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41.
Many air pollutants and greenhouse gases have common sources, contribute to radiative balance, interact in the atmosphere, and affect ecosystems. The impacts on forest ecosystems have been traditionally treated separately for air pollution and climate change. However, the combined effects may significantly differ from a sum of separate effects. We review the links between air pollution and climate change and their interactive effects on northern hemisphere forests. A simultaneous addressing of the air pollution and climate change effects on forests may result in more effective research, management and monitoring as well as better integration of local, national and global environmental policies.  相似文献   
42.
Concentrations of total mercury were determined by cold-vapour atomic absorption spectroscopy (CV-AAS) in 221 caps and 221 stalks of 15 species of wild growing higher fungi/mushrooms and 221 samples of corresponding soil substrate collected in 1997-98 in Manowo County, near the city of Koszalin in North-central Poland. Mean mercury concentrations in caps and stalks of the mushroom species examined and soils varied between 30+/-31 and 920+/-280, 17+/-11 and 560+/-220, and 10+/-9 and 170+/-110 ng/g dry matter, respectively. Cap to stalk mercury concentration quotients were from 1.0+/-0.4 in poison pax (Paxillus involutus) to 2.8+/-0.7 in slippery jack (Suillus luteus). Brown cort (Cortinarius malicorius), fly agaric (Amanita muscaria), orange-brown ringless amanita (A. fulva), red-aspen bolete (Leccinum rufum) and mutagen milk cap (Lactarius necator) contained the highest concentrations of mercury both in caps and stalks, and mean concentrations varied between 600+/-750 and 920+/-280 and 370+/-470 and 560+/-220 ng/g dry matter, respectively. An estimate of daily intake of mercury from mushroom consumption indicated that the flesh of edible species of mushrooms may not pose hazards to human health even at a maximum consumption rate of 28 g/day. However, it should be noted that mercury intake from other foods will augment the daily intake rates. Species such as the sickener (Russula emetica), Geranium-scented russula (R. fellea) and poison pax (P. involutus) did not concentrate mercury as evidenced from the bioconcentration factors (BCFs: concentrations in mushroom/concentration in soil substrate), which were less than 1. Similarly, red-hot milk cap (L. rufus), rickstone funnel cap (Clitocybe geotropa) and European cow bolete (S. bovinus) were observed to be weak accumulators of mercury. Fly agaric (A. muscaria) accumulated great concentrations of mercury with BCFs reaching 73+/-42 and 38+/-22 in caps and stalks, respectively. Mercury BCFs of between 4.0+/-2.3 and 23+/-25 (caps) and 2.6+/-1.9 and 14+/-12 (stalks) were noted for the other mushroom species. Relatively great concentrations of mercury in fly agaric (A. muscaria) were due to preferential uptake of this element by this species.  相似文献   
43.
Chemical carcinogenesis, as presently understood, involves a number of carcinogenic factors which act in series of steps. Some industrial carcinogens may pollute the natural environment and penetrate into food. Many substances which are potent carcinogens in experimental animals exist in nature and are present in the human diet. On the other hand, many substances which are known to inhibit experimental carcinogenesis also exist in human diet. The present review discusses experimental and epidemiological data connected with the human cancer and diet. It also postulates that the dietary prevention of human cancer through prudent modification of diet and dietary patterns may be of importance; many of the present data are still confusing and conflicting.  相似文献   
44.
Phosphatic (possibly secondarily phosphatised) remains of antipatharian coralla, previously unknown in the fossil record, occur abundantly in the early Ordovician Fenxiang Formation in the Hubei Province, southern China. Probably two species (and genera) are represented, which differ in spinosity of branches. The more spinose one, Sinopathes reptans, has its lateral spines bearing regular, longitudinally arranged costellae. The early Floian geological age of this finding, about 470?Ma, supports predictions on the timing of anthozoan phylogeny derived from the molecular phylogenetic evidence. Black corals (Antipatharia) are basal to the scleractinians in the Hexacorallia clade, being more derived than sea anemones and the Zoantharia. Based on calibration of the molecular clock with Mesozoic data, the first split of lineages within the scleractinian hexacorals was proposed to take place approximately 425 million years ago. This implies that the origin of Antipatharia should precede this date. They have not been known in the fossil record because of unmineralised skeleton composed primarily of laminar chitin complexed with a protein. Unlike all recent species, the encrusting basal part of the colony dominated in the Ordovician ones and only occasionally erect branches developed, rather chaotically ramified. This presumably plesiomorphic trait seems consistent with ancient geological age and suggests that some problematic fossils from the Late Cambrian may be their, even less-derived, relatives.  相似文献   
45.
