抄録
Copper pyrithione (CuPT) and zinc pyrithiones used as alternatives to organotin antifoulants are toxic to aquatic organisms and are rapidly photolyzed by sunlight. CuPT residues in some sediments but not in seawater have been reported to date. The purpose of this study is to clarify the effect of sediments on the aquatic fate of CuPT. Adsorption and desorption of CuPT between natural marine sediments and artificial seawater was assessed according to the standardized OECD test guideline. Paint particles prepared from a commercial antifouling paint containing CuPT were added to seawater with the sediments. More than 85 % of CuPT in seawater was adsorbed to the marine sediments after a 24 h shaking, and the CuPT adsorption was independent on the ignition loss of the sediments. On the other hand, the CuPT desorption from sediments into seawater was less than 23 %, indicating about 80 % of the CuPT was remained in the sediments. The CuPT concentrations eluted from commercial antifouling paint particles into seawater in the controls were saturated within 5 days, and the ones with sediments were reduced to 38-90 % of the controls depending on the amounts of sediment added, thus suggesting adsorption of CuPT with sediments. The adsorption of CuPT with sediments may be one of the dissipation pathways of CuPT from seawater.
