Chronic toxicity and cytotoxicity of synthetic pyrethroid insecticide cis-bifenthrin

With the increasing use of synthetic pyrethroids (SPs), the significance of ecological safety and health risk is an emerging concern. In this study, we evaluated the chronic aquatic toxicity of cis-bifenthrin (cis-BF) in Daphnia magna and its cytotoxicity in Chinese hamster ovary (CHO) cells as well as human cervical carcinoma (Hela) cells. Chronic aquatic toxicity tests showed that cis-BF could significantly affect the reproduction of D. magna. The lowest observed effective concentration and the non-observed effective concentration of cis-BF to D. magna were 0.02 and 0.01 μg/L, respectively, and the chronic value was 0.014 μg/L. The intrinsic rate of natural increase was significantly decreased (p < 0.05) to 0.02 μg/L. The cytotoxicity assay demonstrated that cis-BF decreased cell viability in CHO and Hela cells in a concentration-and time-dependent manner. The IC₅₀ values for Hela and CHO cells were 4.0 × 10⁻⁵ and 3.2 × 10⁻⁵ mol/L, respectively. Together, these results indicated that cis-BF induced chronic toxicity in both aquatic invertebrate animals and mammalian cells. These findings assist in understanding the impact of SPs on health and environmental safety. Considering the wide spectrum of SPs, a more comprehensive understanding of the negative effects is indispensible for planning future application and regulation of these pesticides.     

基于Landsat TM/ETM+的天津城区及滨海新区热岛效应时空变化研究

利用1987年、1998年、2004年和2008年4景Landsat TM/ETM+数据的热红外波段数据反演天津市地表亮温,并对绝对亮温值进行归一化处理得到相对亮温。通过对相对亮温分布图进行时空分析可知,自1987年到2008年,天津市热岛效应主要发生在中心城区、滨海新区以及道路沿线等区域。热岛范围在加大,强度也在增加。中心城区热岛效应不断加剧,滨海新区的热岛效应则从无到有,从弱到强,变化十分明显。并分析了热岛现象产生和异常的原因,有降水变化、农作物收割、公路建设和建成区增加。     

Cytotoxicity of lambda-cyhalothrin on the macrophage cell line RAW264.7

The wide use and wide-spectrum toxicity of synthetic pyrethroids (SPs) insecticides make them an emerging ecotoxicological concern. Some previous studies showed that SPs possessed cytotoxicity in some immune cells such as human lymphocytes and rat bone marrow. However, the cytotoxicity of SPs to macrophages, which are crucial to innate immunity, has not been explored. In the present report, we investigated a new pyrethroid insecticide, lambda-cyhalothrin (LCT), which may increase the generation of reactive ...     

Distributions of typical contaminant species in urban short-term storm runoff and their fates during rain events： A case of Xiamen City

The pollutants in urban storm runoff,which lead to an non-point source contamination of water environment around cities,are of great concerns.The distributions of typical contaminants and the variations of their species in short term storm runoff from different land surfaces in Xiamen City were investigated.The concentrations of various contaminants,including organic matter,nutrients(i.e.,N and P) and heavy metals,were significantly higher in parking lot and road runoff than those in roof and lawn runoff.The early runoff samples from traffic road and parking lot contained much high total nitrogen(TN 6-19 mg/L) and total phosphorus(TP 1-3 mg/L).A large proportion(around 60%) of TN existed as total dissolved nitrogen(TDN) species in most runoff.The percentage of TDN and the percentage of total dissolved phosphorus remained relatively stable during the rain events and did not decrease as dramatically as TN and TP.In addition,only parking lot and road runoff were contaminated by heavy metals,and both Pb(25-120 μg/L) and Zn(0.1-1.2 mg/L) were major heavy metals contaminating both runoff.Soluble Pb and Zn were predominantly existed as labile complex species(50%-99%),which may be adsorbed onto the surfaces of suspended particles and could be easily released out when pH decreased.This would have the great impact to the environment.     

三江平原生态环境状况研究

以三江平原各县（市）为研究基本单元,运用生态综合指数法对其生态环境状况进行评价,分析各县（市）生态环境状况。结果表明：三江平原各县（市）生态环境状况分为＂优＂、＂良＂和＂一般＂三个级别。＂优＂类的县（市）共3个,占全区面积的15.96%;＂良＂类的县（市）共19个,占全区面积的82.36%;＂一般＂类的县（市）1个,占全区面积的1.68%。     

聚羧酸系高效减水剂在纸面石膏板生产中的应用

纸面石膏板属于绿色建材,随着中国国民经济的飞速发展,国内对纸面石膏板的需求日益旺盛,该行业得到了很大的发展。将聚羧酸高效减水剂应用于纸面石膏板生产中,减水效果明显,可缩短制品的干燥周期,节约能耗,有利于提高企业经济效益,是纸面石膏板行业一个非常好、值得推广的清洁生产方案。     

重庆地磁台观测环境干扰分析

根据《地震电磁观测技术》中提供的理论计算方法、采用重庆地磁台近15年的21点值和基线值,对该台的地磁观测干扰情况做出合理的分析和解释;并总结了干扰类型和数据变化情况,提出对干扰的解决方法。     

从环评体制、机制及管理的角度探讨提高环评质量的方法

从环评体制、机制及管理等层面上挖掘环评质量不高的原因,提出开展协作化环评、环评招投标、环境影响后评价、严格环评审批及建立环评责任追究机制等改进对策,力求从根本上提高环评质量。     

基于BP神经网络算法的混凝土单层框架损伤识别

基于BP神经网络算法,采用框架结构损伤前后固有频率的变化率作为网络的输入参数,分别对框架梁的单处损伤、框架柱的多处损伤进行损伤位置的识别.数值仿真结果表明,BP神经网络算法对混凝土框架结构损伤位置的识别效果很好.     

加压溶气气浮法处理高浓度氨氮废水的实验研究

本文以氨氮废水吹脱处理技术的原理为基础,采用加压溶气气浮法处理高浓度氨氮废水,通过对氨氯模拟水样的实验研究,确定了加压溶气气浮法去除水榉中氨氮的最佳实验条件。