Organochlorines in antarctic and arctic avian top predators: a comparison between the South Polar Skua and two species of northern hemisphere gulls

Different organochlorine compounds (OCs) were measured in the blood of breeding south polar skuas (Catharacta maccormicki) at Svarthamaren, Dronning Maud Land (Antarctica) and compared to those in two species of northern hemisphere gulls: the Arctic glaucous gull (Larus hyperboreus) and the subarctic great black-backed gull (Larus marinus). The skuas had 8% and 29% of the SigmaOC levels (45 ng/g, wet weight) of glaucous gulls (591 ng/g) and great black-backed gulls (158 ng/g), respectively. Polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) were very low in skuas compared to northern gulls, but the mean hexachlorobenzene (HCB) level was 1.7 times higher than in great black-backed gulls and one-third of the glaucous gull level. Mirex levels in skuas were among the highest reported in birds, the mean level being 3 and 26 times higher than those in glaucous gull and great black-backed gulls, respectively. In skuas, the mean levels of HCB, oxychlordane, p,p'-DDE, and PCBs increased by about 30% during a 2-week period, and mirex increased by nearly 60%. In glacuous gulls, HCB, p,p'-DDE, and PCBs increased by 10-20%. For HCB, mirex, and oxychlordane, only a relatively small proportion of the increase in skuas could be explained by changes in lipid pools and the levels at first sampling, compared to glaucous gulls. Thus, skuas were probably accumulating these compounds when present in Antarctica. p,p'-DDE and PCB levels, in contrast, seemed much more stable in the skuas. Relatively high levels of mirex and HCB in south polar skuas are concerning with regard to potential adverse effects.     

Vertical and lateral redistribution of POPs in soils developed along a hydrological gradient

Study of the dispersion of persistent organic pollutants (POPs) throughout the environment is necessitated by their toxicological properties and propensity to accumulate in biota. In this study, we use data from the analysis of three (210)Pb dated soil profiles collected along a 30-m hydrological gradient to demonstrate postdepositional mobility of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). We found that (i) humus originating from litter exposed to surface fallout during the 1960-1970s contains the highest concentrations of PCDD/Fs and PCBs in the O-horizon of the soils; (ii) accumulation rates of PCDD/Fs and PCBs in the O-horizon (～5.0 and ～210 μg m(-2) yr(-1)) constituted only 9.1% and 3.5%, respectively, of the measured annual input, demonstrating that a minor fraction of the deposited material is retained within the O-horizon; (iii) POP inventories in the upper 0.5-0.9 m of the mineral soil constituted a considerable part (40-70%) of the total pool stored in the soil, implying significant vertical translocation of atmospheric derived POPs; and (iv) increasing downslope inventories of POPs suggest a lateral downward transport of POPs from uphill soils. The findings challenge the commonly accepted view that POPs fallout is effectively retained within O-horizons.     

Arsenic occurrence and species in near-shore macroalgae-feeding marine animals

This study was undertaken to improve the understanding of arsenic species and their pathways of formation in marine animals: fish (Odax cyanomelas), abalone (Haliotis rubra), and sea urchins (Heliocidaris erythrogramma and Centrostephanus rodgersii) that are directly exposed through their diets to dimethyl arsenoriboses in macroalgae (Phyllospora comosa and Halopteris platycena). The identification of dimethyl arsenoriboses (phosphate, sulfonate, and glycerol) in both dominant macroalgae species, and especially digestive tissues of marine animals that consume them, suggests these arsenic species, are to some degree accumulated directly from their diets without degradation or conversion. An unknown arsenic species in H. rubra intestinal tissue was identified using tandem mass spectrometry as 2',3'-dihydroxypropyl 5-deoxy-5-trimethyl arsonioriboside (trimethyl glycerol arsenoribose). The concentration of trimethyl glycerol arsenoribose in H. rubra intestinal tissue was estimated to account for 28% (5.0 microg g(-1) dry mass) of the methanol-water-soluble arsenic fraction. The presence of a trimethyl glycerol arsenoribose in marine animal tissues may be due to microbial-mediated processes that promote the reduction and methylation of dimethyl arsenoriboses released during the breakdown of macroalgae in their diets. Arsenobetaine formation may then occur in the lumen of the digestive tract (i.e., mediated by microorganisms) or in the liver catalyzed by enzymes. The identification of a large amount of trimethyl glycerol arsenoribose in H. rubra intestinal tissue suggests this species is a main constituent in the pathway for arsenic in this marine animal.     

