MICROFLUOROMETRIC STUDY OF BIOACCUMULATION OF BENZO(A)PYRENE AND MARKER XENOBIOTICS IN THE BIVALVE DONAX-TRUNCULUS FROM CLEAN AND POLLUTED SITES ALONG THE MEDITERRANEAN SHORE OF ISRAEL

This study focused on bioaccumulation of benzo(a)pyrene [B(a)P] from a polluted environment and 2 xenobiotic markers under experimental conditions in various organs of the marine bivalve Donax trunculus. The cationic dye acridine orange (AO) and anionic dye fluorescein (FLU) were used as markers. Test molluscs were collected from 3 sites along the Israeli Mediterranean shore: a relatively clean site, an oil-polluted site and a site polluted by chemical effluents from a polyvinylchloride (PVC) factory. B(a)P was determined in tissue samples using benzene extraction and solid-surface luminescent analysis. Bivalves from the oil-polluted site contained 55.6 ng B(a)P g-1 wet wt. B(a)P concentration varied among body compartments: hepatopancreas > total soft tissues > kidney > shell > mantle edge = gills. In experiments, living bivalves from these 3 sites were kept in seawater with 10 muM AO or 100 muM FLU for 24 to 96 h. Accumulation and distribution of AO and FLU in the molluscs was determined by vital contact microfluorometry and from ethanolic extraction of the markers. Following exposure to the markers, D. trunculus from the clean site showed AO concentrations as follows: mantle edge > kidney > hepatopancreas > gills > central part of the mantle. For FLU the order was: kidney > gills > mantle edge > hepatopancreas > -central part of the mantle. D. trunculus from polluted sites demonstrated a decrease in AO concentration and an increase in FLU concentration, especially in specimens from the site polluted by the PVC factory. Experimental thermal stress produced a drastic decrease in AO bioaccumulation. The observed bioaccumulation of B(a)P, AO and FLU reflects the environmental quality and can thus be used for monitoring.