乌鲁木齐树木叶片汞浓度时空特征及环境意义

城市大气环境由于受人为活动影响,具有较高大气汞浓度和时空分布不均一特征。植被叶片虽具有较强富集大气汞的能力,但能否指示城市大气汞时空变化,目前尚有存疑。本文通过连续监测新疆乌鲁木齐市区内6个采样点5种常见树种叶片,在生长季（2019年5～10月）内的汞浓度,分析树叶汞浓度的时空分布变化特征,进而寻找潜在的最优树种叶片,反演乌鲁木齐大气汞污染程度。结果表明,城市内的局地污染能够显著提高叶片汞浓度;树种叶片对大气汞浓度的敏感性存在明显差异（P<0.01）;落叶阔叶树的叶汞浓度与叶片生长时间呈显著正相关关系（P<0.01）,即叶片在整个生长期不断积累大气汞;而针叶汞浓度一年之内与生长时间无显著关系。考虑到圆冠榆叶片对大气汞浓度敏感性较高且分布范围更广,圆冠榆作为乌鲁木齐城市大气汞的生物监测器较为合适。本研究为研究城市大气汞浓度生物监测提供了典型的案例与借鉴。     

Biodiversity: gaps in knowledge

The Convention on Biological Diversity set conservation of biodiversity on the world agenda. Gaps in knowledge need to be addressed for actions to be effective and sustainable. Gaps include: species diversity, micro-organisms and their ecological roles, ecological and geographical status of species, human capacity to assess and forecast bio-ecological degradation. Requirements for global inventories call for worldwide collaboration. Criteria for setting priorities need to be formulated and agreed.Biodiversity in an eco-geographical region, the southern Mediterranean, is discussed as a case study. Outlines of national actions to contribute to world endeavor are outlined.     

Elemental Concentration in Lichen in Western Anatolia

The deposition patterns of Mn, Fe, Cr, Sb, Zn and As wereinterpreted together with enrichment factor calculations. Samples collected around iron-steel plant had very high concentrations and EF values of Mn, Fe, Cr, Sb and Zn implying that these plants are serious pollution sources in the region. High As concentrations around the settlementareas showed that coal combustion is another important anthropogenic source in the region.     

Delonix regia and Casuarina equisetifolia as passive biomonitors and as bioaccumulators of atmospheric trace metals

The suitability of two common and ubiquitously distributed and exotic ornamental plant species in Nigeria-Delonix regia and Casuarina equisetifolia as biomonitors and as effective bioaccumulators of atmospheric trace metals(Cd,Pb,Zn and Cu) has been evaluated.Bark and leaf samples from these plant species were collected in June and July 2006 at five locations in Benin City.Four of the sampling sites were in areas of high traffic density and commercial activities,the fifth site is a remote site,selected to act as a control and also to provide background information for the metals.The plant samples were collected and processed using standard procedures and trace metals were determined using atomic absorption spectrometer.The bark of the plants was able to bioaccumulate the trace metals,especially Pb which originates from anthropogenic contributions in the city.The Pb range of 20.00-70.00 μg/g measured for the bark samples of D.regia,exceeded the normal plant Pb concentration of 0.2-20.0 μg/g and most Pb data available in literature.The bark of the plants was observed to accumulate more metals compared to the leave,while D.regia was found to be slightly better than C.equisetifolia in trace metal uptake efficiency.Spatial variations in the distributions of Pb and Zn were significant(p 0.05),and the continuous use of leaded fuel in Nigeria was identified as the predominant source of Pb in the atmosphere.     

Assessment of human health risk related to metals by the use of biomonitors in the province of Córdoba, Argentina

The evaluation of metal contents in the environment is of vital importance for the assessment of human exposure. Thus the species Usnea amblyoclada, Ramalina celastri and Tillandsia capillaris were tested as bioaccumulators of transition metals in the urban area of Córdoba city, Argentina. The level of metals on biomonitors was compared to that of total deposition samples. All three species discriminated zones within the urban area of Córdoba city with different pollution levels; they revealed high levels of Zn in the downtown area and confirmed high levels of some transition metals in an industrial area. The correlation analysis revealed that the lichen R. celastri had the highest correlation rates with total deposition samples, suggesting it is a valuable biomonitor of atmospheric pollution. A significant relationship was also observed between respiratory diseases in children and the contents of metal accumulated in R. celastri and T. capillaris, indicating their usefulness when assessing human exposure to metals.