Arsenic speciation in blue mussels (Mytilus edulis) along a highly contaminated arsenic gradient

Arsenic is naturally present in marine ecosystems, and these can become contaminated from mining activities, which may be of toxicological concern to organisms that bioaccumulate the metalloid into their tissues. The toxic properties of arsenic are dependent on the chemical form in which it is found (e.g., toxic inorganic arsenicals vs nontoxic arsenobetaine), and two analytical techniques, high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and X-ray absorption spectroscopy (XAS), were used in the present study to examine the arsenic species distribution in blue mussels (Mytilus edulis) obtained from an area where there is a strong arsenic concentration gradient as a consequence of mining impacted sediments. A strong positive correlation was observed between the concentration of inorganic arsenic species (arsenic compounds with no As-C bonds) and total arsenic concentrations present in M. edulis tissues (R(2) = 0.983), which could result in significant toxicological consequences to the mussels and higher trophic consumers. However, concentrations of organoarsenicals, dominated by arsenobetaine, remained relatively constant regardless of the increasing As concentration in M. edulis tissue (R(2) = 0.307). XANES bulk analysis and XAS two-dimensional mapping of wet M. edulis tissue revealed the presence of predominantly arsenic-sulfur compounds. The XAS mapping revealed that the As(III)-S and/or As(III) compounds were concentrated in the digestive gland. However, arsenobetaine was found in small and similar concentrations in the digestive gland as well as the surrounding tissue suggesting arsenobetaine may being used in all of the mussel's cells in a physiological function such as an intracellular osmolyte.     

Method of analysis of astaxanthin and its occurrence in some marine products

A method for the determination of astaxanthin in free and esterified forms is based on silica gel chromatography of a lipid extract to obtain fractions of diester, monoester and free astaxanthin. The fractions are reduced with borohydride and the tetrahydroxy β-carotene is measured by ultra-violet spectrophotomefry at 450 and 476 nm. The method has been applied to different crustacean samples and products to fish oils and to organs from rainbow trout. Values down to 0·1 μg/g sample could be measured. The fractions were identified by thin-layer chromatography.     

Factors affecting the occurrence and transport of atmospheric organochlorines in the china sea and the northern Indian and South East atlantic oceans

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are reported in 97 air samples collected on board the RV Polarstern in November 2007 from the equator to Cape Town, South Africa and the MV Oceanic II (The Scholar Ship) in January-March 2008 from Shanghai, China to Cape Verde in the Central Atlantic Ocean. The atmospheric concentrations were higher close to the coast and lower in remote regions of the Indian and South Atlantic Ocean. Groups of samples were selected in the South China Sea, Indian Ocean and South Atlantic Ocean where the relative wind direction matched the trajectory of the ship, thus all the samples had the same input of sources upwind. In these three regions the concentrations of OCPs and PCBs declined during atmospheric transport following first order kinetics. These sets of measurements provided estimates of field derived residence times (FDRTs) for individual compounds. These values were compared with predicted atmospheric residence times (PARTs) computed using a model of long-range atmospheric transport potential of POPs. The FDRTs are 5-10 times longer for the more volatile PCB congeners and TC, CC, p,p'-DDT and p,p'-DDE than the respective PARTs, while they are similar to PARTs for the less volatile compounds. Possible causes of discrepancies between PARTs and FDRTs are discussed, and revolatilization from the ocean surface seems to be the main cause for the higher values of FDRTs of the more volatile compounds in comparison with the respective PARTs.     

