Project Title:
Toxin Causes Emergency (TCE)

Group No.:


Group Name:


News URL:


Marcia Kramer

News Paper:

Area Key Word:

Water waste, T-Rex, household products

Chemistry Key Word:

Trichloroethylene, oxalate, carcinogen

Editorial Comment:

Trichloroethylene has been linked to several recent reports concerning the health of communities. The adverse effects include headache, nausea, sleepliness, dizziness, blurred vision, and facial numbess around concentrations of 100 ppm. The Environmental Protection Agency has labeled this chemical as a probable human carcinogen. This chemical is found in common household products including typewriter correction fluid, adhesives, and carpet cleaning solutions. Production of trichloroethylene has increased from just over 260000 lbs in 1981 to 320 million lbs in 1991. Major environmental releases of trichloroethylene are due to air emissions from metal degreasing plants. Wastewater from metal finishing paint and ink formulation electronic components and rubber processing industries also may contain trichloroethylene. The acceptable levels of trichloroethylene are around 5 ppb in drinking water. The Occupational Safety and Health Administration has also set an air exposure limit of 100 ppm for an eight hour workday. The reaction below proceeds by reacting with methane monooxygenase then dehydrogenase and finally haloacid dehalogenase to form oxalate. Oxalate can cause kidney stones in subjects exposed to it. Low oxalate diets are implemented to help reduce the risk of kidney stone formation. Why do we care about this problem? A local issue concerning Trichloroethylene was discovered in Denver. Trichloroethylene was found underground on a section of the T-REX project near Interstate 25 and Broadway. A high concentration of fumes were found and a worker who was exposed to TCE was transportated to a local hospital for precautions. In order to rectify the problem situation a metal plate and plastic sheeting has been placed over the hole where the fumes were released. The construction in the area was also suspended. There are several measures that can be taken if and when a person is exposed to trichloroethylene by means of inhalation or skin or eye contact. There was also a study conducted that involved laboratory rats which led to a possibility of the carcinogenic effects of the chemical TCE. During the experiment laboratory mice both male and female were injected with doses of trichloroethylene. The results indicated that both sexes developed malignant tumors of the liver and hepatocellular carcinoma. This study indicates the possible outcomes of internal exposure to trichloroethylene. In examining and understanding the issues surrounding this chemical it becomes vital to exercise caution and awareness of the possible effects this may have on the human population. As educated individuals and pupils of science we can use this knowlegde to educate our own communities. Raising awareness is one of the ways we can help avoid possible toxic exposures to this and other harmful chemicals.

Question 1:

Is trichloroethylene an alkyl halide?

Answer 1:

No trichloroethylene is not an alkyl halide. The definition of an alkyl halide from Organic Chemistry text by Paula Yurkanis Bruice states that an alkyl halide is a compound with a halogen in place of one of the hydrogens of an alkane. An alkane is a hydrocarbon that contains only single bonds. Trichloroethylene contains a carbon to carbon double bond hence it is not an alkane nor a hydrocarbon. TCE is not a hydrocarbon because it does not only contain carbons and hydrogens it also has three chlorines.

Question 2:

Does Trichloroethylene consist of a Acyl chloride functional group in its structure?

Answer 2:

No trichloroethylene does not contain an Acyl chloride functional group in its structure. An Acyl chloride group consists of a carbon double bonded to an oxygen and the carbon is also bonded to a chlorine and an alkyl group. Trichloroethylene does not contain a carbon oxygen double bond nor does it contain an alkyl group.

Question 3:

How many if any chiral carbons does Trichloroethylene have?

Answer 3:

Trichloroethylene does not have any chiral carbons because there are no carbons that are bonded to four different groups. This is because of the double bonded carbon to carbons.

Question 4:

What does the Tri in Trichloroethylene stand for?

Answer 4:

The Tri for Trichloroethylene stands for the three chlorines in the molecule.

Question 5:

Could you have been possibly exposed to Trichloroethylene?

Answer 5:

Yes Trichloroethylene is in air levels around concentrations of 1 ppb.

©2004 Dr. Rainer Glaser's group