楠溪江硝态氮来源定量识别及其不确定性分析

选择温州市楠溪江流域为研究区,通过水化学分析和硝态氮中氮氧稳定同位素示踪技术,对水体硝态氮时空分布特征、迁移转化过程和污染来源进行识别,结合稳定同位素源解析模型（SIAR）,定量识别不同污染源的贡献率,并在此基础上应用概率统计方法对模拟结果的不确定性进行分析.结果表明：研究区水体氮素赋存形态以硝态氮为主;硝态氮含量呈现明显的时空变化,时间上,丰水期硝态氮浓度高于枯水期,空间上,支流硝态氮浓度高于主河道;硝化作用主导了流域内硝态氮的转化过程,化肥、土壤有机氮和粪便污水是楠溪江水体硝态氮的主要来源;SIAR模型计算显示大气沉降、化肥、土壤有机氮、粪便污水对枯水期水体硝态氮的贡献率分别为3.0%~12.9%,25.5%~32.7%,28.7%~36.2%和24.7%~37.5%,对丰水期水体硝态氮贡献率为2.5%~14.3%,28.5%~40.0%,28.8%~39.7%和18.9%~29.90%.模拟结果的不确定性分析表明SIAR模拟结果存在一定程度的不确定性,不同污染源贡献率的不确定性从大到小排序为：土壤有机氮>化肥>粪便污水>大气沉降.     

Occurrence of Norovirus,Rotavirus, Hepatitis a Virus,and Enterovirus in Berries in Argentina

Food and Environmental Virology - Berries have been implicated as the probable vehicle of infection in multiple outbreaks of norovirus and hepatitis A virus (HAV). These foods often receive minimal...     

Vegetation productivity under climate change depends on landscape complexity in tropical drylands

Mitigation and Adaptation Strategies for Global Change - All Clean Development Mechanism (CDM) projects are designed to contribute to the sustainable development of the host country. Livelihood is...     

Toxic effects of the ingestion of water-soluble elements found in soil under the atmospheric influence of an industrial complex

In this study, we investigated the toxic effects of water-soluble elements from a contaminated soil via gavage in a single dose, simulating a geophagy event. The contaminated soil was collected in a field located in an industrial complex, and the control soil was collected in a reference area. Metabolic and behavioral parameters in Wistar male rats were measured after 24 and 96 h of gavage. After 96 h, the major organs were weighed, blood was collected to check hematological parameters, the bone marrow was taken for the micronucleus test, and the liver was used for evaluating the total antioxidant capacity, lipoperoxidation and protein carbonylation. Animals exposed to contaminated soil presented a few significant alterations by comparison with control animals: TBARS and protein carbonyl levels increased, the relative weight of the kidneys increased, metabolic parameters (body weight gain, food intake, water consumption, urine and feces production) depressed and there was behavioral alteration. These findings suggest that soils impacted by atmospheric contaminants can affect the organism physiological status jeopardizing the health of populations living in industrial areas. Finally, this study reassures that ingestion of potentially contaminated soils, even for short periods of time, can cause health risks.     

Effects of lead exposure on salivary glands of rats: insights into the oxidative biochemistry and glandular morphology

Environmental Science and Pollution Research - This study aimed to investigate the effects of lead (Pb) exposure on parotid and submandibular glands through morphological aspects as well as the...     

Plastic pollution in freshwater ecosystems: macro-, meso-, and microplastic debris in a floodplain lake

Plastic pollution is considered an important environmental problem by the United Nations Environment Programme, and it is identified, alongside climate change, as an emerging issue that might affect biological diversity and human health. However, despite research efforts investigating plastics in oceans, relatively little studies have focused on freshwater systems. The aim of this study was to estimate the spatial distribution, types, and characteristics of macro-, meso-, and microplastic fragments in shoreline sediments of a freshwater lake. Food wrappers (mainly polypropylene and polystyrene), bags (high- and low-density polyethylene), bottles (polyethylene terephthalate), and disposable Styrofoam food containers (expanded polystyrene) were the dominant macroplastics recorded in this study. Contrary to other studies, herein macroplastic item surveys would not serve as surrogates for microplastic items. This is disadvantageous since macroplastic surveys are relatively easier to conduct. Otherwise, an average of 25 mesoplastics (mainly expanded polystyrene) and 704 microplastic particles (diverse resins) were recorded per square meter in sandy sediments. Comparisons with other studies from freshwater and marine beaches indicated similar relevance of plastic contamination, demonstrating for the first time that plastic pollution is a serious problem in the Paraná floodplain lakes. This study is also valuable from a social/educational point of view, since plastic waste has been ignored in the Paraná catchment as a pollutant problem, and therefore, the outcome of the current study is a relevant contribution for decision makers.     

Emissions of C&D refuse in landfills: A European case

A field study was developed in a new landfill for refuse from construction and demolition (C&D) material recovery plants of small size (4 Ha.) in Europe, with the aim of evaluating the liquid and gas emissions in this type of facility at a large scale. It included characterization of the materials, monitoring leachate and gas quantity and composition. Besides thermometers, piezometers and sampling ports were placed in several points within the waste. This paper presents the data obtained for five years of the landfill life. The materials disposed were mainly made up of wood and concrete, similar to other C&D debris sites, but the amount of gypsum drywall (below 3% of the waste) was significantly smaller than other available studies, where percentages above 20% had been reported. Leachate contained typical C&D pollutants, such as different inorganic ions and metals, some of which exceeded other values reported in the literature (conductivity, ammonium, lead and arsenic). The small net precipitation in the area and the leachate recirculation into the landfill surface help explain these higher concentrations, thus highlighting the impact of liquid to solid (L/S) ratio on leachate characteristics. In contrast to previous studies, neither odor nuisances nor significant landfill gas over the surface were detected. However, gas samples taken from the landfill inside revealed sulfate reducing and methanogenic activity.     

Physiological and behavioral responses of temperate seahorses (Hippocampus guttulatus) to environmental warming

The aim of the present study was to evaluate, for the first time, the effect of environmental warming on the metabolic and behavioral ecology of a temperate seahorse, Hippocampus guttulatus. More specifically, we compared routine metabolic rates, thermal sensitivity, ventilation rates, food intake, and behavioral patterns at average spring temperature (18 °C), average summer temperature (26 °C), temperatures that they endure during summer heat wave events (28 °C), and in a near-future warming scenario (+2; 30 °C) in Sado estuary, Portugal. Both newborn juveniles and adults showed significant increases in metabolic rates with rising temperatures. However, newborns were more impacted by future warming via metabolic depression (i.e., heat-induced hipometabolism). In adult stages, ventilation rates also increased significantly with environmental warming, but food intake remained unchanged. Moreover, the frequency of swimming, foraging, swinging, and inactivity did not significantly change between the different thermal scenarios. Thus, we provide evidence that, while adult seahorses show great resilience to heat stress and are not expected to go through any physiological impairment and behavioral change with the projected near-future warming, the early stages display greater thermal sensitivity and may face greater metabolic challenges with potential cascading consequences for their growth and survival.