Flame retardants and methoxylated and hydroxylated polybrominated diphenyl ethers in two Norwegian Arctic top predators: glaucous gulls and polar bears

The brominated flame retardants have been subject of a particular environmental focus in the Arctic. The present study investigated the congener patterns and levels of total hexabromocyclododecane (HBCD), polybrominated biphenyls, polybrominated diphenyl ethers (PBDEs), as well as methoxylated (MeO) and hydroxylated (OH) PBDEs in plasma samples of glaucous gulls (Larus hyperboreus) and polar bears (Ursus maritimus) from the Norwegian Arctic. The analyses revealed the presence of total HBCD (0.07-1.24 ng/g wet wt) and brominated biphenyl 101 (< 0.13-0.72 ng/g wet wt) in glaucous gull samples whereas these compounds were generally found at nondetectable or transient concentrations in polar bears. Sum (sigma) concentrations of the 12 PBDEs monitored in glaucous gulls (range: 8.23-67.5 ng/g wet wt) surpassed largely those of polar bears (range: 2.65-9.72 ng/g wet wt). Two higher brominated PBDEs, BDE183 and BDE209, were detected, and thus bioaccumulated to a limited degree, in glaucous gulls with concentrations ranging from < 0.03 to 0.43 ng/g wet wt and from < 0.05 to 0.33 ng/g wet wt, respectively. In polar bear plasma, BDE183 was < 0.04 ng/g wet wt for all animals, and BDE209 was only detected in 7% of the samples at concentrations up to 0.10 ng/g wet wt. Of the 15 MeO-PBDEs analyzed in plasma samples, 3-MeO-BDE47 was consistently dominant in glaucous gulls (sigmaMeO-PBDE: 0.30-4.30 ng/g wet wt) and polar bears (sigmaMeO-PBDE up to 0.17 ng/g wet wt), followed by 4'-MeO-BDE49 and 6-MeO-BDE47. The 3-OH-BDE47, 4'-OH-BDE49, and 6-OH-BDE47 congeners were also detected in glaucous gulls (sigmaOH-PBDE up to 1.05 ng/g wet wt), although in polar bears 4'-OH-BDE49 was the only congener quantifiable in 13% of the samples. The presence of MeO- and OH-PBDEs in plasma of both species suggests possible dietary uptake from naturally occurring sources (e.g., marine sponges and green algae), but also metabolically derived biotransformation of PBDEs such as BDE47 could be a contributing factor. Our findings suggest that there are dissimilar biochemical mechanisms involved in PCB and PBDE metabolism and accumulation/elimination and/or OH-PBDE accumulation and retention in glaucous gulls and polar bears.     

Chemical loading into surface water along a hydrological, biogeochemical, and land use gradient: a holistic watershed approach

Identifying the sources and impacts of organic and inorganic contaminants at the watershed scale is a complex challenge because of the multitude of processes occurring in time and space. Investigation of geochemical transformations requires a systematic evaluation of hydrologic, landscape, and anthropogenic factors. The 1160 km2 Boulder Creek Watershed in the Colorado Front Range encompasses a gradient of geology, ecotypes, climate, and urbanization. Streamflow originates primarily as snowmelt and shows substantial annual variation. Water samples were collected along a 70-km transect during spring-runoff and base-flow conditions, and analyzed for major elements, trace elements, bulk organics, organic wastewater contaminants (OWCs), and pesticides. Major-element and trace-element concentrations were low in the headwaters, increased through the urban corridor, and had a step increase downstream from the first major wastewater treatment plant (WWTP). Boron, gadolinium, and lithium were useful inorganic tracers of anthropogenic inputs. Effluent from the WWTP accounted for as much as 75% of the flow in Boulder Creek and was the largest chemical input. Under both hydrological conditions, OWCs and pesticides were detected in Boulder Creek downstream from the WWTP outfall as well as in the headwater region, and loads of anthropogenic-derived contaminants increased as basin population density increased. This report documents a suite of potential endocrine-disrupting chemicals in a reach of stream with native fish populations showing indication of endocrine disruption.     

