Concentration of some heavy metals in organically grown primitive,old and modern wheat genotypes: Implications for human health

The concentration of six HMs (Cd, Cr, Co, Pb, Hg and Ni) was analysed in 321 organically grown winter and spring wheat genotypes from six genotype groups, i.e. selections, old landraces, primitive wheat, spelt, old cultivars and cultivars. Also the potential risk of individual toxic HM to human health was estimated by using the Hazard Quotient (HQ). Significantly the lowest grain concentration of Cd was found in primitive wheat as compared to all other investigated genotype groups. Intake of HM by consumption of whole wheat grain was not found to pose a health risk to human for any of the investigated genotype groups. The bio-concentration factor of Cd for the different genotype groups indicated a lower ability to accumulate Cd for primitive wheat as compared to other genotype groups. The primitive wheat was found the most promising and might be of interest in future wheat breeding programs to develop wheat genotypes with low HMs concentration in the grain.     

Studies on the residues of phosalone on chilli by GLC after multiband plate cleanup

Abstract

Four sprays of 0.05 ana 0.10% phosalone were given on chilli (Capsicum annuum Linn.) crop at an interval of 15 days starting from 21 days after transplanting. Residues were determined in the green chilli fruits by GLC after cleanup of extract on multiband thin‐layer plate. The half‐lives of residues were 1.55 and 1.68 days on chilli fruits from the crop treated with four sprays of 0.05 and 0.10% phosalone respectively. The time required to reach the tolerance limit of 1 ppm after last spray with 0.05 and 0.10 % emulsion was 4.75 and 7.62 days respectively. Washing of fruits under tap water was found effective in bringing down the level of phosalone residues by 21.64 to 75.11 %.     

Error propagation in pesticide residue measurements estimated by computational simulations and inter-laboratory sample analysis

An assessment of the error associated with conventional pesticide residue analysis has been conducted based on computer simulations and inter-laboratory residue analysis. Computational simulations were conducted based on (i) typical performance and regulatory acceptance criteria of analytical methods, and (ii) field residue distributions. In addition, field samples with incurred residues were sent to different private laboratories and the results compared. The relative difference in pesticide residues obtained when samples from the same field or produce lot are analyzed at separate laboratories was used to quantify the uncertainty associated with residue analyses performed using common analytical technology, and methods that are in compliance with current regulatory requirements. The study showed that differences of > 100% are common and should be expected when samples from the same crop are analyzed at different laboratories. The results also suggest that the error within residue measurements can be particularly detrimental when a result is reported near the maximum residue limit (MRL).     

松花江水质的多元统计分析

采用主成分分析法、因子分析法对松花江干流11个断面的水质监测数据按照不同水期进行分析,研究了各水质参数的相关性并对污染来源及不同水期内反映水质的重要参数进行了初步探讨.结果表明,水中可生物降解污染物对水体DO有一定的影响,水体温度是控制耗氧性污染物降解的主要因素.枯水期NH3-N与生活污水排放有重要关系,且在TN中占有较高比例.丰水期NH3-N与挥发酚相关性增加,这可能与汛期内煤化工类企业排放不达标有关;平水期,NH3-N与NO3-N相关性增加,可能平水期的污染来源及负荷与其他水期有差别.通过因子分析发现,在不同水期有不同的水质参数影响水质,枯水期大肠杆菌、TP是反映水质的重要参数;丰水期NH3-N、TP、石油类、pH为影响水质的主要水质参数;平水期DO、TN、电导率是反映松花江水质状况的重要水质参数,应当针对不同水期的污染负荷构成制定相应的污染防治方案.     

四环素高效降解酵母菌Trichosporon mycotoxinivoransXPY-10降解特性

Trichosporon mycotoxinivorans XPY-10是一株分离自抗生素制药厂的高效四环素降解酵母菌。为了建立该菌株降解四环素的适宜条件,分别研究了碳源、有机氮源、金属离子等营养物质及初始底物浓度、接种量、pH、温度、装液量、摇床转速等理化因素对菌体生长及四环素降解效率的影响。结果表明,菌株XPY-10生长的最适碳源和氮源分别为蔗糖和蛋白胨。在含有0.05% FeSO₄的培养基中,菌株XPY-10降解四环素的适宜条件为：接种量2%,pH 8,温度34℃,装液量100 mL（250 mL 三角瓶）,摇床转速180 r/min。在此条件下,菌株XPY-10在7 d内对初始浓度为600 mg/L的四环素降解率为83.63%。本菌株对养殖废水及制药废水中四环素的污染治理有一定的应用前景。     

Soil pollution assessment and identification of hyperaccumulating plants in chromated copper arsenate (CCA) contaminated sites, Korea