The aim of the study was to determine the effects of land use management on changes in the fecal contamination of water in the ?yna River, one of the main lowland watercourses in the southern watershed of the Baltic Sea (northern Poland). A total of 120 water samples were collected in different seasons of 2011 and 2012 at 15 sites where the river intersected forest (FA), agricultural (AA), and urbanized (UA) areas. Fecal indicator bacteria (FIB), the counts of Enterobacteriaceae and Escherichia coli, total bacterial counts (TBCs), and domain Bacteria (EUB338) were determined by culture-dependent and culture-independent methods. Temperature, pH, chemical oxygen demand, dissolved oxygen, total dissolved solids, ammonia nitrogen, nitrite nitrogen, nitrate nitrogen, orthophosphate, and total phosphorus were also determined. The lowest bacterial counts were noted in water samples collected in FA, and the highest in samples collected in UA. Statistically significant differences were determined between bacterial populations across the analyzed land use types and in different sampling seasons. Significant correlations were also observed between the populations of FIB and physicochemical parameters. The results indicate that land use type influenced FIB concentrations in river water. The combined use of conventional and molecular methods improves the accuracy of fecal contamination analyses in river ecosystems.  相似文献   
46.
The process of biosorption of heavy metal ions (Cr3+, Cd2+, Cu2+) by blue-green algae Spirulina sp. is discussed in this paper. Spirulina sp. was found to be a very efficient biosorbent. The aim of the present study was to investigate quantitatively the potential binding sites present at the surface of Spirulina sp., using both potentiometric titrations and adsorption isotherms. The kinetic experiments showed that the process equilibrium was reached quickly, in less than 5-10 min. It was found that the equilibrium dependence between biosorption capacity and bulk metal ion concentration could be described with Langmuir equation. This suggests that the mechanism of biosorption is rather chemisorption than physical adsorption and was further confirmed by the low surface area associated with physical adsorption and by the presence of cations that appeared in the solution after biosorption. The maximum contribution of physical adsorption in the overall biosorption process was evaluated as 3.7%. It was proposed that functional groups on the cell surface contributed to the binding of metal ions by a biosorbent via equilibrium reaction. Three functional groups capable of cation exchange were identified on the cell surface. The biomass was described as weakly acidic ion exchanger. Since deprotonation of each functional group depends on pH, the process of biosorption is strongly pH-dependent. This was confirmed in the biosorption experiments carried out at different pH. The contribution of functional groups in the biosorption process was confirmed by chemical modification of the groups. Chemically blocked groups did not show neither biosorption nor ion-exchange capabilities. It has been shown that growth conditions can affect the metal adsorption properties of microalgae. The paper also discusses desorption characteristics of the biosorbent. The criteria for desorption were high elution efficiency and preservation of biosorptive properties. Desorbent that possessed these characteristics was nitric acid.  相似文献   
47.
Introduction to the problem of environmental pollution caused by acid depositions. Presentation of principles of the six-year field experiment with simulated acid rain. Short characteristics of particular parts of the series of papers.  相似文献   
48.
49.
The necessity to follow the rules of sustainable development in the everyday industrial practice has led to the formulation of the concept of an industrial ecosystem mimicking the natural ecosystem. Following this analogy, the conceptual model of an eco-industrial park, which is an organised form of the industrial ecosystem, was presented in this paper. The model comprises of (1) the structure of the ecosystem, (2) the classification of the enterprises as producers, consumers and decomposers, (3) mass and energy flows and (4) types of interactions. The classification of the enterprises introduced here as well as the analysis of mass and energy flows indicates that the diversity of the enterprises in eco-industrial parks is desired. Furthermore, the minimal condition to create the symbiotic relationships between the enterprises is established, claiming that at least one industrial producer or decomposer must be involved in the eco-industrial park. The application of this model will facilitate the design and development of eco-industrial parks and enable the identification of symbiotic relationships between the entities of such a park and other types of industrial ecosystems. In order to show the applicability of the proposed model and its potential for the practical implementation two case studies are presented.  相似文献   
50.
Time-related accident risk in shift work may be attributed to internal factors, such as fatigue, level of performance, sleep propensity, and to some external factors, like shift system, physical and social environment. Six hundred and sixty-eight events in the metallurgical industry have been analysed in terms of time of day, time on task, consecutive day of the shift block, day of the week, and season.

The injury rate was similar on all shifts but more severe accidents happened in the nighttime. Somewhat more injuries occurred in the second half of the shift, in the second part of a shift block, and in summer compared with winter. There were fewer injuries at weekends.  相似文献   
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