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91.
This study investigated the presence of 16 priority polycyclic aromatic compounds (PAHs) in waters from the Douro River estuary and nearby Atlantic seacoast, which both bath the Porto metropolis. In the area, there is an oil refinery, an important harbour, an intense maritime traffic, small marinas and highly inhabited cities. For the analysis of PAHs, water samples were taken from four sampling sites, at six different times of the year (2011), and extracted by solid-phase extraction (dissolved fraction) and by ultrasound technique (suspended fraction), before their quantification by gas chromatography–mass spectrometry. Results not only proved the ubiquitous distribution of all analysed PAHs in the present habitat, but also that their global amounts (∑16PAHs) were extremely high at all sampling sites. Their average concentrations attained ≈ 55 ng/L and ≈ 52 μg/g dry weight (dw), respectively, in water and surface sediments. Accordingly, the surveyed area was classified as highly polluted by these organics and so, in view of the concentrations, mutagenic/carcinogenic responses in both humans and aquatic animals are possible to occur. The percentages of carcinogenic PAHs for humans (group 1) dissolved in water and in surface sediments were ca. 5 and 6%, respectively. These results are the first reported in the area and can be used as a baseline for future control of the PAHs levels locally while serving the building of global scenarios of PAHs pollution in Europe.
Graphical abstract Percentage of PAHs, from different categories acordingly to WHO (2016), in both surface sediments and surface waters from Douro River estuary and Porto Atlantic seacoast; group 1 - carcinogenic, group 2A - probably carcinogenic, group 2B - possibly carcinogenic, and group 3 - not classifiable as carcinogenic to humans
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92.
Environmental Geochemistry and Health - Mercury is widely found in nature, however, in low concentrations, but anthropological activities have increased its concentration considerably. This causes...  相似文献   
93.
Environmental Science and Pollution Research - In this work, fast sequential determination and chemical speciation analysis of inorganic arsenic and antimony in airborne particulate matter...  相似文献   
94.

Fluoride is an important element for humans. It inhibits initiation and progression of dental caries and stimulates bone formation. However, excessive intake may lead to the appearance of dental and/or skeletal fluorosis and a decrease in intellectual coefficient in child populations. This study evaluates exposure to fluoride in the child population of Chaco province (Argentina) by analysis of drinking water, food and its bioaccessible fraction (quantity of fluoride solubilised by gastrointestinal digestion and available for intestinal absorption) and urine as a biomarker of internal dose. The concentration of fluoride in drinking water varied between 0.050 and 4.6 mg L?1, and 80% of the samples exceeded the WHO drinking-water guideline value (1.5 mg L?1). Fluoride concentrations in food ranged between 0.80 and 3.0 mg kg?1 fresh weight (fw), being lower in bioaccessible fraction (0.43–1.9 mg kg?1, fw). On the basis of the consumption data declared for the young child population, fluoride intake varies between 4.1 and 6.5 mg day?1, greater than the level recommended for this age group. Moreover, in some cases, concentrations of fluoride found in urine (0.62–8.9 mg L?1) exceeded those reported in areas with declared fluorosis. All data obtained show the worrying situation of child population in this area of Argentina.

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95.
96.
Liver lesions in wild fish have been associated with xenobiotic exposure. Facing reports of pollution in the Douro River estuary (north of Portugal), we have been making field surveys using fishes and targeting histopathological biomarkers of exposure and effect. Herein, we intended to better characterize and report the rate of one poorly understood lesion—hepatocellular fibrillar inclusions (HFI)—found in European flounder (Platichthys flesus). With this report, we aimed to establish sound baseline data that could be viewed as a starting point for future biomonitoring, while offering the world's second only pool of field data on such a liver toxicopathic lesion, which could be compared with data available from the UK estuaries. Sampling was done in the Douro River estuary over 1 year. A total of 72 animals were fished with nets, in spring–summer (SS) and autumn–winter (AW) campaigns. Livers were processed for histopathology and both routine and special staining procedures (alcian blue, periodic acid Schiff (PAS), tetrazonium coupling reaction). Immunohistochemistry targeted AE1/AE3 (pan cytokeratins). The severity of the HFI extent was graded using a system with four levels, varying from 0 (absence of HFI) to 3 (high relative density of cells with HFI). Cells (isolated/groups) with HFI appeared in 35 % or more of the fish, in the total samples of each season, and over 40 % in more homogeneous sub-samples. There were no significant differences when comparing samples versus sub-samples or SS versus AW. When merging the data sets from the two seasons, the frequency of fish with HFI was ≈36 % for the total sample and ≈49 % for the sub-sample. The extreme group (biggest and smallest fish) revealed a HFI frequency of only 16 %, which differed significantly from the total and sub-sampled groups. Immunostaining and PAS were negative for the HFI, and alcian blue could, at times, faintly stain the inclusions. These were positive with the tetrazonium reaction. We showed the presence of HFI in European flounder from the Douro River estuary, proving that they are essentially protein in nature, that no seasonal changes existed in the HFI frequency, and that it was rarer in the smallest and biggest fish groups. Within the ranges of weight/size of our total sample, we estimate that the frequency of HFI in the local flounder is ≈35 %. That rate stands as a baseline value for future assessments, namely for biomonitoring purposes targeting correlations with the estuary pollution status.  相似文献   
97.
