Radionuclides and trace metals in eastern Mediterranean Sea algae

Three types of sea alga distributed along the Syrian coast have been collected and analyzed for radioactivity and trace elements. Results have shown that 137Cs concentrations in all the analyzed sample were relatively low (less than 1.2 Bq kg−1 dry weight) while the levels of naturally occurring radionuclides, such as 210Po and 210Pb, were found to be high in most samples; the highest observed value (27.43 Bq kg−1 dry weight) for 210Po being in the red Jania longifurca alga. In addition, most brown alga species were also found to accumulate 210Po, which indicates their selectivity to this isotope. On the other hand, brown alga (Cystoseira and Sargassum Vulgare) have shown a clear selectivity for some trace metals such as Cr, As, Cu and Co, this selectivity may encourage their use as biomonitor for pollution by trace metals. Moreover, the red alga species were found to contain the highest levels of Mg while the brown alga species were found to concentrate Fe, Mn, Na and K and nonmetals such as Cl, I and Br.