Dose-response curve modeling of excess mortality caused by two forms of stress

A method is presented for modeling the effect of two stresses on mortality. The model assumes a multiplicative simple two-parameter dose-response curve relationship between mortality and the two factors as well as for the effect of combining the two factors. The dose-response curve is modified in order to model survival probabilities. It is shown that the model adequately describes mortality data of Folsomia candida (Collembola) in a two-stress factor design.     

重庆流域嘉陵江和长江水环境中壬基酚污染状况调查

利用固相萃取（SPE）－气相色谱－质谱法（GC－MS）对嘉陵江和长江重庆段河流和以这两条河流为水源的5个自来水厂水样中壬基粉（NP）进行了检测,河流水样中4月份NP的浓度范围为0.02-1.12μg/L，7月份为1．55－6.85μg/L，自来水厂的水样中，4月份NP浓度范围为＜0．01－0．06μg/L,7月份为.10-2.73μg/L，方法的自来水加标回收率大于90％，环境水样中的加标回收率大于80％，检测限为0.01μg/L.     

壬基酚对成体玫瑰无须性腺的毒性效应

以成体玫瑰无须（Puntius conchonius）为实验材料,通过半致死浓度（LC₅₀）、性腺指数以及组织病理学指标对壬基酚（NP）的毒性进行了评价.结果表明,在半静止条件下,壬基酚对成体玫瑰无须96 h的LC₅₀为（1 .72 ± 0 .06） μmol/L;在亚急性毒性（0 .17、0 .34和0 .68 μmol/L）下成体玫瑰无须暴露于壬基酚21 d后,其精巢指数（TSI）与卵巢指数（OSI）显著降低,并具有明显的剂量-效应关系;同时精巢与卵巢也发生了明显的组织病理学变化,精巢中支持细胞增生、生殖细胞数量减少;卵巢中卵泡发育迟缓、闭锁现象增加.结果说明壬基酚对玫瑰无须的雌、雄性腺均具有毒性效应,干扰了精卵的发育成熟.另外,玫瑰无须对壬基酚具有较高的敏感性,也是评价壬基酚毒性的一种理想模式鱼类.     

吸附态壬基酚对菲吸附的影响及位点能量分布分析

采用不同浓度水平壬基酚(NP)的颗粒物对菲的吸附行为进行等温吸附实验,并使用位点能量分布分析吸附态NP对菲吸附的影响机理,结果表明,菲在低浓度水平有机质天然水体颗粒物、去除有机质的水体颗粒物和高岭土颗粒物上的吸附均较符合Freundlich模型,亲水界面上菲的吸附位点能量较低,低浓度吸附态NP存在时,降低了吸附位点的数量,对菲在颗粒物亲水界面上的吸附产生一定抑制作用,但较高浓度的NP存在时,则可为菲的吸附提供新的低能量位点,从而促进菲的吸附.     

壬基酚在蛋白核小球藻和大型溞体内的富集与传递

为探究壬基酚(nonylphenol,NP)在水生生物中的富集传递效应,选择以蛋白核小球藻(Chlorella pyrenoidosa)和大型溞(Daphnia magna)为研究对象,开展蛋白核小球藻对NP的富集效应实验,及NP在蛋白核小球藻和大型溞体内的传递效应实验。研究结果表明,NP对蛋白核小球藻的96 h半数效应浓度(96 h-EC50)为3.13 mg·L~(-1),对蛋白核小球藻的生长和叶绿素含量的影响呈现明显的剂量-时间效应。NP对大型溞的48 h半数效应浓度(48 h-LC50)为37.41μg·L~(-1),属于高毒类化合物。蛋白核小球藻暴露于0.05 mg·L-1NP 4 h后,其生物富集系数(BCF)为5 144.93,富集量为252.2μg·g~(-1),在12 h内对NP的生物富集系数(BCF)最高达12 053.64,富集量为1 181.73μg·g~(-1)。以0.05 mg·L-1NP中暴露4 h后的蛋白核小球藻为饵料投喂大型溞7 d后,大型溞体内NP富集量最高达3.6μg·g~(-1)。0.05 mg·L~(-1)NP直接暴露组大型溞暴露10 d后,大型溞体内NP富集量最高达4.02μg·g~(-1)。蛋白核小球藻对NP具有较强的富集能力,能够通过摄食过程将NP传递到大型溞,经传递的NP能够显著抑制大型溞的生长、繁殖、摄食等生命活动。论文为评估NP在水生生态系统中的污染风险和富集传递效应提供了一定的参考依据。     

