Cancer Markers Associated With Occupational Exposure to Trichloroethylene

Background: * Trichloroethylene (TCE) is a solvent used in many medical and industrial processes. * TCE is a carcinogen (causes cancer) in rats, but its carcinogenicity in humans is unclear. There is some evidence of increased liver and kidney cancers and of an association with non-Hodgkin lymphoma in studies of workers exposed to TCE. * The carcinogenicity and regulation of TCE is a matter of continuing debate. Objectives: * To determine if TCE exposure is associated with higher levels of genetic aberrations in certain white blood cells called lymphocytes. * To determine if TCE exposure affects lymphocyte subsets and levels of certain hormones called cytokines. Eligibility: Workers exposed to two different levels of exposure to TCE and unexposed workers in Guangdong Province, China. Design: * 45 workers exposed to more than 25 parts per million (ppm) TCE, 30 workers exposed to from 10 to less than 25 ppm TCE and 45 unexposed workers will be enrolled. * Subjects wear small instruments at work that measure chemicals in the air for 1 or 2 days during the 2-week study period. Exposed workers also wear several small skin patches on one of the two days. * Subjects provide blood and urine samples. * Subjects answer a questionnaire about work, smoking and drinking, use of medicines, medical history, general health, hobbies, and exposure to radiation and exposure to various substances at home.

Sex

All

Minimum age

18 Years

Maximum age

50 Years

* INCLUSION CRITERIA:

A total of 45 workers exposed to greater than 25 ppm TCE, 30 workers exposed from 10 to less than 25 ppm TCE, and 45 unexposed workers will be enrolled.

We will identify 45 workers from 3 factories who are exposed to greater than 25 ppm TCE. Our colleagues at the Guangdong NPCC will visit potential study factories and carry out air measurements for TCE, epichlorhydrin, methylene chloride, perchloroethylene and benzene. Factories will be selected that use only TCE for degreasing processes, have minimal co-exposures present in the same part of the workplace where TCE is used, and have used a stable manufacturing process for the past five years.

Workers will be chosen who work in part of the factory with TCE exposure, have worked for at least one year in the factory doing the same job in the same part of the manufacturing process, and have not been exposed to other genotoxic, hematotoxic, or immunotoxic compounds in any workplace. We will enroll 45 controls, who have no history of occupational exposure to TCE or to any other genotoxic, hematotoxic or immunotoxic chemicals.

EXCLUSION CRITERIA:

History of cancer, chemotherapy with DNA-damaging or immunotoxic agents, and medical treatment with ionizing radiation.