Size composition of particulate organic matter in the lagoon of Tikehau atoll (Tuamotu archipelago)

Suspended particulate matter was comprehensively investigated from 6 to 17 April 1986 in the lagoon of Tikehau atoll (15°00S; 148°10W). Dry weight (DW), particulate organic carbon (POC), adenosine triphosphate (ATP), and chlorophyll a were measured for five size-classes (0.2 to 0.8 m, 0.8 to 3 m, 3 to 35 m, 35 to 200 m, and 200 to 2000 m). Taxa were identified and counted for the whole plankton (both autotrophic and heterotrophic). Particles <3 m accounted for 81% of the total POC (192 mg m^-3), and detritus comprised 82% of the total POM. Phytoplankton (cyanobacteria plus algae) accounted for 35% of the living carbon, 75% of which consisted of heterotrophic bacteria and cyanobacteria. The zooplankton biomass was composed of 31% nano-, 26% micro-, and 43% mesoplankton.     

Foliar uptake and metal(loid) bioaccessibility in vegetables exposed to particulate matter

At the global scale, high concentrations of particulate matter (PM) enriched with metal(loid)s are currently observed in the atmosphere of urban areas. Foliar lead uptake was demonstrated for vegetables exposed to airborne PM. Our main objective here was to highlight the health risk associated with the consumption of vegetables exposed to foliar deposits of PM enriched with the various metal(loid)s frequently observed in the atmosphere of urban areas (Cd, Sb, Zn and Pb). Leaves of mature cabbage and spinach were exposed to manufactured mono-metallic oxide particles (CdO, Sb₂O₃ and ZnO) or to complex process PM mainly enriched with lead. Total and bioaccessible metal(loid) concentrations were then measured for polluted vegetables and the various PM used as sources. Finally, scanning electronic microscopy coupled with energy dispersive X-ray microanalysis was used to study PM–phyllosphere interactions. High quantities of Cd, Sb, Zn and Pb were taken up by the plant leaves. These levels depended on both the plant species and nature of the PM, highlighting the interest of acquiring data for different plants and sources of exposure in order to better identify and manage health risks. A maximum of 2 % of the leaf surfaces were covered with the PM. However, particles appeared to be enriched in stomatal openings, with up to 12 % of their area occupied. Metal(loid) bioaccessibility was significantly higher for vegetables compared to PM sources, certainly due to chemical speciation changes. Taken together, these results confirm the importance of taking atmospheric PM into account when assessing the health risks associated with ingestion of vegetables grown in urban vegetable crops or kitchen gardens.     

Bacterial activity related to sedimenting particulate matter

The rates of sedimentation of particulate matter were measured at a station in the Eckernförde Bight, Baltic Sea, using sediment traps. Different parameters (C, N, chlorophyll a, phaeopigments, adenosine triphosphate (ATP), heterotrophic activity (glucose maximum uptake velocity, v_max), biological oxygen demand (BOD), and electron-transport-system (ETS) activity) were measured during a 1-year period to evalnate the composition, vertical distribution, and activity of microorganisms associated with sedimenting particulate matter. Measurements indicated that the organic fractions of particulate sedimenting matter were transformed considerably during sedimentation. The seasonal fluctuations showed higher heterotrophic activity durang summer and lower activity during winter. Laboratory experiments also indicated that an important part of planktonic particulate material was susceptible to mineralization within a short period of time: phytoplankton was mineralized by about 35% and zooplankton by about 18% per day, at 20°C; at 5°C mineralization was considerably lower (about 3 and 8%, respectively).Please address all correspondence to: Dr. R. Zimmermann, Institut für Meereskunde an der Universität Kiel, Abteilung Marine Mikrobiologie, Düsternbrooker Weg 20, 2300 Kiel 1, Germany (FRG)     

Atmospheric dinitrogen fixation by benthic communities of Tikehau Lagoon (Tuamotu Archipelago, French Polynesia) and its contribution to benthic primary production

Acetylene reduction rates were measured in lagoonal sediments, cyanobacterial mats and limestone surfaces between 1991 and 1995 at many sites, depths and seasons; all the studied substrata contained cyanobacteria. The acetylene reduction/¹⁵N₂ fixation ratio was measured for the different communities and varied between 1.8 and 4.8, depending on substratum. Fixation rates were 1.7 to 7 times higher during daylight compared to night-time rates. N₂ fixation rates ranged from 0.4 to 3.9 mg N m^-2 day^-1 for the lagoonal sediment/mat communities, and the rate was about 2 mg N m^-2 day^-1 for the lagoonal limestone substrata. Total lagoonal benthic N₂ fixation contributed 24.4% of the total nitrogen requirement for the benthic primary production of benthic communities of the lagoon. The input of N₂ fixation by the microbial planktonic communities (including cyanobacteria) of the lagoon, which are highly productive, is unquantified but is likely to be large.     

