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291.
Levels of 18 elements, including lead, mercury, selenium, and uranium, were examined in three species of snakes from an exposed and reference site on the Department of Energy's Savannah River Site in South Carolina. We tested the hypotheses that there were no differences as a function of species, and there were no difference between the exposed and control site for blood and muscle (tail) samples for banded water snake (Nerodia fasciata), brown water snake (N. taxispilota) and cottonmouth (Akistrodon piscivorous). The banded water snakes collected were significantly smaller than the other two species. For blood, there were significant species differences only for barium, copper, selenium, uranium and zinc, while for muscle tissue there were significant interspecific differences in aluminum, arsenic, barium, cobalt, cesium, copper, iron, lead, mercury, manganese, strontium, vanadium and zinc, suggesting that muscle tissue in the tail is a better indicator of potential interspecific differences. It is also easier logistically to collect tail tissue than blood. Where one species had significantly higher levels than the other species in muscle tissue levels, cottonmouth had higherlevels of five elements (aluminum, cobalt, lead, mercury, vanadium), brown water snake had two (lead, strontium), and banded water snake had only barium. There were few significant differences between the control and reference site for levels of blood, but several for muscle tissue. All three species had significantly higher levels of arsenic and manganese at Tim's Branch than the reference site, and nickel and uranium were significantly higher for banded watersnake and cottonmouth, the larger species. Individuals with high exposure of one element were exposed to high levels of other elements.  相似文献   
292.
It is possible to develop large quantities of energy by installing a comprehensive regional insulation program. This paper develops a computer model for examining the quantity of energy that may be saved in a region if such a program is undertaken. The program requires data on: number of houses, type of houses and present degree of insulation. The results indicate that in the region under consideration it is possible to make available more energy, far cheaper, through insulation than by the alternative of constructing a large power plant.  相似文献   
293.
We compared levels of eight heavy metals in common tern eggs collected in 1982 (n=24) from coastal New Jersey with archived specimens collected from the same colonies in 1971 (N=9). Levels of all metals, except cobalt, showed a significant decrease over the 11 year period, with lead and nickel showing the greatest decline. Mercury levels declined over 50% based on geometric means. Cadmium and mercury showed the lowest levels in both years. Pair-wise correlation coefficients on log-transformed data revealed lower correlations in 1971, whereas most metal pairs showed significant correlations in 1982. Mercury levels showed significant positive correlations with cobalt, cadmium, and nickel in 1971, but were not correlated with levels of any other metal in 1982.  相似文献   
294.
We analyzed cadmium and lead levels in feathers of mated pairs of common terns (Sterna hirundo) and in their eggs to determine if metal levels in eggs correlated with female levels, and whether there were intrapair and intermetal correlations. Eggs had significantly lower lead levels (89 ng g-1) and cadmium levels (4.0 ng g-1) than adult feathers (500 and 50 ng g-1 respectively). Adult females had higher metal levels than males. Cadmium and lead levels were correlated across families for females, males and eggs. Lead, but not cadmium, levels were correlated in females and their eggs.  相似文献   
295.
Mercury bioaccumulation in organisms from three Puerto Rican estuaries   总被引:1,自引:0,他引:1  
We analyzed mercury levels in shrimp (Palaemonetes sp.), Blue Crabs (Callinectes sp.), fish (Tarpon Megalops atlantica and Tilapia Tilapia mossambica), lizards (Ameiva exsul), Cattle Egret (Bubulcus ibis) and Moorhen (Gallinula chloropus) in three estuaries in Puerto Rico in 1988. There were no quantifiable concentrations greater than the method detection limit of mercury in shrimp, crabs and lizards from any site. Mercury levels were also below detection limits in Tilapia, except for specimens collected at Frontera Creek, allegedly contaminated with mercury. However, mercury levels ranged from 92–238 g/kg (wet weight) in Tarpon, a predaceous fish that feeds on smaller fish. Few of the birds had detectable levels of mercury. Our results indicate relatively low concentrations of mercury in biota collected in all of the three estuaries at most trophic levels, although 10 of 12 Tarpon fillet samples from Frontera had detectable mercury compared to 3 of 12 fillet samples for the other two lagoons.This project was partially funded by an EPA consent decree (Dynamac, Inc.) and NIEHS grant (ESO 5022) to EOSHI.  相似文献   
296.
