室内空气和灰尘中全(多)氟烷基化合物的研究进展

全(多)氟烷基化合物(per(poly)fluoroalkyl substances,PFASs)在环境各个介质及人体样品中广泛被检出,近年,在室内空气和灰尘中也普遍发现PFASs.研究表明,室内空气中PFASs的含量普遍高于室外空气,室内空气和灰尘中的PFASs可能是室外空气的污染来源及人体暴露源,因此室内环境中PFASs成为环境领域的又一个研究热点.但目前为止,我国还没有开展室内空气中PFASs的相关研究,室内灰尘中PFASs的研究也相对较少.本文就室内空气和灰尘中PFASs的采样与分析方法、污染现状、来源分析及人体暴露等4个方面进行了综合阐述,以期为我国室内环境中PFASs的研究提供参考.     

Optimized porous clay heterostructure for removal of acetaldehyde and toluene from indoor air

Adsorption is the most widely used technology for the removal of indoor volatile organic compounds (VOCs). However, existing adsorbent-based technologies are inadequate to meet the regulatory requirement, due to their limited adsorption capacity and efficiency, especially under high relative humidity (RH) conditions. In this study, a series of new porous clay heterostructure (PCH) adsorbents with various ratios of micropores to mesopores were synthesized, characterized and tested for the adsorption of acetaldehyde and toluene. Two of them, PCH25 and PCH50, exhibited markedly improved adsorption capability, especially for hydrophilic acetaldehyde. The improved adsorption was attributed to their large micropore areas and high micropore-to-mesopore volume ratios. The amount of acetaldehyde adsorbed onto PCH25 at equilibrium reached 62.7 mg·g⁻¹, eight times as much as the amount adsorbed onto conventional activated carbon (AC). Even at a high RH of 80%, PCH25 removed seven and four times more of the acetaldehyde than AC and the unmodified raw PCHs did, respectively. This new PCH optimized for their high adsorption and resistance to humidity has promising applications as a cost-effective adsorbent for indoor air purification.     

室内灰尘中多环芳烃及其衍生物的赋存与人体暴露研究进展

多环芳烃(polycyclic aromatic hydrocarbons,PAHs)作为典型的持久性有机污染物(persistent organic pollutants,POPs)中的重要类别,具有半挥发性、生物蓄积性、长期残留性和明显的毒性(包括致癌、致畸、致突变)等特点,因此是环境中的一类重要污染物.PAHs衍...     

Geographic patterns of non-carpeted floor dust loading in Syracuse, New York (USA) homes

Residential floor dust loading was measured on the smooth floor surface of 488 houses in Syracuse, New York, during the summers of 2003 and 2004. Using U.S. Environmental Protection Agency (EPA) wipe methods, pre-weighed Ghost Wipes, Lead Wipes, or Whatman Filters were employed to collect duplicate samples from (predominantly) kitchens. The collection efficiency of the various media was determined from multiple wipe tests and side-by-side comparisons. The results were normalized and aggregated at the census tract level to determine whether spatial patterns of dust loading could be observed. Loading was found to be log-normally distributed, with a geometric mean value of 0.311 g m⁻² (29 mg of dust per square foot of floor); 95% of the observations fell in the range of 0.042–2.330 g m⁻² (4–216 mg foot⁻²). The sampling for floor dust loading shows some bias for day of the week in which visits to the residential properties were made. After a first-order correction for this effect, results were aggregated by census tract and mapped in a geographic information system (GIS); strong spatial patterns can be identified in an inverse distance weighted mapping. The geographic patterns exhibit a strong correlation with socio-economic/demographic covariates extracted from the 2000 census summaries. Dust mass on the floors is positively correlated with renter-occupied properties and family size; it is negatively correlated with measures of household income.     

