Lead, Zinc, Copper, and Cadmium in Fish and Sediments from the Big River and Flat River Creek of Missouri's Old Lead Belt

The Old Lead Belt of Missouri was a major lead-producing region for over a century. Several large tailings piles and other industrial wastes remain behind, though mining operations in the region ceased in 1972. Samples of stream sediments and fish were collected from established sites on the Big River and Flat River Creek over a 3-year period from 1998 to 2000 to evaluate ongoing remediation efforts and determine the current impact of residual mining wastes. Benthic sediments and fish taken in the vicinity of inactive industrial sites were found to contain elevated concentrations of Pb, Zn, Cu, and Cd. Concentrations of Pb and Zn in fillets of suckers and sunfish, as well as in whole bodies of sunfish, correlate well with metal concentrations observed in surficial sediments. The results of analyses provide valuable quantitative information regarding specific sources, current levels of contamination, potential risk to public health, and will allow more accurate assessment of continuing remediation efforts.     

环境污染对地下文物的威胁

上个世纪的环境污染造成了健康问题,土地和湖水的酸化以及对文化遗产的损害.不仅露天的文物受环境污染的影响,地下文物也因此遭受不测.然而到目前为止,我们对地下文物受损状况的研究相当有限,而对这个被忽视的领域给予重视是相当重要的.在此文中,我们将报道在瑞典国家文化遗产委员会得到的有关文物受损的研究结果;这些文物是来自史前墓穴中的青铜器、铁器和骨器考古物品,它们的材料仿佛受到污染的影响最大.对调查时采用的方法作了介绍,并对其它相关的研究做了简要的综述.近年来,历史文物(特别是无机材质的文物)遭受侵蚀的速度已明显加快,而文物侵蚀速度的上升主要归因于人类造成的污染.对于污染可能危及的区域,在文中将举例说明.     

Fish from Missouri's lead belt: To eat or not to eat

Data collected over the past four years indicate that filets of suckers and some species of sunfish taken from certain sites in Missouri's Old Lead Belt consistently contain elevated lead concentrations which exceed the limit of 0.3 g/g suggested by the World Health Organization. The problem exists in bottom-feeding species taken from some sites along the Big River affected by erosion from abandoned lead tailings piles. Fish from many other sites within the Old Lead Belt and the New Lead Belt, including current wastewater treatment systems, are within the acceptable limits for lead in food. Public health implications are discussed relative to observed lead concentrations and available data regarding lead toxicity to humans.     

Design and off-design analyses of a pre-combustion CO2 capture process in a natural gas combined cycle power plant

In this study, a cycle designed for capturing the greenhouse gas CO₂ in a natural gas combined cycle power plant has been analyzed. The process is a pre-combustion CO₂ capture cycle utilizing reforming of natural gas and removal of the carbon in the fuel prior to combustion in the gas turbine. The power cycle consists of a H₂-fired gas turbine and a triple pressure steam cycle. Nitrogen is used as fuel diluent and steam is injected into the flame for additional NO_x control. The heat recovery steam generator includes pre-heating for the various process streams. The pre-combustion cycle consists of an air-blown auto-thermal reformer, water–gas shift reactors, an amine absorption system to separate out the CO₂, as well as a CO₂ compression block. Included in the thermodynamic analysis are design calculations, as well as steady-state off-design calculations. Even though the aim is to operate a plant, as the one in this study, at full load there is also a need to be able to operate at part load, meaning off-design analysis is important. A reference case which excludes the pre-combustion cycle and only consists of the power cycle without CO₂ capture was analyzed at both design and off-design conditions for comparison. A high degree of process integration is present in the cycle studied. This can be advantageous from an efficiency stand-point but the complexity of the plant increases. The part load calculations is one way of investigating how flexible the plant is to off-design conditions. In the analysis performed, part load behavior is rather good with efficiency reductions from base load operation comparable to the reference combined cycle plant.     

