重金属在牡蛎(Crassostrea virginica)中的生物积累及其影响因素的研究

牡蛎软体、贝壳和沉积物中Ｃｄ、Ｃｒ、Ｃｕ、Ｆｅ、Ｍｎ、Ｐｂ和Ｚｎ等重金属元素被同步分析研究．研究结果表明，重金属在牡蛎中的生物积累是牡蛎自身的新陈代谢、重金属元素的地球化学性质和环境诸因素综合影响的结果，其中牡蛎的生理作用对重金属在软体中的积累所产生的影响尤为重要，而贝壳中重金属的积累对来自环境的影响更为敏感．     

冬季北京城区PM2.5诱导人肺上皮细胞系A549中多环芳烃受体(AhR)通路的激活

使用冬季北京市城区的细颗粒物（PM_2.5）评估其对人肺上皮细胞系A549中多环芳烃受体（AhR）通路的激活作用.利用CCK-8法检测细胞暴露PM_2.5后的存活率,选取50%抑制浓度（IC₅₀）作为细胞暴露剂量,采用Western blot和免疫荧光检测PM_2.5暴露诱导AhR定位变化,采用荧光定量PCR和Western blot检测AhR的靶基因CYP1A1的转录和翻译水平改变,应用双荧光素酶报告基因法测定AhR与靶基因结合位点（XRE）的活性,利用酶标仪测定CYP1A1的酶活性改变.结果显示,随着暴露时间的增加,AhR逐渐从细胞质易位至细胞核;CYP1A1 mRNA和蛋白质的表达水平也呈时间依赖性显著增加;AhR与XRE结合活性的增加表明了PM_2.5诱导CYP1A1增加的调节机制;最后引起细胞内CYP1A1酶活性显著增加.研究表明,来自冬季北京城区的PM_2.5样品可激活A549细胞的AhR通路,提示AhR介导的信号途径可能与PM_2.5的暴露毒性有关.     

浅水型湖泊蓝藻水华预警监测工作的思考

浅水型湖泊的富营养化进程不断加快,呈现出蓝藻水华暴发现象是逐年增加的。太湖作为长江中下游地区典型的浅水型湖泊更因近年来蓝藻水华频发的态势引起了政府和社会的广泛关注。为确保太湖地区饮水安全,提高政府应对蓝藻水华的能力,对太湖蓝藻水华进行预警监测是判断其发展趋势以及制定相应对策的重要手段。着力分析和总结了太湖蓝藻水华预警监测工作的主要内容,从预警监测工作的统筹、预警监测体系的建立、技术分析、预警监测的启动、分级与评价、预警信息的发布、预警监测的终止到预警监测的保障机制等,以利于同行们更好地应对浅水型湖泊蓝藻水华的发生。     

PM2.5 concentration declining saves health expenditure in China

● Monthly hospitalization expenses are sensitive to increases in PM_2.5 exposure. ● The increased PM_2.5 causes patients with CHD and LRI to stay longer in the hospital. ● The impact of PM_2.5 on total expenses for stroke is greater in southern China. ● Males may be more sensitive to air pollution than females. Air pollution has been a severe issue in China. Exposure to PM_2.5 has adverse health effects and causes economic losses. This study investigated the economic impact of exposure to PM_2.5 pollution using monthly city-level data covering 88.5 million urban employees in 2016 and 2017. This study mainly focused on three expenditure indicators to measure the economic impact considering lower respiratory infections (LRIs), coronary heart disease (CHD), and stroke. The results show that a 10 µg/m³ increase in PM_2.5 would cause total monthly expenses of LRIs, CHD, and stroke to increase by 0.226%, 0.237%, and 0.374%, respectively. We also found that LRI, CHD, and stroke hospital admissions increased significantly by 10%, 8.42%, and 5.64%, respectively. Furthermore, the total hospital stays of LRIs, CHDs, and strokes increased by 2.49%, 2. 51%, and 1.64%, respectively. Our findings also suggest heterogeneous impacts of PM_2.5 exposures by sex and across regions, but no statistical evidence shows significant differences between the older and younger adult subgroups. Our results provide several policy implications for reducing unequal public health expenditures in overpolluted countries.     

双酚芴的清洁生产工艺

根据清洁生产的理论与思维模式,对生产双酚芴的传统工艺进行了改进,以强酸性阳离子交换树脂代替传统的催化剂催化合成双酚芴,以沸水代替甲醇水溶液洗涤反应混合物,产生的废液经液液萃取和蒸馏处理,使苯酚等有效组分被回收利用,解决了废液的排放问题,基本实现了双酚芴产品的清洁生产。采用清洁生产工艺生产双酚芴,每生产1t产品可从废液中回收1．6t苯酚,按30t／a计算,可节约资金约43．2万元/a。与传统工艺相比,双酚芴的清洁生产工艺在经济效益和环境效益方面有明显优势。     

氯化镉、灭多威和硝基苯对日本青鳉(Oryzias latipes) 行为抑制的生物应急监测

研究了氯化镉、灭多威和硝基苯对孵化以后7d左右日本青鳉(Oryzias latipes)行为毒性。结果表明,在不同污染物中,随暴露浓度的增加,第1尾日本青鳉产生行为抑制的时间逐渐缩短,并且半数行为抑制时间(time ofhalf behavior inhibition,THBI,Y)随暴露浓度(X)呈现幂指数关系Y=aXb,其中20相似文献   

化工园区废气管理问题及对策

近年来,化工园区面临绿色转型升级,废气管理提升重要程度日益突显。本文分析了化工园区废气管理存在的主要问题,并提出了化工园区废气管理对策,以期提升化工园区废气综合管理水平,改善化工园区空气环境质量。     

Mechanical properties of incineration bottom ash: The influence of composite species

The mechanical properties, including strength, deformational behavior, and wetting softening phenomena of municipal solid waste incinerator (MSWI) bottom ash are one of the major concerns for reuse applications. However, owing to the complex constituents of municipal solid waste, the properties of MSWI bottom ash are often highly variable. A series of artificial specimens with controlled chemical components were tested in this study. The test results show that the artificial bottom ash possesses the following mechanical characteristics: (1) for the strength, the frictional angles of the bottom ash under dry and saturated conditions vary from 34.8° to 51.1° and 26.0° to 37.2°, respectively; (2) for the deformation, the shear stiffness increases with the normal stress arises and degrades upon increased shearing; (3) significant wetting degradation of the strength and stiffness were observed.The multi-variable regression analysis was conducted to evaluate the associated influence of the chemical components on the strength. Among the evaluated components, Fe₂O₃ and Al₂O₃ are key factors; an increase in either results in higher strength at both dry and saturated conditions. The results were used to propose empirical relationships for ?_dry and ?_sat, expressed in terms of Fe₂O₃ and Al₂O₃. Accordingly, a strength classification chart is proposed for engineering purposes.     

Forest value orientations and importance of forest recreation services

This study employs the notion of environmental value orientations as an approach to examine the relationships between forest value orientations and demand on services available in the National Forest Recreation Areas in Taiwan. Data for this investigation were collected from on-site, off-site, and online surveys (n = 1919). Statistical results suggest that the authorities should highlight the role of Taiwanese forest as public property with aesthetic, historic, and cultural values, and the use of more comprehensive dimensions of environmental value orientations is warranted when using value-related variables to address natural resource management issues. The correlation evidence of service demands of tourists with different forest value orientations indicates that the authorities should focus on maintaining and improving basic services available in the National Forest Recreation Areas.