企业安全管理体系标准模式的比较研究

采用对比分析法和实证分析法,对当前国内外流行的企业安全管理体系标准模式及其评价方法进行比较研究,旨在把握诸多标准模式的原则、路径、结构、方法和共性特征及其可以发挥的具体优点,将研究的标准模式的评价方法归纳为两大类即体系认证审核法和综合考评打分法,并对两类评价方法的优缺点进行剖析。体系认证审核法的优点是过程方法、符合性及抽样,考评打分法则提供了安全绩效准则。对吸收融合两类评价方法的优点形成综合性评价方法的途径和方式进行了探讨,为企业建立有效、适用的安全管理体系提供了依据。     

Analysis of the Trend and Seasonal Cycle of Carbon Monoxide Concentrations in an Urban Area (4 pp)

Background, Aim and Scope Air quality is an field of major concern in large cities. This problem has led administrations to introduce plans and regulations to reduce pollutant emissions. The analysis of variations in the concentration of pollutants is useful when evaluating the effectiveness of these plans. However, such an analysis cannot be undertaken using standard statistical techniques, due to the fact that concentrations of atmospheric pollutants often exhibit a lack of normality and are autocorrelated. On the other hand, if long-term trends of any pollutant’s emissions are to be detected, meteorological effects must be removed from the time series analysed, due to their strong masking effects. Materials and Methods The application of statistical methods to analyse temporal variations is illustrated using monthly carbon monoxide (CO) concentrations observed at an urban site. The sampling site is located at a street intersection in central Valencia (Spain) with a high traffic density. Valencia is the third largest city in Spain. It is a typical Mediterranean city in terms of its urban structure and climatology. The sampling site started operation in January 1994 and monitored CO ground level concentrations until February 2002. Its geographic coordinates are W0°22′52″ N39°28′05″ and its altitude is 11 m. Two nonparametric trend tests are applied. One of these is robust against serial correlation with regards to the false rejection rate, when observations have a strong persistence or when the sample size per month is small. A nonparametric analysis of the homogeneity of trends between seasons is also discussed. A multiple linear regression model is used with the transformed data, including the effect of meteorological variables. The method of generalized least squares is applied to estimate the model parameters to take into account the serial dependence of the residuals of this model. This study also assesses temporal changes using the Kolmogorov-Zurbenko (KZ) filter. The KZ filter has been shown to be an effective way to remove the influence of meteorological conditions on O₃ and PM to examine underlying trends. Results The nonparametric tests indicate a decreasing, significant trend in the sampled site. The application of the linear model yields a significant decrease every twelve months of 15.8% for the average monthly CO concentration. The 95% confidence interval for the trend ranges from 13.9% to 17.7%. The seasonal cycle also provides significant results. There are no differences in trends throughout the months. The percentage of CO variance explained by the linear model is 90.3%. The KZ filter separates out long, short-term and seasonal variations in the CO series. The estimated, significant, long-term trend every year results in 10.3% with this method. The 95% confidence interval ranges from 8.8% to 11.9%. This approach explains 89.9% of the CO temporal variations. Discussion The differences between the linear model and KZ filter trend estimations are due to the fact that the KZ filter performs the analysis on the smoothed data rather than the original data. In the KZ filter trend estimation, the effect of meteorological conditions has been removed. The CO short-term componentis attributable to weather and short-term fluctuations in emissions. There is a significant seasonal cycle. This component is a result of changes in the traffic, the yearly meteorological cycle and the interactions between these two factors. There are peaks during the autumn and winter months, which have more traffic density in the sampled site. There is a minimum during the month of August, reflecting the very low level of vehicle emissions which is a direct consequence of the holiday period. Conclusions The significant, decreasing trend implies to a certain extent that the urban environment in the area is improving. This trend results from changes in overall emissions, pollutant transport, climate, policy and economics. It is also due to the effect of introducing reformulated gasoline. The additives enable vehicles to burn fuel with a higher air/fuel ratio, thereby lowering the emission of CO. The KZ filter has been the most effective method to separate the CO series components and to obtain an estimate of the long-term trend due to changes in emissions, removing the effect of meteorological conditions. Recommendations and Perspectives Air quality managers and policy-makers must understand the link between climate and pollutants to select optimal pollutant reduction strategies and avoid exceeding emission directives. This paper analyses eight years of ambient CO data at a site with a high traffic density, and provides results that are useful for decision-making. The assessment of long-term changes in air pollutants to evaluate reduction strategies has to be done while taking into account meteorological variability     

