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Nitrogen deposition effects on plant species diversity; threshold loads from field data 全文
2013
Tipping, E. | Henrys, P.A. | Maskell, L.C. | Smart, S.M.
National-scale plant species richness data for Great Britain in 1998 were related to modelled contemporary N deposition (Ndep) using a broken stick median regression, to estimate thresholds above which Ndep definitely has had an effect. The thresholds (kg N ha−1 a−1) are 7.9 for acid grassland 14.9 for bogs, 23.6 for calcareous grassland, 7.8 for deciduous woodland and 8.8 for heath. The woodland and heath thresholds are not significantly greater than the lowest Ndep, which implies that species loss may occur over the whole range of contemporary Ndep. This also applies to acid grassland if it is assumed that Ndep has substituted for previous N fixation. The thresholds for bog and calcareous grassland are both significantly above the lowest Ndep. The thresholds are lower than the mid-range empirical Critical Loads for acid grassland, deciduous woodland and heath, higher for bogs, and approximately equal for calcareous grassland.
显示更多 [+] 显示较少 [-]Social [and health] relevance of psychotropic substances monitoring in air 全文
2013
Cecinato, Angelo | Balducci, Catia | Mollica, Roberto | Serpelloni, Giovanni
Drug abuse assessment methods based on measuring illicit substances in waste waters are consolidated. The approach of ambient air monitoring looks questionable, nonetheless it can be explored if the variables determining the drug burdens are accounted for, or suitable co-contaminants are adopted to normalize concentrations to environmental and human contours. The general approach linking the airborne drug concentrations to consumption is presented and the case of cocaine is discussed according to measurements conducted in Italy. The cocaine/nicotine concentration ratio, identified as the most suitable tool, fitted well with anti-drug Police operations and people noticed for drug-related crimes, and with the abuse prevalence estimated in the cities investigated. According to that, the conversion factors of drug concentrations into prevalence estimates seem assessable, provided sufficient databases over space and time are collected. Further investigations are necessary to understand if airborne drugs cause adverse sanitary effects.
显示更多 [+] 显示较少 [-]Dioxin-induced acute cardiac mitochondrial oxidative damage and increased activity of ATP-sensitive potassium channels in Wistar rats 全文
2013
Pereira, Susana P. | Pereira, Gonçalo C. | Pereira, Cláudia V. | Carvalho, Filipa S. | Cordeiro, Marília H. | Mota, Paula C. | Ramalho-Santos, João | Moreno, António J. | Oliveira, Paulo J.
The environmental dioxin 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is classified as a Group 1 human carcinogen and teratogenic agent. We hypothesize that TCDD-induced oxidative stress may also interfere with mitochondrial ATP-sensitive potassium channels (mitoKATP), which are known to regulate and to be regulated by mitochondrial redox state. We investigated the effects of an acute treatment of male Wistar rats with TCDD (50 μg/kg i.p.) and measured the regulation of cardiac mitoKATP. While the function of cardiac mitochondria was slightly depressed, mitoKATP activity was 52% higher in animals treated with TCDD. The same effects were not observed in liver mitochondria isolated from the same animals. Our data also shows that regulation of mitochondrial ROS production by mitoKATP activity is different in both groups. To our knowledge, this is the first report to show that TCDD increases mitoKATP activity in the heart, which may counteract the increased oxidative stress caused by the dioxin during acute exposure.
显示更多 [+] 显示较少 [-]Associations of particulate air pollution and daily mortality in 16 Chinese cities: An improved effect estimate after accounting for the indoor exposure to particles of outdoor origin 全文
2013
Chen, Renjie | Zhou, Bin | Kan, Haidong | Zhao, Bin
People typically spend most of their time indoors. We modeled the daily indoor PM10 concentrations of outdoor origin using a set of exposure parameters, including the fraction of residences with air conditionings (AC), the fraction of time that windows are closed when cooling occurs for buildings with AC, the fractions of time that windows are open or closed for buildings with or without AC, the particle penetration factors, air change rates, and surface removal rate constant of PM10. We calculated the time-weighted average of the simulated indoor PM10 concentration of outdoor origin and the original recorded outdoor PM10 concentration. We then evaluated the acute effects of PM10 using traditional and amended exposure metrics in 16 Chinese cities. Compared with the original estimates, the new effect estimates almost doubled, with improved model fit and attenuated between-city heterogeneity. Conclusively, this proposed exposure assessment approach could improve the effect estimates of ambient particles.
