Advance in the toxic effects of petroleum water accommodated fraction on marine plankton

Recently, the impact of petroleum pollution on marine plankton has been complemented by a great concern. This review summarizes the reports about toxic effects of oil water accommodated fraction (WAF) on marine phytoplankton, zooplankton and early life stage of animal. For the oil WAF, toxicants are mainly composed of the aromatic hydrocarbons, such as the benzene hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) with 2–5 rings. The oil WAF, especially the PAHs, can be accumulated in plankton due to their great lipophilic abilities, and thus elicites various deleterious effects. Toxicological tests show that marine plankton is very sensitive to the petroleum WAF, as the order of median effective/lethal concentration is merely μg/L or mg/L. There are species and developmental stages differences of plankton tolerance to petroleum WAF, and the toxicity of different oil WAF is various. Generally, its toxicity enhances with increasing carbonic chain length and benzene ring number. Many studies on the acute and sub-acute toxic effects of oil WAF have been done, however few researches on its chronic toxic effects has been carried out till now. Besides, most reports focused on the levels from molecule to individual, though very little work of petroleum toxic effects has ever been performed on the marine plankton population or community levels. Therefore, it is necessary to continue these studies in future.     

鸡桑药共生模式库区土壤养分变化及流失风险

密云水库是北京市主要地表水源地,为了有效防控水源保护区坡耕地以氮磷流失为主的农业面源污染,开展污染防控植物篱种植区散养和单独喂养油鸡试验研究;采集两种模式区土壤和散养模式区饲用桑植物样品,测定氮磷钾养分含量,分析土壤养分变化规律及其流失风险,建立经济有效种养生态防控模式。结果表明,与对照相比,两种油鸡养殖模式区土壤有机质、全氮、速效氮磷钾及硝态氮含量都呈显著或极显著性地升高,促进了散养共生模式区饲用桑和药用植物的生长,增加了对土壤养分的吸收;受养殖密度的影响,60只/666.7m2高密度油鸡喂养模式区或散养集中活动区有机质、全氮、全磷含量显著高于散养活动较少低密度区;受地表径流的影响,散养共生模式区坡下部油鸡少活动区域土壤速效氮磷钾含量与上部活动较多区域相比分别升高20.3%、71.9%和21.9%。喂养模式区承载粪便氮磷环境负荷分别为189 kg/hm2和84.8 kg/hm2,超过欧盟农田氮限量标准170 kg/hm2和粪便年施磷限量80 kg/hm2,具有较大的流失污染风险;20只/666.7m2低密度散养模式区承载粪便氮磷负荷分别为75.6 kg/hm2和33.9 kg/hm2,远小于环境限量标准,具有较小的流失污染风险。饲用桑与药用植物间作植物篱种植区散养油鸡排泄粪便矿化分解提供了植物养分资源,促进它们的生长,形成发达根系系统又可有效阻截模式产生有机物和氮磷流失,同时该模式提供了散养油鸡饲料资源。以上结果说明,桑树/药用植物/低密度散养油鸡是一种有效的农业面源污染生态防控共生模式,资源循环利用效率高,生态环境和经济效益好。     

Atmospheric nitrogen deposition in world biodiversity hotspots: the need for a greater global perspective in assessing N deposition impacts

Increased atmospheric nitrogen (N) deposition is known to reduce plant diversity in natural and semi‐natural ecosystems, yet our understanding of these impacts comes almost entirely from studies in northern Europe and North America. Currently, we lack an understanding of the threat of N deposition to biodiversity at the global scale. In particular, rates of N deposition within the newly defined 34 world biodiversity hotspots, to which 50% of the world's floristic diversity is restricted, has not been quantified previously. Using output from global chemistry transport models, here we provide the first estimates of recent (mid‐1990s) and future (2050) rates and distributions of N deposition within biodiversity hotspots. Our analysis shows that the average deposition rate across these areas was 50% greater than the global terrestrial average in the mid‐1990s and could more than double by 2050, with 33 of 34 hotspots receiving greater N deposition in 2050 compared with 1990. By this time, 17 hotspots could have between 10% and 100% of their area receiving greater than 15 kg N ha^?1 yr^?1, a rate exceeding critical loads set for many sensitive European ecosystems. Average deposition in four hotspots is predicted to be greater than 20 kg N ha^?1 yr^?1. This elevated N deposition within areas of high plant diversity and endemism may exacerbate significantly the global threat of N deposition to world floristic diversity. Overall, we highlight the need for a greater global approach to assessing the impacts of N deposition.     

