Heavy metals in rice and garden vegetables and their potential health risks to inhabitants in the vicinity of an industrial zone in Jiangsu, China

Contamination of soil and agricultural products by heavy metals resulting from rapid industrial development has caused major concern. In this study, we investigated heavy metal (Cu, Zn, Pb, Cr, Hg and Cd) concentrations in rice and garden vegetables, as well as in cultivated soils, in a rural-industrial developed region in southern Jiangsu, China, and estimated the potential health risks of metals to the inhabitants via consumption of locally produced rice and garden vegetables. A questionnaire-based survey on dietary consumption rates of foodstuffs showed that rice and vegetables accounted for 64% of total foodstuffs consumed, and over 60% of rice and vegetables were grown in the local region. Average concentrations of Cr, Cu, Zn, Cd, Hg and Pb were 0.75, 2.64, 12.00, 0.014, 0.006 and 0.054 mg/kg dw (dry weight) in rice and were 0.67, 1.18, 4.34, 0.011, 0.002 and 0.058 mg/kg fw (fresh weight) in garden vegetables, respectively. These values were all below the maximum allowable concentration in food in China except for Cr in vegetables. Leafy vegetables had higher metal concentrations than solanaceae vegetables. Average daily intake of Cr, Cu, Zn, Cd, Hg and Pb through the consumption of rice and garden vegetables were 5.66, 16.90, 74.21, 0.10, 0.04 and 0.43 μg/(kg·day), respectively. Although Hazard Quotient values of individual metals were all lower than 1, when all six metal intakes via self-planted rice and garden vegetables were combined, the Hazard Index value was close to 1. Potential health risks from exposure to heavy metals in self-planted rice and garden vegetables need more attention.     

石灰干化污泥稳定后土壤中Pb、Cd和Zn浸出行为的研究

以人工制备Zn、Pb、Cd污染土壤为研究对象,采用城市污水处理石灰干化污泥作为稳定剂,对污染土壤进行稳定化处理,并采用TCLP、SPLP、去离子水浸提和优化的BCR连续提取法对稳定化效果进行分析和评价.结果表明,单独使用石灰干化污泥,TCLP浸出浓度随着干化污泥质量分数的增加而显著减少,干化污泥的质量分数为40%时,稳定化率最大为Zn-99.54%、Pb-99.60%、Cd-99.85%.SPLP和去离子水浸出评价稳定效果时,Pb和Zn在加入质量分数10%和20%的干化污泥时浸出明显降低,但在加入30%和40%时由于在强碱条件Pb和Zn会再溶出,导致稳定效果变差.为了恢复植物生长功能,经过FeSO4和H3PO4调节pH后,石灰干化污泥稳定过的土壤pH有效降低,同时FeSO4和H3PO4有利于促进Pb和Zn的稳定效果.经稳定化后,土壤中的重金属可交换态降低,限制了土壤重金属的迁移.该研究结果表明石灰干化污泥可以再利用,应用于重金属污染土壤的稳定化修复中,并能改善稳定后土壤适宜植物生长的理化性质.     

上海白龙港排污口附近潮滩沉积物中重金属总量及其化学形态分析

利用Tessier分级提取法依次提取了上海白龙港排污口附近潮滩沉积物中几种重金属元素的化学形态 ,结果表明 :Cu、Pb、Fe、Zn、Cr在沉积物中均以残渣态为主 ,Mn以碳酸盐结合态为主 ,占到总量的 5 0 %左右 ;秋季碳酸盐结合态重金属向铁锰氧化物结合态发生形态迁移与转化 ,在低潮滩沉积物中 ,碳酸盐结合态重金属发生分解以后 ,一部分向上覆水发生了迁移和扩散 ;Cu、Pb、Fe、Mn重金属元素之间具有良好的相关性 ,Zn、Cr在沉积物中也表现出相似的化学行为。     

本溪市空气质量控制方案实施评估

利用攻坚计划行动方案所涉及的污染源排放清单和扩散模型计算了环境中的污染物浓度，并将污染物浓度／人口分布和剂量一反应函数联系起来，根据方案实施前后污染物排放量的变化，分析对人体健康影响的变化，将损害的减少程度进行货币化计算，继而将影响成本和削减方案成本进行比较，评估方案的效益。     

城市土地利用下的植物物种资源特征分析

根据对前联邦德国卡尔斯鲁厄市城市自生植被的调查资料,分析了城市植物区系的特征及其与人类活动影响的关系。结论为：①城市植物区系在优势科组成和生态特征方面与其所在地区自然植被明显不同,并在城市之间表现出较大的相似性；②人类活动和城市热岛效应对城市植物区系及其生态特征的作用明显；③城市土地利用和城市绿地管理对许多物种的生存构成威胁     

