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61.
There is a critical need to accurately measure the concentrations of natural steroidal estrogens in flushed dairy manure wastewater (FDMW) to assess any potential risk of waterway contamination resulting from land application. Estrogens are a concern because low concentrations (10-100 ng L-1) in water can adversely affect aquatic vertebrate species such as fish, turtles, and frogs by disrupting the normal function of their endocrine systems. The objective of this study was to develop a sample preparation method that permits the quantification of four natural steroidal estrogens (17alpha-estradiol, 17beta-estradiol, estrone, and estriol) in FDMW by gas chromatography-mass spectrometry (GC-MS). Solid-phase extraction with graphitized carbon black was used for the bulk extraction of estrogens from FDMW and additional sample purification was accomplished with C-18. The sample preparation method allowed estrogens to be detected accurately by GC-MS in FDMW. Spiked recovery experiments indicated that the method is satisfactory for measuring the estrogens of interest in FDMW with average recovery of >90%. As expected in FDMW, characterization of the estrogen profile revealed a large abundance of 17alpha-estradiol relative to 17beta-estradiol and estrone. Estriol was not detected in FDMW. The methodology developed in this research helps provide an analytical foundation for the quantification of steroidal estrogens in FDMW by GC-MS.  相似文献   
62.

Purpose

To investigate the significance of sources around measurement sites, assist the development of control strategies for the important sources and mitigate the adverse effects of air pollution due to particle size.

Methods

In this study, sampling was conducted at two sites located in urban/industrial and residential areas situated at roadsides along the Brisbane Urban Corridor. Ultrafine and fine particle measurements obtained at the two sites in June?CJuly 2002 were analysed by positive matrix factorization.

Results

Six sources were present, including local traffic, two traffic sources, biomass burning and two currently unidentified sources. Secondary particles had a significant impact at site 1, while nitrates, peak traffic hours and main roads located close to the source also affected the results for both sites.

