Hibernation-associated changes in persistent organic pollutant (POP) levels and patterns in British Columbia grizzly bears (ursus arctos horribilis)

We hypothesized that depleted fat reserves in grizzly bears (Ursus arctos horribilis) following annual hibernation would reveal increases in persistent organic pollutant (POP) concentrations compared to those present in the fall. We obtained fat and hair from British Columbia grizzly bears in early spring 2004 to compare with those collected in fall 2003, with the two tissue types providing contaminant and dietary information, respectively. By correcting for the individual feeding habits of grizzlies using a stable isotope-based approach, we found that polychlorinated biphenyls (sigmaPCBs) increased by 2.21x, polybrominated diphenylethers (sigmaPBDEs) increased by 1.58x, and chlordanes (sigmaCHL) by 1.49x in fat following hibernation. Interestingly, individual POPs elicited a wide range of hibernation-associated concentration effects (e.g., CB-153, 2.25x vs CB-169, 0.00x), resulting in POP pattern convergence in a PCA model of two distinct fall feeding groups (salmon-eating vs non-salmon-eating) into a single spring (post-hibernation) group. Our results suggest that diet dictates contaminant patterns during a feeding phase, while metabolism drives patterns during a fasting phase. This work suggests a duality of POP-associated health risks to hibernating grizzly bears: (1) increased concentrations of some POPs during hibernation; and (2) a potentially prolonged accumulation of water-soluble, highly reactive POP metabolites, since grizzly bears do not excrete during hibernation.     

Seabird guano is an efficient conveyer of persistent organic pollutants (POPs) to Arctic lake ecosystems

Migratory seabirds have been linked to localized "hotspots" of contamination in remote Arctic lakes. One of these lakes is Lake Ellasj?en on Bj?rn?ya in the Barents Sea. Here we provide quantitative evidence demonstrating that even relatively small populations of certain seabird species can lead to major impacts for ecosystems. In the present example, seabird guano accounts for approximately 14% of the contaminant inventory of the Lake Ellasj?en catchment area, approximately 80% of the contaminant inventory of the lake itself, and is approximately thirty times more efficient as a contaminant transport pathway compared to atmospheric long-range transport. We have further shown that this biological transport mechanism is an important contaminant exposure route for ecosystems, responsible for POPs levels in freshwater fish that are an order of magnitude higher than those in Arctic top predators. Given the worldwide presence of seabird colonies in coastal marine areas where resources are also harvested by humans, this biological transport pathway may be a greater source of dietary contamination than is currently recognized with consequent risks for human health.     

Coupling passive air sampling with emission estimates and chemical fate modeling for persistent organic pollutants (POPs): a feasibility study for Northern Europe

Passive air samplers (polyurethane foam disks) were deployed at 23 background locations along a broadly west-east transect in 8 northern European countries and analyzed for PCBs, PBDEs, PAHs, and a range of organochlorine pesticides (HCB, DDTs, and DDEs). PCBs and PAHs were highest at the center of the transect (Denmark) and lowest in northern Norway. HCB was relatively uniformly distributed, reflecting its persistence and high degree of mixing in air. Higher DDE and DDT levels occurred in Eastern Europe and at several sites in Central Europe. PBDE levels were generally similar at all sites, but lower for some locations in Eastern Europe and Ireland. Emissions information for PCBs, HCB, and PBDEs was used as input for a multi-media chemical fate model, to generate predicted air concentrations and compare with these measured values. Different scenarios were highlighted by this exercise: (i) country and compound combinations where the national inventory gave predicted air concentrations in close agreement with those measured (e.g., PCBs in the UK); (ii) country and compound combinations where predicted concentrations were well below those measured, but where advection of emissions from elsewhere is likely to be important (e.g., PCBs in Norway); (iii) consistent underestimation of compound concentrations by the emissions modeling (i.e., HCB); and (iv) general overestimation of ambient concentrations (i.e., PBDEs). Air mass trajectory analysis showed the likely role of long-range atmospheric transport (LRAT) on national levels. In general, advection from the south and west of Europe appeared to contribute to ambient POPs levels for countries in the center and northeast of the transect. Guidelines are presented as to how countries that want to assess their POPs source inventories can do so with this relatively cheap initial screening approach.     

