番茄温敏核不育系花药培养诱导愈伤组织的研究

[目的]探讨影响番茄温敏核不育系花药培养诱导愈伤组织的相关因子。[方法]研究不同灭菌处理、不同基本培养基、不同激素种类及浓度对番茄温敏核不育系花药培养诱导愈伤组织的影响。[结果]0．1％HgCl28min＋10％NaClO8min的灭菌处理效果最佳,菌污染率仅为1．95％,出愈率达71．73％;在MS、B5Miller3种基本培养基的比较试验中,以MS为基本培养基对花药愈伤组织的诱导效果最好;诱导愈伤组织的适宜浓度为2,4-D1mg／L、6-BA2mg／L、KT2mg／L。[结论]灭菌处理、基本培养基、激素种类及浓度可以影响番茄温敏核不育系花药培养诱导愈伤组织的效果。     

葫芦岛市连山区、龙港区土壤重金属空间分布及污染评价

本文利用地理信息系统及地统计学,对葫芦岛市连山区和龙港区土壤中重金属的污染状况进行了空间变异性分析,对Cd、Cu、Zn污染进行单因子评价。结果表明:土壤Cd、Cu、Zn的理论模型均为球状模型。Cu的C0/(C0+C)为26%,说明Cu体现为中等的空间相关性,Cd、Zn的C0/(C0+C)分别为0.3%、3.2%,说明这2种重金属体现为强烈的空间相关性。在已有监测数据的基础上,制作了该地区土壤Cd、Cu、Zn污染的预测表面,得到研究区土壤重金属的分布图及污染分布图。研究表明,龙港区和杨杖子矿区的土壤已达到了重度污染的水平,不再适合于农业生产。     

吉林省玉米真菌毒素污染状况及其膳食风险评估研究

采集吉林省主产区玉米280份,采用液相色谱串联质谱法测定13种真菌毒素含量,研究吉林省玉米中多种真菌毒素污染和膳食暴露风险状况,评价膳食暴露风险。结果表明,供试玉米中真菌毒素的平均含量为522.3μg/kg,真菌毒素污染种类分别是伏马菌素(97.9%)、脱氧雪腐镰刀菌烯醇(52.1%)和玉米赤霉烯酮(37.5%),平均污染水平分别为1269.1、284.2、42.8μg/kg。采用残留平均值计算成人和儿童经玉米摄入的伏马毒素、脱氧雪腐镰刀菌烯醇及玉米赤霉烯酮,结果无显著慢性摄入风险。以最大残留值计算摄入呕吐毒素的膳食暴露风险,成人和儿童无显著急性摄入风险。吉林省玉米中真菌毒素的污染呈多种类污染普遍的现象,居民通过玉米摄入真菌毒素的风险熵值很小,对人体健康潜在风险不大。     

陕西关中畜禽肉及凉拌菜中沙门氏菌污染分析

为了解陕西省关中地区食品中沙门氏菌的污染状况及分布,初步确定污染沙门氏菌的高危食品种类,为沙门氏菌检测、监测和食品安全控制提供理论依据。本研究按照GB/T 4789.1-2003规定的方法采集陕西省西安、杨凌和宝鸡等地超市和农贸市场的零售肉样品443份,凉拌菜样品209份;使用选择性培养基分离沙门氏菌,采用PCR技术对沙门氏菌进行鉴定。结果发现5大类食品中,鸡肉被沙门氏菌污染的状况最为严重(69.9%),其他食品污染率由高到低依次为羊肉(55.3%)、牛肉(30.1%)、猪肉(19.4%)和凉拌菜(9.6%);肉类食品的污染状况(45.2%)远高于凉拌菜(9.6%);从超市采集的零售肉样品沙门氏菌污染率(46.8%)低于从农贸市场采集的零售肉样品(54.6%);西安地区零售肉沙门氏菌污染率最高,其次分别为杨凌和宝鸡地区;杨凌地区即食凉拌菜沙门氏菌污染率最高(6.7%),其次分别为宝鸡(2.9%)和西安(0%)。从结果可得出,陕西关中地区的零售肉和即食凉拌菜已在不同程度上受到沙门氏菌污染。     