Diel vertical migration bySalpa aspera and its potential for large-scale particulate organic matter transport to the deep-sea

In mid-summer 1975 throughout the Western Slope Water of the North Atlantic Ocean, massive numbers ofSalpa aspera performed a diel vertical migration of at least 800 m. This resulted in a movement of 85 to 90% of the total zooplankton biomass out of the upper 500 m during the day. Fecal pellet production and losses from this salp population were estimated to contribute approximately 12 mg C m^-2 day^-1 to the deep planktonic and benthic populations. If all this organic matter reached the deep-sea floor, it would represent over 100% of the daily deep-sea benthic infauna energy requirements.     

Oxidative potential (OP) and mineralogy of iron ore particulate matter at the Gol-E-Gohar Mining and Industrial Facility (Iran)

Concentrations of total suspended particulate matter, particulate matter with aerodynamic diameter <2.5 μm (PM_2.5), particulate matter <10 μm (PM₁₀), and fallout dust were measured at the Iranian Gol-E-Gohar Mining and Industrial Facility. Samples were characterized in terms of mineralogy, morphology, and oxidative potential. Results show that indoor samples exceeded the 24-h PM_2.5 and PM₁₀ mass concentration limits (35 and 150 µg m^?3, respectively) set by the US National Ambient Air Quality Standards. Calcite, magnetite, tremolite, pyrite, talc, and clay minerals such as kaolinite, vermiculite, and illite are the major phases of the iron ore PM. Accessory minerals are quartz, dolomite, hematite, actinolite, biotite, albite, nimite, laumontite, diopside, and muscovite. The scanning electron microscope structure of fibrous-elongated minerals revealed individual fibers in the range of 1.5 nm to 71.65 µm in length and 0.2 nm to 3.7 µm in diameter. The presence of minerals related to respiratory diseases, such as talc, crystalline silica, and needle-shaped minerals like amphibole asbestos (tremolite and actinolite), strongly suggests the need for detailed health-based studies in the region. The particulate samples show low to medium oxidative potential per unit of mass, in relation to an urban road side control, being more reactive with ascorbate than with glutathione or urate. However, the PM oxidative potential per volume of air is exceptionally high, confirming that the workers are exposed to a considerable oxidative environment. PM released by iron ore mining and processing activities should be considered a potential health risk to the mine workers and nearby employees, and strategies to combat the issue are suggested.     

城市空气悬浮颗粒物的理化性质及其健康效应

城市空气悬浮颗粒物的理化性质是其他相关研究的理论基础,目前的研究主要集中在分析空气颗粒物的成分组成、来源解析上.空气悬浮颗粒物主要由金属元素、有机化学成分和无机盐类等组成,城市交通、工业等各种源的排放是其主要来源,按照粒径大小不同一般可将其分为总悬浮颗粒物(TSP)、可吸入颗粒物(PM10)、细颗粒物(PM2.5)等.空气悬浮颗粒物达到一定浓度后,会对环境和人体产生一定的危害,而且颗粒物粒径大小不同,来源和成分组成就有别,其产生的危害程度也不一样.文章从粒径大小、来源、成份以及三者间的相互关系等几个方面详细阐述了城市空气悬浮颗粒物的理化性质,并从其对人体、其他动植物和环境等方面造成的影响综述了空气颗粒物的健康效应及影响因素,最后又提出了今后的研究方向和发展途径.     

Improved characterisation of inorganic components in airborne particulate matter

We set up a microanalytical procedure for non-volatile ions by ion chromatography (IC) and for elements by energy-dispersive X-ray fluorescence (ED-XRF) and inductively coupled plasma optical emission spectroscopy (ICP-OES). We analysed NO₃, SO₄, NH₄, Na, Mg, Ca, Fe, S, Zn, As, Cd, Cu, Mn, Ni, Pb, Sb, Se, Ti, and V. The use of complementary techniques yields reliable data for both trace and crustal elements, overcoming the analytical restrictions characteristic of the individual techniques. Some elements determined by two or by all three techniques can be used as data quality markers. The application of the procedure to a short PM_2.5 monitoring campaign is also described, aimed to the identification of fireworks tracers.     

