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231.
Two cores collected in 2001 and 2004 from Flanders Moss ombrotrophic peat bog in central Scotland were dated (14C, 210Pb) and analysed (ICP-OES, ICP-MS) to derive and compare the historical atmospheric deposition records of Sb and Pb over the past 2500 years. After correction, via Sc, for contributions from soil dust, depositional fluxes of Sb and Pb peaked from ca. 1920-1960 A.D., with >95% of the anthropogenic inventories deposited post-1800 A.D. Over the past two centuries, trends in Sb and Pb deposition have been broadly similar, with fluctuations in the anthropogenic Sb/Pb ratio reflecting temporal variations in the relative input from emission sources such as the mining and smelting of Pb ores (in which Sb is commonly present, as at Leadhills/Wanlockhead in southern Scotland), combustion of coal (for which the Sb/Pb ratio is approximately an order of magnitude greater than in Pb ores) and exhaust emissions (Pb from leaded petrol) and abrasion products from the brake linings (Sb from heat-resistant Sb compounds) of automobiles. The influence of leaded petrol has been most noticeable in recent decades, firstly through the resultant minima in Sb/Pb and 206Pb/207Pb ratios (the latter arising from the use of less radiogenic Australian Pb in alkylPb additives) and then, during its phasing out and the adoption of unleaded petrol, complete by 2000 A.D., the subsequent increase in both Sb/Pb and 206Pb/207Pb ratios. The extent of the 20th century maximum anthropogenic enrichment of Sb and Pb, relative to the natural Sc-normalised levels of the Upper Continental Crust, was similar at approximately 50- to 100-fold. Prior to 1800 A.D., the influence of metallurgical activities on Sb and Pb concentrations in the peat cores during both the Mediaeval and Roman/pre-Roman periods was discernible, small Sb and Pb peaks during the latter appearing attributable, on the basis of Pb isotopic composition, to the mining/smelting of Pb ores indigenous to Britain.  相似文献   
232.
There is considerable concern about the effects of contaminants on organisms at higher trophic levels, as well as interest in developing bioindicators of ecological health. In this article we examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the gonads, liver and muscle of Florida gar (Lepisosteus platyrhincus) from Lake Okeechobee in south-central Florida. Gar are top-level predators in freshwater ecosystems. We expected that there would be differences in metal levels as a function of tissue, and predicted differences as a function of sex, size, and location around the lake. There were significant differences among tissues for all metals, but there were few differences as a function of size and gender, which may relate to the generally low levels of metals. Mercury levels were significantly higher in gar collected from the north, and arsenic levels were significantly higher in the gar collected from the south. All metal levels in the muscle of gar collected from Lake Okeechobee were similar to, or lower than those generally reported from other areas of the United States. Thus, although the levels of mercury from the Everglades to the south of Lake Okeechobee are sufficiently high to result in human fish consumption advisories, there are none for Lake Okeechobee. The mercury levels in fish muscle from Lake Okeechobee are lower than from many waters in the U.S. and do not pose a problem for humans. However, liver levels average over the 0.5 microg g(-1) level considered safe for human consumption, and might pose a problem for non-human consumers that eat the fish whole.  相似文献   
233.
Feathers serve as a useful, non-destructive approach for biomonitoring some aspects of environmental quality. Birds can eliminate over 90% of their body burden of mercury by sequestration in growing feathers, and they molt their feathers at least annually. Thus mercury concentrations should not vary in avian feathers as a function of age. We tested the null hypothesis that there are no age differences in the concentrations of mercury, lead, cadmium, selenium, copper, chromium and manganese in the feathers of immature and adult common loons Gavia immer from the Northeastern United States where the species is declining. Adults had significantly higher mean levels of mercury (20245 ppb) than immature loons (9677 ppb), but there were no age-related differences for other elements. Even with the small number of immatures, females had significantly higher levels of mercury than males, although the gender difference was not significant for adults.  相似文献   
234.
Summary Incubation temperatures in vertebrates affect incubation periods, and in some reptiles incubation temperature determines sex ratios and some limited behavior. Here I present evidence that incubation temperature in pine snakes (Pituophis melanoleucus) affects not only incubation periods and posthatching behavior in the laboratory, but also the behavior of hatchlings required for successful emergence and survival. These behavioral differences have evolutionary implications for selection of hatchlings from particular temperature nests. With increasing temperature, incubation periods decreased in the laboratory. In addition, incubation temperature affected hatching and emergence times as well as movement speed and foraging ability. Hatchlings from medium temperature conditions emerged from nests in the field in less time than hatchlings incubated at high or low temperatures, and hatchlings from low temperatures moved slower and were less able to capture and eat mice in the laboratory than hatchlings incubated at medium or high temperatures. Taken together, these laboratory and field experiments suggest that hatchlings from low temperature nests, compared to those from higher temperature nests, would be less able to emerge, find food, and locate hibernation sites prior to the onset of cold temperatures in the New Jersey Pine Barrens. These results suggest that incubation temperature affects a whole range of behavior and that distributional ranges of reptiles and other poikilotherms could be affected by summer temperatures (via incubation period and subsequent behavior) as well as ambient winter temperatures.  相似文献   
235.