Headspace and small-chamber studies of airborne diacetyl release from selected food flavoring mixtures: activity coefficients and air modeling implications

Laboratory studies were conducted to evaluate airborne release of diacetyl from selected mixtures simulating butter flavorings added to foods. The test materials included diacetyl (97% purity); 0.015%, 0.15%, 1.5%, and 3.0% diacetyl in a water/propylene glycol mixture; 1.5% diacetyl in deionized water or soybean oil; and 3% or 6% diacetyl in a commercial steam distillate from milk fermentation known as “butter starter distillate.” Diacetyl was quantified by gas chromatography with flame ionization detection. Expected concentration-dependent emission patterns based on liquid diacetyl content were demonstrated, but were significantly altered by mixture composition. Soybean oil and deionized water more readily released diacetyl when compared with starter distillate, propylene glycol solutions, and pure diacetyl. Measured diacetyl concentrations under static headspace and dynamic flow-chamber conditions were compared to estimated concentrations utilizing Raoult's law with published and fitted activity coefficient corrections for each mixture, indicating that published coefficients often understated the measured concentrations. It is concluded that headspace (static) and small-chamber (dynamic) measurements of airborne diacetyl provide data to assist in validating model-estimated airborne diacetyl concentrations by using mixture-specific activity coefficients. Implications of these empirical data for validating exposure estimates for diacetyl based on near-field/far-field modeling in workplace settings are discussed.     

Characteristics of carbonyls and volatile organic compounds (VOCs) in residences in Beijing,China

Volatile organic compounds (VOCs) and carbonyl compounds were measured both indoors and outdoors in 50 residences of Beijing in heating (December, 2011) and non-heating seasons (April/May, 2012). SUMMA canisters for VOCs and diffusive samplers for carbonyl compounds were deployed for 24 h at each site, and 94 compounds were quantified. Formaldehyde, acetone and acetaldehyde were the most abundant carbonyl compounds both indoors and outdoors with indoor median concentrations being 32.1, 21.7 and 15.3 μg·m⁻³, respectively. Ethane (17.6 μg·m⁻³), toluene (14.4 μg·m⁻³), propane (11.2 μg·m⁻³), ethene (8.40 μg·m⁻³), n-butane (6.87 μg·m⁻³), and benzene (5.95 μg·m⁻³) showed the high median concentrations in indoor air. Dichloromethane, p-dichlorobenzene (p-DCB) and toluene exhibited extremely high levels in some residences, which were related with a number of indoor emission sources. Moreover, isoprene, p-dichlorobenzene and carbonyls showed median indoor/outdoor (I/O) ratios larger than 3, indicating their indoor sources were prevailing. Chlorinated compounds like CFCs were mainly from outdoor sources for their I/O ratios being less than 1. In addition, indoor concentrations between two sampling seasons varied with different compounds. Carbonyl compounds and some chlorinated compounds had higher concentrations in the non-heating season, while alkanes, alkenes, aromatic compounds showed an increase in the heating season. Indoor concentration of VOCs and carbonyls were influenced by locations, interior decorations and indoor activities, however the specific sources for indoor VOCs and carbonyls could not be easily identified. The findings obtained in this study would significantly enhance our understandings on the prevalent and abundant species of VOCs as well as their concentrations and sources in Beijing residences.     

Tube-worm-sediment relationships in populations of Pectinaria gouldii (Polychaeta: Pectinariidae) from Barnegat Bay,New Jersey,USA

Pectinaria gouldii (Verrill), which lives for 1 year in Barnegat Bay, New Jersey, constructs over its lifetime a conical tube of increasingly large sand grains, regardless of surrounding sediment characteristics. However, the rate of increase of mean grain size of the tube and the population density of the worm vary with sediment type. The distribution of this species is limited by sediment composition. Worms of equal length will always have equal anterior tube apertures, although the thickness of the tube walls may be unequal. Tube surface-area, worm dry weight, and tube weight all increase as a power function of tube length. The conical shape and increasing mass of the tube impose an upper limit to worm growth, but do not interfere with worm mobility.     

有机磷酸酯阻燃剂的人群暴露和甲状腺毒性的研究进展

有机磷酸酯(organophosphate esters,OPEs)是使用最为广泛的有机磷阻燃剂,并兼具增塑剂、消泡剂和萃取剂等功能,被广泛用于电子产品、建筑材料和塑料材料等中,导致其在环境介质中普遍存在,对生态系统和人体健康构成巨大威胁.作为一种新型环境污染物,OPEs的人群暴露特征和生物毒性成为环境健康领域的研究热...     

