Apparatus for the continuous dissolution of poorly water-soluble compounds for bioassays

An apparatus was designed and constructed to supply a continuous flow of water, saturated with soluble components of JP8 jet fuel. The product water, used to supply continuous flow bioassays, was found to be comparable in quality to that obtained with static dissolution techniques. The apparatus is constructed of inert materials and operates without pumps or other electro-mechanical regulating devices.     

Polybrominated diphenyl ethers and organochlorine compounds in biota from the marine environment of East Greenland

Ten black guillemot eggs, 19 ringed seals, 20 shorthorn sculpins and 20 Arctic chars were collected around Ittoqqortoormiit (Scoresbysund, Central East Greenland) in summer 2001 and analysed for 11 brominated diphenyl ether congeners (BDEs) and organochlorine compounds. Congeners BDE85 and BDE183 were not detected in any sample. SigmaBDE was highest in black guillemot eggs, with a median value of 80 ng/g lipid weight. This was approximately three times higher than that found for black guillemot eggs from West Greenland, thus supporting the spatial trend observed for organochlorines in Greenland. The median SigmaBDE concentration in ringed seal blubber was 36 ng/g lipid weight. This was clearly higher than SigmaBDE concentrations in ringed seal from the Canadian Arctic, but slightly lower than those found in ringed seals from Svalbard collected in 1981 and approximately 10 times lower than levels in seals from the Baltic Sea. Adult ringed seals had significantly higher SigmaBDE concentrations than animals less than 5 years old. Shorthorn sculpin liver and Arctic char muscle had similar concentrations of SigmaBDE, both with a median value of 7-10 ng/g lipid weight. The levels in shorthorn sculpin were similar to those reported from a previous study in Southwest Greenland. SigmaBDE levels correlated with PCB, DDT and chlordane-concentrations in the same samples, indicating similar mechanisms of uptake, bioaccumulation and biomagnification. The summed chlorobiphenyl concentrations in the same samples exceeded the SigmaBDE concentrations by a factor of approximately 15-30. The BDE congener patterns in black guillemot eggs and ringed seals were investigated using compound ratios and multivariate data analysis. The intraspecies variance was relatively small for black guillemot eggs and larger for ringed seals. Ringed seals had higher relative levels of the lower BDE congeners, e.g. BDE28 and BDE47 than black guillemots. The reasons for these different accumulation patterns are largely unknown and may reflect species-related differences in pollutant exposure, bioavailablity and metabolism.     

Partitioning of marine antifoulants in the marine environment

The partitioning behaviour of the organic biocides, Irgarol 1051 and diuron and two inorganic biocides (copper and zinc) was investigated using six sediments of differing physico-chemical properties collected from unimpacted sites along the south coast of England. The kinetics of sorption and equilibrium partitioning between the sediments and seawater were investigated over a period of 20 days. Resulting organic carbon/water partition coefficients (log Koc) were related to suspended sediment concentration and ranged from 2.28 to 5.20 for diuron; and from 2.41 to 4.89 for Irgarol 1051. Sediment/water partition coefficients (log Kp) for copper and zinc varied from 2.46 to 5.08 l/kg and from 2.49 to 4.97 l/kg, respectively. Kinetic data indicated that there were significant interactions between the dissolved and particulate phases at the start of the experiments, just after mixing. This is thought to be a result of redistribution of organic carbon between the two phases.     

海岸工程对海洋环境的影响

总结分析了海岸工程对海洋环境的具体影响,包括改变海洋水文动力环境,影响海水水质,破坏近岸海域生态环境等,对环境保护部门进行海洋环境影响因子识别有着重要的意义和参考价值。     

A pharmacokinetic model for estimating exposure of Americans to dioxin-like compounds in the past,present, and future