藻类有机质的组成结构对菲和壬基酚生物吸附的影响

对不同来源藻及其有机级分进行元素分析,利用高级核磁共振技术(multi/CP13C NMR)来准确地定量其有机官能团,并研究它们对菲和壬基酚的生物吸附行为和机理。结果表明游离脂和非水解有机碳级分对菲和壬基酚有最高的吸附能力,其吸附容量与脂肪结构呈极显著的正相关,而与极性官能团呈极显著的负相关;而且对壬基酚的吸附容量都大于对菲的吸附容量,可以用专性作用(如π-π键作用和氢键作用)来解释。     

Chemical characterization of Tan‐Sui River sediment in North Taiwan

Surface sediment samples from four downstream sites of Tan‐Sui River in Taipei metropolitan area were collected from 1997 to 1999. The semivolatile organic pollutants present in the sediments were screened by GC/MSD. Several target compounds including sixteen polycyclic aromatic hydrocarbons (PAHs), seven chlorobenzenes, two phthalates and the total amount of C8‐C32 aliphatic hydrocarbons were quantified. The concentration of the 16 PAHs ranges from 0.21 to 5.69 μg/g of which fluoranthene, pyrene and phenanthrene were the highest. The concentration of the total chlorobenzenes ranged from 0.04 to 5.85 μg/g. The concentration of bis(2‐ethylhexyl)phthalate ranges from 3.8 to 35.3 μg/g and that of the total C8‐C32 aliphatic hydrocarbons ranges from 0.94 to 10.6 μg/g. Some of these values are higher than similar sediment survey in Japan in the eighties. The concentration of bis(2‐ethylhexyl)phthalate is much higher than the no‐effect level (0.184 μg/g) set by McDonald. Some of the PAHs have already reached the level of biological effects. As compared with the sediment samples collected from Tou‐Chien River and Pu‐Ze River located at the west of Taiwan, the chlorobenzene concentrations of sediments in Tan‐Sui River are 5–6 times higher, the PAHs are 6–10 times higher and the phthalates are 11–20 times higher. Nonylphenol was also commonly found in the Tan‐Sui River sediment. There is a decreasing tendency of PAHs and phthalates concentration from surface to bottom for the core sample at Taipei Bridge site. Such tendency is less obvious for chlorobenzenes.     

Endocrine disruptors in the Leça River and nearby Porto Coast (NW Portugal): presence of estrogenic compounds and hypoxic conditions

The Leça River and two beaches close to the north and south margins of the estuary, nowadays an important seaport harbor, show signs of contamination. However, the chemical nature of that contamination is uncertain. Therefore, this study checked for the presence of 11 endocrine disrupting compounds (EDCs) of animal (17β-estradiol and estrone), pharmaceutical (17α-ethynylestradiol), and industrial (alkylphenols, alkylphenol ethoxylates, and bisphenol A) origins in water samples collected from six points at the river gradient and at two sites in the coastline (Atlantic Ocean). Along with the EDCs, evaluated by gas chromatography – mass spectroscopy (GC-MS) during spring, summer, and autumn, physico-chemical parameters were also assessed and particular attention was given to dissolved oxygen (DO) levels. Data showed the presence of high amounts of estrogens (up to 10?ng?L^?1 for estrone) and industrial compounds (up to 2?µg?L^?1 for the nonylphenol ethoxylates) at both river and seacoast. Along with this, clear signs of hypoxia were found in the river (DO??1 at several sampling sites). Taking into account these issues, it was concluded that there are local conditions for the occurrence of endocrine disruption in aquatic animals.     