海岸带综合管理的区域性特征及其发展机制

在综述国内外海岸带综合管理（ＩＣＺＭ）进展的基础上，以人地关系地域系统为理论基础，论述了ＩＣＺＭ的区域性特征。从地理学看，海岩带是一个开放的复杂的巨系统，有着明确的边界范围，具有可度量性。从管理学看，其模式的多样性反映了区域自然条件和社会条件的差异性，是人地关系双向运动平衡协调的结果，从社会学看，其战略实施先在地方级别上应用，在获得足够的经验或成熟之后，再推广到地区级、省级和国家级的计划中去的空间     

二噁英的毒性及其对人体健康影响的研究进展

二噁英(dioxin),是一类毒性很强的三环芳香族有机化合物。近年来随着二噁英污染事件的频频发生,人们对二噁英的危害也日益关注。文章从二噁英的结构、理化性质、检测方法、毒性机理以及它对人体健康的影响等方面,对近年来已取得的成果进行了综述,并对今后有效的控制管理措施提出了相应的建议。     

Ecological service assessment of human-dominated freshwater ecosystem with a case study in Yangzhou Prefecture, China

Freshwater ecosystems provide a host of services to humanity. These services are now rapidly being lost, not least because of the inability of making the impacts measurable. To overcome this obstacle, assessment frameworks for freshwater ecosystem services are needed. A simple water equivalent framework to assess the ecological services provided by freshwater ecosystems was developed in this study. It translated the occupation of freshwater ecosystem services into biologically freshwater volumes and then compares this consumption to the freshwater throughput, that is, the ecological capacity available in this region. In this way, we use the example of Yangzhou Prefecture, to account the main categories of human occupation of water ecosystem services. The result showed that there is a huge gap between the consumption and the supply of freshwater ecosystem services. This must encourage local government to make land-use and water management decisions both economically rational and environmentally sound.     

金刚石膜电极对有机污染物的电催化特性

研究了化学气相沉积法(CVD)制备得到的掺硼金刚石膜电极的物理性质和电化学性能.用扫描电子显微镜(SEM)法表征了金刚石膜的表面微观结构,采用循环伏安法和交流阻抗法研究了电极的电化学性质.结果表明,金刚石薄膜表面形态为复晶结构,颗粒大小均匀,掺硼后使电极具有良好的导电性能.金刚石膜电极具有很宽的电势窗口,在酸性、中性和碱性3种介质中分别为4.3V、4.0V和3.0V.同时,金刚石膜电极的背景电流非常低,为-9×10^-6～5×10^-7A.在铁氰化钾电解液中,金刚石膜电极表面在反应过程中始终保持良好的活性,在表面进行的电化学反应具有良好的准可逆性,其电极动力学主要是受扩散过程所控制.金刚石膜电极对有机污染物的催化氧化作用具有选择性.与铂电极和石墨电极相比,金刚石膜电极对苯酚、硝基苯等芳香化合物的催化氧化强烈,氧化过程较为简单、彻底.这些性质表明金刚石膜电极是一种非常适用于环保处理的新型电极.     

骆马湖表层水体中32种PPCPs类物质的污染水平、分布特征及风险评估

为评价骆马湖水体中药品和个人护理品(PPCPs)的污染水平、空间分布特征及生态风险,利用高效液相色谱-串联质谱测定了骆马湖水体中22个采样点的32种PPCPs.结果表明,骆马湖表层水体中共检出了23种PPCPs,总浓度范围为892~1 536 ng·L~(-1),其中浓度最高的为诺氟沙星(256~707 ng·L~(-1)),其次是酮洛芬(85~438 ng·L~(-1))、安赛蜜(101~290 ng·L~(-1))及萘普生(1.9~112 ng·L~(-1)).不同采样位点的PPCPs浓度存在一定的空间差异,呈现湖东北部地区较高,西南部地区较低的趋势.房亭河入湖口处PPCPs浓度较高,嶂山闸出湖口处浓度较低.对13种药物类PPCPs生态风险评价结果表明,诺氟沙星RQs为0.26~0.72,对于骆马湖水生生态系统表现为中风险,吉非罗齐在大部分采样点RQs0.01,表现为低风险,其余的化合物RQs0.01未表现出生态环境风险.采用简单叠加模型计算PPCPs的联合毒性风险熵范围为0.29~0.75,整体上看,骆马湖PPCPs对于水生生物表现出中风险.对6种PPCPs的人体健康风险结果表明,RQs均小于1,表明骆马湖PPCPs对人体健康无直接风险.