US Federal law mandates that mined land be returned by mine operators to a condition capable of supporting its pre-mining use or a higher use. Previously forested lands have commonly been reclaimed to hayland/pasture or wildlife habitat, and most of these lands have been abandoned from management and rendered non-productive. This situation has left landowners in the position of converting these reclaimed mined lands to forests at a later date, if they choose to make them economically productive. Such land-use conversion, however, comes with a substantial up-front cost to the landowner, which makes the financial viability of such a conversion questionable. We examine the financial viability of reforestation of these previously reclaimed mine lands by calculating land expectation value (LEV) under a range of conditions that include forest type, site quality, and reforestation intensity. We find that conversion to white pine is viable on higher quality sites under low to moderate interest rates with low or high timber prices, but conversion to mixed hardwoods is only profitable under the high price scenario with low interest rates, and only on higher quality sites. We also consider the implications of a shift in reforestation burden from the landowner to the mine operator, and results suggest that including costs of reforestation as part of the mining operation creates a financially viable forest enterprise for landowners under all scenarios for both white pine and mixed hardwoods. Two forms of carbon payments that could encourage reforestation of previously reclaimed mined lands also are examined: an annual payment based upon the total accumulated carbon found on-site in a given year, and an annual payment based on only the increment of carbon storage each year. Our carbon payment results indicate that annual values of up to $5.17 per ton of carbon stored in hardwoods and $9.39 per ton of carbon stored in pines would be required to make reforestation profitable under the poorest conditions (high interest rates, low prices, and poor quality site) when the payment is based on accumulated on-site carbon, although lower values are required under more favorable scenarios. Payments that are based upon the annual increment of carbon must fall in the range of $8.66–$71.88 per ton of carbon stored in hardwoods and $0–$83.29 per ton of carbon stored in pines to make reforestation financially viable.  相似文献   
297.
Information on the spatial distribution and speciation of metals in nonhyperaccumulator plants is lacking. This study used synchrotron X-ray fluorescence (SXRF) compositional imaging to investigate the spatial distribution of Ni, Mn, Cu, Zn, and Fe in annual rings of black willow (Salix nigra L.) collected from a metal-contaminated area, and used X-ray absorption spectroscopy (XAS) to investigate Ni and Mn speciation in regions of the annual rings with elevated Ni concentrations. Annual rings were recollected in early 2003 from an individual known to be enriched with Ni from previous studies. Compositional imaging showed Ni and associated co-contaminants conservatively located in an annual ring. When compared with a corresponding photomicrograph, SXRF compositional images showed that metals were sharply constrained by the boundaries of the annual ring, indicating a sudden onset and cessation of uptake, and a lack of post-growth mobility of the metals. There was a particularly strong correlation between Ni and Mn in the metal-enriched annual ring (r = 0.8822), which suggested similar transport and binding behavior of these elements. X-ray absorption spectroscopy showed Ni and Mn to be present in the 2+ oxidation state. X-ray absorption near edge structure spectroscopy (XANES) fingerprinting of localized, highly Ni-enriched regions within the lumen of willow xylem vessels found similarities with Ni-pectic acid complexes, Ni-histidine, and NiSO4.  相似文献   
298.
299.
This article presents a database developed to determine the potential reuse of contaminated sites for primarily ecologically and culturally based activities. The database consists of 172 quantitative and qualitative measures of on‐site land suitability, ecological, cultural, and recreational value, and off‐site suitability, economic, and demographic information. Using sites owned by the U.S. Department of Energy (DOE) as a case study, the article evaluates the quality of available data and suggests ways of using it for planning ecologically sensitive remediation activities and future land use. This type of database can be developed and used by anyone who needs to select, review, or evaluate site remediation and future land use options. Also discussed are the challenges associated with compiling and using data that has been generated by many sources over several years. © 2003 Wiley Periodicals, Inc.  相似文献   
300.
This article discusses a process for finding insights that will allow federal agencies and environmental professionals to more effectively manage contaminated sites. The process is built around what Etzioni (1968) called mixed‐scanning, that is, perpetually doing both comprehensive and detailed analyses and periodically re‐scanning for new circumstances that change the decision‐making environment. The article offers a checklist of 127 items, which is one part of the multiple‐stage scanning process. The checklist includes questions about technology; public, worker, and ecological health; economic cost and benefits; social impacts; and legal issues. While developed for a DOE high‐level radioactive waste application, the decision‐making framework and specific questions can be used for other large‐scale remediation and management projects. © 2002 Wiley Periodicals, Inc.  相似文献   
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