Anthropogenic atmospheric emissions of antimony and its spatial distribution characteristics in China

An integrated inventory of atmospheric antimony (Sb) emissions from anthropogenic activities in China is compiled for the years 2005-2009. Emissions are estimated for all major anthropogenic sources for the first time. We estimate that the national emissions of antimony are 818 metric tons (t) in 2009, with the largest contribution from coal combustion at 61.8% of the total, while 26.7% of Sb is emitted from nonferrous metals smelting. Emissions are heaviest in Guizhou province, mainly due to small-scale combustion of high-Sb coal without emission control devices, and in Hunan province, where extensive smelting occurs. Furthermore, Sb emissions from 2188 large point sources and area sources are distributed within latitude/longitude-based grids with a resolution of 30 min × 30 min where Sb emissions are largely concentrated in highly populated and industrialized southwestern China, the east central region, and coastal areas. The uncertainties in our bottom-up inventory are quantified as -11% to 40% by Monte Carlo simulation. We recommend continuous field testing of coal combustors and smelters in China to improve the accuracy of these estimates.     

A dynamic model to study the exchange of gas-phase persistent organic pollutants between air and a seasonal snowpack

An arctic snow model was developed to predict the exchange of vapor-phase persistent organic pollutants between the atmosphere and the snowpack over a winter season. Using modeled meteorological data simulating conditions in the Canadian High Arctic, a single-layer snowpack was created on the basis of the precipitation rate, with the snow depth, snow specific surface area, density, and total surface area (TSA) evolving throughout the annual time series. TSA, an important parameter affecting the vapor-sorbed quantity of chemicals in snow, was within a factor of 5 of measured values. Net fluxes for fluorene, phenanthrene, PCB-28 and -52, and alpha- and gamma-HCH (hexachlorocyclohexane) were predicted on the basis of their wet deposition (snowfall) and vapor exchange between the snow and atmosphere. Chemical fluxes were found to be highly dynamic, whereby deposition was rapidly offset by evaporative loss due to snow settling (i.e., changes in TSA). Differences in chemical behavior over the course of the season (i.e., fluxes, snow concentrations) were largely dependent on the snow/air partition coefficients (K(sa)). Chemicals with relatively higher K(sa) values such as alpha- and gamma-HCH were efficiently retained within the snowpack until later in the season compared to fluorene, phenathrene, and PCB-28 and -52. Average snow and air concentrations predicted by the model were within a factor of 5-10 of values measured from arctic field studies, but tended to be overpredicted for those chemicals with higher K(sa) values (i.e., HCHs). Sensitivity analysis revealed that snow concentrations were more strongly influenced by K(sa) than either inclusion of wind ventilation of the snowpack or other changes in physical parameters. Importantly, the model highlighted the relevance of the arctic snowpack in influencing atmospheric concentrations. For the HCHs, evaporative fluxes from snow were more pronounced in April and May, toward the end of the winter, providing evidence that the snowpack plays an important role in influencing the seasonal increase in air concentrations for these compounds at this time of year.     

Gas/solid partitioning of semivolatile organic compounds (SOCs) to air filters. 3. An analysis of gas adsorption artifacts in measurements of atmospheric SOCs and organic carbon (OC). WHen using teflon membrane filters and quartz fiber filters