Soil and vegetation carbon stocks in Brazilian Western Amazonia: relationships and ecological implications for natural landscapes

The relationships between soils attributes, soil carbon stocks and vegetation carbon stocks are poorly know in Amazonia, even at regional scale. In this paper, we used the large and reliable soil database from Western Amazonia obtained from the RADAMBRASIL project and recent estimates of vegetation biomass to investigate some environmental relationships, quantifying C stocks of intact ecosystem in Western Amazonia. The results allowed separating the western Amazonia into 6 sectors, called pedo-zones: Roraima, Rio Negro Basin, Tertiary Plateaux of the Amazon, Javari-Juruá-Purus lowland, Acre Basin and Rondonia uplands. The highest C stock for the whole soil is observed in the Acre and in the Rio Negro sectors. In the former, this is due to the high nutrient status and high clay activity, whereas in the latter, it is attributed to a downward carbon movement attributed to widespread podzolization and arenization, forming spodic horizons. The youthful nature of shallow soils of the Javari-Juruá-Purus lowlands, associated with high Al, results in a high phytomass C/soil C ratio. A similar trend was observed for the shallow soils from the Roraima and Rondonia highlands. A consistent east–west decline in biomass carbon in the Rio Negro Basin sector is associated with increasing rainfall and higher sand amounts. It is related to lesser C protection and greater C loss of sandy soils, subjected to active chemical leaching and widespread podzolization. Also, these soils possess lower cation exchangeable capacity and lower water retention capacity. Zones where deeply weathered Latosols dominate have a overall pattern of high C sequestration, and greater than the shallower soils from the upper Amazon, west of Madeira and Negro rivers. This was attributed to deeper incorporation of carbon in these clayey and highly pedo-bioturbated soils. The results highlight the urgent need for refining soil data at an appropriate scale for C stocks calculations purposes in Amazonia. There is a risk of misinterpreting C stocks in Amazonia when such great pedological variability is not taken into account.     

Funipuncture for fetocide in late termination of pregnancy

The most widely used method for fetocide in late termination of pregnancy for fetal abnormalities (TOPFA) consists of injecting of potassium chloride (KCl) into the fetal heart and is likely to be painful after 22 weeks of gestation. We studied ten consecutive women undergoing TOPFA between 22 and 38 weeks. This technique for fetocide consisted of a single umbilical vein puncture under ultrasound guidance with injections of sufentanil 5 µg followed by KCl 2 g. No electrocardiographic modifications could be observed and maternal plasma potassium levels did not show any significant variation throughout the procedure. Fetal umbilical phlebotomy for fetal analgesia followed by fetocide therefore appears to be a safe procedure for the mother and allows the fetus to die without pain when late termination of pregnancy (TOP) is indicated. Copyright © 2002 John Wiley & Sons, Ltd.     