植物的臭氧污染胁迫效应研究进展

近地面空气中的臭氧(O₃)属于二次污染物,是由氮氧化物(NO_x)和挥发性有机物(VOCs)等前体物在一定的环境条件下形成的。近年来,全球受O₃污染的区域增加,污染程度也日趋严重。O₃污染对植物的危害引起了国内外研究人员的广泛关注。众多研究发现,不同植物对O₃的敏感性不同,其大小主要取决于植物自身的特性及环境因素;O₃污染降低植物的净同化作用,减缓植物生长,改变同化物的分配,可对物种间的相互关系以及生态系统结构产生深远影响。该文在综述了国内外研究进展的基础上,提出我国在O₃污染研究领域应深入研究以下几个方面:1)选育具有对O₃污染抗性较强的植物尤其是作物品种;2)深入研究减轻O₃污染对植物危害的栽培管理措施;3)加强研究O₃污染对我国自然生态系统的影响;4)研究植被在治理O₃污染中的积极作用。     

广东省水质现状及驱动因素

水质现状评估及其驱动因素分析是实现水生态保护、水资源利用和水污染治理的关键,对于水生态系统的可持续发展具有重要意义。以广东省七大流域为研究区,基于2019-2020年间的溶解氧（DO）、透明度（SDD）、悬浮物（SPM）、叶绿素a （Chla）、氨氮（NH₃N）、总氮（TN）、总磷（TP）7个指标的水质监测数据,综合运用单因子指数法（SI）和综合水质指数（WQI）评价方法,分丰水期（N=66）和枯水期（N=54）评估研究区的水质现状,并探讨水质参数与地形、气象、社会经济和土地覆被类型等驱动因素之间的相关关系。SI评估结果显示广东七大流域主要以工业污水、农业面源等造成的Chla和TN浓度超标、部分水体富营养化严重为主,同时伴有溶解氧浓度偏低的问题;WQI评估结果显示研究区有57%以上的采样点属于中等以下水质。Chla、SPM、NH₃N和TP浓度具有显著的季节和驱动因素差异：丰水期的Chla和TP浓度低于枯水期,但SPM和NH₃N浓度高于枯水期。枯水期DO、TN和WQI的显著性影响因子为丰水期的1/3左右;这种季节差异可能是流域内降雨、营养盐负荷和土地覆被类型导致的复杂地表径流及面源污染所致。珠江三角洲河网区、粤西诸河、韩江下游以及粤东诸河练江流域的水质问题突出。未来水生态系统的可持续发展研究可以借助长时间序列、多频次、高分辨率的遥感监测手段和多种数值模拟方法以及常规水质评估模型,探讨气候变化、河岸带产业结构和流域土地利用方式对面源污染的影响,以进一步厘清降雨强度、三产结构和土地利用方式转变对区域水质变化的影响。     

Biomagnetic monitoring of urban air pollution using moss bags (Sphagnum girgensohnii)

Active moss biomonitoring is widely applied in polluted areas for monitoring of airborne particle-bound trace element pollution. This study explored the suitability of the moss Sphagnum girgensohnii for biomagnetic monitoring in cities. To this end S. girgensohnii moss bags were exposed at three different microenvironments characterized by heavy traffic – street canyons, a city tunnel and parking garages during the summer and autumn of 2011 in the city of Belgrade. The ferro(i)magnetic PM fraction in the moss samples was quantified by Saturated Isothermal Remanent Magnetization (SIRM) and the measured values were compared with the trace element concentration in the moss samples. SIRM values were significantly different across the considered urban microenvironments. Moreover, a high correlation between moss SIRM values and concentrations of Al, Ba, Co, Cr, Cu, Fe, Ni and Pb was found. These results demonstrate that moss bags can be effectively applied for biomagnetic monitoring of the spatio-temporal distribution of road traffic and vehicles derived pollutants in urban areas.     

基于通量分析方法的河川型水库生态屏障区位设计

区位选择是水生态屏障研究及建设过程中面临的重要科学问题.针对河川型水库入流方式多样、地形起伏大的特征,本研究从水生态屏障的非点源污染去除功能出发,提出一种基于通量分析的河川型水库生态屏障区位选择方法.以我国三峡库区为例,选择库区典型研究区运用该方法进行生态屏障区位研究.结果表明: 按照三峡库区沿岸100 m宽度的设计方案,研究区内水生态屏障作用不能得到有效发挥,其中,最佳功能区仅占设计面积的11%,无效区占设计面积的10%,流域内79%的总氮与93%的总磷集中在占生态屏障区总面积21%的区域进入水库.根据污染物通量及流量通量过程,可提取出高污染通量汇流区域及高污染物浓度区,根据保护目标,分别对应开展以污染物总量削减及污染物浓度达标的生态工程措施.采用该方法可充分考虑地形对污染物质通量的影响,划分出水生态屏障的重点保护区域,能有效解决河川型水体的水生态屏障区位设计问题.     

