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1.
This study focused on establishing trends in the period 1988–2001 in PM2.5, PM10 and ozone concentrations in Santiago, Chile, and linking those to population exposure. There is strong seasonality in the concentration levels, driven by prevailing meteorological conditions, with the concentration of particulates peaking at the beginning of winter, whereas the ozone concentration is highest during the summer. The levels of PM2.5 and PM10 have substantially decreased since the late 1980s and so has the population exposure. Nevertheless, the majority of the population is still exposed to annual average levels that are above standard values. The situation with ozone exposure is different; no substantial decrease can be observed in the data. If anything, certain parts of Santiago, notably the south-east, have shown increased levels of ozone. Overall population exposure indicates that the average person was more at risk of ozone in the year 2000 than they were in 1993.  相似文献   

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3.
Polkowska Z 《Chemosphere》2004,57(10):1265-1274
Chlorinated and brominated derivatives of methane and ethene were determined in samples of atmospheric precipitation collected between November 2000 and May 2001 at four sites in two cities, Gdańsk and Sopot, located on the Gulf of Gdańsk (Baltic Sea, Poland). The analytes were determined by direct aqueous injection of the samples to the capillary column using ECD detection (DAI-GC-ECD). Chloroform and carbon tetrachloride were detected the most often at all sites. The highest concentrations of the analytes were recorded at the intersection of two major streets (no. 3), next to a major route leading to two subdivisions (no. 2) and at Narutowicza Street (no. 1). In general, analyte concentration levels were lower during the spring months. During precipitation, concentrations of the analytes were higher in samples collected at the beginning of the event due to scavenging of the volatile compounds from the atmosphere. After a period of 75 min from the beginning of the precipitation event, analyte concentrations were lower by 10-80%, depending on the initial concentration and nature of the analyte.  相似文献   

4.
Zusammenfassung  Es wurden 25 Lebensmittel-, 5 Frauenmilch-, 4 Staub- und 16 Textilproben auf Phthals?ureester untersucht. In allen Proben waren Phthalate nachweisbar, wobei Di(2-ethylhexyl)phthalat (DEHP) und Di-n-butylphthalat (DBP) am h?ufigsten gefunden wurden. In Rohmilchproben lagen die Gesamtphthalat-Konzentrationen im Mittel bei 0,1 mg/kg. Konsummilch wies keine h?here Belastung als Rohmilch auf, auch die Lagerung von Milchproben bis zum Ablauf des Mindesthaltbarkeitsdatums führte nicht zu h?heren Gehalten. Fettarme Milch war weniger belaster als Vollmilch. Die in Sahneproben gefundenen h?heren DEHP-sowie Gesamptphthalatgehalte lassen sich durch den h?heren Fettgehalt erkl?ren. Mit Konzentrationen von bis zu 1,54 mg/kg zeigten gemahlene Haselnüsse, Mandeln und Muskatnüsse, die in Kunststofffolie verpackt waren, eine vergleichsweise hohe Belastung. In S?uglingsnahrung waren nur Spuren von DEHP und DBP zu finden, weitete Phthals?ureester konnten nicht nachgewiesen werden. Auch die Frauenmilchproben wiesen nur geringe Gehalte von ca. 0,1 mg/kg auf, eine Akkumulation der Phthalester im menschlichen K?rper scheint also nicht stattzufinden. Au?ergew?hnlich hohe Konzentrationen wurden in Staubproben gefunden; die Werte lagen zwischen 300 und 5370 mg/kg Staub, wobei DEHP die Hauptkomponente darstellte. Die Belastung des Staubes l?sst auf eine erhebliche Bedeutung des Luftpfades beim Transfer der Phthals?ureester schlie?en. Da Staub erhebliche Anteile an Textilfasern enth?lt, wurden auch Textilien untersucht. Die Phthals?ureester-Gehalte in den Textilproben reichten von 3,42 bis 34,44 mg/kg. Die hohen Phthalester-Kontaminationen des Staubes k?nnen daher nicht durch Textilfasern erkl?rt werden. Online-Publikation: 07. Februar 2000  相似文献   

