First report on the uptake of automobile catalyst emitted palladium by European eels (Anguilla anguilla) following experimental exposure to road dust

Following the introduction of automobile catalysts in the middle of the 198 0s in Germany there is an increasing emission of the platinum-group-metals platinum, palladium (Pd) and rhodium. Still, it remains unclear if these me tals are bioavailable for aquatic animals and to which extent they become a ccumulated by the aquatic biosphere. Because of analytical problems in dete cting Pd in small biological samples the present investigation concentrates on the bioavailability of this metal. To answer the question of a Pd uptak e by aquatic organisms experimental studies were conducted with European ee ls maintained in water containing road dust at a concentration of 10 kg/100 l. Following an exposure period of four weeks, samples of liver and kidney were analysed by total-reflection X-ray fluorescence analysis after co-pre cipitation of Pd with mercury. These experiments revealed an uptake of traf fic related Pd by European eels which showed a mean liver Pd concentration of 0.18 +/-0.05 ng/g (wet wt.), whereas the Pd concentration in the kidney ranged below the detection limit. Thus, in this study we can demonstrate fo r the first time that automobile catalyst emitted Pd is bioavailable for aq uatic animals. (C) 2001 Elsevier Science Ltd. All rights reserved.