Heavy metal contamination in the vicinity of an industrial area near Bucharest

BACKGROUND, AIMS AND SCOPE: Chromium enters into the aquatic environment as a result of effluent discharge from steel works, electroplating, leather tanning industries and chemical industries. As the Cr(VI) is very harmful to living organisms, it should be quickly removed from the environment when it happens to be contaminated. Therefore, the aim of this laboratory research was to develop a rapid, simple and adaptable solvent extraction system to quantitatively remove Cr(VI) from polluted waters. METHODS: Aqueous salt-solutions containing Cr(VI) as CrO4(2-) at ppm level (4-6 ppm) were prepared. Equal volumes (5 ml) of aqueous and organic (2-PrOH) phases were mixed in a 10 ml centrifuge tube for 15 min, centrifuged and separated. Concentrations of Cr(VI), in both the aqueous and organic phases, were determined by atomic absorption spectrometry. The effects of salt and acid concentrations, and phase-contact time on the extraction of Cr(VI) were investigated. In addition, the extraction of Cr(VI) was assessed in the presence of tetramethylammonium chloride (TMAC) in 2-PrOH phase. Effects of some other metals, (Cd(II), Co(II), Cu(II), Ni(II) and Zn(II)), on the extraction of Cr(VI) were also investigated. RESULTS AND DISCUSSION: The Cr(VI) at ppm level was extracted quantitatively by salting-out the homogeneous system of water and 2-propanol(2-PrOH) using chloride salts, namely CaCl2 or NaCl, under acidic chloride media. The extracted chemical species of Cr(VI) was confirmed to be the CrO3Cl-. The ion-pair complex extracted into the organic phase was rationalized as the solvated ion-pair complex of [2-PrOH2+, CrO3Cl-]. The complex was no longer stable. It implied the reaction between extracted species. Studies revealed that salts and acid directly participated in the formation of the above complex. Use of extracting agents (TMAC) didn't show any significant effect on the extraction of Cr(VI) under high salting-out conditions. There is no significant interference effect on the extraction of Cr(VI) by the presence of other metals. The Cr(VI) in the organic phase was back-extracted using an aqueous ammonia solution (1.6 mol dm(-3)) containing 3 mol dm(-3) NaCl. The extraction mechanism of Cr(VI) is also discussed. CONCLUSIONS: Salting-out of homogeneous mixed solvent of 2-propanol can be employed to extract Cr(VI) quantitatively, as an ion-pair of [2-PrOH2+ * CrO3Cl-] solvated by 2-PrOH molecules. Then, the complex becomes 'solvent-like' and is readily separated into the organic phase. The increase of Cl- ion concentration in the aqueous phase favors the extraction. The 2-PrOH, salts and acid play important roles in the extraction process. There is no need to use an extracting agent at a high salting-out condition. RECOMMENDATIONS AND PERSPECTIVES: Chromium(VI) must be quickly removed before it enters into the natural cycle. As the 2-PrOH is water-miscible in any proportion, ion-pairing between 2-PrOH2+ and CrO3Cl- becomes very fast. As a result, Cr(VI) can easily be extracted. Therefore, the method is recommended as a simple, rapid and adaptable method to quickly separate Cr(VI) from aqueous samples.     

Some observations of the structure of the choroid plexus and its cysts

The structure of the choroid plexus was studied in five normal human embryos, three normal fetuses and three fetuses with choroid plexus cysts. These were detected by ultrasound and the fetuses were karyotypically normal. The choroid plexus appears in the lateral cerebral ventricles at the seventh developmental week. The early structure is lobulated with vessels running in the mesenchymal stroma and forming capillary nets under the single-layered ependymal epithelium. This embryonal structure is converted into the fetal type during the ninth developmental week as the embryonal capillary net is replaced by elongated loops of wavy capillaries that lie under regular longitudinal epithelial folds. The choroid plexus cysts exhibited accumulation of fluid within distended mesenchymal stroma and did not show the wavy folds on this surface, which was smooth. Within this connective tissue of the cyst wall were distended angiomatous interconnecting thin-walled capillaries. Therefore, filled cavities were not lined by any epithelium. We suggest that fetal choroid plexuses cysts (at least in many cases) are in fact pseudocysts exhibiting angiomatous patterns of capillaries in their walls. Copyright © 2002 John Wiley & Sons, Ltd.     

Exploring Chemical Variables in Ligustrum lucidum Ait. F. Tricolor (Rehd.) Rehd. in Relation to Air Pollutants and Environmental Conditions

Ligustrum lucidum Ait. f. tricolor (Rehd.) Rehd. in relation to atmospheric pollutants in Córdoba city, Argentina. The study area receives regional pollutants and was categorized taking into account traffic level, industrial density, type of industry, location of the sample point in relation to the street corner, treeless condition, and topographic level. Dried weight/fresh weight ratio (DW/FW) and specific leaf area (SLA) were calculated, and concentrations of chlorophylls, carotenoids, total sulfur, soluble proteins, malondialdehyde (MDA), and hydroperoxy conjugated dienes (HPCD) were determined in leaf samples. Sulfur content correlates positively with traffic density and SLA correlates negatively with some combinations of the categorical variables; MDA correlates positively with topographic level and total protein concentration correlates negatively with treeless condition. On the basis of our results, traffic, location of trees, type of industry, situation of a tree with respect to others, and topographic level are the environmental variables to bear in mind when selecting analogous sampling points in a passive monitoring program. An approximation to predict tree injury may be obtained by measuring DW/FW ratio, proteins, pigments, HPCD, and MDA as they are responsible for the major variability of data.     