Empirical evidence suggests that exposure of Americans to dioxin-like compounds was low during the early decades of the 20th century, then increased during the 1940s and 1950s, reaching a peak in the 1960s and 1970s, and progressively decreased to lower levels in the 1980s and 1990s. Such evidence includes dioxin analysis of carbon-dated sediment cores of lakes and rivers, preserved meat samples from different decades of the 20th century, and limited body burden measurements of dioxin-like compounds. Pinsky and Lorber (1998) summarized studies measuring 2,3,7,8-TCDD in blood and adipose tissue, and found a range of 10-20 pg/g (ppt) lipid during the 1970s, and 2-10 ppt lipid during the 1980s. This study reviews body burdens of dioxin toxic equivalents, TEQs, to find a range from approximately 50 to 80 ppt lipid during the 1970s, 30-50 ppt lipid during the 1980s, and 10-20 ppt lipid during the 1990s (TEQs comprised of the 17 dioxin and furan congeners only). Pinsky and Lorber (1998) investigated historical exposure trends for 2,3,7,8-TCDD by using a single-compartment, first-order pharmacokinetic model. The current study extends this prior effort by modeling dioxin TEQs instead of the single compound, 2,3,7,8-TCDD. TEQs are modeled as though they were a single compound, in contrast to an approach where the individual dioxin and furan congeners are modeled separately. It was found that body burdens of TEQs during the 1970s, 1980s and 1990s could be modeled by assuming a historical dose which began the century at low levels of approximately 0.5 pg TEQ/kg/day, rose during the middle decades of the 20th century to over 6 pg TEQ/kg/day, and declined to current levels of approximately 0.5 pg TEQ/kg/day. Trends in individual and population body burdens of TEQs are also investigated using this PK modeling framework. A key uncertainty of this effort - assuming that TEQs behave as though they were a single compound - is discussed and analyzed.     

海工高耐久自密实混凝土的研制

针对跨海桥梁工程特点与环境条件,采取七元组分设计混凝土配合比,通过限制骨料含量、采用低水胶比、复掺磨细矿粉与Ⅰ级粉煤灰以及外掺聚羧酸系高性能减水剂等技术措施,配制出适合海洋环境条件、中等强度等级、具有良好体积稳定性的高耐久自密实混凝土.     

海洋环境锈蚀钢筋混凝土结构修补方法

海边建筑物经常由于氯离子的侵入而发生钢筋锈蚀破坏.介绍了由于锈蚀引起的不连续裂缝的封闭和修补,贯通裂缝的灌浆和修补,混凝土保护层的修补和结构的碳纤维补强等施工方法;这些方法可供锈蚀结构修复时参考.     

Population level effects of intersexuality in the marine environment

Whilst there have been many studies indicating links between anthropogenic contaminants and reproductive abnormalities in wildlife, very few studies have addressed the effects that might be occurring at the population level. In this study we aimed to assess the mid and long-term population effects of different levels of intersexuality in an amphipod species, Echinogammarus marinus. This aim was achieved by modelling the dynamics of a population of E. marinus with possible contaminant or parasite induced intersexuality over a ten-year period. The model considers five population groups: juveniles, males, immature females, adult normal females and adult intersex females. The costs associated with intersexuality in E. marinus were incorporated into the model using data from previous studies. The basic run of the model considers a population with 50% normal males and 50% normal females, which are prevalent in some field populations of E. marinus. Results of increasing proportions of intersex females were compared with the basic run and suggest that if intersex females occur at the expense of normal females, the population collapses after approximately 6 and 2.3 years when intersex females account for 5 and 10% of the population, respectively. Conversely, the population density increases exponentially if intersex females occur at the expense of males. However, if the number of intersex females reaches approximately (1/2) of the number of normal females, even if the percent of males in the population is as low as 27% (e.g. 27% males, 45% normal females, 28% intersex females), the population will be extinguished within 10 years. These results suggest a selective advantage in female-biased sex ratios in populations with significant levels of intersexuality, up to a certain threshold, where the increase in the total number of females seems to compensate the lower recruitment rates of intersex individuals, namely, intersex females. Furthermore, even in this scenario, if the recruitment rate of normal females is negatively affected, the population survivorship may be compromised. Modelling the effects of intersexuality in this manner should aid both environmental toxicologists and ecologists in predicting the population level effects of endocrine disrupting chemicals and/or parasites.     