Prospective spatial prediction of infectious disease: experience of New York State (USA) with West Nile Virus and proposed directions for improved surveillance

Infectious disease surveillance has become an international top priority due to the perceived risk of bioterrorism. This is driving the improvement of real-time geo-spatial surveillance systems for monitoring disease indicators, which is expected to have many benefits beyond detecting a bioterror event. West Nile Virus surveillance in New York State (USA) is highlighted as a working system that uses dead American Crows (Corvus brachyrhynchos) to prospectively indicate viral activity prior to human onset. A cross-disciplinary review is then presented to argue that this system, and infectious disease surveillance in general, can be improved by complementing spatial cluster detection of an outcome variable with predictive “risk mapping” that incorporates spatiotemporal data on the environment, climate and human population through the flexible class of generalized linear mixed models.

Dissolution of zinc oxide nanoparticles in exposure media of algae,daphnia, and fish embryos for nanotoxicological testing

Zinc oxide nanoparticles (ZnO NPs) are being widely investigated in a bioassay due to potential negative effects to biological receptor. The dissolution of metal nanoparticles such as ZnO NPs is crucial to interpret nanotoxicity results because ZnO NPs can release toxic-free ions in exposure media. In the present study, dissolution of ZnO NPs was evaluated in three selected synthetic media for aquatic toxicological testing: Elendt M4 daphnia medium, OECD algal medium, and fish embryo rearing solution. Both media are currently recommended for OECD testing for daphnia and algae. Time-dependent dissolution of ZnO NPs has been investigated in terms of sonication time to be used for the preparation of aqueous NPs suspension, and dissolution time corresponding to exposure period in toxicity testing. Since sonication is widely applied for NPs dispersion in the most of nanotoxicological testing, the emphasis of this study was on the dissolution of NPs as a function of sonication time. We also investigated the concentration-dependent dissolution of ZnO NPs. Our results demonstrated that dissolution of ZnO NPs was significantly affected by sonication and dissolution time, as well as NPs concentration. This study showed that parameters affecting dissolution of ZnO NPs should be considered in nanotoxicological testing.     

Morphometric and meristic comparison of orange roughy (Hoplostethus atlanticus: Trachichthyidae) from the Puysegur Bank and Lord Howe Rise,New Zealand,and its implications for stock structure

Significant morphological differences were found between orange roughy, Hoplostethus atlanticus, caught in 1993 on the Puysegur Bank and those caught on the Lord Howe Rise, New Zealand. A total of 17 separate body measurements and counts were taken from each fish. Treating the sexes separately, significant differences were found between sites when linear relations between eight particular body measures and standard length were compared. The eight measures indicating differences in shape were head length, snout length, orbit diameter, maxilla width, premaxilla length, caudal peduncle, gill raker count, and anal fin count. Discriminant functions were used to compare sites and sexes, and these permitted a >90% success rate in distinguishing fish from the two sites. A discriminant function could not be found which successfully separated two separate tows made on the Puysegur Bank, indicating that phenotypic differences do not vary as much within a site as they do between sites. All analyses made suggested that fish from the two different areas had different body shapes. Morphological differences, such as those found in the current investigation, could only arise if the fish populations from the two areas were relatively discrete. There may be some movement of fish between areas, quite possibly enough to bring about relative genetic homogeneity, but clearly there is insufficient to prevent the two populations from differing phenotypically. These differences suggest that morphometric analysis may be a useful tool for distinguishing New Zealand orange roughy stocks.     

Chemical cocktail party in East Greenland: A first time evaluation of human organohalogen exposure from consumption of ringed seal and polar bear tissues and possible health implications

East Greenland polar bears (Ursus maritimus) are among the mammals with the highest bioaccumulated concentrations of organohalogen contaminants (OHCs). Since Greenlanders in this region ingest significant quantities of adipose tissue from polar bears and also ringed seals (Pusa hispida), initial conservative estimates of the daily oral exposure to this chemical cocktail are thus presented. The tolerable daily intake was exceeded approximately five-fold for polychlorinated biphenyls and chlordane pesticides and metabolites, while the estimated daily toxic equivalent (TEQ) (based on the 2,3,7,8-tetrachlorodibenzo-rho-dioxin toxicity equivalence factors) for East Greenland subsistence hunters was three- to ten-fold higher than the WHO ∑TEQ guidelines even though the estimations were conservative. The daily oral OHC exposure from polar bear and ringed seal blubber consumption is markedly high and needs to be reduced in order to remove this co-factor with respect to the influence on the development of chronic diseases. Furthermore, it is warranted that a physiologically based pharmacokinetic model for Greenlander's exposure to OHCs is constructed and that risk quotients calculated to estimate the threats to health for East Greenland subsistence hunters.     

