城市环境变化对银杏树轮中铅含量的影响

为更好了解四川省宜宾市环境的动态变化状况,选择当地银杏树轮为材料,分别选取远郊、近郊与城区的3组样品,对其进行室内处理与消解,而后运用原子吸收分光光度计,对银杏树轮中的铅含量进行测定,对远郊、近郊与城区的铅含量变化情况开展系统化分析。结果显示,城区环境对银杏树轮铅含量影响最大,离城区越远影响越小。要明显减小城市Pb等重金属污染,除了工业合理布局和改造,进行燃料改进,新能源车辆替代传统车辆,回收利用含Pb等废品,做到污染物资源化。     

十二种绿化树木叶片硫、铅、铜含量分析

以悬铃木、国槐、白蜡、广玉兰、女贞、石楠、大叶黄杨、小叶女贞、海桐、雪松、圆柏、龙柏12种新乡市道路绿化树木为试材,对新乡市12种道路绿化树木叶片硫、铅和铜的含量进行分析,研究了绿化树木叶片富集大气污染物的差异性。结果表明:除广玉兰和女贞叶片硫含量秋季比春季略有减少外,所有供试绿化树种叶片的硫、铅、铜含量随春、秋季节变化呈递增趋势,硫、铅和铜的递增范围分别为18%~216%、4%~385%和27%~334%;与清洁区相比较而言,污染区域所供试的所有绿化树木叶片污染物硫、铅和铜的含量都较高,其变化幅度范围分别为9%~223%、37%~390%和85%~374%。根据绿化树木叶片污染物含量的综合分析,将其分成3类,第1类以雪松和广玉兰为代表,叶片中含污染物硫、铅、铜的量较高;第2类包括白蜡、女贞、悬铃木和大叶黄杨,叶片中3种污染物含量居中;龙柏、国槐、小叶女贞、圆柏、海桐和石楠叶片硫、铅和铜的含量相对较低,归为第3类。运用隶属函数法对不同类型绿化树种叶片硫、铅、铜含量进行综合分析,结果表明常绿乔木叶片综合污染物含量最高,针叶树种次之,其次是落叶乔木,常绿灌木最低。     

不同加工程度对稻米中铅含量的影响

通过对一系列稻谷不同加工程度样品的铅含量检测试验,探讨加工程度对粮食铅含量的影响.试验结果表明,加工程度对稻谷铅含量降低的影响仅为35.1％.经砻谷碾白具有一定的去毒效果,但效果仅限于铅含量轻微超标的粮食,对于铅含量严重超标的粮食,控制其含量还是应该从种植环节入手,控制土壤和水源污染.     

吉林地产野生蔬菜中铅含量的测定

采用原子吸收分光光度法对四种吉林地产野生蔬菜中铅的含量进行了测定，其含量均在2×10-6以下。结果表明，野生蔬菜因其受工业三废、汽车尾气等污染少，其铅含量显著低于农田蔬菜，而且野菜中其它营养元素也非常丰富，因此野生蔬菜必将成为我们日常生活中最理想的蔬菜食品。     

茶树与茶园土壤的铅含量及分布特征

采用火焰原子分光光度法,对不同茶园的茶树树体及其土壤样品的铅含量及其分布进行测定.探讨树体及土壤中铅的分布状况,并以富集系数(BAF)为指标对茶树吸收累积铅的能力进行评价.结果表明,茶树新梢与树体铅含量平均值分别为2.26 mg/kg和9.43 mg/kg;茶树各部位铅含量顺序为:侧根(15.37 mg/kg)＞主根(...     