Characterization of airborne particulate matter in thessaloniki,Greece

TSP samples, collected at two stations in the area of Thessaloniki during the period July 1987‐June 1988, were analysed for heavy metals (Fe, Pb, Zn, Cu, Mn, Cr, Co, Ni and V). Flame and flameless atomic absorption spectrophotometry was used for metal determinations. Metals determined were characterized with respect to their origin from natural or man‐made emission sources. Source identification was attempted by relation of metal concentrations to wind direction, and interelement correlations.

Results obtained showed that Pb, Zn and Cu are emitted from man‐made sources (traffic, domestic heating, industry), V, Ni and Co are derived partially from natural and man‐made sources, while Cr is mainly soil‐derived.     

A correlation of secondary aerosol (nitrate and sulfate) with respirable particulate matter (RPM) in ambient air at different traffic junctions of Vadodara city

The correlation study of secondary aerosol (nitrate and sulfate) with RPM in ambient air at different traffic junctions of Vadodara city is reported. RPM was analyzed using Ion Chromatography technique and measured the level of nitrate and sulfate in ambient air. The correlation studies of these particulates with RPM have been established. The average concentration of sulfate and nitrate in ambient air was found 35.74 microg/m3 and 24.22 microg/m3, which ranged of 5.33-84.69 and 1.93-77.86 microg/m3 respectively. The correlation of RPM and SO4 (r = 0.813, P<0.01), RPM-NO3 (r = 0.5549, P<0.01) and SO4-NO3 (r = 0.6133, P<0.01) were found significant. The presence of sulfate and nitrate in RPM is 8.25% and 5.60% . The pH of water extract of RPM averaged 6.81, which ranged 6.17-7.28. Regression analysis result showed that the relationship between RPM-SO4 was significantly (R2=0.66215) correlated. This indicate that probably the secondary aerosols such as nitrate and sulfate in excess may cause irritation and increasing lung disease.     

祁连山中部土壤颗粒组分有机质碳含量及其与海拔和植被的关系

调查分析了祁连山中段不同海拔土壤颗粒有机碳及其与植被的关系.结果显示,土壤颗粒组分比例在0～15 cm和15～35cm土层随海拔升高而呈现下降趋势(P>0.2);土壤颗粒有机碳比例在0～15 cm土层随海拔升高也呈现下降趋势(P≤0.001).土壤颗粒组分比例0～15 cm土层在阴坡3 000 m～3 500 m、15～35 cm土层在阴坡3 200 m和3 500 m及半阴坡2 200和2 800 m处较高;土壤颗粒有机碳比例0～15 cm土层在阴坡3 000 m和3 200 m、半阴坡2 200 m和2 800 m,以及15～35 cm土层在阴坡3 200 m和3 500 m、阳坡3 300 m和3 500 m处较高(P<0.05).土壤颗粒有机碳和颗粒组分碳含量随海拔升高变化不显著(P<0.9).土壤颗粒有机碳含量0～15cm土层在阴坡3 000 m～3 500 m、15～35 cm土层在阴坡3 000 m～3 500 m及阳坡3 300m处较高;土壤颗粒组分碳含量0～15 cm土层在阴坡3 000 m～3 400 m和阳坡3 300 m,以及15～35 cm土层在阴坡3 200 m和3 400 m及阳坡3 300 m处较高.土壤颗粒组分比例0～15 cm土层在森林和灌丛草甸中较高;15～35 cm土层在森林、灌丛草甸和干旱草原中较高(P<0.05).土壤颗粒有机碳比例0～15 cm土层在荒漠草原和干旱草原,以及15～30 cm土层在森林和灌丛草甸中较高(P<0.05).土壤颗粒组分碳含量0～15 cm和15～35 cm土层在森林和灌丛草甸中较高(P<0.05).土壤颗粒有机碳含量0～15cm和15～35cm土层在森林中最高(P<0.05).土壤颗粒组分碳含量和颗粒有机碳含量与土壤有机碳含量有显著的正相关性(P<0.001),土壤颗粒有机碳含量与颗粒组分碳含量也有显著的正相关性(P<0.001),土壤颗粒组分比例与有机碳含量相关性不显著(P=0.15),土壤颗粒有机碳含量与颗粒组分比例有显著正相关性(P<0.005).结果说明祁连山中部北坡土壤有机碳稳定性受植被和海拔共同影响,荒漠草原和干旱草原表层土壤有机碳稳定性较低,森林和灌丛草甸土壤中非保护性碳含量较高.     