In recent decades, heavy metal contamination in soil adjacent to chromated copper arsenate (CCA) treated wood has received increasing attention. This study was conducted to determine the pollution level (PL) based on the concentrations of Cr, Cu and As in soils and to evaluate the remediative capacity of native plant species grown in the CCA contaminated site, Gangwon Province, Korea. The pollution index (PI), integrated pollution index (IPI), bioaccumulation factors (BAF_shoots and BAF_roots) and translocation factor (TF) were determined to ensure soil contamination and phytoremediation availability. The 19 soil samples from 10 locations possibly contaminated with Cr, Cu and As were collected. The concentrations of Cr, Cu and As in the soil samples ranged from 50.56-94.13 mg kg⁻¹, 27.78-120.83 mg kg⁻¹, and 0.13-9.43 mg kg⁻¹, respectively. Generally, the metal concentrations decreased as the distance between the CCA-treated wood structure and sampling point increased. For investigating phytoremediative capacity, the 19 native plant species were also collected in the same area with soil samples. Our results showed that only one plant species of Iris ensata, which presented the highest accumulations of Cr (1120 mg kg⁻¹) in its shoot, was identified as a hyperaccumulator. Moreover, the relatively higher values of BAF_shoot (3.23-22.10) were observed for Typha orientalis, Iris ensata and Scirpus radicans Schk, suggesting that these plant species might be applicable for selective metal extraction from the soils. For phytostabilization, the 15 plant species with BAF_root values > 1 and TF values < 1 were suitable; however, Typha orientalis was the best for Cr.     

微囊藻毒素的酶联免疫法分析影响因素探讨

考察样品与抗微囊藻毒素(MC)-LR的单克隆抗体(单抗)加入间隔时间、温育温度、检测时间、pH、H2O2、Fe2+等不同因素对酶联免疫法(ELISA)测定MC-LR的影响。结果表明:(1)随着样品与单抗加入间隔时间延长,MC-LR测定值逐渐降低。(2)25、37℃下,MC-LR测定值几乎没有差别,测定结果与取用标准样品具有很好的一致性。(3)不同检测时间下,无论是低浓度还是高浓度标准样品,MC-LR测定值均有一定变化,虽然幅度均不大,但仍然建议终止反应后尽快比色。(4)当pH为7～9时,MC-LR测定值变化不大。(5)当H2O2摩尔浓度为0.1、1.0、10.0mmol/L时,均会对ELISA产生干扰。通过水浴去除H2O2后,H2O2初始摩尔浓度分别为0.1、1.0mmol/L时,MC-LR回收率分别达到87%及81%。(6)Fe2+对酶有显著的抑制作用,可通过沉淀过滤的方式消除干扰。     

沙雷氏菌发酵蓝藻生产蛋白酶

以富含蛋白质的蓝藻作有机氮源进行微生物发酵生产蛋白酶,为蓝藻的资源化利用提供一条新途径。采用单因素实验,研究了影响沙雷氏菌发酵蓝藻生产蛋白酶的培养基主要成分。结果发现,在实验范围内,沙雷氏菌发酵蓝藻生产蛋白酶的最佳碳源是蔗糖,最佳速效氮源是尿素,最佳金属离子(盐)是ZnSO4,最佳产酶促进剂是吐温80。在单因素实验中,发酵上清液的蛋白酶活最高可达到941 U/mL,而且发酵周期短,发酵培养18 h即可达到最高酶(活)值。     

Contamination and emission factors of PCDD/Fs, unintentional PCBs, HxCBz, PeCBz and polychlorophenols in chloranil in China

The production of chloranil is regarded as a potentially significant source of unintentional POPs. This research aimed to identify the contamination levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), hexachlorobenzene (HxCBz), pentachlorobenzene (PeCBz) and polychlorophenols in chloranil samples and identify the formation pathways. The toxicity equivalent (TEQ) values for PCDD/Fs in the chloranil samples ranged from 163 to 1 540 200 pg I-TEQ g⁻¹, while the PCB TEQ values ranged from 1.9 to 3.3 pg WHO-TEQ g⁻¹. High levels of HxCBz, PeCBz and polychlorophenols were also detected in the chloranil samples. The average emission factors were 522.2 mg I-TEQ t⁻¹ (PCDD/Fs), 0.0026 mg WHO-TEQ t⁻¹ (PCBs), 32.6 mg t⁻¹ (HxCBz), and 136.6 mg t⁻¹ (PeCBz). The PCDD/Fs and PCBs are thought to be formed from the polychlorophenols and polychlorobenzenes generated during the chloranil production process. Purification of the chloranil products can reduce the unintentional POPs releases and protect the environment.     

可持续发展研究的3个关键课题与中国转型发展

从数量扩张的增长模式转向质量提升的发展模式,是中国未来30年转型发展的核心问题.本文介绍了20世纪90年代以来可持续发展在3个关键课题上的研究进展.在经济增长与社会富祉的关系上,指出经济增长对于社会富祉的贡献存在着门槛,跨过这个门槛经济增长对福利贡献的边际效用开始递减;在经济增长与资源环境的关系上,指出经济增长没有导致资源环境消耗的倒U型曲线,在自然资本存在限制的情况下无限的经济增长是不可能的;在政府支出与民生发展的关系上,指出公共支出增大并不必然导致社会福利的提高,而公共支出的结构与方式对民生发展却是极其重要的.在对每个问题分析事实依据、原因解释、政策意义的基础上,针对中国转型发展提出了一些具有长期意义的理论思考与政策思考.