5.
Chlorinated hydrocarbons (CHs) were determined in blubber samples of 18 California sea lions (Zalophus californianus californianus) that stranded dead along Todos Santos Bay, Ensenada, Baja California, México, January 2000-November 2001. Summation operatorDDTs were the dominant group (geometric mean 3.8 microg/g lipid weight), followed by polychlorinated biphenyls ( summation operatorPCBs, 2.96 microg/g), chlordanes (0.12 microg/g) and hexachlorocyclohexanes (0.06 microg/g). The summation operatorDDTs/ summation operatorPCBs ratio was 1.3. We found CH levels more than one order of magnitude lower than those reported for California sea lion samples collected along the California coast, USA, during the same period as our study. This sharp north-south gradient suggests that Z. californianus stranded in Ensenada (most of them males) would probably have foraged during the summer near rookeries 500-1000 km south of Ensenada and the rest of the year migrate northwards, foraging along the Baja California peninsula, including Ensenada, and probably farther north.  相似文献   

6.
The study of mercury (Hg) cycle in Arctic regions is a major subject of concern due to the dramatic increases of Hg concentrations in ecosystem in the last few decades. The causes of such increases are still in debate, and an important way to improve our knowledge on the subject is to study the exchanges of Hg between atmosphere and snow during springtime. We organized an international study from 10 April to 10 May 2003 in Ny-Ålesund, Svalbard, in order to assess these fluxes through measurements and derived calculations.Snow-to-air emission fluxes of Hg were measured using the flux chamber technique between ∼0 and 50 ng m−2 h−1. A peak in Gaseous Elemental Mercury (GEM) emission flux from the snow to the atmosphere has been measured just few hours after an Atmospheric Mercury Depletion Event (AMDE) recorded on 22 April 2004. Surprisingly, this peak in GEM emitted after this AMDE did not correspond to any increase in Hg concentration in snow surface. A peak in GEM flux after an AMDE was observed only for this single event but not for the four other AMDEs recorded during this spring period.In the snow pack which is seasonal and about 40 cm depth above permafrost, Hg is involved in both production and incorporation processes. The incorporation was evaluated to ∼5–40 pg m2 h. Outside of AMDE periods, Hg flux from the snow surface to the atmosphere was the consequence of GEM production in the air of snow and was about ∼15–50 ng m−2 h−1, with a contribution of deeper snow layers evaluated to ∼0.3–6.5 ng m−2 h−1. The major part of GEM production is then mainly a surface phenomenon. The internal production of GEM was largely increasing when snow temperatures were close to melting, indicating a chemical process occurring in the quasi-liquid layer at the surface of snow grains.  相似文献   

7.
Nine structurally different phenolic chemicals, which have been reported to mimic estrogen effects, were determined in various aquatic environmental compartments. Twenty-three water samples from five streams and rivers showed levels up to 458 ng/l for 4-nonylphenol (4NP), 189 ng/l for 4-t-octylphenol (4tOP), 272 ng/l for bisphenol A (BPA) and 47 ng/l for 2-hydroxybiphenyl (2OHBiP). Elevated levels of these compounds in a stream with a high load of effluents of sewage treatment plants (STPs), compared to a brook free of sewage, identified STPs as major sources. With a similar order, 4NP (10-259 micrograms/kg dry matter), 4tOP (< 0.5-8 micrograms/kg), BPA (< 0.5-15 micrograms/kg), and 2OHBiP (2-69 micrograms/kg) were also detected regularly in riverine sediment (n = 11). Levels in sewage sludge were one order of magnitude higher than in sediments. 4-Hydroxybiphenyl and 4-chloro-3-methylphenol were found predominantly in sludge and sediment in the lower ppb range.  相似文献   

8.
Ferreira PD  Castro Pde T 《Ambio》2005,34(3):212-217
The giant Amazon river turtle (Podocnemis expansa) nests on extensive sand bars on the margins and interior of the channel during the dry season. The high concentration of nests in specific points of certain beaches indicates that the selection of nest placement is not random but is related to some geological aspects, such as bar margin inclination and presence of a high, sandy platform. The presence of access channels to high platform points or ramp morphology are decisive factors in the choice of nesting areas. The eroded and escarped margins of the beaches hinder the Amazon river turtle arriving at the most suitable places for nesting. Through the years, changes in beach morphology can alter nest distribution.  相似文献   