壬基酚聚氧乙烯醚暴露下赤子爱胜蚓（Eisenia foetida）的生理损伤

利用急性接触试验和人工土壤试验分别研究了壬基酚聚氧乙烯醚（NPEO）对赤子爱胜蚓（Eisenia foetida）的致死性和氧化损伤.急性接触试验结果显示,NPEO对赤子爱胜蚓的48 h毒性半致死剂量p（48 h,LD50）为0.58 mg·L^-1;人工土壤试验结果显示,NPEO可诱导赤子爱胜蚓CAT酶活力、GST酶活力、GSH含量和氧化产物（MDA）含量上升,暴露28 d时,NPEO浓度与赤子爱胜蚓CAT酶活力、GST酶活力、GSH含量和MDA含量呈正相关,且均存在显著的剂量-效应关系（P＜0.05）,NPEO剂量增加对赤子爱胜蚓SOD酶活性和Cu-Zn SOD酶活性有轻微抑制作用.以上结果表明NPEO在亚致死暴露浓度下＜0.50 mg· kg^-1）会对赤子爱胜蚓产生生理胁迫并导致一定程度的氧化损伤.     

多种聚氧乙烯牛脂胺混合物MON 0818的水生环境危害评估：脉冲暴露后沉积物、温度和恢复能力的影响

我们对一种商业表面活性剂混合物(多种聚氧乙烯牛脂胺)MON 0818进行了一系列毒性测试：1. 测定底栖无脊椎动物和鱼类在沉积物存在的情况下受到的毒性;2.测定大型蚤(Daphnia magna)和4种初级生产者经过24 h的脉冲暴露之后的恢复能力;3.鉴定水体温度上升对于2种冷水鱼类所受到MON 0818毒性的潜在影响。在沉积物存在的情况下,5种生物中有3种在最高10 mg/L的浓度下短期(24 h)死亡率为零。其余2种物种的中位有效浓度则显著高于仅对水体进行测试的结果。15 ℃下北极红点鲑(Salvelinus alpinus)的半数有效浓度统计上低于10 ℃下。绿藻(Rhabdocelis subcapitata)和普通小球藻(Chlorella vulgaris)在经过24 h 1 mg/L的暴露后的恢复期中显示出生长延迟的状况,表明该暴露可能存在潜在影响。尽管如此,2个物种的最大绝对生长速率并未改变,表明其均可恢复。1.5 mg/L下的蝾螈共生藻(Oophila sp.)和100 mg/L下的浮萍(Lemna minor)经过24 h的暴露并未显示显著反应。24 h 5 mg/L暴露之后的恢复期中,大型蚤显示出潜在的死亡率。然而存活个体的生殖终端指标并未受到影响。结果表明在沉积物的存在下MON 0818的快速损耗可以减轻对于被暴露生物的效果,在不小于环境中可能出现的MON 0818浓度情况下,24 h暴露以后的生物的完全恢复是可能的。
精选自Jose L. Rodriguez-Gil, Ryan Prosser, Gregory Hanta, David Poirier, Linda Lissemore, Mark Hanson, Keith R. Solomon. Aquatic hazard assessment of MON 0818, a commercial mixture of alkylamine ethoxylates commonly used in glyphosate-containing herbicide formulations. Part 2: Roles of sediment, temperature, and capacity for recovery following a pulsed exposure. Environmental Toxicology and Chemistry: Volume 36, Issue 2, pages 512–521, July 2017. DOI: 10.1002/etc.3558
详情请见http://onlinelibrary.wiley.com/wol1/doi/10.1002/etc.3558/full