土壤-水稻体系总砷含量的测定及其相关性研究

对韶关地区土壤及其水稻不同部位的砷含量进行了采样测定,分析了水稻中重金属砷含量与土壤的关系。结果表明：水稻不同部位中砷的含量不尽相同,其根、茎、叶及米粒中的砷含量依次为：根〉茎〉叶〉大米,且与土壤中的砷含量呈正相关,说明水稻中金属砷含量与其生长环境密切相关,水稻对金属砷具有一定的富集性。     

几种市售鲜食用菌重金属含量及评价

对兰州市市售的8个鲜食用菌样品中的铅、镉、砷、汞含量进行检测,并结合国家卫生质量标准(GB7096-2003)及《绿色食品-食用菌》NY/T749-2003,对被测食用菌中的重金属含量进行安全评价,结果表明,兰州市市售食用菌的重金属含量总体上是安全的,但有个别样品出现汞含量超过国家标准。     

Three Filter Beds for Arsenite and Chromate Removal

Abstract

Arsenic (As) and chromium (Cr) are two of the most toxic pollutants introduced into natural waters from a variety of sources, and they cause various adverse effects on living bodies when their concentrations exceed permissible limits. Laboratory experiments have been conducted to investigate the sorption of As and Cr on carbon steel and removal of trace elements from drinking water with a household filtration process. The affinity of As and Cr species for iron/iron carbide (Fe/Fe₃C) sites is the key factor in controlling the removal of the elements. The method is based on the use of powder carbon steel, powdered block carbon, and ball ceramic in the ion‐sorption columns as a cleaning process. The presence of carbon steel in a system that contains As³⁺ and Cr⁶⁺ might have a potential effect.     

Effects of Arsenic‐Contaminated Irrigation Water on Growth,Yield, and Nutrient Concentration in Rice

Abstract

A study was undertaken to determine the effects of different concentrations of arsenic (As) in irrigation water on Boro (dry‐season) rice (Oryza sativa) and their residual effects on the following Aman (wet‐season) rice. There were six treatments, with 0, 0.1, 0.25, 0.5, 1, and 2 mg As L^?1 applied as disodium hydrogen arsenate. All the growth and yield parameters of Boro rice responded positively at lower concentrations of up to 0.25 mg As L^?1 in irrigation water but decreased sharply at concentrations more than 0.5 mg As L^?1. Arsenic concentrations in grain and straw of Boro rice increased significantly with increasing concentration of As in irrigation water. The grain As concentration was in the range of 0.25 to 0.97 µg g^?1 and its concentration in rice straw varied from 2.4 to 9.6 µg g^?1 over the treatments. Residual As from previous Boro rice showed a very similar pattern in the following Aman rice, although As concentration in Aman rice grain and straw over the treatments was almost half of the As levels in Boro rice grain. Arsenic concentrations in both grain and straw of Boro and Aman rice were found to correlate with iron and be antagonistic with phosphorus.     

不同土地利用类型下土壤-作物砷的积累特征及健康风险

以菜地、稻田、果园、旱地等4种典型土地利用为研究对象,通过413个土壤和对应作物样品的测试分析,探讨了研究区不同土地利用方式下土壤及其种植作物的As积累特征和对人体的健康风险。结果表明,稻田土壤As含量在5.69～148.5 mg kg-1,积累程度最高;果园土壤As含量在3.29～24.7 mg kg-1积累程度最低。研究区各土地利用类型下土壤As变异系数均在0.5以上,为中等变异性,各样点之间土壤As含量变化较大。研究区不同土地利用方式下,作物As含量差异较大,油料作物As平均含量最高达2.15 mg kg-1,旱地谷物和水果As含量均值最低,均为0.032 mg kg-1。根据研究区作物As的富集系数进行聚类分析,将研究区作物划分为4类,油料作物富集系数最高可划分为第1类,水稻划分为第2类,叶菜类蔬菜划分第3类,而富集系数较低的水果、瓜果类蔬菜、豆荚类蔬菜、根菜类蔬菜和谷物划分为第4类。依据JECFA推荐的ADI值和研究区居民膳食结构进行计算,结果表明研究区不同土地利用类型土壤As对人体健康的风险为稻田>菜地>旱地>果园,尤其是稻田土壤As对人体健康的风险较大,因水稻食用导致的居民As摄入量高达0.00...     

