广东鼻咽癌高发区土壤-作物系统重金属迁移特征及健康风险评价

为揭示广东鼻咽癌高发区土壤-作物系统重金属迁移特征及健康风险,选择鼻咽癌高发区四会市农田系统为研究对象,采集了稻谷和油麦菜样品及对应的土壤样品,在分析土壤和农作物样品中As、Cu、Hg、Mn、Ni、Pb和Cd这7种重金属含量及化学形态的基础上,采用统计学分析、污染指数评价法、迁移系数法和健康风险评价法等开展土壤-作物系统重金属的迁移特征及健康风险评价.结果表明,研究区农田土壤基本清洁（P_综=0.43）;土壤中Cd和Mn主要以生物可利用态存在,Hg主要以潜在可利用态存在,As、Cu、Ni和Pb主要存在于残渣态中.研究区油麦菜基本安全（P_综=0.48）,稻米污染指数（P_综=7.66）高于油麦菜,主要污染元素为Pb（PI=10.25）.研究区土壤中Cd和Cu更容易被油麦菜吸收富集,Cd、Cu和As更容易被稻米吸收富集,农田土壤重金属污染防治工作应特别关注Cd和Cu污染,对于稻田应同时关注As的污染.研究区成人和儿童食用油麦菜的非致癌风险指数（HI）均小于1,总致癌危害指数（Risk）均值小于1×10^-4,食用当地油麦菜的人体健康风险在可接受范围内.当地成人和儿童食用稻米的平均HI指数大于1,主要非致癌因子为Pb,食用稻米的Risk指数均高于1×10^-4,主要致癌因子为As,研究区人群食用当地稻米具有一定的健康风险,且对成人的威胁大于儿童.稻米中的As可能与当地鼻咽癌高发有关.     

Persistent organic pollutants in environment of the Pearl River Delta,China: an overview

In the Pearl River Delta of China, the rapidly developing industrial and agricultural activities, municipal development and use of chemicals caused serious environmental problems. This report summarizes the published scientific data on POPs in the environment of the Pearl River Delta, including the levels of POPs in the air, water, soil, river and estuarine sediments, the marine organisms like fish and shellfish in this region. The data preliminarily reveal the state of contamination in this region and give insight into the fate of POPs in this sub-tropical area. However, most research in this area is limited to a few kinds of POP compounds.     

鼠李糖脂对微生物菌剂降解石油的影响

以石油烃降解微生物菌剂和铜绿假单胞菌株A6为对象,考察不同浓度鼠李糖脂对菌剂细胞表面疏水性、原油降解性能和微生物生长的影响,采用GC-MS分析石油中正构烷烃组分的降解情况。结果表明,低浓度鼠李糖脂就可提高菌剂细胞的表面疏水性和原油降解效果。以250mg／L添加组最明显,第7天疏水性达最高,为58．6％,比对照组提高约26．2％;降解第15天原油降解率达71．6％,分别比对照组和TW20组提高16％和13．3％。GC-MS结果显示鼠李糖脂对高碳数烷烃的降解作用大于低碳数烷烃,正二十三烷和正三十三烷的降解率分别较对照提高了21．5％和33．7％。菌剂对奇数碳烷烃的降解效果优于偶数碳烷烃。鼠李糖脂分别使菌剂中细菌、放线菌和霉菌的最大生物量提高了5．7、2．4和1．8倍。鼠李糖脂对微生物细胞疏水性和生物量的提高与石油降解效果正相关。     

辽宁省区域性空气污染的天气分型

应用2003-2004年主要污染物浓度和气象资料,对辽宁省全年的PM10产生的区域性3级空气污染进行环流分型,按污染源划分为冬季煤烟型、春季沙尘型和夏秋大雾型.其中冬季煤烟型又分为长白山高压地形槽型、高压内部均压场型、东北高压脊,西部倒槽型、蒙古高压前均压场、蒙古低压前均压场、高压内部小范围均压场型6个型;春季沙尘型分为东北低压型、南大风型和干冷锋北大风型;夏秋大雾型分为低压槽型和低压前均压场.上述类型几乎概括了近两年PM10 3级污染的所有个例,为大气环境质量预报、总量控制等提供依据.     

Unusual thermal properties of graphene origami crease:A molecular dynamics study

Graphene is a two-dimensional material that can be folded into diverse and yet interesting nanostructures like macro-scale paper origami.Folding of graphene not only makes different morphological configurations but also modifies their mechanical and thermal properties. Inspired by paper origami, herein we studied systemically the effects of creases, where sp² to sp³ bond transformation occurs, on the thermal properties of graphene origami using molecular dynamics(MD) simula...     

Temporal dynamics of microcystins in two reservoirs with different trophic status during the early growth stage of cyanobacteria

Environmental Science and Pollution Research - Harmful cyanobacterial blooms are increasing in frequency and severity, which makes their toxic secondary metabolites of microcystins (MCs) have been...     

Predicting the effect of promotion measures on waste separation behavior: a case study in Da Nang City,Vietnam

Journal of Material Cycles and Waste Management - Recycling is one of the priority solutions for reducing the amount of waste entering landfills. To achieve high rates of recycling, citizens are...     

PM2.5-bound phthalates and phthalate substitutes in a megacity of southern China: spatioseasonal variations,source apportionment,and risk assessment

Environmental Science and Pollution Research - Plasticizers are ubiquitous pollutants in the environment, whereas few efforts have been made to elucidate their emission sources in the atmosphere....