Yang Yu, Hunter Wesley, Tao Shu, Gan Jay
Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, China.
J Agric Food Chem. 2009 Jan 14;57(1):232-8. doi: 10.1021/jf8026759.
Pyrethroids are widely used synthetic insecticides with the characteristics of high hydrophobicity and broad-spectrum aquatic toxicity. Many studies indicate that black carbon (BC) plays an important role in the bioavailability of hydrophobic compounds such as polycyclic aromatic hydrocarbons and polychlorinated biphenyls in soils and sediments. However, the effect of BC on bioavailability of other compounds such as pyrethroids in sediments is less known. In this study, we simultaneously measured pyrethroid uptake into polydimethylsiloxane (PDMS) fibers and 24 h bioaccumulation in Chironomus tentans in a sediment amended with a charcoal at different rates. There were significant negative correlations between the accumulation of pyrethroids in PDMS fibers (C(PDMS)) and the charcoal level in sediment. When the charcoal content was increased from 0 to 1.0%, C(PDMS) decreased by 5.7-9.1%. Amendment of 1.5% charcoal to the original sediment decreased biota sediment accumulation factor (BSAF) of (14)C-permethrin in C. tentans from 2.8 to 1.7. The effect of charcoal was further found to be similar for the different subcellular fractions of C. tentans, including cell debris, organelles and proteins, and granules. The overall effect of charcoal on pyrethroid availability, however, was modest, and adsorption of pyrethroids on pure charcoal was found to be similar to that on sediment organic carbon. The relatively weak sorption on charcoal was likely due to the large molecular weight and sizes of pyrethroids, which might hinder their diffusion into charcoal nanopores.
拟除虫菊酯是广泛使用的合成杀虫剂，具有高疏水性和广谱水生毒性的特点。许多研究表明，黑碳（BC）在土壤和沉积物中多环芳烃和多氯联苯等疏水性化合物的生物可利用性方面发挥着重要作用。然而，BC对沉积物中拟除虫菊酯等其他化合物生物可利用性的影响却鲜为人知。在本研究中，我们同时测量了拟除虫菊酯在聚二甲基硅氧烷（PDMS）纤维中的吸收以及在不同比例添加木炭的沉积物中摇蚊的24小时生物累积情况。拟除虫菊酯在PDMS纤维中的累积量（C(PDMS)）与沉积物中木炭含量之间存在显著的负相关关系。当木炭含量从0增加到1.0%时，C(PDMS)下降了5.7 - 9.1%。在原始沉积物中添加1.5%的木炭，使摇蚊中¹⁴C - 氯菊酯的生物沉积物累积因子（BSAF）从2.8降至1.7。进一步发现，木炭对摇蚊不同亚细胞组分（包括细胞碎片、细胞器、蛋白质和颗粒）的影响相似。然而，木炭对拟除虫菊酯可利用性的总体影响较小，并且发现拟除虫菊酯在纯木炭上的吸附与在沉积物有机碳上的吸附相似。拟除虫菊酯在木炭上相对较弱的吸附可能是由于其分子量和尺寸较大，这可能会阻碍它们扩散到木炭纳米孔中。
