Alternative antifouling biocides become less active in sediments?

对新型防污化合物三苯硼-吡啶（TPBP）的环境动力学及其降解产物的生态毒性进行了评价。通过天然海水生物降解和近紫外线光降解，苯酚和联苯是主要的降解产物。根据沉积物的有机质含量，TPBP被沉积物吸附，而不会从沉积物中解吸。TPBP吸附沉积物中产生的苯酚和联苯。检测到的两种降解产物以及其他推定产物如苯、二苯硼烷、单苯硼烷的生态毒性远低于TPBP。TPBP在自然环境中的命运估计如下：从船底涂料中释放的TPBP与悬浮物结合，最终落入沉积物中。TPBP在上层水柱中会部分被光降解，但在海底有机质含量较少的沉积物中可能降解较少，这可能对底栖生物产生不利影响。采用光杆菌毒性试剂盒TOX Screen 2进行底泥毒性评价。采用改进的方法将实验菌直接暴露于天然沉积物中，以插值沉淀物的浊度和颜色对生化发光的影响。采用基于沉积物湿重的EC50定量评价了三个海湾沉积物的污染情况。大内湾未检测到毒性，舞津湾部分样品检测到中度毒性，大阪湾部分样品检测到高毒性。毒性与沉积物中有机质含量有关。观察到的毒性与防污杀菌剂和其他有毒化学物质的持久性之间的关系，需要进行更多的研究。

Environmental fate of the new antifouling compound, triphenylborane-pyridine (TPBP), was evaluated in terms of its kinetics with sediments and ecotoxicity of its degradation products. Phenol and biphenyl was detected as major degradation products via biodegradation with natural seawater and via photodegradation with near ultra-violet irradiation. TPBP was adsorbed with sediment depending on organic matter contents of sediments and was not desorbed from the sediments. TPBP adsorbed with sediments produced phenol and biphenyl. Ecotoxicity of the two degradation products detected and other putative products such as benzene, diphenylborane, and monophenylborane was much lower than one of TPBP. The fate of TPBP in natural environment was estimated as follows: TPBP released from ship bottom paint is incorporated with suspended solids and finally fall into sediments. TPBP will be partly photodegraded in upper water column but may be less degraded in sediments with less organic matter contents at sea bottom, this may lead possible adverse effects on benthic organisms.A toxicity kit, TOX Screen 2 using Photobacterium leiognathi SB, was applied for sediment toxicity evaluation. Test bacteria was directly exposed to natural sediments using an improved method to interpolate the effects by turbidity and color of sediment on biochemiluminescence. Pollution of the sediment s collected in three bays were quantitatively evaluated with EC50 based on wet weight of sediments. No toxicity was detected in Othuchi Bay, moderate toxicity was detected in some specimen from Maizuru Bay, and high toxicity was bind in several sediments from Osaka Bay. The toxicity was dependent on the organic matter contents of sediments. More research is needed to investigate how the toxicity observed was related with the persistence of antifouling biocides and other toxic chemicals.