Occurrence of polybrominated diphenylethers, polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in coastal sediments from Spain

Fifteen sediment samples were analysed in order to determine their content of polybrominated diphenylethers (PBDEs), polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). Samples were collected from several hot spots on the Spanish coast, such as the harbours of Almeria and Tarragona, and the mouths of the Besos and Llobregat rivers in Barcelona. A generic analytical procedure based on Soxhlet extraction followed by an automated cleanup system and gas chromatography-ion trap-mass spectrometry was employed for determining the toxic congeners of PCDDs and PCDFs, as well as dioxin-like PCBs. As regards PBDE determinations, a rapid method based on the use of selective pressurized liquid extraction followed by gas chromatography-negative ion chemical ionization-mass spectrometry was applied. Total toxicity equivalent (WHO-TEQ) values were calculated using the toxicity equivalent factors proposed by WHO for dioxin-like PCBs, PCDDs and PCDFs. WHO-TEQ values ranged from 0.3 to 75 pg/g dry weight (dw), with PCB contribution on the toxicity of the samples between 1 and 84%. Total PBDE levels ranged from 2.7 to 134 ng/g dw, with BDE-209 contribution on the total PBDE contamination between 50 and 99%.     

水环境容量研究在环境管理中的实施过程初探

本文在地表水环境容量测算分析的基础上，分析测算中需要重视的关键问题，提出几个对测算结论影响较大的关键参数，并分析了环境容量在管理中应用的技术方法与手段，提出了水环境容量资源分配与管理中的解决方案。     

Prediction of an abnormal karyotype in fetuses with omphalocele

The aim of this study was to assess the value of ultrasonographic evaluation in predicting abnormal karyotypes in fetuses with omphalocele. Forty fetuses with antenatally diagnosed omphalocele and available karyotype results were reviewed. Ultrasound evaluation included herniation contents and size, and the detection of other anomalies. Nine of 40 consecutive fetuses had abnormal karyotypes: trisomy 18 (n = 5), trisomy 13 (n = 3), 47,XXX (n = 1). Only 1/25 with an extracorporeal liver versus 8/15 with an intracorporeal liver had abnormal chromosomes [P = 0·0006, RR = 0·14 (0·02 < RR <0·9)]. Small defects (<3 cm) were associated with abnormal karyotypes [P = 0·01, RR = 4·7 (1·4<RR <15·6)]. Finding concurrent malformations was highly associated with chromosomal anomalies [P = 0·00004, RR = 4·4 (2·3 < RR < 8·5)]. The presence of associated malformations, an intracorporeal liver, and a small herniation size are highly suggestive of an associated abnormal karyotype.     

Effect of different radiotracer labelling techniques on radionuclide excretion from marine organisms

Experiments were designed to assess the effect of different techniques of radiotracer labelling on subsequent radioisotope excretion rates in marine crustaceans. A small amphipod (Gammarus locusta) that accumulated ⁶⁵Zn under a close approximation of natural conditions excreted the radiotracer during a 3-month period at a markedly different rate than those of comparable amphipods labelled with ⁶⁵Zn in the laboratory via different combinations of radioactive food and seawater. Shrimp (Lysmata seticauda) administered ⁶⁵Zn by three different methods in the laboratory displayed different excretion kinetics during the first 2 months of loss. The difference between excretion rates most likely was a reflection of the degree to which the various zinc pools within the shrimp had equilibrated with the radiotracer. During the next several months all ⁶⁵Zn loss rates were quite similar, probably indicating that radiotracer excretion was taking place from similar zinc pools within the shrimp. The importance of adequate radiotracer labelling techniques as well as proper design of subsequent excretion experiments, used to gain reliable information on flux rates of the corresponding stable metal, is discussed. It is concluded that laboratory radiotracer experiments which are intended to supply information on actual situations in the sea require careful design and execution.     

Factors affecting methyl and inorganic mercury dynamics in mussels and shrimp

Radiotracer experiments were designed to study the effect of certain factors on the accumulation and loss of methyl and inorganic mercury in mussels (Mytilus galloprovincialis) and benthic shrimp (Lysmata seticaudata). Methyl mercury was accumulated from both food and water to a greater degree than inorganic mercury by both species. There was a tendency for small mussels to concentrate more mercury than larger individuals, but the reason for this difference remains unclear. A trend towards greater mercury accumulation at higher temperatures was noted for mussels, but the temperature effect was relatively small over a 10 C^o range between 8° and 19°C. Methyl mercury residues were eliminated by both species more slowly than those of the inorganic form. Loss from mussels was somewhat more rapid at higher temperatures; however, as in the case of accumulation, the effect of temperature was relatively small. Loss rates for small mussels were not significantly different from those for large individuals. Enhanced methyl mercury elimination was noted for the group of mussels maintained in their natural environment. The more rapid metal turnover in these individuals compared with mussels held in the laboratory was attributed to differences in the availability of natural particulate food matter and, hence, subsequent growth of the animals in the two experimental systems. The observed differences underscore the need for caution in predicting in situ flux of metals such as mercury in certain species based solely on data derived from laboratory experiments.     

