As is discussed in the Laboratory Tests section, direct indications of tetrachloroethylene exposure can be obtained by measuring levels in breath or blood and by measuring metabolites in urine. Perhaps a first step would be to halt the exposure and determine if the symptoms resolve.
You should inform your patient of the adverse effects of acute and chronic exposure to tetrachloroethylene and advise her and her cousin to use a well-ventilated area when cleaning cloth during silk-screening. You should also review the potential long-term risks, particularly to nursing infants.
Questions about symptoms and temporal association of the use of “Clean Cloth” may reveal a direct connection. The type and amount of ventilation also may have an effect. (Your questioning reveals that the patient sprays the cloth in late afternoon in a small garage and keeps the door closed to prevent dust from entering. She recalls that one day last week when it was hot, she felt particularly ill after spraying the cloth.)
You should review the factors that may reduce the cousin’s actual exposure. For example, the cousin may work outdoors or in a better ventilated area, or she may not leave rags soaked with the compound lying about, etc. You could also discuss individual variability as a reason why some people become ill and others do not after similar exposures.
The urinary trichloroacetic acid level indicates an average ambient air exposure of about 30 ppm tetrachloroethylene (calculated using the occupationally based ratio on page 11). While this level indicates definite exposure, it may not be high enough to cause her symptoms; however, the patient could have been periodically exposed to short-term levels much higher than this average level, which could have caused her symptoms.
Although not relevant here, the linear correlation between urinary trichloroacetic acid and tetrachloroethylene exposure levels breaks down when the exposure is above 100 ppm tetrachloroethylene. The plateau effect resulting from saturation of the tetrachloroethylene metabolic pathway limits the effectiveness of the assay when the ambient level is above 100 ppm.
The slightly elevated levels of SGOT and SGPT are inconclusive for tetrachloroethylene exposure because of the confounding factor of alcohol consumption. An SGOT:SGPT ratio greater than 1 (i.e., SGOT greater than SGPT) tends to support an alcoholic etiology; a ratio less than 1 (i.e., SGOT less than SGPT) supports toxic, infectious, or other etiologies. The patient should be advised to reduce alcohol consumption and be counseled regarding alcoholism if this is a problem. Liver function tests should be repeated in several months.
It would be preferable to seek a less toxic replacement. However, if the patient insists on continuing with “Clean Cloth,” you should advise her to get proper industrial hygiene consultation or other professional assistance. The local or state health department may be able to provide some information.
Your patient would be well-advised to avoid breast feeding while exposed to tetrachloroethylene. Should she find a “Clean Cloth” alternative that has no chlorinated solvents, the tetrachloroethylene presently in her milk can be eliminated in several days if she continues to pump her breasts.
OSHA has regulatory responsibility for the workplace and should be notified if employees may be dangerously exposed. You could also request that NIOSH initiate a Health Hazard Evaluation of the workplace. A product with hazardous potential used by a number of hobbyists would be reported to the local or state health department.