广州帽峰山林区空气负离子动态及与环境因子的关系

采用定位连续观测方法,研究了广州帽峰山森林公园负离子含量近5年的年、季、月变化及不同天气的变化规律,并以此对帽峰山森林公园的空气质量进行了计量评价.分析了空气负离子含量与环境因子的相关关系.结果表明:林区不同观测区的负离子含量差异较大,山下瀑布空间负离子含量最高.平均水平达达2l 729 ions.cm-3;林内负离子含量年间及月间变化不大,沟谷小溪和山中部瀑布空间由于人为干扰,负离子含量年动态呈现降低趋势,山下瀑布空间年负离子含量维持在20000 iotis·cm-3左右;负离子含量的季节差异显著,春夏季大于冬秋季,夏季最高、冬季最低.空气质量评价系数CI的最低在2月份、最高在8月份.不同天气条件下负离子含量大小顺序为下雨>晴天>阴天.负离子含量与空气温度呈正相关,与空气湿度呈正相关.与空气气压呈负相关.     

Winter mortality, growth, and behavior of young-of-the-year of four coastal fishes in New Jersey (USA) waters

Winter mortality has been hypothesized to select for large body size in young-of-the-year (YOY) fishes, yet substantiation of winter mortality and its cause(s) are available for few estuarine or marine species. We examined seasonal length distributions of wild populations of four common marine species, black sea bass (Centropristis striata), tautog (Tautoga onitis), cunner (Tautogolabrus adspersus), and smallmouth flounder (Etropus microstomus), and mortality (i.e., frequency of death), growth, and behavior of their YOY in the laboratory at ambient winter temperatures (mean 7°C, range 2-13°C) during a 135-day period (December 1992 through mid-April 1993) to establish potential causes of their mortality in the field. Young-of-the-year black sea bass experienced 100% mortality when water temperatures decreased to 2-3°C in February, emphasizing the importance of winter emigration from estuaries in this southern species. The low mortality of two labrid species, YOY tautog (14%) and YOY cunner (3%), was consistent with their northern distribution and year-round occurrence in estuarine and nearshore coastal waters. Laboratory mortality of YOY smallmouth flounder (33%) was higher for small (<35 mm total length) fish, suggesting that this small species may experience high winter mortality in estuaries and nearshore coastal waters. Seasonal differences in fish length result potentially from several mechanisms (e.g., mortality and/or migration) that are difficult to assess, but our laboratory experiments suggest that seasonal temperature changes cause size-specific mortality of YOY smallmouth flounder and offshore migration of YOY black sea bass.     

Catalytic wet air oxidation of phenol,nitrobenzene and aniline over the multi-walled carbon nanotubes (MWCNTs) as catalysts

Wet air oxidation (WAO) is one of effective technologies to eliminate hazardous, toxic and highly concentrated organic compounds in the wastewater. In the paper, multi-walled carbon nanotubes (MWCNTs), functionalized by O₃, were used as catalysts in the absence of any metals to investigate the catalytic activity in the catalytic wet air oxidation (CWAO) of phenol, nitrobenzene (NB) and aniline at the mild operating conditions (reaction temperature of 155°C and total pressure of 2.5 MPa) in a batch reactor. The MWCNTs were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), gas adsorption measurements (BET), fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The functionalized MWCNTs showed good catalytic performance. In the CWAO of phenol over the functionalized MWCNTs, total phenol removal was obtained after 90 min run, and the reaction apparent activation energy was ca. 40 kJ·mol^-1. The NB was not removed in the CWAO of single NB, while ca. 97% NB removal was obtained and 40% NB removal was attributed to the catalytic activity after 180 min run in the presence of phenol. Ca. 49% aniline conversion was achieved after 120 min run in the CWAO of aniline.     