9.
Total mercury concentrations were measured in dorsal muscle tissue of two edible fish species, Prochilodus scrofa 'curimba' and Pseudoplatystoma corruscans 'pintado', respectively detritivorous and carnivorous. Fish species were sampled monthly between February 1993 and January 1994 and bimonthly between April 1994 and February 1995 in three subsystems of Paraná river' system (Ivinhema River/Lake Patos; Baía River/Lake Guaraná and Paraná River/Cortado Channel), between Paraná and Mato Grosso do Sul. Total mercury was determined by HNO3/H2SO4/V2O5 digestion, SnCl2 reduction, and vapour generation method analysis (CGCH 900), adapted to Atomic Absorption Spectrometer (CGAA 7000 ABC). The mean mercury concentrations varied from 82.0 to 310.5 ng g(-1) and from 68 to 294.4 ng g(-1) in 'curimbas' and 'pintados', respectively. Mercury level increases in sexually mature 'curimbas'. Mercury values detected do not exceed the prevailing criteria for issuance of fish consumption advisories (< 500 ng g(-1)).  相似文献   

10.
The Jacarepaguá lagoon receives the waste from 239 industries and domestic sewage. Bottom sediment analysis revealed that metal pollution is not spread over the lagoons but restricted to the discharge areas of the main metal-carrier rivers. Metal concentrations in superficial water showed the following concentrations values in ng/ml: Zn, 9.63+/-3.59; Pb, 0.61+/-0.43; Cu, 0.94+/-0.45; Mn, 12.7+/-8.0. Metal concentration in fish (average of seven different species) presented the following results, in mg/kg wet weight: Cr, 0.08+/-0.01; Cu, 0.4+/-0.15; Zn, 4.6+/-3.4; Fe, 2.4+/-1.3; Mn, 0.4+/-0.3. These results imply, considering fish consumption rate and the RfD (USEPA Reference Dose), that the local population is not exposed to undue health risks. Metal concentrations in the water may, however, increase due to their dissolution induced by pH and redox changes in the sediments.  相似文献   

11.

The interaction between green finance and other factors, such as ecological environment, has been a research hotspot nowadays. Especially, the reasonable guiding of capital into energy conservation and environmental protection industries would greatly affect those factors, so as to the relation between them. This paper aimed to analyze the relationships between green finance, technological progress, and ecological performance quantitatively. The entropy method was used to respectively construct the system of index for green finance and technological progress, and index for ecological performance was measured by the super-SBM model. The panel vector autoregressive (PVAR) model was selected to empirically analyze dynamic relationships based on datasets from 30 provinces in China during 2008–2019 period. The results told that (1) from 2008 to 2019, China’s overall level of green finance, technological progress and ecological performance increased to varying degrees. Spatially, the areas with high-developed green finance greatly coincided with those such as large cities or the eastern coast that had good financial development. The distribution of technological progress index were similar, except some underdeveloped areas with relatively advanced scientific research institutes. The ecological performance, however, was high in the South and low in the north. (2) In the lag for 3 years, the influence of green finance on ecological performance in different regions was all positive for that all the coefficient symbols that passed the significance test were above 0, while that on technological progress was negative first and then positive. And the effects of technological progress on ecological performance were positive in ecological regions and negative in low ecological regions (0.0893 and -0.1211 in the case of three-stage lag respectively). (3) The contribution of green finance to ecological performance was high according to the results of variance decomposition, maintained at about 30%, and that of technological progress increased year by year (from 0.000 to 0.039). Therefore, we proposed to strengthen the development of green finance in underdeveloped regions. The emphasis should be laid on the researches and applications of green technology, the formulation of financing policies in innovation compensation and the establishment of a dynamic monitoring system for the ecological environment.

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Environmental Science and Pollution Research - Rare information on the seafood safety and the coastal water-food-energy nexus sustainability in terms of seafood safety is available. This study...  相似文献   