海洋环境下混凝土桥梁耐久性设计

介绍了海洋环境下混凝土桥梁由于环境的影响出现较为常见的病害,有针对性地分析了病害的产生原因,根据已有危桥的经验教训对海洋环境下混凝土桥梁结构设计提出了一些建议,以提高混凝土桥梁的寿命。     

PCP in the freshwater and marine environment of the European Union.

This study collates monitoring data principally from 1991 to 1996, relating levels of pentachlorophenol (PCP) in the freshwater and marine environments of the European Union (EU) Member States of Belgium, France, Germany, the Netherlands and the UK. In general, PCP levels in the open freshwater and marine environments displayed a downward trend in these countries, and where increased PCP concentrations were observed, these were tentatively linked to specific point discharges. The monitoring data were compared against the relevant predicted no-effect concentration (PNEC) for PCP in a particular environmental medium. On this basis, the study suggests that PCP does not pose a risk to the coastal, estuarine, marine waters or marine sediments of the above countries, and that any risks posed by PCP to the freshwater environment can largely be attributed to sediments contaminated with PCP from historic usage, or due to the continued use of small quantities of sodium pentachlorophenyl laurate in northern France. Further analysis of the data was not possible owing to the lack of systematic reporting by Member States, the lack of information on usage quantities and patterns, and inconsistent environmental surveillance and reporting of environmental data. This is particularly relevant for south-west France, Portugal and north-east Spain, the region which accounts for almost 90% of the EU's consumption of NaPCP. These issues need to be addressed at a pan-European level to better inform the selection of risk management measures and to improve the effectiveness of such measures.     

Identification of estrogen-like effects and biologically active compounds in river water using bioassays and chemical analysis

The Nackdong River is the longest river in South Korea and passes through major cities that have several industrial complexes, including chemical, electric, and petrochemical complexes, and municipal characteristics such as apartment complexes. Along the river, the Gumi region has an electric industrial complex and an apartment complex that may be possible point sources of xenoestrogens such as phenolic compounds. To identify the causative chemicals for estrogenic activity in the river water of this region, bioassay-directed chemical analysis was performed. All samples from six sampling sites (an upstream point: S1; hot spot points: S2-1, S2-2, and S2-3; and downstream points: S3, and S4) showed estrogenic activity in the E-screen assay, with bio-EEQs (17β-E₂-equivalent quantities) ranging from 25.35-677.15 pg/L. Samples from S2-2, the sampling point downstream of the junction of stream water, and domestic and industrial wastewater, contained the highest estrogenic activity. Since the bio-EEQ of the organic acid fraction (F2) of the S2-2 sample had the highest activity (823.25 pg-EEQ/L) and F2 may contain phenolic compounds, GC-MS analyses for phenolic xenoestrogens were conducted with the organic acid fractions of the river water samples. Six estrogenic phenolic chemicals, 4-NP, BPA, 4-t-OP, 4-t-BP, 4-n-OP, and 4-n-HTP, were detected, with the highest concentrations (I-EEQ) found in S2-2 (231.80 pg/L). Among these phenolic chemicals, 4-NP was the most potent estrogen (bio-EEF; 8.12 × 10^− 5) and acted as a full agonist. Furthermore, 4-NP was present at levels (2.0 µg/L in S2-2) that can induce VTG induction in fish (>1 µg/L). In addition, we confirmed that river water (S2-2) significantly increased serum VTG levels in crucian carp (Carassius auratus) in a fish exposure experiment under laboratory conditions. Therefore, phenolic xenoestrogens, especially 4-NP, may be the main causative compounds responsible for the estrogenic effect on the Nackdong River.     

A two-species marine algal bioassay for detecting aquatic toxicity of chemical pollutants

A simple, rapid and sensitive two-species marine algal bioassay for determining the toxicity of chemical pollutants was developed. The bioassay employs the marine diatoms Phaeodactylum tricornutum (clone Phaeo) and Cyclotella cryptica (clone 03A), which were selected after screening 40 clones of 32 species for an optimum pair of organisms. These algae are easily grown in the laboratory, and the cells can be differentiated and counted with an electronic particle counter. Alteration of species ratio and/or total biomass were used to determine toxicity. Polychlorinated biphenyls (PCB, Aroclor 1254) at 10 parts per thousand million (10⁹; ptm) significantly altered species ratio in favor of Phaeo, and 10 ptm of DDT (1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane) and 20 ptm of dieldrin produced a significant species alteration opposite to that produced by PCB.     