显示更多 [+] 显示较少 [-]Trophodynamics of inorganic pollutants in a wide-range feeder: The relevance of dietary inputs and biomagnification in the Yellow-legged gull (Larus michahellis) 全文
2013
Ramos, Raúl | Ramirez, Francisco | Jover, Lluís
Trophodynamics of inorganic pollutants in a wide-range feeder: The relevance of dietary inputs and biomagnification in the Yellow-legged gull (Larus michahellis) 全文
2013
Ramos, Raúl | Ramirez, Francisco | Jover, Lluís
The suitability of sentinel species to monitor environmental pollution is often hampered by an insufficient knowledge on pollutant trophodynamics. We simultaneously evaluated the influence of individuals' trophic position (as revealed by δ15N values) and dietary exploitation of particular systems (using δ13C and δ34S as proxies) on inorganic pollutant concentrations measured on fledglings' feathers of a wide-range feeder, the Yellow-legged Gull (Larus michahellis), sampled at four locations throughout the Western Mediterranean. Concentrations of total Hg and Se in fledgling feathers (2.43 ± 1.30 and 1.16 ± 0.43 μg/g, respectively) were under the threshold points for deleterious effects on seabirds. On the contrary, alarming Pb concentrations were found in one colony (mean: 1.57 ± 2.46 μg/g, range: 0.16–12.13). With the exception of Pb, pollutant concentrations were positively influenced by consumption of marine resources (as suggested by the positive relationship with δ34S values), whereas trophic position played a minor role in determining pollutant body burdens.
显示更多 [+] 显示较少 [-]Trophodynamics of inorganic pollutants in a wide-range feeder: The relevance of dietary inputs and biomagnification in the Yellow-legged gull (Larus michahellis) 全文
2013
Ramos, Raül | Ramírez Benítez, Francisco | Jover, Lluís
The suitability of sentinel species to monitor environmental pollution is often hampered by an insufficient knowledge on pollutant trophodynamics. We simultaneously evaluated the influence of individuals' trophic position (as revealed by ο15N values) and dietary exploitation of particular systems (using ο13C and ο34S as proxies) on inorganic pollutant concentrations measured on fledglings' feathers of a wide-range feeder, the Yellow-legged Gull (Larus michahellis), sampled at four locations throughout the Western Mediterranean. Concentrations of total Hg and Se in fledgling feathers (2.43 ± 1.30 and 1.16 ± 0.43 οg/g, respectively) were under the threshold points for deleterious effects on seabirds. On the contrary, alarming Pb concentrations were found in one colony (mean: 1.57 ± 2.46 οg/g, range: 0.16-12.13). With the exception of Pb, pollutant concentrations were positively influenced by consumption of marine resources (as suggested by the positive relationship with ο34S values), whereas trophic position played a minor role in determining pollutant body burdens. © 2012 Published by Elsevier Ltd. | Peer Reviewed
显示更多 [+] 显示较少 [-]Within- and among-population level differences in response to chronic copper exposure in southern toads, Anaxyrus terrestris 全文
2013
Lance, Stacey L. | Flynn, R Wesley | Erickson, Matthew R. | Scott, David E.
Environmental contaminants are implicated in the global decline of amphibian populations. Copper (Cu) is a widespread contaminant that can be toxic at concentrations just above the normal physiological range. In the present study we examined the effects of chronic Cu aqueous exposure on embryos and larvae of southern toads, Anaxyrus (Bufo) terrestris. Measurable levels of Cu were found in larvae, with tissue concentrations up to 27.5 μg Cu/g dry mass. Aqueous concentrations of Cu as low as 10 μg/L significantly reduced survival to the free-swimming stage and no larvae reached metamorphosis at concentrations above 15 μg/L. Clutches from populations with prior Cu exposure had the lowest survivorship. Among several populations there was significant variation in survivorship at different levels of Cu. More data are needed to understand the underlying causes of within- and among-population resilience to anthropogenic stressors.
