Closed spaces with little or no ventilation, constant inhalation and handling of toxic chemicals—this was the life of tool-men, servicemen, nuclear weapons specialists, and other service members who were exposed to cleaning solvents such as trichloroethylene. TCE was used as a powerful degreaser for machinery parts and equipment. These pieces of machinery or equipment would be cleaned with the use of TCE and some kind of cleaning cloth or simply dunked into the fluid. Years later, those servicemen discover that they now have multiple health problems due to exposure to those chemicals.
Trichloroethylene (TCE) is a colorless, non-flammable halocarbon that dissolves most fixed and volatile oils. It is a powerful solvent action for fats, greases, waxes, oils, and tars, and it is one of the most important chlorinated solvents for use in degreasing and dry-cleaning. Type 1 TCE is used in dry-cleaning and for general solvent purposes. Type 2 TCE is used for vapor degreasing of metals. Over 90 percent of TCE is consumed by the metal degreasing and dry-cleaning trades.
Exposure to TCE has appeared in numerous instances in conjunction with the MOS of servicemen since the 1950s. Some of these include:
- Missile techs
- Jet engine mechanics
- Radar technicians
- Systems technicians
- Aircraft structural mechanics
- Corrosive control technicians
- Avionics technicians
- Weapons specialists
- Computer specialists
- Communications equipment repairmen
TCE was also used in anticorrosive paint, as used on Navy vessels, and in adhesive bonding.
While TCE has not been proven as a known carcinogen (to humans), it has been proven to have a number of hazardous effects on human health when exposed or ingested over extended periods of time. Once TCE is inhaled or ingested, the pulmonary and gastrointestinal organs absorb most of the TCE. This means that the organs related to breathing (lungs, diaphragm) and to digestion (stomach, colon, intestines, etc) are the most affected by TCE. Effects of chronic and intermediate exposure are as follows:
- Chronic occupational exposure to TCE by inhalation affects the central nervous system, producing central nervous system depression, and sometimes resulting in general anesthesia. These effects include decreased appetite, headache, short-term memory loss, ataxia, sleep disturbances, vertigo, and reduced number of word associations.
- Intermediate exposure produces effects that resemble those of alcohol use, such as dizziness, headache, sleepiness, nausea, confusion, blurred vision, facial numbness, and weakness.
Effects on the liver, kidneys, and immune and endocrine systems have also been seen in humans exposed to trichloroethylene occupationally or from contaminated drinking water.
Due to studies conducted in 2005 and 2007, the use of TCE in the industry and in the military has been cut back substantially. In April of 2007, the EPA (Environmental Protection Agency) issued a document, Economic Impact Analysis of the Halogenated Solvent Cleaners Residual Risk Standard, which identified the industries that have used TCE as a cleaning solvent. This document revised the emission limits on halogenated solvents that were previously established in a Maximum Achievable Control Technology (MACT) standard in 1994. These revised limits have further restricted the use of halogenated solvents (such as TCE) in manufacturing industries and in the military.
Recent studies have shown that TCE, as used in the situations discussed previously, is a risk factor for Parkinson’s and other neurological diseases. Increasingly, cases involving Parkinson’s have arisen, shedding more light on soldiers who worked on, repaired, and serviced machinery in the military. Because Parkinson’s, like other such diseases, manifest many years after separation from service, attorneys and representatives are seeing these cases appear more and more as veterans begin to exhibit the symptomology.