Pergamon Chemosphere, Vol. 34, No. 2, pp. 335-344. 1997 Copyright 0 1997 Elsevier Science Ltd Printed in Great Britain. All rights reserved PII: SOO45-6535(96)00382-7 0045-6535/97 $17.00+0.00 zyxwvutsrq LEACHING OF SELECTED PAH’s AND HETERO-ANALOGUES FROM AN ORGANIC MATRIX INTO SYNTHETIC GROUND WATER. INFLUENCE OF DISSOLVED HUMIC MATERIAL. Pia Lassen, Mette E. Paulsen, Frank Stuer-Lauridsen and Lars Carlsen* National Environmental Research Institute, Department of Environmental Chemistry, DK-4000 Roskilde, Denmark, (Received in Germany 15 Apnl 1996; accepted I I October 1996) ABSTRACT Polycyclic aromatic hydrocarbons as well as the corresponding heteroanalogues, zyxwvutsrqponmlkjihgfedcb i.e. azar- enes, thiarenes and oxarenes, can be leached from organic matrixes into an aqueous phase. The compounds exhibiting the highest aqueous solubilities are leached to the highest extent. The presence of dissolved humic material causes an increased apparent aqueous solubility of the polycyclic aromatic compounds @‘AC’s), the effect being more pronounced for the compounds with the highest aqueous solubilities. It is suggested that the interaction between dissolved humic material and PAC’s should be included in risk evaluations. (0 1997 Elsevier Science Ltd. All rights reserved INTRODUCTION Polycyclic aromatic hydrocarbons (PAH’s) is the largest single class of chemical carcino- gens known today. M,ore than 30 PAH’s and several hundred PAH derivatives and analogues have been reported to exhibit carcinogenic effects. Potential hazards from the possible occurrence of PAH’s in the environment have been noted, resulting in standards for drinking water, food, working atmosphere as well as for effluents from industrial and mobile sources [Bjerseth and Ramdahl, 19851. A wide variety of sources apparently are responsible for the omnipresent contamination with PAH’s and PAH analogues [Bjorseth and Ramdahl, 19851. In addition to the variety of stationary and mobile sources contaminated soils, e.g. due to industrial activities such as gas works, oil refining, garage activities, incomplete combustion of fossil fuels, wood preservation, as well as various types of waste disposal sites may constitute as potential sources of pollution. Obviously the potential exposure are closely connected to the fate, e.g. the persistence and the mobility of the pollutants in the environment. The potential mobility in the environment 335