沱江流域水系沉积物重金属的潜在生态风险评价

通过对沱江流域水系沉积物的系统研究,查明了重金属元素含量的空间分布特征,进行了潜在生态风险质量评价。研究结果显示,在两支流交汇之前,沉积物中重金属的污染水平从上游到下游呈上升趋势,矿业活动是水环境中重金属的主要来源,两支流交汇之后元素含量有较明显升高,显示两河汇流叠加对沱江下游水系沉积物有较大的影响;与前人研究相比,各元素含量有较明显的增加;沱江水系沉积物中重金属的潜在生态风险水平较低,大多属于轻微生态风险,Cd的潜在生态危害程度最严重;多种重金属的潜在生态风险指数(R1)表明河流重金属污染属于轻微生态危害,其受危害程度由大到小的顺序为:沱江>石亭江>绵远河。     

利用紫露草微核效应检测工业废水技术的研究

利用紫露草微核技术检测废水微核效应,往往会遇到因废水pH值过高、过低,或由于废水成分复杂、毒性大,难以进行微核检测。为此,作者研究了有关的技术,取得了理想的结果。研究结果表明,调节废水pH值会使废水中金属离子价态发生改变而改变其化学形态,所以在进行微核检测时,以不调pH值的原状态废水为最好。废水在一定剂量范围内对紫露草微核具有诱变作用,所以处理剂量要视废水的毒性、pH值的不同而不同。最好在检测前作好预实验,找出处理紫露草花序的适宜剂量;同时还要以四分体中不出现死细胞为宜。     

上海地表灰尘重金属污染的健康风险评价

对上海中心城区文教区、居民区和城市广场等儿童日常活动区域代表样点进行定期采样,共采集48个地表灰尘样品,应用美国EPA人体暴露风险评价方法对地表灰尘重金属进行健康风险评价.结果表明,研究区域地表灰尘重金属污染较为严重,Zn、Pb、Cu和Cd平均值分别为上海市土壤背景值的6~8倍,Cr和Ni超出2~3倍.暴露模型计算表明,重金属慢性每日平均暴露量为手-口接触摄入量＞皮肤吸收量＞吸入空气量,经手-口接触行为直接摄入是儿童地表灰尘暴露风险的主要途径.重金属非致癌风险Pb＞Cr＞Ni＞Cu＞Zn＞Cd,均小于非致癌风险阈值1,对人体不会造成健康危害;致癌重金属致癌风险Cr＞Ni＞Cd,均低于癌症风险阈值,表明不具有致癌风险.     

某省医用电子直线加速器治疗室辐射环境监测分析

通过对省内医用电子直线加速器辐射环境监测,对比不同等级医院医用电子直线加速器辐射防护水平的差异,为放射治疗工作正常开展提供放射防护数据参考,确保放射工作人员、受检者及公众健康安全.按照标准方法采用辐射剂量仪AT1123及中子周围剂量当量仪BH3105E对加速器治疗室周围环境进行光子及中子的监测,采用热释光法对放疗科放射...     

Gamma dose measurement in dwellings of Agastheeswaram Taluk of Kanyakumari district, lying 30 km Radius from Kudankulam nuclear power plant site

Most of the building materials contain naturally occurring radioactive elements, the most important of which are potassium ⁴⁰K and the members of two natural radioactive series, which can be represented by the isotopes of thorium ²³²Th and Uranium ²³⁸U. The presence of these radioisotopes in the materials causes external exposure to the people who live in the building. In addition, the disintegration of Uranium ²³⁸U increases the concentration of radon gas ²²²Rn and of its daughters in the house. So a systematic indoor gamma dose measurement has been performed in the dwellings of Agastheeswaram Taluk of Kanyakumari district, which is lying within the 30 km radius from the upcoming Kudankulam nuclear power plant site. The geometric mean of annual absorbed dose from gamma radiation in dwellings has been found to be 278 nGyh⁻¹. The seasonal variation of indoor gamma dose measurements has also been studied. Significant differences have been observed in dwellings built of different materials such as concrete, tiled, etc.     

德宏州耕作土壤表层重金属含量特征及潜在生态风险评价

利用Hakanson潜在生态危害指数法,对云南省德宏州耕作土壤表层重金属Pb、Cd、Hg、As、Cr和Cu进行分析评价。结果表明,德宏州耕地土壤中Pb、Cd、Hg、As、Cr、Cu含量分别为ND~249、ND~0.68、0.01~0.55、0.04~52.18、ND~195、0.79~64.3 mg/kg。6种重金属元素富集系数Cif均小于1,平均值从大到小依次为CuCdCrPbHgAs,属于轻微污染;单因子潜在生态风险指数Eir均小于40,平均值从大到小依次为CdHgCuAsPbCr,属于轻微生态风险危害;7种土壤利用方式潜在生态危害指数RI均小于150,平均值从大到小依次为菜园胶园蔗园玉米地茶园稻田果园。研究区潜在生态危害水平为轻微危害,不同利用方式重金属元素富集存在差异,局部表现出中度污染现象。总体上,德宏州耕地土壤清洁安全,潜在生态危害以Cd、Hg为主,Pb、Cr危害较小,菜园土壤重金属生态危害风险最高。     