Adsorption of gaseous semivolatile organic compounds (SOCs) onto the filter(s) of a filter/sorbent sampler is a potential source of measurement error when determining specific SOCs as well as organic carbon (OC) levels in the atmosphere. This work examines partitioning to both Teflon membrane filters (TMFs) and quartz fiber filters (QFFs) for purposes of predicting the magnitude of the compound-dependent gas adsorption artifact as a function of various sampling parameters. The examination is based on values of Kp,face (m3 cm(-2)), the gas/filter partition coefficient expressed as [ng sorbed per cm2 of filter face]/[ng per m3 in the gas phase]. Values of Kp,face were calculated based on literature values of the gas/solid partition coefficient Kp,s [ng sorbed per m2 of filter]/[ng per m3 in gas phase] for the adsorption of various polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) to TMFs, and for the adsorption of PAHs to QFFs. At relative humidity (RH) values below approximately 50%, the Kp,face values for PAHs are lower on TMFs than on ambient-backup QFFs. The gas adsorption artifact will therefore be lower for PAHs with TMFs than with QFFs under these conditions. In the past, corrections for the gas/filter adsorption artifact have been made by using a backup filter, and subtracting the mass amount of each compound found on the backup filter from the total (particle phase + sorbed on filter) amount found on the front filter. This procedure assumes that the ng cm(-2) amounts of each SOC sorbed on the front and backup filters are equal. That assumption will only be valid after both filters have reached equilibrium with each of the gaseous SOCs in the incoming sample air. The front filter will reach equilibrium first. The minimum air sample volume Vmin,f+b required to reach gas/filter sorption equilibrium with a pair of filters is 2Kp,face Afilter where Afilter (cm2) is the per-filter face area. Kp,face values, and therefore Vmin,f+b values, depend on the compound, relative humidity (RH), temperature, and filter type. Compound-dependent Vmin,f+b values are presented for PAHs and PCDD/Fs on both TMFs and QFFs. Compound-dependent equations which give the magnitude of the filter adsorption artifact are presented for a range of different sampling arrangements and circumstances. The equations are not intended for use in actually correcting field data because of uncertainties in actual field values of relevant parameters such as the compound-dependent Kp,face and gas/particle Kp values, and because of the fact that the equations assume ideal step-function chromatographic movement of gas-phase compounds through the adsorbing filter. Rather, the main utility of the equations is as guidance tools in designing field sampling efforts that utilize filter/sorbent samplers and in evaluating prior work. The results indicate that some backup-filter-based corrections described in the literature were carried out using sample volumes that were too small to allow proper correction for the gas adsorption artifactfor some specific SOCs of interest. Similar conclusions are reached regarding artifacts associated with the measurement of gaseous and particulate OC.     

Fine-scale spatial variation of persistent organic pollutants in bottlenose dolphins (Tursiops truncatus) in Biscayne Bay, Florida

Bottlenose dolphins (Tursiops truncatus) are long-term residents and apex predators in southeast U.S. estuaries and are vulnerable to bioaccumulation of persistent organic pollutants (POPs). Dart biopsy samples were collected from 45 dolphins in Biscayne Bay (Miami, FL), 34 of which were matched using fin markings to a photo identification catalogue. Blubber samples were analyzed for 73 polychlorinated biphenyl (PCB) congeners, six polybrominated diphenyl ether (PBDE) congeners, and organochlorine pesticides including dichloro-diphenyl-trichloroethane (DDT) and metabolites, chlordanes, and dieldrin. Total PCBs (sigma 73PCBs) were present in the highest concentrations and were 5 times higher in males with sighting histories in the northern, metropolitan area of Biscayne Bay than males with sighting histories in the southern, more rural area [geometric mean: 43.3 (95% confidence interval: 28.0-66.9) vs 8.6 (6.3-11.9) microg/g wet mass, respectively]. All compound classes had higher concentrations in northern animals than southern. The differences in POP concentrations found on this small geographic scale demonstrate that differential habitat use can strongly influence pollutant concentrations and should be considered when interpreting bottlenose dolphin POP data. The PCB concentrations in northern Bay dolphins are high as compared to other studies of estuarine dolphins and may place these animals at risk of reproductive failure and decreased immune function.     