AQUATIC ORGANISMS AND HEAVY METALS IN MISSOURI'S NEW LEAD BELT1

The New Lead. Belt of southeastern Missouri has recently become the largest lead producing region of the world. The impact of this rapid development on the previously rural and undeveloped region of the Missouri Ozarks is the subject of a continuing interdisciplinary study. Since the industrial development began, there have been a number of nuisance biological blooms in several of the small streams receiving effluent from the mines and mills. The major constituents of the problem algal growths were identified and found to include: Cladophora, Oscillatoria, Mougeotia, Zygnema, Spirogyra, Cymbella, and a variety of other stalked and non-stalked diatoms. Secondary blooms of Sphaerotilus were observed to reach problem proportions in some streams, particularly in the autumn. Finely ground rock flour and mineral particles escaping from tailings dams were found to be trapped by the stream vegetation. Concentrations of lead, zinc, copper, and manganese in the algal and bacterial mats were found to be inversely related to distance downstream from the tailings dams. Consumer organisms, including crayfish, snails, aquatic insects, tadpoles, minnows and larger sunfish were analyzed to determine the extent of dissemination and concentration of the heavy metals through food chains. Preliminary results indicated insignificant concentrations of heavy metals in those consumer organisms studied, though in at least one problem stream the normal consumer organisms mentioned were markedly reduced in numbers.     

Managing material transfer and nutrient flow in an agricultural watershed

Place-based resource management, such as watershed or ecosystem management, is being promoted to replace the media-focused approach for achieving water quality protection. We monitored the agricultural area of a 740-ha watershed to determine the nature and scale of farm material transfers, N and P balances, and farmer decisions that influenced them. Using field data and farmer interviews we found that 3 of 15 farms, emphasizing hog, dairy, or cash crops with poultry production, accounted for more than 80% of the inputs and outputs of N and P for the 362-ha agricultural area (332 ha of managed cropland and animal facilities). Feed for hogs (38% each of total N and P) and manure applied to fields as part of the cash crop and poultry operation (28 and 38% of total N and P, respectively) were the dominant inputs. No crops grown in the watershed were fed to animals in the watershed and more manure nutrients were applied from animals outside than from those in the watershed. A strategic decision by the hog farmer to begin marketing finished hogs changed the material transfers and nutrient balances more than tactical decisions by other farmers in allocating manure to cropland. Since the components of agricultural production were not all interconnected, the fundamental assumption of place-based management programs is not well-suited to this situation. Alternative approaches to managing the effect of agriculture on water quality should consider the organization of agricultural production and the role of strategic decisions in controlling farm nutrient balances.     

Perfluorooctane sulfonate increases β-oxidation of palmitic acid in chicken liver

Purpose

Perfluorooctane sulfonate (PFOS) belongs to a group of chemicals called perfluoroalkyl acids that have been extensively used in various applications such as stain and oil resistant treatments for fabrics, fire-fighting foams, and insecticides. These chemicals present an environmental and health risk being present in many samples both in wildlife and humans. In this study, we investigate the effect of PFOS on fatty acid ??-oxidation in developing chicken embryos.

Methods

Fertilized chicken eggs were exposed in ovo to PFOS at day?4 of incubation. On day?10, the eggs were dissected and livers were incubated in vitro with ³H-palmitic acid for 2?h. The media were collected, and after clean up, the amount of tritiated water was measured with liquid scintillation counting to determine the rate of palmitic acid ??-oxidation.

Results

PFOS was found to induce fatty acid ??-oxidation at doses starting from a lowest observed effect level (LOEL) of 0.1???g/g egg weight. Maximum induction of 77?% compared to control was seen at 0.3???g/g.

Conclusions

The administered doses in which effects are seen are around and even lower than the levels that can be found in wild populations of birds. General population human levels are a factor of two to three times lower than the LOEL value of this study. The environmental contamination of PFOS therefore presents a possibility of effects in wild populations of birds.