Toxicity, uptake and survey studies of boron in the marine environment

Little is known about the toxic and bioaccumulative dangers to aquatic life posed by borate discharge recently initiated by coastal British Columbia groundwood pulp mills. Bioassays with sodium metaborate and underyearling coho salmon (Onchorhynchus kisutch) in fresh water yielded a 283-h lc₅₀ of 113 μg ml⁻¹ (104, 123 = 95% confidence limits). Toxicity to underyearling coho in sea water appeared considerably greater with a 283 h lc₅₀ of 12.2 μg ml⁻¹ (10.89, 14.56 = 95% confidence limits). The disparity between fresh and saltwater boron toxicity to coho is not understood at this time. In salmonids, boron enters the tissues slowly, necessitating prolonged bioassay tests. Sockeye salmon (O. nerka) and juvenile oysters (Crassostrea gigas) exposed to sublethal doses of boron take up boron roughly in relation to its availability. Oysters show no bioaccumulative potential or prolonged retention of boron following cessation of dosage. Field surveys conducted before and after industrial borate emission confirm the lack of evidence for tissue bioaccumulation. Results of a survey of boron levels in receiving waters are reported. No hazard to salmonids of oysters at the present level of industrial discharge of boron (≤1 μg B ml⁻¹) is apparent from this work.     

海洋环境中混凝土桥梁的腐蚀劣化与防护

针对海洋环境中混凝土桥梁出现的腐蚀和耐久性不足现象介绍了海洋环境中混凝土结构的劣化机理,包括硫酸盐和镁盐对混凝土的腐蚀以及氯离子诱发的钢筋锈蚀。为提高海洋环境中混凝土桥梁的抗腐蚀性能,延长结构寿命,从设计、混凝土表层防护和电化学防护角度简述了加强防护的措施。     

海洋环境混凝土防腐涂料研究及发展趋势

海洋环境下,钢筋混凝土结构会因海洋环境腐蚀而过早发生耐久性失效乃至破坏,进而带来巨大经济损失.如果对海洋工程采取有效防护措施,可以有效地延长结构的服役寿命,大大降低因腐蚀而造成的经济损失.针对混凝土表面涂层防腐措施,介绍了海洋环境下混凝土防腐涂料的种类、主要性能,指出了未来海洋防腐涂料的发展趋势,为防腐涂料的选取提供了参考.     

Levels and trends of poly- and perfluorinated compounds in the arctic environment

Poly- and perfluorinated organic compounds (PFCs) are ubiquitous in the Arctic environment. Several modeling studies have been conducted in attempt to resolve the dominant transport pathway of PFCs to the arctic—atmospheric transport of precursors versus direct transport via ocean currents. These studies are generally limited by their focus on perfluorooctanoate (PFOA) fluxes to arctic seawater and thus far have only used fluorotelomer alcohols (FTOHs) and sulfonamide alcohols as inputs for volatile precursors. There have been many monitoring studies from the North American and European Arctic, however, almost nothing is known about PFC levels from the Russian Arctic. In general, there are very few measurements of PFCs from the abiotic environment. Atmospheric measurements show the widespread occurrence of PFC precursors, FTOHs and perfluorinated sulfonamide alcohols. Further, PFCAs and PFSAs have been detected on atmospheric particles. The detection of PFCAs and PFSAs in snow deposition is consistent with the volatile precursor transport hypothesis. There are very limited measurements of PFCs in seawater. PFOA is generally detected in the greatest concentrations. Additional seawater measurements are needed to validate existing model predications. The bulk of the monitoring efforts in biological samples have focused on the perfluorinated carboxylates (PFCAs) and sulfonates (PFSAs), although there are very few measurements of PFC precursors. The marine food web has been well studied, particularly the top predators. In contrast, freshwater and terrestrial ecosystems have been poorly studied. Studies show that in wildlife perfluorooctane sulfonate (PFOS) is generally measured in the highest concentration, followed by either perfluorononanoate (PFNA) or perfluoroundecanoate (PFUnA). However, some whale species show relatively high levels of perfluorooctane sulfonamide (PFOSA) and seabirds are typically characterized by high proportions of the C₁₁-C₁₅ PFCAs. PFOA is generally infrequently detected and is present in low concentrations in arctic biota. Food web studies show high bioaccumulation in the upper trophic-level animals, although the mechanism of PFC biomagnification is not understood. Spatial trend studies show some differences between populations, although there are inconsistencies between PFC trends. The majority of temporal trend studies are from the Northern American Arctic and Greenland. Studies show generally increasing levels of PFCs from the 1970s, although some studies from the Canadian Arctic show recent declines in PFOS levels. In contrast, ringed seals and polar bears from Greenland continue to show increasing PFOS concentrations. The inconsistent temporal trends between regions may be representative of differences in emissions from source regions.     