武汉市售典型蔬菜硝酸盐和亚硝酸盐污染现状分析

[目的]调查武汉市售蔬菜硝酸盐和亚硝酸盐污染现状,并评价其食用安全性。[方法]对武汉市7大城区蔬菜市场市售的典型蔬菜进行随机抽样,参考国标法采用分光光度法分析蔬菜样品中硝酸盐和亚硝酸盐含量。[结果]武汉城区市售的蔬菜硝酸盐含量大小依次为叶菜类、根茎类、瓜果类、豆类,而同类型不同种类的蔬菜硝酸盐含量差异明显;在所调查的81个蔬菜样品中,亚硝酸盐含量均在食用安全范围内,而硝酸盐含量达到严重污染等级的占35.8%、重度污染占8.6%、中度污染占9.9%、轻度污染占45.7%。[结论]武汉城区市售蔬菜中亚硝酸盐含量均在食用安全范围内,而硝酸盐污染突出,尤其是叶菜类蔬菜硝酸盐积累严重。     

循环水养殖欧洲鲈鱼(Dicentrarchus labrax)重金属污染状况与富集分布特征

为了解并评估天津市某循环水养殖企业的养殖产品重金属安全性和分布规律,本研究采用电感耦合等离子体发射光谱法(ICP法)和原子荧光法(AFS法),对该封闭循环水养殖系统中欧洲鲈鱼(Dicentrarchus labrax)幼鱼、养殖中期和成鱼3个阶段的鱼体肌肉、肝脏和鳃中8种重金属(As、Cd、Cr、Cu、Ni、Pb、Zn和Hg)含量进行测定.结果显示,从生长阶段来看,随养殖过程推进,各重金属在欧洲鲈鱼体内分布特征不同,肌肉中As含量随时间增加而增加,最大值为1.93 mg/kg,Cu和Hg则相反,最大值分别为0.354和0.021 mg/kg;肝脏中As、Cd和Cu含量均随时间增加,最大值分别为1.47、1.09和143.00 mg/kg;鳃中As含量随时间增加而增加,最大值为0.321 mg/kg,Cr、Cu、Zn和Hg含量呈先降后升的趋势,最大值分别为0.356、45.8、19.2和0.0137 mg/kg.从组织分布特征来看,As含量为肌肉＞肝脏＞鳃,Cd、Cu和Zn含量均为肝脏＞鳃＞肌肉,Hg含量为肌肉＞鳃＞肝脏,Cr含量为鳃＞肝脏＞肌肉.可食部分,即肌肉中各重金属含量均符合食品安全国家标准(GB 2762-2012),参考鱼体重金属残留污染程度分级,该系统中的欧洲鲈鱼均属于未污染.水体样本,除养殖中期进水中Pb和Cd超标,其余重金属含量均符合我国渔业水质标准(GB 11607-89).表明该养殖系统中重金属污染在安全范围内.     