显示更多 [+] 显示较少 [-]Pollution level, inhalation exposure and lung cancer risk of ambient atmospheric polycyclic aromatic hydrocarbons (PAHs) in Taiyuan, China 全文
2013
Xia, Zhonghuan | Duan, Xiaoli | Tao, Shu | Qiu, Weixun | Liu, Di | Wang, Yilong | Wei, Siye | Wang, Bin | Jiang, Qiujing | Lü, Bin | Song, Yunxue | Hu, Xinxin
Passive air samplers were deployed to collect both gas and particulate phase polycyclic aromatic hydrocarbons in Taiyuan between 2009 and 2010. Annual average concentrations of BaP equivalent concentration (B[a]Peq) in background, rural and urban areas were 2.90 ± 0.29, 23.2 ± 30.8 and 27.4 ± 28.1 ng/m3, respectively, with higher concentration in the winter than in other seasons. The median B[a]Peq concentrations of annual inhalation exposure were estimated to be in the range of 103–347 ng/d for all population groups in rural as well as in urban areas. The median values of incremental lifetime cancer risk (ILCR) induced by whole year inhalation exposure for all groups were basically larger than 10−6, with higher values in winter than in other seasons and in urban than in rural area. In the same season and area, the ILCR of adults was larger than other age groups and that of females was a little higher than males.
显示更多 [+] 显示较少 [-]Assessing the combined risks of PAHs and metals in urban soils by urbanization indicators 全文
2013
Peng, Chi | Ouyang, Z. (Zhiyun) | Wang, Meie | Chen, Weiping | Li, Xiaoma | Crittenden, John C.
We quantitatively describe the impacts of urbanization on the accumulation of polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) in urban soils as well as their health risks to residents. Residential building age, population density, road density, and distance from urban center were used as urbanization level indicators. Significant correlations were found between those urbanization indicators and the amounts of PAHs, Cu, Cd, Pb, Zn and As in residential soils. The exposure time of soils to urban air was the primary factor affecting soil pollution, followed by local road density and population density. Factor analysis suggested that 59.0% of the elevated pollutant concentrations were caused by citywide uniform deposition, and 15.3% were resulted from short-range deposition and/or non-combustion processes. The combined health risks posed by soil PAHs and HMs were aggravated with time and can be expressed as functions of residence age, road density, and other urbanization indicators.
显示更多 [+] 显示较少 [-]Assessing urban habitat quality using spectral characteristics of Tilia leaves 全文
2013
Khavanin Zadeh, A.R. | Veroustraete, F. | Buytaert, Jan | Dirckx, J. | Samson, R.
Monitoring environmental quality in urban areas is an important issue offering possibilities to control and improve urban habitat quality as well as to avoid adverse effects on human health. A tree leaf reflectance-based bio-monitoring method was used to assess the urban habitat quality of two contrasting habitat classes in the city of Gent (Belgium). As test trees, two Tilia species were selected. Custom made Matlab code is applied to process the measurements of leaf reflectance. This enables the discrimination between polluted and less polluted habitats. The results elicit, that leaf reflectance in the PAR range, as well as the NDAI (Normalised Difference Asymmetry index) are species dependent while Dorsiventral Leaf Reflectance Correlation (DLRC) seems to be independent of species. Therefore the assessment of urban habitat quality is perfectly feasible using leaf reflectance, when taking account of the species specificity of tree leaf physiological and structural responses to habitat quality.
显示更多 [+] 显示较少 [-]Antibiotics in riverine runoff of the Pearl River Delta and Pearl River Estuary, China: Concentrations, mass loading and ecological risks 全文
2013
Xu, Weihai | Yan, Wen | Li, Xiangdong | Zou, Yongde | Chen, Xiaoxiang | Huang, Weixia | Miao, Li | Zhang, Ruijie | Zhang, Gan | Zou, Shichun
Ten antibiotics belonging to three groups (macrolides, fluoroquinolones and sulfonamides) were investigated in riverine runoff of the Pearl River Delta (PRD) and Pearl River Estuary (PRE), South China for assessing the importance of riverine runoff in the transportation of contaminants from terrestrial sources to the open ocean. All antibiotics were detected in the eight outlets with concentrations ranging from 0.7 to 127 ng L−1. The annual mass loadings of antibiotics from the PRD to the PRE and coast were 193 tons with 102 tons from the fluoroquinolone group. It showed that antibiotics decreased from the riverine outlets to the PRE and open ocean. Risk assessment showed that most of these antibiotics showed various ecological risks to the relevant aquatic organisms, in which ofloxacin (OFL), erythromycin (ETM) and ciprofloxacin (CIP) posed high ecological risks to the studied aquatic environments.
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