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91.
In this communication we present data on S-phenylcysteine (SPC) in human serum albumin in an Estonian cohort. A total of 112 human samples were collected from workers of a benzene processing plant in Kohtla-Järve, Estonia and another 56 samples from nearby countryside residents. Albumin was isolated using a sequential precipitation method designed for low volume plasma samples. The adducted cysteine derivatives were cleaved off from the albumin and subsequently derivatized to phenyl trifluorothioacetate (PTTA) derivatives. Derivatized adducts were subjected to GC/MS analysis utilizing negative chemical ionization and a selected ion monitoring (SIM) technique. The detection limit for the PTTA adduct was 0.2?pmol?g?1 albumin and the limit of quantification was 2?pmol?g?1 albumin. The method utilized deuterated SPC as an internal standard. The analysis revealed that adduct levels were also high in the population that was not occupationally exposed to benzene. The reason for this is unknown, but may cause problems if not of environmental origin, when one is attempting to monitor low level occupational or environmental benzene exposure.  相似文献   
92.
The seasonal changes in the concentrations of aluminium (Al), calcium (Ca), cadmium (Cd), chromium (Cr), copper (Cu), magnesium (Mg), manganese (Mn), lead (Pb), and zinc (Zn) in the leaves of Taraxacum officianale, Plantago lanceolata and Plantago major are investigated. the most convenient periods for sampling are established when the elemental concentrations have minimal variation and are independent on the development of the plant itself. On this basis, the presumption is made that the most appropriate sampling period for herbaceous species for biomonitoring processes is the end of blossoming of the plant or immediately after that.  相似文献   
93.
The aim of this study was to identify possible relationships between biochemical- superoxide dismutase (SOD), glutathione peroxidase (GPx), thiobarbituric acid reactive substances (TBARS) of mussels (Mytilus galloprovincialis) and chemical (Hg, Cd, Pb, Cr, Cu, Zn, Mn and Fe) contaminants from relatively clean area (Middle Bay) and heavily polluted area (Inner Bay) of the Izmir Bay. Sampling of mussels was performed in the beginning of May 2004. Mussel digestive glands have been used for biochemical assays. Trace metal content was determined by atomic absorption spectrophotometer using standard procedures. Metal contents in mussels collected at polluted site increased compared to the middle part of the bay. While there was a positive correlation between metals and SOD enzyme activity, there was a negative correlation between metals and GPx enzyme activity. An increase was observed in SOD enzyme activity and a decrease of GPx enzyme activity at the inner part of the bay.  相似文献   
94.
硅藻指数在水环境监测与评价中的应用   总被引:6,自引:0,他引:6  
介绍了硅藻种类组成对水环境状态的指示作用及硅藻指数法的基本原理,通过比较、分析发现:硅藻属指数适用于综合评价亚热带、热带地区的水体污染程度;硅藻模型相似性指数适用于评价气候稳定地区的水污染状况;生物硅藻指数适用范围广,稳定性最好;湖泊富营养化硅藻指数、营养指数、富营养化硅藻指数均为可靠的水体富营养化评价指数。指出目前硅藻的分类与鉴定体系不够完善,还应开展研究消除季节变化对硅藻指数方法稳定性的影响。  相似文献   
95.
Long-term variability of bioassessments has not been well evaluated. We analyzed a 20-year data set (1984–2003) from four sites in two northern California streams to examine the variability of bioassessment indices (two multivariate RIVPACS-type O/E scores and one multimetric index of biotic integrity, IBI), as well as eight metrics. All sites were sampled in spring; one site was also sampled in summer. Variability among years was high for most metrics (coefficients of variation, CVs ranging from 16% to 246% in spring) but lower for indices (CVs of 22–26% for the IBI and 21–32% for O/E scores in spring), which resulted in inconsistent assessments of biological condition. Variance components analysis showed that the time component explained variability in all metrics and indices, ranging from 5% to 35% of total variance explained. The site component was large (i.e., >40%) for some metrics (e.g., EPT richness), but nearly absent from others (e.g., Diptera richness). Seasonal analysis at one site showed that variability among seasons was small for some metrics or indices (e.g., Coleoptera richness), but large for others (e.g., EPT richness, O/E scores). Climatic variables did not show consistent trends across all metrics, although several were related to the El Ni?o Southern Oscillation Index at some sites. Bioassessments should incorporate temporal variability during index calibration or include climatic variability as predictive variables to improve accuracy and precision. In addition, these approaches may help managers anticipate alterations in reference streams caused by global climate change and high climatic variability.  相似文献   
96.
