Combined toxic impacts of thiamethoxam and four pesticides on the rare minnow (Gobiocypris rarus)

To examine pesticide mixture toxicity to aqueous organisms, we assessed the single and combined toxicities of thiamethoxam and other four pesticides (chlorpyrifos, beta-cypermethrin, tetraconazole, and azoxystrobin) to the rare minnow (Gobiocypris rarus). Data from 96-h semi-static toxicity assays of various developmental phases (embryonic, larval, juvenile, and adult phases) showed that beta-cypermethrin, chlorpyrifos, and azoxystrobin had the highest toxicities to G. rarus, and their LC₅₀ values ranged from 0.0031 to 0.86 mg a.i. L^?1, from 0.016 to 6.38 mg a.i. L^?1, and from 0.39 to 1.08 mg a.i. L^?1, respectively. Tetraconazole displayed a comparatively high toxicity, and its LC₅₀ values ranged from 3.48 to 16.73 mg a.i. L^?1. By contrast, thiamethoxam exhibited the lowest toxic effect with LC₅₀ values ranging from 37.85 to 351.9 mg a.i. L^?1. Rare minnow larvae were more sensitive than embryos to all the pesticides tested. Our data showed that a pesticide mixture of thiamethoxam–tetraconazole elicited synergetic toxicity to G. rarus. Moreover, pesticide mixtures containing beta-cypermethrin in combination with chlorpyrifos or tetraconazole also had synergetic toxicities to fish. The majority of pesticides are presumed to have additive toxicity, while our data emphasized that the concurrent existence of some chemicals in the aqueous circumstance could cause synergetic toxic effect, leading to severe loss to the aqueous environments in comparison with their single toxicities. Thence, the synergetic impacts of chemical mixtures should be considered when assessing the ecological risk of chemicals.

     

Occurrence of dioxin-like POPs in soils from urban green space in a metropolis,North China: implication to human exposure

Environmental Science and Pollution Research - Urban green space is a special space for urban life and natural contact and has an important impact on human health. However, little information is...     

Joint use of data and modeling in coastal wave transformation

In the framework of a research project entitled ??BRISA??BReaking waves and Induced SAnd transport??, a methodology was devised to characterize the waves joining together in-situ measurements and numerical wave propagation models. With this goal in mind, a number of in-situ measurements were made, for selected positions in front of Praia de Faro (South Portugal), during four days (25th to 28th March, 2009) by using different types of equipments (e.g., resistive wave gauges, pressure sensors, currentmeters and a new prototype pore pressure sensor using optical fibre). Wave records were obtained simultaneously offshore (at a water depth of 11.7?m below mean sea level, MSL) and at the surf and swash zones. The data processing and analysis were made by applying classical time domain techniques. Numerical simulations of the wave propagation between offshore and inshore for the measurement period were performed with two numerical models, a 1D model based on linear theory and a nonlinear Boussinesq-type model, COULWAVE, both forced by the measured offshore wave conditions of 27th March 2009. Comparisons between numerical results and field data for the pressure sensors placed in the surf and swash zones were made and discussed. This approach enables to evaluate the performance of those models to simulate those specific conditions, but also to validate the models by gaining confidence on their use in other conditions.     

环境雌激素o,p′-DDT和抗雌激素氟维司群对斑马鱼胚胎的复合效应

为探究雌激素与抗雌激素的复合效应,将斑马鱼(Danio rerio)的胚胎暴露于o,p′-DDT和氟维司群2种典型的环境内分泌干扰物中,考察胚胎孵化率、孵化时间和总畸形率,并用实时荧光定量PCR技术检测Vtg1、Vtg2和ERα等雌激素效应相关基因的mRNA转录水平.结果显示,与单一化合物的暴露相比,o,p′-DDT和氟维司群的二元混合物暴露对斑马鱼的发育毒性增强.在诱导Vtg1和ERα基因的mRNA表达水平上调方面,氟维司群对o,p′-DDT的诱导效应表现出拮抗作用,而当50或250 μg· L-1氟维司群与100 μg·L-1 o,p′-DDT共存时,对Vtg2有明显的诱导效应.研究表明,     