Space view of the decadal variation for typical air pollutants in the Pearl River Delta (PRD) region in China

The Pearl River Delta (PRD) is one of the most industrialized, urbanized and populated regions in China, and thus has been long suffering from severe air pollutions. Space data provide a unique perspective for investigating the atmospheric environment at a regional scale. By utilizing multiple satellite retrievals from 2005 to 2013, this study presented, for the first time, the spatial patterns and temporal trends of typical air pollutants over PRD and its vicinity. As viewed from space, aerosol optical depth (AOD), NO₂ and SO₂ all had their higher values at the central part of PRD, and showed clear descending gradients as moving to the outskirt of this region. As to the inter-annual variation, all these pollutants had decreasing trends in PRD during the study period, which generally agreed with the relevant in situ measurements. However, the satellite retrievals differed from ground measurements when addressing NO₂ and SO₂ in the vicinity of PRD. This work also provides the inter-comparison among PRD and three other metropolitan clusters in China: PRD had relatively high AOD, moderate NO₂ and low SO₂ levels, and it was the only region achieving the effective reduction of NO₂ and SO₂ during last decade. Unlike the previous three pollutants, HCHO observed by satellite showed very special patterns: it had a relatively homogeneous spatial distribution over both of PRD and its vicinity, and presented an opposite increasing trend from 2005 to 2010. Moreover, PRD had the highest HCHO level among all the metropolitan clusters, hinting a considerable contribution of biogenic origins of HCHO in PRD.

Open image in new window

     

Egg buoyancy of Baltic cod (Gadus morhua) and its implications for cod stock fluctuations in the Baltic

Successful spawning of Baltic cod (Gadus morhua L.) is restricted to the deep basins of the Baltic Sea and is dependent on abiotic conditions such as salinity and water oxygen content. Due to irregular inflows of saline water from the North Sea, the conditions for spawning fluctuate and consequently so does the cod stock. In May and June 1990 eggs were obtained from spawning cod caught off northern Gotland, Sweden. Our investigation revealed neutral egg buoyancy for Baltic cod at a salinity of 14.4±1.1 ppt, with a slight decrease some days before hatching. Today salinities of this magnitude occur only in the Bornholm basin, whereas in the Gdansk and Gotland basins the eggs sink toward the bottom and are exposed to lethal oxygen conditions.     

Pseudomonas sp.L19抗除草剂AHAS基因的克隆、表达及特性

乙酰羟酸合酶(AHAS)是磺酰脲类、咪唑啉酮类、三唑嘧啶类、磺酰胺类和嘧啶水杨酸类等乙酰羟酸合酶抑制剂类除草剂的作用靶标,获得能抗此类除草剂的AHAS突变基因资源具有非常重要的理论和应用价值.从长期使用甲磺隆的农田土壤中分离到1株对乙酰羟酸合酶抑制剂类除草剂有广谱抗性的菌株L19,根据表型特征、生理生化特性和16S rDNA序列系统发育分析,将其鉴定为假单孢菌属(Pseudomonas sp.).利用PCR技术从Pseudomonas sp.L19的总DNA中克隆AHAS基因,氨基酸序列比对结果表明,L19与对除草剂敏感菌株P.putida KT2440的AHAS调节亚基氨基酸序列完全相同,而催化亚基有4个氨基酸位点不同:[Val 29→Ala(L19→KT2440),Pro93→Ser,Val 345→Ala,Pro 484→Arg].分别将菌株L19与KT2440的AHAS催化亚基克隆到pET29a(+)的多克隆位点,构建了表达载体pET-L19AHASc和pET-KT2440AHASc,通过镍柱亲和层析纯化得到带有组氨酸标签的乙酰羟酸合酶.抗性试验结果表明菌株L19的乙酰羟酸合酶对四大类乙酰羟酸合酶抑制剂类除草剂的抗性均要强于KT2440的乙酰羟酸合酶,对甲磺隆、咪唑乙烟酸、唑嘧磺草胺和嘧草醚的抗性倍数分别达到53.6、9.3、8.2和9.5倍.菌株L19的乙酰羟酸合酶比活力、对ThDP和Mg2+的Kc值相应地比KT2440乙酰羟酸合酶的要低;而对底物丙酮酸钠的米氏常数Km值要比KT2440乙酰羟酸合酶的要高近1倍.