Chorionic mosaicism: Association with fetal loss but not with adverse perinatal outcome

Cytogenetic data from the United States NICHD collaborative study of chorionic villus sampling (CVS) were used to evaluate the clinical significance of chorionic mosaicism. The 10 754 patients with normal cytogenetic results were compared wtih 108 patients (1.0 per cent) with placental mosaicism and 181 patients (1.6 per cent) with pseudomosaicism. Of the pregnancies intended to continue, the pregnancy loss rate was significantly greater in patients with placental mosaicism than in the cytogenetically normal cohort (8.6 vs. 3.4 per cent, p <0.05). However, there was no difference in the frequencies of abruptio placenta, preterm labour or delivery, small-for-gestational-age newborns, pregnancy-induced hypertension, or neonates with Apgar scores less than 7.     

Effect of pH on Anti-Rotavirus Activity by Comestible Juices and Proanthocyanidins in a Cell-Free Assay System

Cranberry (Vaccinium macrocarpon) and grape (Vitis labrusca) juices, and these species?? secondary plant metabolites [i.e., proanthocyanidins (PACs)] possess antiviral activity. An understanding of the mechanism(s) responsible for these juices and their polyphenolic constituents?? direct effect on enteric virus integrity, however, remains poorly defined. Using the rotavirus (RTV) as a model enteric virus system, the direct effect of manufacturer-supplied and commercially purchased juices [Ocean Spray Pure Cranberry 100?% Unsweetened Juice (CJ), Welch??s 100?% Grape Juice (GJ), 100?% Concord (PG) and 100?% Niagara juices (NG)] and these species?? cranberry (C-PACs) and grape PACs (G-PACs) was investigated. Loss of viral capsid integrity in cell-free suspension by juices and their PACs, and as a factor of pH, was identified by an antigen (RTV) capture enzyme-linked immunosorbent assay. At native and an artificially increased suspension at or near pH 7, loss of viral infectivity occurred after 5?min, in the order CJ?>?NG?=?GJ?>?PG, and PG?>?GJ?=?NG?=?CJ, respectively. Antiviral activity of CJ was inversely related to pH. Grape, but not cranberry PACs, displayed a comparatively greater anti-RTV activity at a suspension pH of 6.7. Anti-RTV activity of C-PACs was regained upon reduction of RTV-cranberry PAC suspensions to pH 4. An alteration or modification of Type A PAC (of V. macrocarpon) structural integrity at or near physiologic pH is suggested to have impacted on this molecule??s antivirus activity. Type B PACs (of V. labrusca) were refractive to alternations of pH. Significantly, findings from pure system RTV?CPAC testing paralleled and in turn, supported those RTV-juice antiviral studies. Electron microscopy showed an enshroudment by PACs of RTV particles, suggesting a blockage of viral antigenic binding determinants. The implications of our work are significant, especially in the interpretation of PAC (and PAC-containing food)?CRTV interactions in the differing [pH] conditions of the gastrointestinal tract.     

A New Ozonated Cassava Film with the Addition of Cellulose Nanofibres: Production and Characterization of Mechanical,Barrier and Functional Properties

Journal of Polymers and the Environment - In this study cassava starch modified by ozone technology and cellulose nanofibres were used to produce films. These nanocomposites were produced by...     

Influence of hydrodynamic conditions on the production and fate of Posidonia oceanica in a semi-enclosed shallow basin (Stagnone di Marsala,Western Sicily)

An integrated approach using hydrodynamic and transport numerical models, lepidochronology and stable isotope analysis was used to investigate how local hydrodynamic conditions influence the primary production and fate of the seagrass Posidonia oceanica in a Mediterranean semi-enclosed marine system (Stagnone di Marsala). The water mass exchange aptitude of different sectors of the basin was analysed, and data collected were used to select two sectors (colonized by Posidonia oceanica showing the lowest and highest water exchange values) for biological analyses. According to the mean dispersal coefficient differences simulated by the hydrodynamic model, growth rate and primary production of P. oceanica differed between sectors, with average values lower in the central sector where water exchange is lower than in the southern sector. Although P. oceanica coverage and primary production were higher in the southern sector, carbon and nitrogen stable isotope analysis suggests that the transfer of seagrass organic matter to higher trophic levels of the food web was higher in the central sector. The possibility of a link between hydrodynamism, production and fate of organic matter is proposed to explain the observed patterns.     

Speciation of inorganic arsenic in alimentary and environmental aqueous samples by using derivative anodic stripping chronopotentiometry (dASCP)

The purpose of this research was to develop a sensitive and accurate chronopotentiometric method at a gold film electrode, to determine trace and ultra trace levels of As(III) and As(V) in alimentary and environmental water systems. As(III) was directly determined in the aqueous matrix at a deposition potential of -300 mV for 180 s and at a constant anodic current of 2.5 microA, without any sample pre-treatment; moreover the chronopotentiometric method did not require a time-consuming de-oxygenation step prior to the analysis. A 3M HCl solution was chosen as the best stripping medium. The direct analysis of As(V) required the application of a high negative over-potential and, thus, measurements were characterized by poor reproducibility; therefore As(V) was determined after reduction to As(III) with KI in a strong hydrochloric acid solution. Under the optimised electrochemical conditions, detection limits of 0.08 microg As(III) l(-1) were achieved and no significant interferences from Cd, Cu, Pb, Zn and organic substances were observed. As(V) was the most abundant species in all the studied environmental and alimentary aqueous matrices. Amongst the beverages, tea and coffee presented the As(V) highest concentration ranges (934-1740 microg l(-1) and 850-1290 microg l(-1), respectively) while bottled mineral water the lowest (<1.61 microg l(-1)); whereas As(III) levels lower than 5.0 microg l(-1) were detected only in wine samples.