海洋环境下混凝土墩柱的耐久性模拟

海洋环境条件下混凝土墩柱的耐久性配合比和构造一直是耐久性设计的重点,因耐久性设计不足给国家和社会带来了严重损失.基于全寿命成本分析软件life-365,通过分析保护层厚度、水灰比、掺合物、扩散系数对氯离子侵蚀期的影响,得到了如下结论:①保护层厚度的增加能极大地延长氯离子侵蚀期,有效地延迟了钢筋锈蚀发生的时间.②降低水灰比可以提高氯离子侵蚀期,但增幅相对有限.③掺合料的种类和掺和量对氯离子侵蚀期的长短影响显著,添加掺合料对提高混凝土构筑物的耐久性有着极大意义.④海洋环境下混凝土墩柱的耐久性不仅与扩散系数有关,还与水化系数有关,仅通过判断特定时间点氯离子扩散系数大小无法判断其耐久性性能的优劣.     

Tracers of sewage sludge in the marine environment: a review

A review of the available and potential tracers of the movement and distribution of sewage sludge ('sludge') in and on marine sediments is presented. A brief review of 'active' sludge tracers is followed by a more extensive review of 'passive' sludge tracers. These can be broken down into five categories: Natural organic components of sludge--organic carbon, faecal steroids, carbohydrate/TOC ratio, tomato seeds. Synthetic organic compounds--silicones, chlorinated hydrocarbons, non-ionic surfactants and their degradation products, linear alkylbenzenes. Stable isotopes of carbon, nitrogen, hydrogen and sulphur. Inorganic substances and their properties--minerals, paint pigments, trace elements, magnetic properties. Biological/Microbiological--faecal bacteria, Clostridium welchii spores, amoebae, viruses, nitrogen-fixing enterobacteriaceae. A wide variety of sludge tracers are available with the choice of suitable tracers in an individual situation governed by the available equipment and expertise, cost considerations, ease of sampling requirements and determination, and the nature of other pollutant inputs in the vicinity of the input of interest. Ideally, the sludge tracers chosen should be unique to the input of interest, but this will rarely be achievable in practice. In areas of gross sludge contamination, a marine geophysical survey technique can be used to delineate the area affected and this provides a rapid cost-effective method for large areas.     

A study of the effectiveness of antifouling electrodes in the marine environment

Antifouling systems based upon Cu/Al and Cu/Fe electrodes were tested both in enclosed pipes and chambers (simulating cooling systems), and upon panels and metal structures exposed to the full influence of tides and wave action. Fouling organisms failed to settle/grow in treated enclosed systems, while electrode-protected glass fibre panels/steel structures mounted intertidally in the Menai Strait remained almost devoid of biological fouling during the summer months when control installations became heavily fouled. Laboratory tests established that the antifouling action of electrodes was due to the dissolution of copper (in the ppb range), and not to the formation of a colloidal copper complex between copper and aluminium hydroxide. The unexpected effectiveness in non enclosed situations is believed to be due to high local copper concentrations maintained near the electrodes during slack water periods, and suggests a novel function for such electrodes—the localized protection of structures or instruments which cannot be treated with antifouling paints.