Accuracy of seven vapour intrusion algorithms for VOC in groundwater

Background, aim and scope  During the last decade, soil contamination with volatile organic contaminants (VOC) received special attention because of their potential to cause indoor air problems. Moreover, research has shown that people spend 64% to 94% of there time indoors; therefore, the indoor air quality is of a primary importance for exposure to VOC. Human health risks to VOC—in cases of soil contamination—are often dominated by the exposure route ‘inhalation of indoor air’. Exposure is often a result of vapour transport from the soil or groundwater to the indoor air of the building. Within human health risk assessments, a variety of algorithms are available that calculate transfer of soil gas to the indoor air. These algorithms suffer from a relatively high uncertainty due to a lack of representation of spatial and temporal variability. For such an application, these algorithms need to be further verified empirically against field observations so that they can be sufficiently reliable for regulatory purposes. This paper presents the accuracy for seven algorithms by using observed and predicted soil and indoor air concentrations from three sites, where the groundwater had been contaminated with aromatic and chlorinated VOC. Materials and methods  The algorithms for vapour intrusion that are frequently used in European countries were included in this study and were Vlier–Humaan (Flanders), CSoil (Netherlands), VolaSoil (Netherlands), Johnson & Ettinger (USA), Risc (United Kingdom), and the dilution factor (DF) algorithms from Sweden and Norway. Three sites were investigated in more detail and samples were taken synoptically from the groundwater, soil and indoor air on four occasions. On the petroleum sites, the aromatic hydrocarbons benzene, toluene, ethylbenzene and xylenes were analysed and, on the dry cleaning sites, the chlorinated hydrocarbons tetrachloroethylene, trichloroethylene and cis 1,2-dichloroethene. To increase spatial resolution, measurements in groundwater and soil air were taken in three different zones at each site, in the close proximity of or in the building. During sampling, several relevant soil properties were measured like the bulk density, water and air filled porosity, soil temperature and depth of the groundwater. Also, building properties like the dimensions of the building and the quality of the floor were registered. The seven algorithms were applied to compare that observed with the predicted concentrations in soil and indoor air. The groundwater concentrations were used as a source contamination. The results from the algorithms were compared by using performance criteria to assess the accuracy of each algorithm. Results  All calculations are presented in a box plot that contains the predicted soil or indoor air versus the observed concentrations. Results from the applied criteria are presented for each algorithm. Discussion  Differences between predictions and observations were up to three orders of magnitude and can be partially related to the amount of parameters included in each algorithm and the mathematical concept used. For example, the inclusion or exclusion of a capillary fringe or temperature correction for the Henry constant: it is not clear why all algorithms tend to over-predict the soil air concentration. The prediction mostly starts with the calculation of a soil air concentration related to the Henry constant, followed by diffusive and/or convective transport to the soil surface and zone of influence around the building foundation. Further research is needed to investigate the over-predictions and the use of the Henry constant to calculate the soil air concentration should be reviewed. Conclusions  The algorithms with the highest accuracy were the Johnson and Ettinger and the Vlier–Humaan algorithms. The DF algorithms from Sweden and Norway resulted in higher over- and underpredictions than others. Results for the indoor air showed that all the algorithms calculate high and low concentrations in the indoor air when compared to observations. The algorithms with the highest accuracy were JEM, Vlier–Humaan and CSoil. The DF algorithm from Norway calculated concentrations that were frequently higher than observed concentrations and the Swedish DF algorithm showed frequent higher and lower concentration than observed. The conservatism of the most accurate algorithms is sufficient for regulatory purposes, and they can trigger an integrated programme of field observations (monitoring) or/and modelling. Recommendations and perspectives  The dataset used for this paper was derived from three sites with groundwater contamination and further verification of these algorithms should be done for other sites that have a vadose zone contamination.     

马铃薯组织培养中常见的污染问题及解决办法

概述了植物组织培养的基本概念。讨论了马铃薯组织培养过程中易出现的问题,包括污染产生的途径、污染来源及主要菌类、培养基污染问题,提出了减少污染的措施。     

Why won’t they grow? – Inhibitory substances and mollusc hatcheries

Molluscs are known to be seriously affected by trace amounts of environmental pollutants such as tributyltin at concentrations in seawater that are below the level of detection by all but the most sensitive chemical analytical techniques. This extreme sensitivity by molluscs has led to use of both adults and larvae as biomonitors for environmental pollution. Mollusc aquaculture has led to an increasing demand for commercial hatcheries to supply seed stock, including selected genetic lines of spat and juveniles. It is becoming apparent that many of the unexplained “crashes”, ill thrift or failures of larvae to metamorphose in such hatcheries are primarily due to their being compromised for a range of reasons including traces of inhibitory or toxic substances in the water supply. Because dead and dying larvae are ideal substrates for bacterial and ciliate growth, such invaders are often assumed to be the primary cause of the problem and this hinders finding a solution. In addition, many of the toxins which may be implicated in crashes are sporadic in occurrence and are both difficult to detect and hard to remove from the water supply. This paper provides evidence for these toxic effects and suggests ways of reducing the problems.