14.
To seasonally evaluate littoral contamination, toxicity and quality values of sediments from the Gulf of Cádiz, we measured chemical concentrations and conducted toxicity tests in winter and summer and linked these results by means of multivariate analysis. Sediment samples were subjected to two separate, replicated sediment toxicity tests (Microdeutopus gryllotalpa amphipod survival, and Ruditapes philippinarum clam reburial), and to comprehensive sediment chemistry analyses (grain size, organic carbon, 14 heavy metals, and the surfactant linear alkylbenzenesulfonate (LAS)). Only sediments associated with an untreated urban discharge were toxic and related to high levels of surfactant LAS, Ag, and Pb. Multivariate analysis indicated that variables and chemicals associated with geochemical matrix and background levels (specific surface, Fe, Zn, Cu, V, Ni, and Co), chemicals associated with untreated urban discharge sources, and toxicity effects showed no seasonal variability. Only copper concentrations showed seasonal differences, being toxic during the winter and not toxic during summer. Multivariate analysis permits us to derive sediment quality values (SQVs); in terms of concentrations at or below which biological effects were not measured (mg kg(-1) dry sediment), are: LAS, 2.6; lead, 66.8; silver, 0.78; copper, 69.6.  相似文献   

15.
Córdoba, as well as many other Latin American cities, is facing problems concerning air pollution. The increase in the number of cars, the poor control on emissions and the little use of catalytic converters, produce a great amount of toxic gases and particulate. Many cities have started air quality measurement programs being the size of the network strongly dependent on the available funds. In 1995, Córdoba started a measurement campaign with two mobile stations. A major part of the city has been characterized, mostly the city center and the suburban zone. Lack of data at the prevailing wind direction is the major shortcoming, but this is mainly a political decision. In this work, we review the air quality measurements performed, and we attempt to explain the causes for the low ozone values found.  相似文献   

16.
In 1997, the United States National Ambient Air Quality Standard (NAAQS) for ozone was revised from a 1-h average of 0.12 parts per million (ppm) to an 8-h average of 0.08 ppm. Analysis of ozone data for the ensemble of the contiguous United States and for the period 1980–1998 shows that the average number of summer days per year in exceedance of the new standard is in the range 8–24 in the Northeast and in Texas, and 12–73 in southern California. The probability of exceedance increases with temperature and exceeds 20% in the Northeast for daily maximum temperatures above 305 K. We present the results of several different approaches to analyzing the long-term trends in the old and new standards over the continental United States from 1980 to 1998. Daily temperature data are used to resolve meteorological variability and isolate the effects of changes in anthropogenic emissions. Significant negative trends are found in the Northeast urban corridor, in the Los Angeles Basin and on the western bank of Lake Michigan. Temperature segregation enhances the detection of negative trends. Positive trends occur at isolated sites, mostly in the Southeast; a strong positive trend is found in Nashville (Tennessee). There is some evidence that, except in the Southwest, air quality improvements from the 1980s to the 1990s have leveled off in the past decade.  相似文献   

17.
Environmental Science and Pollution Research - By revealing the temporal and spatial differentiation of China’s regional tourism carbon emissions and its decoupling relationship with tourism...  相似文献   

18.
Environmental Science and Pollution Research - Water pollution is a constant challenge for humanity. Sustainable economic development and environmental protection through a green economy structure...  相似文献   

19.
The distribution of air temperature and wind speed was investigated in Reykjavı́k, the capital of Iceland, during the period from November 1991 to September 1992. The obtained data reveal that the climate in Reykjavı́k is mainly affected by the subarctic radiation budget, frequent cyclones penetrating into the investigation area and the closeness to the ocean. Nevertheless, Reykjavı́k shows a weak heat island effect, which converts to a `cold island’ by day in mid summer. The anthropogenic heat release amounts to ca. 35 W m−2. The study also indicates that the bioclimate and human comfort in Reykjavı́k is determined more by a high wind discomfort than by severe winter temperatures or high air pollution typical for high-latitude cities.  相似文献   

20.
van Gils HA  Ugon AV 《Ambio》2006,35(2):81-85
The conversion of closed forest (CCF) in Carrasco Province, Bolivia, was monitored using a series of four midresolution satellite images from 1986 to 2002. The conversion of forests into nonforests from 1986 to 2002 was 1.5% annually. Inclusion of conversions into open forest doubles the annual CCF rate to 3.1%. Five predictors of CCF were tested in a spatial model: land tenure regime, distance from roads, distance from settlements, topography, and soil suitability for farming. Only three out of the five predictors tested were found to be reliable predictors of CCF: land tenure regime, distance from roads, and distance from settlements. University reserve and indigenous land show substantially less CCF than national park and untitled land. In addition the spatial model shows that the greater the distance of forest from roads or settlements, the less CCF. Topography and soil suitability for farming lack predictive power for CCF and are therefore excluded from the spatial model.  相似文献   

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