In sexually dimorphic, polygynous species, where males provide little parental care and competition between males for access to fertile females is high, sexual selection theory predicts sex differences in age-specific reproductive output and mortality profiles, and greater variance in lifetime reproductive success in males than in females. We examined age-specific reproductive output, mortality patterns and the extent and causes of variation in reproductive success for a semi-free-ranging colony of mandrills (Mandrillus sphinx, Cercopithecidae) in Franceville, Gabon, using long-term (20 year) demographic records and microsatellite parentage analysis. Although differences in the demography and feeding ecology of this closed, provisioned colony, in comparison with wild mandrills, limit interpretation of our results, sex differences in reproductive output and mortality showed the patterns predicted by sexual selection theory. Mortality was higher in males than in females after sexual maturity, and lifespan was significantly shorter in males (mean 14 year) than in females (>22 year). Age at first reproduction was significantly earlier in females (mean 4.2 year) than in males (11.6 year), and male reproductive output declined earlier. All females of breeding age produced offspring; while only 17 of 53 sexually mature males (32%) sired. Males sired a maximum of 41 offspring, versus 17 in females, and variance in male reproductive output was significantly greater than in females at all ages. The most important influence on variation in lifetime reproductive output in both sexes was joint variation between length of the breeding period and reproductive rate, due to lower reproductive rates in younger animals. Finally, social rank significantly influenced reproductive output in both sexes: high-ranking females began their reproductive careers earlier and had a higher subsequent reproductive rate than low-ranking females, while males that achieved top rank during their career sired far more offspring than males that did not.Electronic Supplementary Material Supplementary material is available for this article at  相似文献   
236.
The short-spined toxopneustid sea urchin Tripneustes gratilla feeds on a wide variety of algal species and on sea grasses. However, the urchin does show preferences when offered a selection of macroalgal species, which it encounters in nature. Preferences among macroalgae were evident in field-collected urchins exposed to pair-wise tests where the variable was either the consumption rate of the algae or observation of which algal species the urchins chose to touch with their lantern teeth. Exposure of lab-housed urchins to one of five species of macroalgae for 5 months did not seem to alter preferences of urchins in three of the exposure groups, but those exposed to Padina sanctae-crucis seemed to show an enhanced preference for this species when offered a choice of the five species of macroalgae at the end of the exposure period, and those exposed to Gracilaria salicornia seemed to avoid the species when offered the choice of the five species. Perhaps more ecologically important than their preferences were two other observations on these urchins: first, when offered only a single species of algae, the urchins on four of five diets ate the same quantity per day. Second, when simultaneously offered the choice among the five macroalgal species, the urchins consumed more macroalgae per day than when offered only one species. These urchins move about a meter a day. They probably encounter food resources in a relatively coarse-grained fashion and have evolved to eat what is available. Because of their limited movements, their habitat overlap with grazing fishes, their acceptance of a wide variety of macroalgae and their preference for macroalgae, these native urchins are thought to have the potential to serve as biological control agents of alien and invasive macroalgae, which have come to dominate some reef zones normally occupied by corals in Hawaii.  相似文献   
237.
Increasingly public and governmental agencies are concerned aboutrevitalizing coastal environments. Understanding how the publicuses these areas, and what they see as the most important improvements to these regions is critical to their assessment andmanagement. Uses of three estuaries, and perceptions of possiblemanagement and restoration options, were examined for people whowere interviewed in the New York/New Jersey Harbor, Manasquan Inlet, and Barnegat Bay, New Jersey. Nearly 90% of the people interviewed listed pollution as New Jersey's most important environmental problem. Most people (68%) used the habitat for outdoor sports, but rated communing with nature, walking, and the provision of open `green' space as the most valued uses. Pollution prevention was the most often mentioned habitat improvement desired, and people rated removing pollution, cleaning up garbage, and creating more fish breeding habitat the highest. There were significant locational differences inhow people used the estuaries, and in how they thought they should be improved. People from Barnegat Bay ranked most uses higher than did people from elsewhere, while the people from Manasquan Inlet rated the importance of most remediation and restoration actions higher. Many of the improvements fall withinenvironmental management, including (rank order from high to low)creating more fish breeding habitat, improving native vegetation,improving habitat for birds, increasing plant diversity,improving habitat for butterflies, and enlarging adjacentmarshes. The data provide clear support for the importance ofthese coastal habitats for communing with nature and having open`green space' spaces, and for providing recreationalopportunities. To enhance their value, people want to removepollution and improve both the habitat quality and the educational and recreational facilities.  相似文献   
238.