Assessment of occupational exposure to PAHs in an Estonian coke oven plant- correlation of total external exposure to internal dose measured as 1-hydroxypyrene concentration

The exposure of cokery workers to polynuclear aromatic hydrocarbons at an Estonian oil shale processing plant was assessed by using occupational hygiene and biomonitoring measurements which were carried out twice, in midwinter and in the autumn. To assess the external dose of polynuclear aromatic hydrocarbons, pyrene and benzo[a]pyrene concentrations were measured from the breathing zone of workers during a workshift. Skin contamination with pyrene and benzo[a]pyrene was assessed by skin wipe sampling before and after the workshift. As a biomarker of overall exposure to polynuclear aromatic hydrocarbons, and as an integral of all absorption routes of pyrene, 1-hydroxypyrene concentration was measured from post shift urine samples. Of the personal air samples, 18% exceeded the Finnish threshold limit value of benzo[a]pyrene (10 μg m^-3). Mean value (two separate measurements together) for benzo[a]pyrene was 5.7 μg m^-3 and for pyrene, 8.1 μg m^-3. Based on skin wipe sample analyses, the skin contamination was also obvious. The mean value of benzo[a]pyrene in the samples collected after the shift was 1.2 ng cm^-2. Benzo[a]pyrene was not found in control samples. The mean value of urinary 1-hydroxypyrene concentration was 6.0 μmol mol^-1 creatinine for the exposed workers and 0.5 μmol mol^-1 creatinine for the controls. This study undoubtedly shows the usefulness of 1-hydroxypyrene as an indicator of internal dose of polynuclear aromatic hydrocarbons. It can be concluded that the cokery workers at the Kohtla-Järve plant are exposed to high concentrations of polynuclear aromatic compounds, and the exposure level is considerably higher during the winter measurements.     

淹水和干旱生境下铅对芦苇生长、生物量分配和光合作用的影响

芦苇(Phragmites australis)作为典型的根茎型多年生湿地植物, 具有广泛的环境耐受性。该研究采用盆栽实验, 采取裂区实验设计, 水分处理为主区, 包括淹水和干旱两个水平, 铅(Pb)为副区, 包括0、500、1500、3β000、4β500 mg·kg^-1 5个水平, 共10个处理, 每个处理12个重复, 研究淹水和干旱条件下Pb污染对芦苇生长、生物量分配及光合作用的影响, 以期明确不同生境下芦苇适应或忍耐重金属污染而采取的策略, 为芦苇应用于湿地恢复和污染修复提供理论依据。结果表明, 在淹水处理中, Pb显著抑制地下芽形成和根茎生长, 但对子株数没有影响; 与母株相比子株具有高的日生长速率、光合速率和生物量(母株的3-7倍)。在干旱环境中, Pb显著抑制根、地下芽和根茎生长, 母株和子株生物量积累及光合作用, 且这些指标均小于淹水处理的。无论在淹水还是干旱环境中, 芦苇体内绝大部分Pb积累在根中, 根茎和子株中Pb含量较少, 被转运至母株中的Pb大约是子株的3倍。淹水条件下子株体内Pb含量小于干旱处理的。结果表明, 干旱和Pb的协同作用显著抑制芦苇生长、生物量积累和光合作用, 可能导致子株生产力和种群密度减小甚至种群衰退。但淹水芦苇能够采取相应的Pb分配策略减缓Pb污染对芦苇生长、生理和繁殖的负面影响, 有利于芦苇种群的繁衍和稳定。     

Bioaccumulation and rhizofiltration potential of Pistia stratiotes L. for mitigating water pollution in the Egyptian wetlands

The bioaccumulation and rhizofiltration potential of P. stratiotes for heavy metals were investigated to mitigate water pollution in the Egyptian wetlands. Plant and water samples were collected monthly through nine quadrats equally distributed along three sites at Al-Sero drain in Giza Province. The annual mean of the shoot biomass was 10 times that of the root. The concentrations of shoot heavy metals fell in the order: Fe < Mn < Cr < Pb < Cu < Zn < Ni < Co < Cd, while that of the roots were: Fe < Mn < Cr < Pb < Zn < Ni < Co < Cu < Cd. The bio-concentration factor (BCF) of most investigated heavy metals, except Cr and Pb, was greater than 1000, while the translocation factor (TF) of most investigated metals, except Pb and Cu, did not exceed one. The rhizofiltration potential (RP) of heavy metals was higher than 1000 for Fe, and 100 for Cr, Pb and Cu. Significant positive correlations between Fe and Cu in water with those in plant roots and leaves, respectively were recorded, which, in addition to the high BCF and RP, indicate the potential use of P. stratiotes in mitigating these toxic metals.