微波消解-原子荧光法测定仙草产品中砷、汞元素含量

[目的]建立微波消解-原子荧光法测定仙草及其产品中砷、汞微量元素的含量。[方法]样品经微波消解,氢化物发生原子荧光法测定砷、汞元素的含量。[结果]所测元素标准曲线相关系数均≥0.999 9,加标回收率分别为砷88.3%~96.2%、汞85.4%~90.5%,RSD均在5%以内。[结论]该研究建立的方法简便、准确、成本低廉,可用于仙草及其产品中砷、汞元素含量的检测。     

砷元素对水花生生长影响

用6个不同砷浓度的营养液对水花生进行培养,结果表明：低浓度砷（〈50μmol/L）能够促进水花生的生长;高浓度砷（〉100μmol/L）使水花生的生长受到抑制,砷浓度越高水花生生长受抑制越强。水花生还具有较强的吸收砷元素的能力,在砷浓度为25～400μmol/L时植株砷吸收量随浓度增大而增加,其中茎为水花生主要吸收部位。     

地下水除砷技术的研究进展

砷是一种毒性很高的物质,地下水中存在砷污染,将对人体健康产生危害。重点介绍了地下水除砷技术的研究进展,评价了各种方法的优缺点。新型吸附材料具有较高的砷吸附容量,氧化法与吸附法等相结合是处理地下水中As(III)的有效途径,生物除砷成本低,无二次污染,具有广阔的发展前景。最后,展望了砷去除技术的发展方向。     

砷对烤烟氮代谢的影响

采用盆栽试验,系统研究了砷对烤烟全生育期氮代谢的影响。结果表明,砷毒害对烤烟的氮代谢有显著影响。砷降低了整个生育期的硝酸还原酶(NR)活性,抑制了烤烟对硝态氮(NO₃^--N)的同化;提高了全生育期的谷氨酰胺合成酶(GS)活性,增强了烤烟对铵态氮(NH₄⁺-N)的同化。砷提高了全生育期的谷氨酸—丙酮酸转氨酶(GPT)活性和天冬酰胺酶(Asparaginase, ASG)活性,以及现蕾以后的游离氨基酸含量,使烤烟的氮转化代谢旺盛。与此同时,砷降低了烤烟生育前期的蛋白质含量,随着生育进程的推进,又引起中、后期的蛋白质含量增加,最终导致烤烟蛋白质的积累,但使整个生育期的烟碱含量降低。     

Effect of SET7/9-mediated endoplasmic reticulum stress on arsenic-induced hepatocyte apoptosis

AIM:To investigate the effect of SET7/9 (SET domain containing 7/9)-mediated endoplasmic reticulum stress (ERS) on protein kinase R-like endoplasmic reticulum kinase (PERK) signaling pathway, and to explore the mechanisms of arsenic-induced hepatocyte apoptosis. METHODS:Human liver LO2 cells were divided into control group, arsenic poisoning model group, negative transfection group and SET7/9 siRNA transfection group. The apoptosis of the LO2 cells in each group was analyzed by flow cytometry. The protein levels of SET7/9, glucose-regulated protein 78 (GRP78), PERK and p-PERK in the LO2 cells of each group were observed by Western blot. RESULTS:Inhibition of SET7/9 expression reduced the apoptotic rate of arsenic-induced LO2 cells. Arsenic exposure increased the expression of SET7/9 in the LO2 cells. Arsenic exposure increased the protein levels of GRP78 and p-PERK in the LO2 cells, but decreased the protein levels of GRP78 and p-PERK after transfection with SET7/9 siRNA (P<0.05). CONCLUSION:Arsenic exposure induces hepatocyte apoptosis by increasing SET7/9 to activate ERS by PERK signaling pathway.