The aim of this study was to evaluate the potential role of office fomites in respiratory (human parainfluenza virus 1—HPIV1, human parainfluenza virus 3—HPIV3) and enteric (norovirus GI—NoV GI, norovirus GII—NoV GII) viruses transmission by assessing the occurrence of these viruses on surfaces in office buildings. Between 2016 and 2017, a total of 130 surfaces from open-space and non-open-space rooms in office buildings located in one city were evaluated for HPIV1, HPIV3, NoV GI, and NoV GII viral RNA presence. Detection of viruses was performed by RT-qPCR method. Study revealed 27 positive samples, among them 59.3% were HPIV3-positive, 25.9% HPIV1-positive, and 14.8% NoV GII-positive. All tested surfaces were NoV GI-negative. Statistical analysis of obtained data showed that the surfaces of office equipment including computer keyboards and mice, telephones, and desktops were significantly more contaminated with respiratory viruses than the surfaces of building equipment elements such as door handles, light switches, or ventilation tracts (χ 2 p = 0.006; Fisher’s Exact p = 0.004). All examined surfaces were significantly more contaminated with HPIVs than NoVs (χ 2 p = 0.002; Fisher’s Exact p = 0.003). Office fomites in open-space rooms were more often contaminated with HPIVs than with NoVs (χ 2 p = 0.016; Fisher’s Exact p = 0.013). The highest average concentration of HPIVs RNA copies was observed on telephones (1.66 × 102 copies/100 cm2), while NoVs on the light switches (1.40 × 102 copies/100 cm2). However, the Kruskal–Wallis test did not show statistically significant differences in concentration levels of viral RNA copies on surfaces between the all tested samples. This study unequivocally showed that individuals in office environment may have contact with both respiratory and enteric viral particles present on frequently touched surfaces.  相似文献   
239.
Many public agencies and private entities are faced with assessing the risks to humans from contamination on their lands. The United States Department of Energy (US DOE) and Department of Defense are responsible for large holdings of contaminated land and face a long‐term and costly challenge to assure sustainable protectiveness. With increasing interest in the conversion of brownfields to productive uses, many former industrial properties must also be assessed to determine compatible future land uses. In the United States, many cleanup plans or actions are based on the Comprehensive Environmental Responsibility, Compensation, and Liability Act, which provides important but incomplete coverage of these issues, although many applications have tried to involve stakeholders at multiple steps. Where there is the potential for exposure to workers, the public, and the environment from either cleanup or leaving residual contamination in place, there is a need for a more comprehensive approach to evaluate and balance the present and future risk(s) from existing contamination, from remediation actions, as well as from postremediation residual contamination. This article focuses on the US DOE, the agency with the largest hazardous waste remediation task in the world. Presented is a framework extending from preliminary assessment, risk assessment and balancing, epidemiology, monitoring, communication, and stakeholder involvement useful for assessing risk to workers and site neighbors. Provided are examples of those who eat fish, meat, or fruit from contaminated habitats. The US DOE's contaminated sites are unique in a number of ways: (1) huge physical footprint size, (2) types of waste (mixed radiation/chemical), and (3) quantities of waste. Proposed future land uses provide goals for remediation, but since some contamination is of a type or magnitude that cannot be cleaned up with existing technology, this in turn constrains future land use options, requiring an iterative approach. The risk approaches must fit a range of future land uses and end‐states from leave‐in‐place to complete cleanup. This will include not only traditional risk methodologies, but also the assessment and surveillance necessary for stewards for long‐term monitoring of risk from historic and future exposure to maintain sustainable protectiveness. Because of the distinctiveness of DOE sites, application of the methodologies developed here to other waste site situations requires site‐specific evaluation © 2007 Wiley Periodicals, Inc.  相似文献   
240.
Recent interest in restoring urban ecosystems has engendered studies on public perceptions of these ecosystems and future land use. This paper examines the perceptions of people using the waterfront area of the New York/New Jersey harbour estuary about their use of the area, and how this environment could be improved. Pollution was viewed as the most important problem in New Jersey, and removing pollution was rated the most important way to improve the waterfront habitat. Using the remaining undeveloped area for natural habitat and to improve quality of life were rated as the most important uses of the waterfront. People valued the waterfront for walking, providing open green space, and as a place to commune with nature without people. Management options people favoured were removing pollution and cleaning up rubbish and adding educational signs and information brochures about the remaining, natural habitat. Age, income and education influenced which activities people said they undertook. For improvements to the waterfront: Hispanics rated adding educational signs and creating information brochures higher, Blacks rated building promenades as more important, and Asians and Whites rated improving habitat for birds and butterflies more important than others. The data indicate that the public has a firm understanding of the big picture (pollution in the region and locally), habitat improvement, and of the small improvements that can be done locally. Planners and managers could move forward on three fronts: source reduction, wildlife habitat improvement, and amenity (signs, brochures, cleaning up rubbish) development. Understanding how people use an environment, and wish to improve it, can provide valuable information for future restoration and management of urban environments generally, as well as for structuring a citizen advisory committee.  相似文献   
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