微咸水膜下滴灌对白僵土盐碱地水盐特性及油葵生长的影响

为了解滴灌条件下不同微咸水矿化度及覆膜与否对盐碱地土壤水盐特性及油葵生长的影响,在宁夏平罗西大滩盐碱地进行不同灌水矿化度(0.2、1、2、3 g/L)膜下滴灌田间试验.结果表明,地膜覆盖比不覆盖处理土壤含水量高约2%,盐分表聚减缓,油葵株高、产量及其构成均高于不覆膜处理,产量最高增幅达82.5%;不同矿化度微咸水之间比较发现,利用矿化度为1 g/L的微咸水进行灌溉时,下层土壤含水量较高,微咸水滴灌不但没有为上层土壤带去过多盐分,反而由于土壤有一定的渗透性能,灌水将土壤上层盐分逐渐淋洗至下层.膜下滴灌微咸水矿化度为1 g/L时,油葵产量最大.因此在适宜条件、合理措施下,微咸水覆膜滴灌技术可以促进作物生长,确保作物产量,在淡水缺乏而微咸水较为丰富的盐碱地地区应积极推广利用.     

基于3D体外培养模型的化学物质肝毒性预测研究进展

精准预测化学物质肝毒性对保护人类生命健康安全具有重要意义。为了避免动物实验固有的物种间差异性和局限性,开发和利用与人源肝脏生理功能直接相关的体外模型至关重要。三维(3D)体外细胞培养模型相比于二维(2D)模型能更好地保留肝细胞代谢功能,再现肝脏内多种细胞相互作用的复杂环境,是体外模拟肝脏生理功能的一大进步,并初步在药物毒性评估方面获得应用的同时,也被引入到环境毒理学领域用于预测环境化学物质的肝毒性。本文介绍了目前常用3D体外细胞培养模型的制备方法,综述了其在环境化学物质(纳米材料、持久性有机污染物和新型有机污染物等)肝毒性预测方面的应用现状,最后探讨了3D肝细胞体外培养模型在有害结局路径指导下开展肝毒性预测的研究与应用前景。     

安全心理测量技术在安全科学技术中的地位和作用

探讨心理测量在安全科学中的地位和作用,提出将心理测量用于安全科学的必要性,着重论述心理测量运用于安全科学技术领域的可行性和科学性,分析和讨论了安全心理测量在安全领域中的应用前景。     

对某煤矿29年防尘投入的成本效益分析报告

从卫生经济学角度出发,对山东某煤矿就尘肺病所造成经济损失进行了调查分析,采用类回顾性群组对比法,分析、评价了29年来(1962—1990年)该矿采取防尘措施所取得的经济效益,为进一步开展预防尘肺病的卫生经济学研究提供科学依据。     

The fungicide difenoconazole alters mRNA expression levels of human CYP3A4 in HepG2 cells

The fungicide difenoconazole has been frequently detected in agricultural products, soils and surface waters, causing increasingly public concern due to toxicological properties. Although systemic triazole fungicides can inhibit the enzymatic activity of many CYP450 isozymes, how difenoconazole affects the human CYP3A4 still remains largely unknown. We thus investigated the effect of difenoconazole on normal mRNA expression and protein expression of human CYP3A4 by real-time quantitative PCR and western blot, respectively. Results show that the exposure to difenoconazole from 0.01 to 0.5 μM for 24 h down-regulates mRNA expression levels of human CYP3A4 in HepG2 cells. We also found that difenoconazole could inhibit the enzymatic activity of human CYP3A4 in a concentration-dependent mode. The IC₅₀ of difenoconazole for inhibition of CYP3A4 activity is 0.41 µM, showing a stronger inhibitor in comparison with ketoconazole. Overall, our findings indicate the potential risk of difenoconazole for the disruption of human CYP3A4.