2010全球纸业200强排行榜

说明：1、本排行榜所指的2010全球纸业200强,是指全球范围内从事纸浆、造纸、纸制品等相关业务,并以2009年销售额从高到低排序的最大200家企业。除特别指出的外,当企业实际业务超过上述范围时,不再予以剔除,合并计算排名。考虑到对纸浆、造纸和纸制品业务理解的差异,以及财务数据的公开性和完整性等因素,不能保证所有的相关公司都被列入榜单。     

The occurrence of isoperoxidases in conference pears

Soluble and ionically-bound peroxidases have been obtained from the pulp and peel of Conference pears. The peel soluble fraction contained the highest level of peroxidase activity. The peel peroxidases, both soluble and ionically bound, were particularly heat stable. Following heat inactivation, regeneration of enzymic activity was observed for the peel peroxidases and soluble pulp enzymes. Plots of the percentage of heat inactivation for the pear peroxidases against heating time were non-linear.     

Arsenolipids in marine oils and fats: A review of occurrence,chemistry and future research needs

Numerous studies have focused on arsenic in marine organisms, and relatively high natural levels of the element have been reported in marine samples. Despite their seemingly consistent presence in marine oils and fats, there is currently only limited knowledge available on arsenic compounds that exhibit lipid soluble characteristics, the arsenolipids, in contrast to the water-soluble arsenic species. The development of analytical techniques has, however, renewed the interest in these arsenic species and significant novel findings have been published in the last couple of years. The aim of this review is to present current knowledge on the occurrence and chemistry of arsenolipids in marine oils, and to identify future research needs. The occurrence of arsenolipids and their relevance in marine organisms will be discussed, in addition to their relevance for consumers and industry, with respect to feed and food safety and legislative issues. Analytical techniques, including techniques in the early work on arsenolipids in addition to methods employed today, and relevant sample preparation will be discussed.     

Comparison of copper speciation in coastal marine waters measured using analytical voltammetry and diffusion gradient in thin-film techniques

The diffusion gradient in thin-film hydrogel (DGT) probe is a promising tool for metal speciation work. Based on a passive sampling principle, it provides the potential for large data sets in complex regimes. DGT probes were deployed in waters characterized independently using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV). The CLE-ACSV used benzoyl acetone as the competitive ligand in discrete water samples collected during the deployment of the DGT probes. The DGT probes used a 15% polyacrylamide/0.4% bis-acrylamide cross-linker hydrogel and a Na-form of Chelex-100 to complex metal that fluxed into the probe through the hydrogel. Probes were deployed in locations characterized by the degree of pollution impact: the relatively pristine Vineyard Sound, MA, [Cu]total approximately 6 nM, small seasonally active harbors on Cape Cod, MA, [Cu]total = 12-64 nM, as well as a large polluted estuary, the Elizabeth River, VA, [Cu]total = 44-58 nM, and a large polluted port, San Diego Harbor, CA, [Cu]total = 23-103 nM. This is the first study where DGT probes have been compared with an independent speciation technique in marine systems and used to establish the diffusion coefficient of Cu-complexing ligands in situ. Results showed that the probes produced highly precise data sets, with substantial differences in copper accumulation between contaminated and pristine waters. Comparison of DGT results with CLE-CSV indicate that at least 10-35% of the organically complexed copper derived by CLE-ACSV measurements was DGT-labile. Diffusion coefficients (corrected to 25 degrees C) of organically complexed DGT-labile Cu through the hydrogel ranged from 0.77 x 10(-6) cm2 s(-1) in Vineyard Sound to 2.16 x 10(-6) cm2 s(-1) in the Elizabeth River estuary. Accumulation rates of copper were substantially higher in contaminated waters than in pristine waters, suggesting that the probes in their current form may be useful as tracking tools to detect episodic sources of contamination.     