World air particulate matter: sources,distribution and health effects

Particulate matter (PM) is both a major driver of climate change and a source of toxicity for health. In the upper atmosphere, particulate matter modifies the earth radiation budget, cloud formation and acts as a reaction center for air pollutants. In the lower atmosphere, particulate matter changes atmospheric visibility and alters biogeochemical cycles and meteorology. Most critical effects are observed in ambient air, where particulate matter degrades human health. Here we review the sources, spatial and temporal variability, and toxicity of PM₁₀, the particulate matter having particle sizes 10 micrometers or less in diameter, in world regions. For that we analyzed information from the world wide web and databases from government organizations after the year 2000. Findings show that PM₁₀ is a major risk in both developed and developing countries. This risk is more severe in Asian countries compared to Europe and USA, where decreasing trends are recorded during the last two decades. Meteorological factors modify particulate matter variations at local and regional levels. PM_2.5/PM₁₀ ratio provides information of particulate matter sources under different environment conditions. Crustal matter, road traffic and combustion of fuels are major sources of particulate matter pollution. Health studies indicate that long-term exposure to particulate matter has multiple health effects in people from all age groups. Identification of possible sources and their control with regular epidemiological monitoring could decrease the impact of particulate matter pollution.     

Metals concentration associated with respirable particulate matter (PM10) in industrial area of Eastern U.P. India

The present study deals with the assessment of ambient air quality with respect to respirable suspended particulate matter (RSPM or PM10 < or = 10 microm) and trace metals (Fe, Zn, Cu, Cr Ni, Cd, Mn and Pb) concentrations in RSPM at five locations of Renukoot, an industrial area of Eastern Uttar Pradesh. The 24 hr mean concentrations of PM10 ranged between 69.3 to 118.9 microg m(-3), which is well within the permissible limit (150 microg m(-3)) of national ambient air quality standards (NAAQS) but found higher than the prescribed annual daily limit of US EPA (50 microg m(-3)). The ambient air was mostly dominated by the Fe and least by the Cd among the metal analysed. Murdhawa, a commercial place influenced by vehicular population, is found to be the most polluted area of Renukoot and Dongia nalla (forest area) the least. The ambient air of Murdhawa is rich in Cu and Ni, indicating contribution of mobile sources. The Rammandir a residential place near the industry, is rich in Cd and Cr suggesting contribution of point sources. The Ni concentration is found to be alarmingly high in the air at all the locations except Dongia nallah, when compared with the EC (European Commission) limit (20 ng m(-3)). The Cd concentration is found to be higher only at Rammandir as compared with the EC limit (5 ng m(-3)). Mean concentrations of Zn, Pb and Mn are found to be almost equal in the ambient air of all the locations, suggesting the significance of sources contributing to presence of these metals. Zn, Cu, Pb and Ni having a significant correlation with PM10 indicate the same source contributing these metals as well as PM10. The present study has focused on the quantitative variation in different metals in the PM10, which is extremely harmful due to their toxic and carcinogenic nature.     

Evaluation of the levels and sources of trace elements in urban particulate matter

An assessment of air quality of Belgrade, Serbia, was performed by determining the trace element content in airborne daily PM₁₀ and PM_2.5 samples collected from a central urban area. The ambient concentrations of Zn were the highest in PM_2.5 (1,998.0 ng m⁻³). Multivariate receptor modelling (principal component analysis and cluster analysis) has been applied to determine the contribution of different sources of specific metallic components in airborne particles. The obtained results showed that vehicle traffic and fossil fuel combustion in stationary objects were the main sources of trace metals in Belgrade urban aerosols.     

Transition zone in otoliths of orange roughy (Hoplostethus atlanticus) and its relationship to the onset of maturity

A transition zone in the otoliths of orange roughy (Hoplostethus atlanticus) is described where annulus width decreases markedly. For fish sampled at spawning time, the relationship between gonad stage and the presence or absence of a transition zone is consistent with the hypothesis that this zone marks the onset of maturity, if allowance is made for some error in gonad staging and identification of the zone. Another data set from a non-spawning area after the spawning season is not consistent with the hypothesis. However, these latter data are considered less reliable because of the small size of the fish in the sample and difficulties in determining, outside the spawning season, whether a fish has been reproductively active. This hypothesis was used to provide estimates of the median age (30 yr) and length (31 cm) at the onset of maturity for the Chatham Rise, New Zealand population. These estimates are unaffected by the biases associated with the usual ogive method of estimation. Received: 27 June 1997 / Accepted: 1 July 1997     

Natural and anthropogenic influences on the diversity structure of reef fish communities in the Tuamotu Archipelago (French Polynesia)

