The Incidence of Fungi and Mycotoxins in South Africa Wheat and Wheat-Based Products

This investigation was undertaken to survey the fungal and mycotoxin contamination of South African wheat ranging from that growing in the field to processed wheat products. Samples of wheat were taken from various growing areas in South Africa and screened for fungi and mycotoxins, using a range of methodologies, including chromatography, immunoaffinity/fluorimetry, and cytotoxicity testing. Similar samples were taken from supermarkets and retail outlets in South Africa and analyzed in a similar manner. The result showed that a range of fungi and mycotoxins could be detected in wheat in all these sample types. The major fungal contaminants were Fusarium spp. and their attendant mycotoxins, in particular deoxynivalenol, which is in keeping with the observations made in the rest of the world. An interesting observation was that samples of wheat taken from the field with heavy Fusarium contamination were contaminated with fumonisin B₁, which is not normally associated with this crop. Of more concern were the low but persistent levels of mycotoxins and fungi in wheat-based products sold directly to the public.     

Characterization of PBDEs in soils and vegetations near an e-waste recycling site in South China

The concentration and composition of PBDEs in the soils and plants near a typical e-waste recycling site in South China were investigated. The total concentration of PBDEs (ΣPBDEs) in soil ranged from 4.8 to 533 ng/g dry wt. The ΣPBDEs in vegetation were from 2.1 to 217 ng/g dry wt. For the vegetable, the highest concentration of 19.9 ng/g dry wt. was observed in the shoot of Brassica alboglabra L. BDE 209 was the predominant congener in all samples. In comaprison with other e-waste contaminated sites in China, lower concentrations of PBDEs and higher concentrations of PCBs were observed in both soils and plants suggesting different e-waste types involved in the present study. The PBDEs contaminated vegetables around the e-waste dismantling site may pose a potential health risk to the local inhabitants.     

南海北部海域经济水产品的重金属污染及其评价

调查研究了南海北部海域鱼类、是类、蟹类、头足类和双壳类等５大类经济水产品中的Ｃｕ、Ｐｂ、Ｚｎ、Ｃｄ、Ｃｒ和Ｎｉ。研究结果表明，各类生物的重金属含量差异显著，重金属在鱼虾不同器官组织中的分布是不均衡的。鱼类的重金属含量与其栖息水层有关；除肉食性鱼类的Ｃｄ含量较高小，不同食性鱼类重金属含量间的差异不显著；近海鱼类的重金属含量与河口咸淡水鱼类的重金属含量之间无显著差异；鱼类重金属含量的季节变化不明显。游     

珠江三角洲及南海北部海域表层沉积物中多溴联苯醚的分布特征

自珠江三角洲和南海北部海域采集了66个表层沉积物样品,以研究该区域中PBDEs的含量、分布、来源和在环境中的迁移.研究结果表明,东江和珠江是PBDEs的高污染区,含量为12.7～7361ng·g-1,其中BDE209平均含量为1199ng·g-1,是目前世界上已报道沉积物中含量最高的区域之一.在几乎所有被分析的样品中BDE209都是最主要的同系物.东江和珠江的PBDEs主要来自东莞和广州的本地排放,而西江的PBDEs主要通过大气的传播输入.另一个高污染区澳门水域被验证是珠江三角洲水体环境中有机污染物的“汇”.     

闽南地区自然资源开发利用初探

福建省闽南地区处于南亚热带,为全省纬度最低的一个区。本区自然资源丰富,气候条件优越,是我国东南沿海自然资源尚需深度开发的区域。本区资源开发利用过程中,存在着水土流失严重、生态环境日趋恶化的状况。为了探索本区自然资源的合理利用途径,通过近两年来的调查研究,我们提出了四方面的合理利用途径,对于闽南经济开放区的国土整治和资源开发,具有十分重要的意义。     

冀中南平原区气溶胶标高变化及估算模型研究

作为反映大气气溶胶垂直分布的重要参量,气溶胶标高被广泛应用于气溶胶反演及模型订正研究中.为研究气溶胶标高时空变化规律并构建其简易计算模型,基于2009～2016年气象站点观测资料及MODIS卫星反演数据,利用Peterson模型及多元回归分析对冀中南平原区气溶胶标高进行了估算分析.研究结果表明:区域气溶胶标高夏季最高,...     

