Effects of exposure source, worm density, and sex on DDT bioaccumulation and toxicity in the marine polychaete Neanthes arenaceodentata
Effects of exposure source, worm density, and sex on DDT bioaccumulation and toxicity in the marine polychaete Neanthes arenaceodentata
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DOI：
10.1002/etc.5620190229
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发表时间：
2000-02-01
影响因子：
4.1
通讯作者：
Bridges, TS
中科院分区：
文献类型：
--
作者：
Lotufo, GR;Farrar, JD;Bridges, TS
研究了暴露源、虫口密度和性别对C-14标记滴滴涕生物蓄积和毒性的影响。在28天的毒性实验中，将出现的幼虫暴露于添加了DDT的沉淀物(SED)、添加了DDT的补充食物(TetraMarin；TM)或两者的组合(SEDTM)。在有机碳的基础上，沉积物和食物中的滴滴涕浓度相同。与SED相比，TM暴露下获得了更高的体内残留量，表明非沉积有机物作为污染物吸收的来源的重要性。与沉淀物相比，滴滴涕与四环素结合时的生物利用度更高，这表明除了对有机碳的吸附之外，其他因素也会影响污染物的生物利用度。高达0.5mol/g湿重的体内残留物与存活率的下降无关，表明全身麻醉是滴滴涕对齿纹夜蛾的致死毒性模式。体内负荷以DDT非代谢化合物为主(约占70%)。在所有暴露下观察到的生长减少，在较低浓度下，当蠕虫被添加DDT的食物(TM和SEDTM)喂养时，生长显著减少。石龙鱼可能检测到了四头马林鱼中滴滴涕的存在，从而降低了它们的摄食率，代价是生长减慢。通过将1条或5条蠕虫(分别为74条和370条/m(2))暴露于添加的沉积物中，研究了蠕虫密度对DDT毒性和生物积累的影响。尽管在低密度下获得了较高的体内残留量，但以五组为一组暴露的蠕虫对DDT对生长的影响明显更敏感。性别对滴滴涕吸收动力学也有较大影响。在底泥暴露(SED)中，成熟雄性的摄取清除速率(mg(OC)/g脂/h)是成熟雌性的2倍，消除速度是成熟雌性的5倍。
The influence of exposure source, worm density, and sex on the bioaccumulation and toxicity of C-14-labeled DDT was evaluated for Neanthes arenaceodentata. Emergent juvenile worms were exposed to DDT-spiked sediment (SED), DDT-spiked supplemental food (TetraMarin; TM), or a combination of both (SEDTM) in 28-d toxicity experiments. The DDT concentrations in the sediment and in the food were equal on an organic carbon basis. Higher body residues were attained under the TM exposure compared to SED, indicating the importance of nonsedimentary organic matter as a source for contaminant uptake. The DDT was more bioavailable when associated with TetraMarin compared to sediment indicating that factors other than sorption to organic carbon can influence contaminant bioavailability. Body residues as high as 0.5 mol/g wet weight were not associated with decreased survival, suggesting general narcosis as the mode of lethal toxicity of DDT to N. arenaceodentata. Most of the body burden was DDT unmetabolized compound (similar to 70%). Reduced growth, observed under all exposures, was significant at lower concentrations when worms were fed DDT-spiked food (TM and SEDTM). Neanthes arenaceodentata may have detected the presence of DDT in the TetraMarin and decreased their feeding rate, at the cost of reduced growth. The influence of worm density on DDT toxicity and bioaccumulation was examined by exposing one or five worms per beaker (74 and 370 worms/m(2), respectively) to spiked sediment. Although higher body residues were attained under low density, worms exposed in groups of five were significantly more sensitive to the effects of DDT on growth. Sex also had a large influence on DDT uptake kinetics. In sediment exposures (SED) to a trace concentration, the uptake clearance rate (mg(OC)/g lipids/h) was two times more efficient and the elimination rate was five times faster in mature males than in mature females.