Distribution of aromatic amines,phenols, chlorobenzenes,and naphthalenes in the surface sediment of the Dianchi Lake,China

• The total organic pollutant concentrations in sediment were 27.4-1620 ng/g. • The phenol concentrations were relatively high in the sediment of the Dianchi Lake. • Average total concentrations decreased as follows: Caohai>Waihai>Haigeng Dam. • 1,4-dichlorobenzene, 3- or 4-methylphenol, 1,2,4-trichlorobenzene might be risks. Organic pollutants are widespread environmental pollutants with high toxicity, persistence, and bioaccumulation. Our aim was to investigate the distribution of aromatic amines, phenols, chlorobenzenes, and naphthalenes in the surface sediment of the Dianchi Lake, China. Nineteen surface sediment samples were collected from the Dianchi Lake, and 40 types of organic pollutants were analyzed via gas chromatography–mass spectrometry. The total organic pollutant concentrations in the surface sediment of the Dianchi Lake varied from 27.4 to 1.62 × 10³ ng/g. The concentrations of phenols were much higher than those in other water bodies but still within a controllable range, whereas the concentrations of the other organic pollutant classes were similar or even lower. The detection ratio of 3- or 4-methylphenol was the highest (100.00%) among the pollutants. The average total organic pollutant concentrations decreased in the following order: Caohai (540 ng/g)>the middle of Waihai (488 ng/g)>the edge of Waihai (351 ng/g)>Haigeng Dam (90.4 ng/g). Pearson analysis showed a strong correlation among 1-methylnaphthalene, 2-methylnaphthalene, 1,3-dinitronaphthalene, and 1,4-dinitronaphthalene (p<0.01). Caohai, the north lakeshore of Waihai and the south of Waihai showed higher risk because of high concentration; meanwhile, 1,4-dichlorobenzene, 3- or 4-methylphenol and 1,2,4-trichlorobenzene were more likely to cause risks.     

Assessment of health risk from organochlorine pesticides residues in high-fat spreadable foods produced in Poland

Currently, butter and margarine are food products attracting wide customer interest. Every day, consumers around the world buy these products for human consumption. Butter is obtained from milk fat, while margarine is derived from vegetable oils. The content of organochlorine pesticide (OCP) residues was examined in both types of these high fatty products. A gas chromatograph with MSD (HP 5973) detector was used for the determination of pesticides such as α-HCH, β-HCH, γ-HCH, DDT, DDD, DDE, aldrin, dieldrin, endrin, heptachlor and heptachlor epoxide. The examined products had diverse concentrations of the analyzed compounds. Visible was the division based on the origin of the product, which might be composed of animal or vegetable fats. The research has revealed the presence of OCP residues in all examined spreads. Quantities of organochlorine compounds did not pose an immediate danger to the consumers’ health. Human and environmental health risk assessment was carried out by the estimation of lifetime average daily dose (LADD) and non-carcinogenic health hazard quotient (HQ). Total estimated LADD ranged between 1.3 × 10^?5 and 3.1 × 10^?5 mg kg^?1 d^?1 for butter, and 1.9 × 10^?6 and 4.6 × 10^?6 mg kg^?1 d^?1 for margarine and mix spread. The HQ ranged between 1.1 × 10^?4 and 3.7 × 10^?4 for butter, and 1.4 × 10^?5 and 9.0 × 10^?6 for margarine and mix spread for adults. These estimated HQs were within the safe acceptable limits, indicating a negligible risk to the residents of the study area.     

Knowing fire incidence through fuel phenology: A remotely sensed approach

Fire is a basic ecological factor that contributes to determine vegetation diversity and dynamics in time and space. Fuel characteristics play an essential role in fire ignition and propagation; at the landscape scale fuel availability and flammability are closely related to the vegetation phenology that directly affects wildfire pattern in time and space. In this view, the annual normalized difference vegetation index (NDVI) profiles derived from high temporal resolution satellites, like SPOT Vegetation, represent an effective tool for monitoring the coarse-scale vegetation seasonal timing. The objective of this study thus consists in quantifying the explanatory power of multitemporal NDVI profiles on the fire regime characteristics of the potential natural vegetation (PNV) types of Sardinia (Italy) over a 5-year period (2000-2004). The results obtained show a good association between the NDVI temporal dynamics of the PNV of Sardinia and the corresponding fire regime characteristics, emphasizing the role of the bioclimatic timing of the vegetation in controlling the coarse-scale wildfire spatio-temporal distribution of Sardinia. By providing a sound phytogeographical framework for describing different wildfire regimes, PNV maps can thus be considered helpful cartographic documents for fire management strategies at the landscape scale.     

环境中氡辐射水平及控制措施分析

近年来,随着社会经济的发展,居民生活不断提高,对居室进行美化装修既成一种时尚。然而由安装（选用劣质材料）而引发的居室辐射水平超标,特别是氡辐射超标问题,已越来越受到人们的关注。为使人们对辐射环境有一基本认识和了解,作者根据多年从事辐射环境监测的经验,对环境空气中氡的性质、来源、辐射水平、危害及室内氡浓度控制措施作一简单分析介绍。