camp Lejeune. The chemical contaminated underground sources of drinking water at 300 times above safe levels. Those 20-year olds, exposed for two years to the chemical, are now found to have a 70% increased risk of developing Parkinson's disease in later life.