NDT Advance Access originally published online on February 20, 2006
Nephrology Dialysis Transplantation 2006 21(6):1618-1625; doi:10.1093/ndt/gfl036
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© The Author [2006]. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org
Original Articles: Dialysis and Transplantation
Organic contamination in dialysis water: trichloroethylene as a model compound
1 National Institute of Occupational Safety and Prevention Research Center at the University of Parma and 2 Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Via Gramsci 14, 43100 Parma, Italy
Correspondence and offprint requests to: Diana Poli, National Institute of Occupational Safety and Prevention Research Center at the University of Parma, Department of Clinical Medicine, Nephrology and Health Sciences, Via Gramsci 14, University of Parma, 43100 Parma, Italy. Email: diana.poli{at}unipr.it
Background. Routine water monitoring in a haemodialysis centre revealed high trichloroethylene (TCE) concentrations. The aim of this study is to describe the measures adopted after organic contamination of dialysis water in order to avoid the possibility of patient exposure. We also carried out in vitro experiments to evaluate the accumulation of TCE in various devices normally used in a dialysis water treatment system (DWTS).
Methods. In vivo and in vitro blood and water TCE levels were determined by means of solid phase microextraction-gas chromatography/mass spectrometer.
Results. High TCE concentrations were found throughout the DWTS; acceptably low levels were obtained only by replacing the activated charcoal, ionic-exchange resins, microfilters and PVC pipes. The adsorption and realising capacities of these devices were tested in vitro, and the elimination curves made it possible to calculate the total percentage of the previously absorbed TCE mass released into the water. Evidence of exposure was confirmed by the relatively high TCE levels in the patient blood samples taken 30 days after the last exposure even if the subjects were asymptomatic. In vivo experiments showed that the blood gain of TCE through the low flux membrane during the course of dialysis was about 77±10.4% of the amount carried by dialysis fluid as calculated on the basis of its partition coefficient value (Kb/w 3.75).
Conclusions. This study shows that, when present in dialysis water, the lipophilic TCE contaminant can accumulate in various devices, thus transforming them into possible sources of exposure. This highlights the importance of periodically monitoring dialysis water for organic substances that have a great affinity to the blood compartment, in order to prevent occasional or chronic patient exposure.
Keywords: dialysis; organo-halogenated compounds; trichloroethylene; water contamination