Butter as an indicator of regional persistent organic pollutant contamination: further development of the approach using polychlorinated dioxins and furans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (PCBs)

The potential for use of butter as a widely available, relatively uniform lipid-rich matrix for the determination of spatial distributions of persistent organic pollutants has already been demonstrated. The present study determines the contributions to toxicity equivalence (TEQ) from polychlorinated dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) using butter samples from 24 countries world wide. Concentrations of PCDD/Fs and dioxin-like PCBs ranged from 0.07 to 5.69 pg ΣWHO-TEQ g -1 lipid. For most samples, PCDD/F TEQ fell within ranges reported for European dairy products over the last decade (0.3-2 pg g -1 lipid I-TEQ), though a single sample from Spain was a notable exception. Other than this sample, the highest values were recorded for samples from the Netherlands and Italy, with those from India, China and Tunisia also being relatively high. The contribution from non- ortho -PCBs was particularly significant in samples from Germany, Austria, Italy, the Czech Republic, Tunisia, India and Argentina. Although overall TEQs were generally highest in European and Mediterranean butters, elevated levels were also apparent in industrializing regions of Asia (India, China) and Latin America (Argentina). More detailed regional studies would be necessary to identify likely dioxin and PCB sources in each case. Nevertheless, this study supports the utility of butter as a monitoring matrix that may be especially applicable in regions for which monitoring programmes are currently lacking.     

Analysis of organic acids in Chinese raisin tree (Hovenia dulcis) peduncle and their changes in liquid fermentation process

Chinese raisin tree (Hovenia dulcis) peduncle is a wonderful food material for fermented food for high contents of sugars and a variety of organic acids. The organic acids in the fresh peduncle, fermented wine, and vinegar were identified and quantified by HPLC, and changes in biochemical parameters and organic acids in the fermentation process were studied. Skin-on fermentation was carried out in the alcoholic fermentation, and 9 identified organic acids fluctuated by physical or biochemical reactions during the alcoholic fermentation. Submerged fermentation was carried out in the acetic fermentation. It took 72 h to finish the 1^st cycle of acetification with the titratable acidity 5.42%(w/v), and 30 h to finish the 2^nd cycle. The contents of acetic acid, formic acid, and α-ketoglutaric acid increased, while the rest identified organic acids decreased in the acetification process. The fermentation developed in this study appeared to be a practical processing method for Chinese raisin tree peduncles.     

Polycyclic aromatic hydrocarbons (PAHs) in indoor and outdoor air of Hangzhou, China

Twelve polycyclic aromatic hydrocarbons were simultaneously measured in indoor and outdoor air of eight homes in Hangzhou, China in both summer and autumn in 1999. It was observed that the sum of PAHs concentrations in indoor air were ranged from 1.418 to 20.466 micrograms/m3 in summer and from 3.897 to 29.852 micrograms/m3 in autumn; the corresponding concentrations in outdoor air were between 1.380 and 20.468 micrograms/m3 in the summer and between 2.721 and 30.678 micrograms/m3 in autumn. The PAHs concentrations in indoor air generally exceeded that in the corresponding outdoor air. It was indicated that the two-, three-, and four-ring PAHs were predominantly in vapor phase, while the five-ring PAHs were primarily associated with the particulate phase. The fraction of PAHs in vapor phase will increase with the increase of temperature. Among the 12 PAHs, naphthalene was the most abundant PAHs found in indoor and outdoor air. Both in summer and autumn, it contributed more than 60% to the sum of PAHs. Because of the different functions and ventilation conditions, the concentrations of PAHs in the rooms were bedroom > kitchen > living room > balcony. By the contrast of BaP concentrations in smoker and nonsmoker's homes, we know that smoking in indoors could contribute 67% of BaP to the homes.     