Regional Environmental Change - This paper reviews the current knowledge of climatic risks and impacts in South Asia associated with anthropogenic warming levels of 1.5–4 °C...  相似文献   
98.
The <8 mm fraction of aged incinerator bottom ash from a commercial incinerator (energy from waste) plant has been collected at regular intervals, characterised and processed to form ceramic materials. Ashes were sieved, wet ball milled, dried, compacted and sintered at temperatures between 1080 and 1115 degrees C. Variations in the chemical composition and mineralogy of the milled ash, and the mineralogy, physical properties and leaching of sintered products have been assessed. Milling produces a raw material with consistent chemical and mineralogical composition with quartz (SiO(2)), calcite (CaCO(3)), gehlenite (Ca(2)Al(AlSi)O(7)) and hematite (Fe(2)O(3)) being the major crystalline phases present. Different batches also milled to give consistent particle size distributions. Sintering milled incinerator bottom ash at 1110 degrees C produced ceramics with densities between 2.43 and 2.64 g/cm(-3) and major crystalline phases of wollastonite (CaSiO(3)) and diopside (CaMgSi(2)O(6)). The sintered ceramics had reduced acid neutralisation capacity compared to the as-received ash and exhibited reduced leaching of Ca, Mg, Na and K under all pH conditions. The leaching of heavy metals was also significantly reduced due to encapsulation and incorporation into glassy and crystalline phases, with Cu and Al showing greatly reduced leaching under alkali conditions.  相似文献   
99.
In spite of its outstanding ecological and touristic importance the Ria Formosa Lagoon shows signs of anthropogenic pollution. Nonetheless, until the present survey no studies had ever documented the measurement of natural and pharmaceutical estrogens (17β-estradiol, estrone, and 17α-ethynylestradiol), xenoestrogenic industrial pollutants (4-octylphenol, 4-nonylphenol, and their mono and diethoxylates and bisphenol A), phytoestrogens (formononetin, biochanin A, daidzein, genistein), and sitosterol in this area. The 17 compounds measured herein are known as endocrine disrupters (EDCs) and act over the endocrine system even in few amounts (ng L?1–μg L?1). Thus to conclude about the influx of EDCs in the lagoon, water samples were taken every 2 months, during 1 year (2010), in low tide at nine sites distributed along the coastline. Water samples (1 L) were preconcentrated in the Oasis HLB cartridges and cleaned in silica cartridges before their analysis by GC-MS. Data showed the ubiquitous presence of potentially hazardous amounts of estrogens (particularly of ethynylestradiol, up to 24.3 ng L?1), nonylphenol (up to 547 ng L?1), and sitosterol (up to 12,300 ng L?1), mainly in summer, suggesting that the increase of the local number of inhabitants (tourists), the rise of the water temperature (up to 26 °C), and the blooming of local flora may interfere with the water quality parameters. This makes the lagoon a potential model to study. Taking into account the data, it was concluded that there are conditions for the occurrence of endocrine disruption in aquatic animals, even in areas included in the natural park of the Formosa. Besides, both the high amounts of un-ionized ammonia (up to 0.3 mg L?1) and phosphates (up to 1.6 mg L?1) my pose risks for local fauna and humans.  相似文献   
100.
The herbicide imazaquin has both an acid and a basic ionizable groups, and its sorption depends upon the pH, the electric potential (psi0), and the oxide and the organic carbon (OC) contents of the soil. Sorption and extraction experiments using 14C-imazaquin were performed in surface and subsurface samples of two acric oxisols (an anionic "rhodic" acrudox and an anionic "xanthic" acrudox) and one non-acric alfisol (a rhodic kandiudalf), treated at four different pH values. Imazaquin showed low to moderate sorption to the soils. Sorption decreased and aqueous extraction increased as pH increased. Up to pH 5.8, sorption was higher in subsurface than in surface layers of the acric soils, due to the positive balance of charges resulted from the high Fe and Al oxide and the low OC contents. It favored electrostatic interactions with anionic molecules of imazaquin. For the subsurface samples of these highly weathered soils, where psi0 was positive and OC was low, it was not possible to predict sorption just by considering imazaquin speciation and its hydrophobic partition to the organic domains of the soil. Moreover, if Koc measured for thesurface samples were assumed to represent the whole profile in predictive models for leaching potential, then it would result in underestimation of sorption potential in subsurface, and consequently result in overestimation of the leaching potential.  相似文献   
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