A comparison of different lysis buffers to assess allele dropout from single cells for preimplantation genetic diagnosis

Single cell polymerase chain reaction (PCR) for preimplantation genetic diagnosis (PGD) requires high efficiency and accuracy. Allele dropout (ADO), the random amplification failure of one of the two parental alleles, remains the most significant problem in PCR-based PGD testing since it can result in serious misdiagnosis for compound heterozygous or autosomal dominant conditions. A number of different strategies (including the use of lysis buffers to break down the cell and make the DNA accessible) have been employed to combat ADO with varying degrees of success, yet there is still no consensus among PGD centres over which lysis buffer should be used (ESHRE PGD Consortium, 1999 ). To address this issue, PCR amplification of three genes (CFTR, LAMA3 and PKP1) at different chromosomal loci was investigated. Single lymphocytes from individuals heterozygous for mutations within each of the three genes were collected and lysed in either alkaline lysis buffer (ALB) or proteinase K/SDS lysis buffer (PK). PCR amplification efficiencies were comparable between alkaline lysis and proteinase K lysis for PCR products spanning each of the three mutated loci (ΔF508 in CFTR 90% vs 88%; R650X in LAMA3 82% vs 78%; and Y71X in PKP1 91% vs 87%). While there was no appreciable difference between ADO rates between the two lysis buffers for the LAMA3 PCR product (25% vs 26%), there were significant differences in ADO rates between ALB and PK for the CFTR PCR product (0% vs 23%) and the PKP1 PCR product (8% vs 56%). Based on these results, we are currently using ALB in preference to PK/SDS buffer for the lysis of cells in clinical PGD. Copyright © 2001 John Wiley & Sons, Ltd.     

Metals in vineyard soils of the Penedès area (NE Spain) after compost application

The application of organic wastes to improve soil physical characteristics in mechanized vineyards planted after land levelling is becoming a common practice in Mediterranean areas. It may be useful as an additional source of organic matter and nutrients, but these wastes could also have negative effects due to their metal content. The aim of the study was to evaluate the influence of compost application on soil metal contents in mechanized vineyard soils of the Spanish Mediterranean area, where this practice is repeated every three years. The study was carried out in a ten-year-old vineyard where the main soil type is Typic Calcixerept. Composted cattle manure was applied in alternate rows, at a rate of 40 Mgha(-1) dry-weight. Nine sampling points were located along the slopes of two plots: a levelled plot prepared for mechanization with large soil disturbance movements within the plot, and a plot of undisturbed soil. At each location, soil samples were taken in both treated and untreated soils. Total concentrations (digestion with aqua regia) and the extractable DTPA (Diethylene-triaminepentacetic)-CaCl2-TEA (Triethanolamine) fractions of Cu, Zn and Mn were analyzed in each sample. For Cu and Zn, the initial concentration was higher in the undisturbed plot. In both cases, total Cu and total Zn were positively affected by manure input and the concentration in treated soils was significantly higher than in untreated soil. For Mn, the initial concentration was higher in disturbed soils than in undisturbed ones, and although in both scenarios the concentrations increased with manure, no significant differences were found between treated and untreated soils. The extractable fraction also increased in treated versus untreated soils, although for Cu and Mn the extractable/total metal ratio was similar in treated and untreated soils. After one compost application, total metal contents increased significantly, particularly for Zn. Most of those metals are accumulated in the soil, due to the soil characteristics.     

Fluctuations of Population Size and Structure in the Northern Mole Vole: Preliminary Analysis

Long-term stationary studies on the ecology of the northern mole vole (Ellobius talpinus Pall.), performed by the mark–recapture method from 1985 to 1997, have provided original data on population dynamics and structure. The analysis shows that, to reveal cyclic fluctuations of population size in this species, the period of three years should be taken as a unit of time for estimating the duration of one phase. The 12-year population cycle in E. talpinus has four distinct phases: an increase, a peak, a decline, and a minimum. At each phase, the population is characterized by certain features of family structure, age composition, birth and death rates, and the composition of migrants.