Conclusions

This significant traffic corridor exemplifies the type of sources present in heavily trafficked locations and future attempts to control pollution in this type of environment could focus on the sources that were identified.  相似文献   
63.
The aim of this study was to characterise and quantify the fungal fragment propagules derived and released from several fungal species (Penicillium, Aspergillus niger and Cladosporium cladosporioides) using different generation methods and different air velocities over the colonies. Real time fungal spore fragmentation was investigated using an Ultraviolet Aerodynamic Particle Sizer (UVASP) and a Scanning Mobility Particle Sizer (SMPS). The study showed that there were significant differences (p < 0.01) in the fragmentation percentage between different air velocities for the three generation methods, namely the direct, the fan and the fungal spore source strength tester (FSSST) methods. The percentage of fragmentation also proved to be dependent on fungal species. The study found that there was no fragmentation for any of the fungal species at an air velocity ≤0.4 m s?1 for any method of generation. Fluorescent signals, as well as mathematical determination also showed that the fungal fragments were derived from spores. Correlation analysis showed that the number of released fragments measured by the UVAPS under controlled conditions can be predicted on the basis of the number of spores, for Penicillium and A. niger, but not for C. cladosporioides. The fluorescence percentage of fragment samples was found to be significantly different to that of non-fragment samples (p < 0.0001) and the fragment sample fluorescence was always less than that of the non-fragment samples. Size distribution and concentration of fungal fragment particles were investigated qualitatively and quantitatively, by both UVAPS and SMPS, and it was found that the UVAPS was more sensitive than the SMPS for measuring small sample concentrations, whilethe results obtained from the UVAPS and SMAS were not identical for the same samples.  相似文献   
64.
The content of arsenic (As) in mushrooms can vary depending on the concentration level of this metalloid in the soil/substrate. The present study evaluated the content of arsenic in Boletus badius fruiting bodies collected from polluted and non-polluted sites in relation to the content of this element in overgrown substrate. It was found that mushrooms from the arsenic-polluted sites contained mean concentrations from 49 to 450 mg As kg?1 dry matter (d.m.), with the greatest content found for specimens growing in close proximity of sludge deposits (490±20 mg As kg?1d.m.). The mean content of total arsenic in mushrooms from clean sites ranged from 0.03 to 0.37 mg kg?1 It was found that B. badius could tolerate arsenic in soil substrate at concentrations of up to 2500 mg kg?1, at least. In different years of investigation, shifts in particular arsenic forms, as well as a general increase in the accumulation of organic arsenic content, were observed. The results of this study clearly indicate that B. badius should not be collected for culinary purposes from any sites that may be affected by pollution.  相似文献   
65.
Determination of seven congeners of PCBs was carried out for sewage sludge before, during and after thermophilic digestion. The overall content of heavy metals (Zn, Cu, Ni, Cd, Pb, Cr) in sludge before and after digestion was determined. Moreover the concentration of heavy metals in particular chemical fractions of the sludge was analyzed. After the thermophilic digestion total concentration of seven PCBs was reduced by 47%, which suggests that thermophilic digestion affects PCB reduction positively. On the 10th d of the process, concentration of lower chlorinated PCBs increased, whereas those of higher chlorinated PCBs decreased. The thermophilic digestion process showed no accumulation of the studied heavy metals in the mobile fractions (exchangeable and carbonate) of the stabilized sewage sludge, except for nickel. The highest increase in zinc, copper, cadmium, and chromium concentration was observed in the organic-sulfide fraction, whereas the highest increase in lead was found in the residual fraction of the sludge. In case of nickel both fractions of organic-sulfide and exchangeable-carbonate fractions were enriched.  相似文献   
66.
Tropical delta regions are at risk of multiple threats including relative sea level rise and human alterations, making them more and more vulnerable to extreme floods, storms, surges, salinity intrusion, and other hazards which could also increase in magnitude and frequency with a changing climate. Given the environmental vulnerability of tropical deltas, understanding the interlinkages between population dynamics and environmental change in these regions is crucial for ensuring efficient policy planning and progress toward social and ecological sustainability. Here, we provide an overview of population trends and dynamics in the Ganges–Brahmaputra, Mekong and Amazon deltas. Using multiple data sources, including census data and Demographic and Health Surveys, a discussion regarding the components of population change is undertaken in the context of environmental factors affecting the demographic landscape of the three delta regions. We find that the demographic trends in all cases are broadly reflective of national trends, although important differences exist within and across the study areas. Moreover, all three delta regions have been experiencing shifts in population structures resulting in aging populations, the latter being most rapid in the Mekong delta. The environmental impacts on the different components of population change are important, and more extensive research is required to effectively quantify the underlying relationships. The paper concludes by discussing selected policy implications in the context of sustainable development of delta regions and beyond.  相似文献   
67.
Use of pharmaceuticals in animal production may cause an indirect route of contamination of food products of animal origin. This study aimed to assess, through mathematical modelling, the transfer of pharmaceuticals from contaminated soil, through plant uptake, into the dairy food production chain. The scenarios, model parameters, and values refer to contaminants in emission slurry production, storage time, immission into soil, plant uptake, bioaccumulation in the animal's body, and transfer to meat and milk. Modelling results confirm the possibility of contamination of dairy cow's meat and milk due the ingestion of contaminated feed by the cattle. The estimated concentration of pharmaceutical residues obtained for meat ranged from 0 to 6 ng kg?1 for oxytetracycline, from 0.011 to 0.181 μg kg?1 for sulfamethoxazole, and from 4.70 to 11.86 μg kg?1 for ketoconazole. The estimated concentrations for milk were: zero for oxytetracycline, lower than 40 ng L?1 for sulfamethoxazole, and from 0.98 to 2.48 μg L?1 for ketoconazole. Results obtained for the three selected pharmaceuticals indicate a minor risk for human health. This study showed that supply chain modelling could be an effective tool in assessing the indirect contamination of feedstuff and animal products by residues of pharmaceuticals. The model can easily be adjusted to other contaminants and supply chain and, in this way, present a valuable tool to underpin decision making.  相似文献   
68.
The Naples's harbour is one of the largest and most important commercial and tourist port of the Mediterranean basin. It is located on the southeast coast of Italy and receives industrial and municipal wastewaters from the city of Naples. Due to its social and economic impact, a comprehensive assessment of levels and sources of contamination of bottom sediments in this area of the Mediterranean basin is essential to identify potential danger due to mobilization of contaminants produced by managing of the same sediments. In this study, superficial sediments collected from 189 sampling sites were analyzed for grain size, heavy metals (Cr, Cu, Ni, Pb, V, Zn, Co, Sn, Cd, Hg, As, Al and Fe), 16 priority polycyclic aromatic hydrocarbons (PAHs) and perylene and 38 individual polychlorinated biphenyl (PCB) congeners. Compared to the estimated local background, Cu, Zn, Pb, Cd, Sn and Hg show enrichment factors >3 and only Hg evidences a median value higher than the NOAA (effects range - median) guidelines. Principal component analysis allowed us to clearly discriminate two areas mainly affected by heavy metals contamination and influenced by different sources related to industrial, commercial and/or urban activities. Priority PAHs are predominantly represented by three-five-ring compounds with concentrations ranging between 9 and 31774 ng g(-1) and frequently higher than the NOAA ER-M index. A prevalent pyrolitic origin of PAH was assessed on the basis of the relative abundance of the different congeners and selected isomer ratios. The concentrations of PCBs, as sum of the 38 congeners, ranged from 1 to 899 ng g(-1), with a predominance of highly chlorinated (tetra- and penta-chlorobiphenyls) congeners. WHO-TEQ values, calculated for the PCDD-like PCB congeners, suggest a relatively high level of toxicity. Generally, the concentration of PAHs and PCBs were higher near the sites of intense industrial, shipping and/or commercial activities suggesting a direct influence of these sources on the pollutant distribution patterns.  相似文献   
69.
Intensive forest monitoring by means of harmonised methods has been conducted in Europe for more than a decade. Risks of atmospheric nitrogen and sulphur deposition are assessed by means of calculations of critical loads and their exceedances. In the present study throughfall and bulk deposition of nitrate (N-NO(3)), ammonium (N-NH(4)) and sulphate (S-SO(4)) show marked spatial patterns and temporal trends. In the period of observation (1999-2004), sulphate deposition on intensive monitoring plots decreased by about one quarter. This is in line with the reduction of S deposition by 70% since 1981 in Europe as a result of successful air pollution control politics under the Convention on Long-range Transboundary Air Pollution (CLRTAP). However, sulphate and especially nitrate and ammonium deposition were found to still exceed critical loads at many forest sites, indicating a continued need for further implementation of air pollution abatement strategies.  相似文献   
70.

Background, aim and scope  

Urban motor vehicle fleets are a major source of particulate matter pollution, especially of ultrafine particles (diameters < 0.1 μm), and exposure to particulate matter has known serious health effects. A considerable body of literature is available on vehicle particle emission factors derived using a wide range of different measurement methods for different particle sizes, conducted in different parts of the world. Therefore, the choice as to which are the most suitable particle emission factors to use in transport modelling and health impact assessments presented as a very difficult task. The aim of this study was to derive a comprehensive set of tailpipe particle emission factors for different vehicle and road type combinations, covering the full size range of particles emitted, which are suitable for modelling urban fleet emissions.  相似文献   
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