The occurrence of Listeria monocytogenes in cheese from a manufacturer associated with a case of listeriosis

A case of listeriosis was associated with the consumption of a soft cheese produced in England. Goats cheese and other products from the same food manufacturer were examined for the presence of Listeria over the following 11 months. Listeria monocytogenes was isolated from 16 of 25 cheese samples on retail sale, 12 of 24 cheese samples obtained directly from the factory, and from shelving within the plant. Phage-typing of 68 isolates of L. monocytogenes from cheese samples and the factory showed that 66 (97%) were indistinguishable from the strain isolated from the patient's cerebrospinal fluid and stool. L. monocytogenes was not isolated from seven goats milk or two yoghurt samples. Listeria innocua was isolated from 10 cheese samples, two of which contained no other species of Listeria. Levels of L. monocytogenes shortly after production were low (<10/g), but were higher (10⁵–10⁷ cfu/g) in six of the 16 cheese samples obtained from retail outlets. Multiplication of L. monocytogenes was demonstrated in cheeses contaminated at the factory and held at 4°C in the laboratory.     

The occurrence of ochratoxin A in blue cheese

Evidence for the occurrence of ochratoxin A in blue cheeses is reported for the first time. The development of an accurate and reliable procedure for the extraction of OTA from cheese, as well as the availability of a new sensitive HPLC-FLD method, has allowed us to determine ochratoxin A in complex matrices such as cheeses, even at very low levels (LOD in cheese: 0.02 μg/kg). A good linearity for the OTA concentration, between 0.2 and 2.5 μg/kg, was obtained and no matrix effect was observed in the same concentration range. The mean recovery for OTA was 97%, while the average RSD was 3%, within a spiking range of 0.5–2.0 μg/kg.     

The temperature dependence of anaerobic glycolysis in beef muscle held in a linear temperature gradient

Measurements have been made of the rate of pH fall post-mortem in excised beef sternomandibularis muscles held in a linear temperature gradient. A minimum rate of pH fall was observed between 10 and 12°C and the rate increased as the temperature was further reduced towards 0°C, a phenomenon known to be accompanied by cold-shortening and attributable to increased activity of the contractile actomyosin ATPase which stimulates glycolysis. The increase in rate observed as the temperature was raised above the 10–12°C minimum, had an activation energy of 40kJ/mol, similar to that of the calcium-independent myosin ATPase.     

The occurrence of a Maillard-type protein-polysaccharide reaction between β-lactoglobulin and chitosan

Reaction mixtures containing β-lactoglobulin and chitosan (1:4 weight ratio) were dry-heated at 40 °C and 79% relative humidity for 2 weeks. Absorbance measurements and SDS-PAGE analysis indicated the occurrence of the Maillard reaction and conjugate formation, respectively. Some β-lactoglobulin and chitosan properties were modified. For example, the emulsifying capacity at pH 4 and bactericidal activity against Escherichia coli of the Maillard reaction products (MRPs) increased with incubation period up to 2 days, after which these properties deteriorated. The latter was explained by MRPs degradation, which was confirmed by the increased appearance of degradation products in electrophoresis gels at longer incubation times. Data show that the Maillard reaction, under the studied conditions, can be successfully employed to generate MRPs from β-lactoglobulin and chitosan, which exhibit improved properties with respect to β–lactoglobulin alone.     

The occurrence and nature of electrochemical activity in milk from a herd of dairy cows

Amperometric sensors may be used in milk analysis but electrochemical interference from compounds other than the analyte is an on-going problem. A survey was made of the level of electrochemical activity (potential interference) in milk from a herd of dairy cows grazing on summer pasture. It was a ubiquitous feature of the aqueous phase of whey and de-proteinized milk over about 3 months. The nature of the interference was studied by differential pulse voltammetry and responses to ascorbic acid oxidase and uricase. The principal source of interference appeared to be uric acid.     

The occurrence and growth of yeasts in dairy products

Yeasts were isolated, identified and enumerated from 161 samples of retail dairy products. Highest yeast populations (up to 10⁶–10⁷ cells/g) were found in yogurt and cheese samples while lower counts occurred in samples of pasteurized milk, cream, butter and ice cream. Candida famata, Kluyveromyces marxianus, Candida diffluens and Rhodotorula glutinis were the most frequency isolated species. The growth of these and other species was demonstrated during the refrigerated storage of cream, butter and cheese samples and by their inoculation and incubation in milk and yogurt samples. The predominance and growth species was probably related to their production of protein and fat hydrolysing enzymes and the ability to grow at 5°C.