香榧和山核桃中铅含量水平及富集原因分析

在浙江香榧和山核桃生产基地、超市和农贸市场实地抽样检测,对数据进行统计分析,研究浙江省香榧和山核桃中铅含量水平。香榧有效样本数158个,铅含量平均值0．113mg／kg,符合NY5324--2006（（无公害食品常绿果树坚果》标准要求（铅≤0．2mg／kg）,含量范No．034～0．382mg／kg;山核桃有效样本数216个,铅含量平均值0．211mg／kg,符合NY5307--2005《无公害食品落叶果树坚果》标准要求（铅≤0．4mg／kg）,含量范围0．013—0．409mg／kg。     

Influence of Montmoriilonite Nanocomposite on Tissue Levels of Lead and Blood Biochemical Parameters in Pigs Exposed to Lead1

ABSTRACT： Eighteen （Duroc x Landrace x Yorkshire） castrated boars, 55 days of age and weig- hing approximately 19 kg, were used to investigate the effects of montmorillonite nanocomposite on tissue levels of lead as well as changes in blood biochemical parameters in pigs fed lead contaminated diets. The barrows were randomly assigned to one of three treat- ments （n = 6） including a control which were fed a basal diet based on corn and soybean meal. The re- maining two groups were fed the basal diet supple- mented with 10 mg/kg lead either with or without 0.5% montmorillonite nanocomposite for 50 days. Pigs treated with lead had significantly increased lev- els of lead in their tissues. Lead accumulated in all tis- sues of the body with the highest accumulation found in the hair. When montmorillonite nanocomposite was given along with lead, tissue concentrations of lead did not differ from the control. Fecal excretion of leadincreased significantly in lead-exposed pigs treated with montmorillonite nanocomposite. A progressive and appreciable accumulation of lead was seen in blood with a concomitant increase in zinc protopor- phyrin levels during the course of treatment. Howev- er, zinc protoporphyrin levels did not differ from the control when montmorillonite nanocomposite was ad- ministered along with lead. The activity of ~-amino le- vulinic acid dehydratase in blood was significantly in- creased in lead treated pigs compared with the con- trol. However, in pigs treated with lead and montmo- riltonite nanocomposite in combination, the activity of δ-amino levulinic acid dehydratase was similar to con- trol pigs. Our results indicate that montmorillonite nanocomposite treatment of pigs exposed to lead re- suited in reduced lead concentrations in body tissues. It appears that montmorillonite nanocomposite func- tions by increasing fecal excretion of lead.     

泰山茶树铅含量与茶园土壤铅含量的相关性分析

本试验以泰山茶产区的茶树鲜叶、茎、根及土壤为材料,测定了2015—2017年其铅(Pb)含量的变化,以分析探明泰山茶茶园土壤铅含量与树株中铅含量的关系。结果表明,泰山茶产区30个样点的土壤全铅含量均处于安全水平;从各样地来看,泰山区省庄镇小津口村(S2)和叶家庄村(S4)的土壤全铅含量一直保持较高水平,泰山区省庄镇刘家庄村(S9)和肥城市老城街道办事处张花峪村(S29)则保持较低水平;铅在茶树体内的积累量大致呈现为根系>茎>叶,且茶树鲜叶内铅含量处于正常水平。分析表明,泰山茶树体内的铅含量与茶园土壤铅含量无显著相关性。     

土壤水稻体系总铅含量的测定及其相关性研究

本文对韶关地区土壤及其水稻不同部位的铅含量进行了采样测定．分析了水稻中重金属铅含量与其土壤的关系。结果表明。水稻不同部位中铅的含量不尽相同,其根、茎、籽粒及叶中的铅含量依次为：根〉茎〉籽粒〉叶,且与土壤中的铅含量呈正相关．说明水稻中金属铅含量与其生长环境密切相关,水稻对金属铅具有一定的富集性。为土壤的使用、修复处理及水稻生长机制的研究提供了借鉴。     

园林灌木对城市环境中镉和铅吸收积累作用研究

测定了南京城市不同功能区12个取样点的园林灌木中茎和叶片的镉及铅的含量。结果表明:测定的20种园林灌木中,毛鹃、海桐、珊瑚树、圆柏等对镉或铅的吸收积累能力较强;彩叶灌木中红花檵木对环境镉积累能力较强,而红叶石楠对环境铅的积累能力相对较强;利用污染指数和重金属含量平均值可以比较不同环境的污染程度。