Despite the rapid rate of human-induced species losses, the relative influence of natural and anthropogenic factors on the functional diversity of species assemblages remains unknown for most ecosystems. A model was previously developed to predict the diversity structure of coral reef fish assemblages in 10 atolls of low human pressure and contrasting morphology of the Tuamotu Archipelago (French Polynesia). This existing model predicted smoothed histograms (spectra) of species richness according to size classes, diet classes and life-history classes of fish assemblages using a combination of environmental characteristics at different spatial scales. The present study applied the model to Tikehau, another atoll of the same archipelago where commercial fishing is practiced and where the same sampling strategy was reproduced. Significant differences appeared between predicted and observed species richness in several size, diet and life-history classes of fish assemblages in Tikehau. Two parameters which were not accounted for in the initial model, i.e. fishing pressure and atoll position within the archipelago, explained together 63% of variance in model residuals, >60% being explained by fishing pressure only. The respective effects of fishing and atoll position on the diversity of coral reef fish assemblages are discussed, with the potential of such modelling approach to assess the relative importance of factors affecting functional diversity within communities.     

北京市2012-2013年秋冬季大气颗粒物污染特征分析

大气颗粒物一直是影响我国城市空气质量的重要污染物,2013年1月北京市的严重灰霾污染更是带来了重大的健康危害和经济损失。为了摸清北京市颗粒物污染的特征,本文利用北京市实时发布的颗粒物污染监测数据,选取污染最为严重的2012-2013年秋冬季时段,对颗粒物的达标情况、变化趋势及其与气象因子相关性等方面进行研究。研究结果表明：1）2012年,北京市年均ρ（PM10）为109.0μg.m-3,超过了新国标二级标准限值,日均ρ（PM10）的超标天数为84天,全年超标天数比例为23.0%。2）2012年10月至2013年2月,ρ（PM10）达标天数比例为77.9%,ρ（PM2.5）的达标天数比例为51.9%。各月ρ（PM2.5）的达标天数比例均低于ρ（PM10）,某些月份二者达标天数比例差异很大。3）ρ（PM2.5）与ρ（PM10）的逐小时连续变化趋势基本相同,变化特征为＂快速积累,迅速消散,持续时间不定＂。ρ（PM2.5）与ρ（PM10）平均值24 h的变化呈双峰双谷曲线,颗粒物质量浓度夜间高于白天。4）研究期日均ρ（PM10）和ρ（PM2.5）与日均相对湿度呈显著正相关关系,与平均风速和最大风速呈显著负相关关系,ρ（PM2.5）比ρ（PM10）更易受气象条件变化影响。5）ρ（PM10）和ρ（PM2.5）日均值有着非常显著的线性相关关系。本研究得出的ρ（PM2.5）/ρ（PM10）的均值高于之前北京市及我国其他城市研究得出的数值,严重污染现象是由特殊的气象背景条件与污染物高排放共同导致的。     

Nitro polycyclic aromatic hydrocarbons in atmospheric particulate matter of Athens,Greece

Polycyclic aromatic hydrocarbons (PAHs) and nitro polycyclic aromatic hydrocarbons (N-PAHs) are chemical species of proven mutant and carcinogenic activity. In this study, the concentrations of seven different N-PAHs [2-nitronaphthalene (2N-NAP), 2-nitroflourene (2N-FLU), 2-nitroflouranthene (2N-FLA), 3-nitroflouranthene (3N-FLA), 1-nitropyrene (1N-PYR) and 2-nitropyrene (2N-PYR)] were determined in two fractions of atmospheric particulate matter from the atmosphere of Athens: coarse (2.4 μm?10 μm ) and fine (<2.4 μm ). 3N-FLA was not detected, whereas 1N-PYR, mostly originating from emissions from burning fuel, showed the maximum observed concentrations for both fractions and for the whole experimental period (especially during winter). In addition, 2N-FLA, a secondary nitro-PAH produced by photochemical reactions, showed relatively high values. Analysis of statistical data for N-PAH concentrations, using clustering technique, showed that: (1) 1N-NAP, 2N-FLU and 1N-PYR are mainly produced by direct burning; and (2) photochemical reactions are the dominant sources of 2N-NAP, 2N-PYR and 2N-FLA.     

Trace elements in particulate matter of ambient air at petroleum filling stations

Size segregated suspended particulate matter (PM_2.5 and PM_10-2.5) in air at four major petroleum-filling stations in Ile-Ife, Nigeria, were monitored using double staged “Gent” stacked samplers to assess variations in mass loads and elemental concentrations of 25 elements. Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Zr, Cs, Ta, W, and Pb were determined in both fractions by external ion beam proton-induced X-ray emission technique. Enrichment factors and pollution indices were calculated and results revealed that most elements were anthropogenic in both fractions with concentrations exceeding the World Health Organization guideline standards.