Efficacy of atmospheric and pressurized carbon dioxide or air against Sitophilus zeamais Motchulsky (Coleoptera: Curculionidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in milled rice

Carbon dioxide gas was evaluated in the laboratory for control of Sitophilus zeamais Motchulsky and Tribolium castaneum (Herbst) in milled rice using a specially designed pressure chamber. Tests were conducted at atmospheric pressure with 60, 80 and 100% carbon dioxide and with 100% carbon dioxide pressurized to 4, 6 and 8 bars. LT₉₉ were ≤79, ≤78, and ≤148 h for all life stages of S. zeamais exposed to 60, 80 and 100% carbon dioxide, whereas, they were ≤59, ≤51 and ≤66 h for T. castaneum. Pure carbon dioxide controlled the adult stage, but there tended to be no significant differences of carbon dioxide concentrations on mortality of immature stages. When pure carbon dioxide was pressurized, mortalities of the two insect species were increased significantly. LT₉₉ values decreased with levels of applied pressure: ≤29, ≤9.0 and ≤4.8 h for S. zeamais and ≤15, ≤5.8 and ≤2.3 h for T. castaneum at pressures of 4, 6 and 8 bars, respectively. Sitophilus zeamais was more tolerant than T. castaneum to carbon dioxide gas. The adult was the most susceptible stage, however, immature stages responded differently to carbon dioxide gas applied at varying concentrations and pressure levels. Adult mortalities were lower when air was used in the pressure chamber instead of carbon dioxide. Pressurized carbon dioxide at relatively low pressure (4–8 bars) was found effective in controlling all live stages of S. zeamais and T. castaneum in milled rice with shorter exposure times than at atmospheric pressure using an inexpensive set of equipment as compared to high pressure carbon dioxide fumigation (20–30 bars).     

Impacts of climate and feeding conditions on the annual accumulation (1986-2009) of persistent organic pollutants in a terrestrial raptor

The relationships between climate variability, feeding conditions, and the annual accumulation of polychlorinated biphenyls (PCB), 1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE) and polybrominated diphenyl ethers (PBDE) in eggs (n = 168) of tawny owls (Strix aluco) were assessed over a 24-year period (1986-2009) in Central Norway. Winter climate variables included the North Atlantic Oscillation (NAO) and snow conditions, whereas feeding conditions were assessed using vole abundance. The concentrations of all compounds declined between 79% (p,p'-DDE) and 86% (PBDE) over the time period. For PCB and p,p'-DDE, the accumulation was positively associated with snow depth, and negatively associated with NAO (i.e., high accumulation in cold and dry winters) when vole abundance was low, suggesting trade-offs between winter severity and feeding conditions. That is, females mobilize more body fat reserves in cold winters when feeding conditions are poor, which results in increased circulating contaminant concentrations and maternal transfer to the eggs. Owls may also have been forced to feed on prey with higher contaminant loads due to restricted prey availability. For the recently banned PBDEs, the accumulation was high when NAO was low, while snow depth was positively associated with PBDE accumulation only when feeding conditions were good. This suggests somewhat different dynamics of PBDE in the environment or in the owls, compared to PCB and p,p'-DDE. However, climate and feeding conditions explained as much of the annual variation in concentrations of all POPs, as the overall decreasing trend over the 24 years. Hence, such factors should be considered in monitoring programs for POPs. Moreover, to better understand the mechanisms of climate effects on POP accumulation, future studies should measure pollutants in different components of the food chain.     

β-环状糊精的化学改性及其在茶饮料生产中的应用(二)

３．３延长速溶茶的保质期 Ｈａｓｈｉｍｏｔｏ Ｈ．研究表明，在速溶绿茶中加入环糊精可以显著地提高产品保质期。将含有速溶绿茶１份、环糊精１份和水５份的混合物经重新喷雾干燥制成速溶绿茶，试验中这种速溶绿茶在６０℃下置于一开放容器中保持了４０ｄ，只观测到轻微的退色，而作为对照的普通产品在同样条件下１０ｄ就完全退色［２３］。３．４包埋外源芳香物质 往茶叶中添加芳香物以增加或改善茶叶的香味，正日益受到人们的重视，其主要方法是用环糊精将香精油包埋后，然后添加到茶饮料中。 Ｓｚｅｎｔｅ Ｌ研究报道［２４］，经环糊…     

