Exposure of patients to phthalates from polyvinyl chloride tubes and bags during dialysis.

Abstract

The exposure of patients to the plasticizer di-(2-ethylhexyl)phthalate (DEHP) from polyvinyl chloride (PVC) tubes and bags during dialysis has been investigated. In vitro studies of the migration of DEHP from hemodialysis tubes into plasma revealed a migration coefficient of 7.7 micrograms/ml/h. An artificial kidney did not influence the plasma concentration of DEHP. The calculated exposure from a single hemodialysis can be as much as the total annual exposure using continuous ambulatory peritoneal dialysis (CAPD). CAPD fluids in PVC bags contain low concentrations of DEHP and its hydrolysis product mono-(2-ethylhexyl)phthalate (MEHP). These phthalates were analyzed in serum from patients receiving both CAPD and hemodialysis using gas chromatography. A group of patients not yet on dialysis treatment was used as control. In no case could MEHP be detected. The DEHP concentration was 0.8-4.2 micrograms/ml serum in the 17 hemodialysis patients after dialysis and 0.1-0.9 microgram/ml in 4 of the CAPD patients. In 3 of the CAPD and all of the predialysis patients, DEHP could not be detected (less than 0.1 microgram/ml).