南黄海中部E2柱样沉积物来源的稀土元素及微量元素示踪

应用稀土元素地球化学示踪方法,分析了南黄海中部E2柱样的∑REE、∑LREE、∑HREE、∑LREE/∑HREE、δEu和δce的变化特征.结果表明,近200年来南黄海中部沉积物的稀土元素可能均受相同来源控制,稀土元素分布具上陆壳特征.南黄海中部E2柱样和中国东部上地壳的稀土分布模式一致,而与深海沉积物的稀土分布模式相差较大,反映了黄海沉积物和中国大陆壳的亲缘性.近200年来沉积物的δCe和δEu变化不大,且其平均值与上陆壳基本一致,说明近200年来源区的氧化-还原条件和酸碱性可能变化不大,稀土元素主要是由大陆岩石风化和搬运而来,而不是海水提供的.高场强元素丰度及其特征比值的变化幅度不大,与中国东部上地壳一致,指示中国大陆岩石的风化产物是黄海沉积物的主要源区.∑REE与TiO2具有良好的相关性,指示稀土元素与TiO2一样主要来自陆源碎屑物质.     

南亚高压对四川盆地夏季区域持续性O3污染的影响

基于2015~2020年四川盆地臭氧（O₃）浓度监测数据,构建O₃区域性持续性污染过程个例库,并进一步时空匹配高低空气象资料,探究夏季南亚高压系统对四川盆地地面气象要素及O₃污染生成的影响机制.结果表明：（1）2015~2018年四川盆地O₃区域性持续性污染（ORPP）逐年加重,2018~2020年保持相对稳定的污染态势,且ORPP多集中于春、夏两季.盆地中南部成都、重庆、泸州等城市O₃污染形势最为严峻,且高值区逐渐向南北方向转移.（2）基于南亚高压（系统存在率、中心离散度与东西振荡量）对地面气象要素的影响阐释ORPP的生成机制：系统存在率均值偏低且位置偏东时,平均气温、气温日较差及日照时数偏高,相对湿度偏低,利于O₃生成;南亚高压东模态中心显著聚集时,气温日较差与日照时数激增,易造成O₃异常高值;西模态剧烈振荡时,气温日较差、日照时数及相对湿度改变,易使O₃浓度波动.（3）对比清洁期与污染期,南亚高压系统存在率、中心离散度与东西振荡量综合作用于清洁期,而污染期则主要受中心离散度与东西振荡量影响.当南亚高压西模态剧烈振荡与东模态显著聚集配合出现时,极易诱发四川盆地内ORPP二级过程.     

A preliminary investigation on the occurrence and distribution of antibiotic resistance genes in the Beijiang River, South China

The occurrence of antibiotic resistance genes (ARGs) was investigated and quantified in 20 water samples collected in the Beijiang River, South China. Sulfonamide- and tetracycline-resistant bacteria were present in 17 and 14 of the collected 20 samples. For sulfonamide ARGs, sulI and sulII were frequently observed in the Beijiang River. The levels of sulI were higher than sulII (p < 0.05), with the mean values of (1.41 ± 1.12) × 10-2 and (1.58 ± 1.71) × 10-3 copies/16S rDNA, respectively. For tetracycline ARGs, tetG had the highest frequency, 100%, followed by tetA (85%), tetO (85%), tetC (70%), tetX (60%), tetM (40%) and tetQ (20%), while tetE and tetS were not detected in all the samples from the Beijiang River. On the other hand, tetC had the highest concentration, ranging from 8.30 × 10-2 to 13.20 copies/16S rDNA. The poor correlation between ARGs and antibiotic concentrations revealed that the self-amplification and persistence of ARGs were the reasons that made ARGs exist in the water environment even though the antibiotic selecting pressure was absent. Because so few field measurements have been conducted for investigating the levels of ARGs in rivers in South China, this study provides an important insight on better understanding the occurrence and spread of ARGs in such an ecosystem.