This work aimed at comparing the dynamics of atmospheric metal accumulation by the lichen Flavoparmelia caperata and bark of Platanus hybrida over different periods of time. Transplants were exposed in three Portuguese coastal cities. Samples were retrieved (1) every 2 months (discontinuous exposure), or (2) after 2-, 4-, 6-, 8- and 10-month periods (continuous exposure), and analysed for Cu, Ni and Pb. Airborne accumulation of metals was essentially independent of climatic factors. For both biomonitors [Pb]>[Ni]>[Cu] but Pb was the only element for which a consistent pattern of accumulation was observed, with the bark outperforming the lichen. The longest exposure periods hardly ever corresponded to the highest accumulation. This might have been partly because the biomonitors bound and released metals throughout the exposure, each with its own dynamics of accumulation, but both according to the environmental metal availability.  相似文献   
97.
This study compared the heavy metal bioaccumulation capacity in the epiphytic moss Scorpiurum circinatum and the epiphytic lichen Pseudevernia furfuracea, exposed in bags for 3 months in the urban area of Acerra (S Italy). The content of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Ti, V, and Zn was measured by ICP-MS. The results showed that both species accumulated all the heavy metals assayed. The moss had the highest bioaccumulation capacity for all metals and showed a more constant and linear accumulation trend than the lichen. Intra-tissue heavy metal bioaccumulation was assessed by X-ray microanalysis applied to ESEM operated in high and low vacuum and ESEM modes.  相似文献   
98.
The effect of Pb + Zn on coelomocyte riboflavin content in the epigeic earthworm Dendrodrilus rubidus inhabiting three metalliferous soils and one reference soil was measured by flow cytometry and spectrofluorimetry. A reciprocal polluted↔unpolluted worm transfer experiment (4-week exposure) was also performed. High proportions of autofluorescent eleocytes were counted in worms from all localities, but intense riboflavin-derived autofluorescence was detectable only in reference worm eleocytes. Other findings were: (i) fluorophore(s) other than riboflavin is/are responsible for eleocyte autofluorescence in residents of metalliferous soils; (ii) riboflavin content was reduced in the eleocytes of worms transferred from unpolluted to metal-polluted soil; (iii) the riboflavin content of D. rubidus eleocytes is a promising biomarker of exposure; (iv) COII mitochondrial genotyping revealed that the reference population is genetically distinct from the three mine populations; (v) metal exposure rather than genotype is probably the main determinant of inter-population differences in eleocyte riboflavin status.  相似文献   
99.
Polybrominated diphenyl ethers (PBDE) are used as flame retardants in a wide variety of products. As part of the Integrated Exposure Assessment Survey (INES), this study aimed to characterize the exposure of an adult German population using duplicate diet samples, which were collected daily over seven consecutive days, and indoor air and house dust measurements. Our study population consisted of 27 female and 23 male healthy subjects, aged 14–60 years, all of whom resided in 34 homes in southern Bavaria. In these 34 residences the air was sampled using glass fiber filters and polyurethane foams and the dust was collected from used vacuum cleaner bags.The median (95th percentile) daily dietary intake of six Tetra- to HeptaBDE congeners was 1.2 ng/kg b.w. (3.3 ng/kg b.w.) or 67.8 ng/day (208 ng/day) (calculated from the 7-day median values of each study subject). Concentrations in indoor air and dust (cumulative Tri- to DecaBDE congener readings) ranged from 8.2 to 477 pg/m³ (median: 37.8 pg/m³) and 36.6 to 1580 ng/g (median: 386 ng/g), respectively. For some congeners, we identified a significant correlation between air and dust levels.The median (95th percentile) blood concentration of total Tetra- to HexaBDE congener readings was 5.6 (13.2) ng/g lipid. No significant sex differences were observed, but higher blood concentrations were found in younger participants. Using a simplified toxicokinetic model to predict the body burden from exposure doses led to results that were of the same order of magnitude as the measured blood concentrations.Based on these measurements and given our exposure assumptions, we estimated for the total tetra- to heptabrominated congener count an average (high) comprehensive total daily intake of 1.2 ng/kg b.w. (2.5 ng/kg b.w.). Overall, our results suggest that dietary exposure is the dominant intake pathway at least in our study population, responsible for 97% (average intake) and 95% (high intake) of the total intake of an adult population.  相似文献   
100.
A biomonitoring network with leafy vegetables was established near a chlor-alkali plant in order to compare the accumulation of mercury to the atmospheric total gaseous mercury (TGM) concentration. Based on data obtained in the reference area the ‘normal’ mercury concentration in vegetables is between 0.6 and 5.4 μg kg−1 FW. The effect detection limits (EDLs) are between 1.2 and 11.0 μg kg−1 FW and the biological detection limits (BDLs), the lowest [TGM] that can be detected significantly, are between 3 and 4 ng m−3. The accumulation rate is lowest for lettuce and high for curly kale that proved to be an excellent accumulator and as such it is very useful for biomonitoring purposes. A comparison made in the 1980s between biomonitoring results with grass and the mercury concentration in leafy vegetables from private gardens nearby proved to be valid when applied to the current biomonitoring results with vegetables.  相似文献   
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