Characterization and source apportionment of water-soluble organic matter in atmospheric fine particles (PM2.5) with high-resolution aerosol mass spectrometry and GC-MS

Water-soluble organic matter (WSOM) in fine particles (PM(2.5)) collected at one rural and three urban sites from the Southeastern Aerosol Research and Characterization network were characterized with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). These samples were also analyzed for a suite of molecular markers by Gas Chromatography-Mass Spectrometry (GC-MS) to assist in the interpretation of WSOM sources. The HR-ToF-AMS measurements allow a direct determination of the organic mass-to-carbon ratios (average ± 1σ = 1.93 ± 0.12) and hence the quantification of WSOM on the same filters used to close the aerosol mass budget. WSOM constitutes a major fraction of total PM(2.5) mass (26-42%) and organic mass (50-90%) at all sites. The concentrations of WSOM are substantially higher in summer, mainly due to enhanced production of biogenic secondary organic aerosol (SOA). WSOM is composed mainly of oxygenated species with average oxygen-to-carbon (O/C) ratio of 0.56 (± 0.08). Positive matrix factorization (PMF) of the high resolution mass spectra of WSOM identifies a less oxidized component (denoted as lOOA, O/C = 0.50) associated with biogenic SOA and a more oxidized component (denoted as mOOA, O/C = 0.60) associated with WSOM contributed by wood combustion. On average, lOOA accounts for 75 (± 13) % of WSOM in summer while mOOA accounts for 78 (± 21) % in winter, suggesting that WSOM in the southeastern U.S. is primarily contributed by SOA production from biogenic species in summer and by wood burning emissions in winter. This work also demonstrates the utility of HR-ToF-AMS for investigating the bulk chemical composition of WSOM as well as for evaluating its source contributions.     

产酒酵母的筛选鉴定及其在小曲中的应用

以采自川西南片区的10种曲样中分离出的18株酵母为研究对象,以产酒能力为主要指标,通过三级筛选得到一株优良产酒酵母Y-18,经分子鉴定确定其为酿酒酵母（Saccharomyces cerevisiae）。将其制作成纯种的酵母曲并和根霉曲进行复配试饭。结果表明,酵母Y-18在大米粉发酵培养基中的残糖含量最低,酒精度最高,分别为0.69 g/100 mL和10.3%vol;在60 g蒸熟大米中,添加酵母曲1.8 g、根霉曲0.5 g时,试饭酒精度最高（7.24%vol）、酸度适中、糖分最低。     

现代分析测试技术在印染行业的应用(十)——电感耦合等离子体(ICP)分析技术及其在纺织工业上的应用(1)

简要回顾了电感耦合等离子体（ICP）分析技术的发展历程，重点介绍了ICP技术的原理，包括ICP设备的作用原理、ICP光源的激发机理、ICP温度分布的不均匀性，ICP的环形结构和趋肤效应等。目前纺织品检测中常用的ICP分析仪器有ICP-OES（光谱仪）和ICP-MS（质谱仪）两大类，介绍了这两类系统中的高频发生器和样品引入系统，以及ICP应用中的干扰问题。采用ICP技术测定纺织品中的重金属含量，具有操作简单、测试精度高和重现性好的优点。     

4-磺酸苯基卟啉与铅显色反应测定食品中的痕量铅

采取分光光度法研究了铅与TPPS4的显色反应条件,结果表明,用盐酸羟胺作辅助络合剂,以邻二氮菲、硫氰酸铵、酒石酸钾钠作联合掩蔽剂,在室温及碱性介质(pH12)条件下,TPPS4与铅只需12min即可完全生成淡紫色络合物,该络合物的最大吸收波长为465nm,络合比为1:1,当铅含量在0μg/mL～0.2μg/mL时,萃取曲线呈线性关系。通过APDC/MIBK体系萃取分离并富集样品中的铅离子,将TPPS4络合显色方法用于部分食品中痕量铅的测定,结果令人满意。