The plant availability of auto-cast platinum group elements

The introduction of automobile catalysts has raised environmental concern, as this pollution control technology is also an emission source for platinum group elements (PGE). The main aim of this study was to assess soil and grass PGE concentrations in soils adjacent to five road networks. The soil and grass samples were collected from four distances at each site; they were 0, 1, 2 and 5 m from the road edges. The maximum soil Pt, Rh and Pd concentrations were measured at the road perimeters. Pd concentrations were much higher than Pt or Rh, possibly due to differences in its use, emission and/or soil chemistry. Rh and Pt soil concentrations accounted for 66 and 34% (P < 0.01) of the variability observed, respectively, in their plant concentrations. Grass Pd concentrations had no relationship with its total soil concentrations.     

Determination of trace elements in total suspended particles at the Southwest of Mexico City from 2003 to 2004

The purpose of the present study is to describe the relationships of eight elements analysed in total suspended particles collected in Mexico City, during 2003 and 2004. Al, Cd, Cr, Fe, Mn, Ni, Pb and V were analysed in to the atmospheric samples and the results were treated by Principal Components Analysis and Cluster Analysis trying to identify the possible sources of aerosols in the sampling site. Factor analysis calculations allowed the elements classification, related to their source on oil combustion, crustal and urban dust, smelting industries and motor vehicle emissions. A further statistical analysis of chemical results from the atmospheric samples was also performed, in order to see what environmental concentrations of those elements have been affected by industrial and mining activities. The eight elements analysed were arranged into two groups that presents high and positive Pearson r values suggesting common emission sources.     

Biosorption for the recovery and analysis of rare earth elements and platinum group metals from real samples. A review

Environmental Chemistry Letters - The increasing demand of rare earth elements and platinum group metals requires alternative approaches for their recycling from waste. Decades of fundamental...     

Porous materials for the recovery of rare earth elements,platinum group metals,and other valuable metals: a review

Environmental Chemistry Letters - The demand for valuable metals such as rare earth elements and platinum group metals is rising fast in the context of the&nbsp;depletion of natural resources...     

Platinum in PM2.5 of the metropolitan area of Mexico City

The increase in platinum (Pt) in the airborne particulate matter with size ≤2.5 µm (PM_2.5) in urban environments may be interpreted as result of the abrasion and deterioration of automobile catalyst. Nowadays, about four million vehicles in Mexico City use catalytic converters, which means that their impact should be considered. In order to evaluate the contribution of Pt to environmental pollution of the metropolitan area of Mexico City (MAMC), airborne PM_2.5 was collected at five different sites in the urban area (NW, NE, C, SW, SE) in 2011 during April (dry-warm season), August (rainy season) and December (dry-cold season). Analytical determinations were carried out using a ICP-MS with a collision cell and kinetic energy discrimination. The analytical and instrument performance was evaluated with standard road dust reference material (BCR-723). Median Pt concentration in the analyzed particulate was is 38.4 pg m^?3 (minimal value 1 pg m^?3 maximal value 79 pg m^?3). Obtained Pt concentrations are higher than those reported for other urban areas. Spatial variation shows that SW had Pt concentration significantly higher than NW and C only. Seasonal variation shows that Pt median was higher in rainy season than in both dry seasons. A comparison of these results with previously reported data of PM₁₀ from 1991 and 2003 in the same studied area shows a worrying increase in the concentration of Pt in the air environment of MAMC.     

Hydrocarbons in benthic algae from the eastern Gulf of Mexico

Thirty-six samples of benthic algae were collected from the continental shelf along the eastern Gulf of Mexico. The algae contain 82.8±143 ppm aliphatic hydrocarbons by dry weight and 11.8±22.7 ppm aromatic and polyolefinic hydrocarbons. The aliphatic constituents of red algae are composed almost entirely of n-C₁₇ (70 to 95% of aliphatic weight); green algae have varying amounts of n-alkanes in the range of n-C₁₅ to n-C₁₉, with homologous series of odd carbon number n-alkenes. Phytadienes occur as high as 740 ppm dry weight in the green algae and do not appear to be related to time or place of collection or to presence of any petroleum pollutants. The single brown algal species contains predominantly n-C₁₅. About 30% of the samples have hydrocarbons resembling degraded petroleum residues, but no petroleum pollution of recent origin was detected in any specimen.     

微量元素对红豆杉菌根菌生长的影响

微量元素对植物的生长发育有着十分重要的意义。对太行山野生红豆杉(Taxus chinensis var.mairei)菌根菌菌丝在分别加有硫酸锌、钼酸铵以及硫酸亚铁的PDA培养基中的生长发育状况进行了试验研究。所得数据同PDA对照组进行比较分析后,结果表明:Mo元素对红豆杉菌根菌菌丝的生长发育有很好的促进作用;Fe元素明显地促进红豆杉菌根菌菌丝的生长发育;Zn元素在一定范围内对红豆杉菌根菌菌丝的生长发育有一定的抑制作用。实验结果揭示出红豆杉菌根菌生长发育的一些营养因素。     

Wintering areas of adult Atlantic puffins Fratercula arctica from a North Sea colony as revealed by geolocation technology

Most seabirds die outside the breeding season, but understanding the key factors involved is hampered by limited knowledge of nonbreeding distributions. We used miniature geolocating loggers to examine the movements between breeding seasons of Atlantic puffins Fratercula arctica from a major North Sea colony where numbers have declined in recent years, apparently due to increased overwinter mortality. The most intensively used region was the northwestern North Sea but most puffins also made excursions into the east Atlantic in the early winter. Ringing recoveries previously indicated that adults from British east coast colonies remained within the North Sea and hence were spatially segregated from those breeding on the west throughout the year. Updated analyses of ringing recoveries support results from geolocators suggesting that usage of Atlantic waters is a recent phenomenon. We propose that the increased adult mortality is related to changes in distribution during the nonbreeding period and reflects worsening conditions in the North Sea.     

Population structure of red drum (Sciaenops ocellatus) in the northern Gulf of Mexico, as inferred from variation in nuclear-encoded microsatellites

Allelic variation at eight nuclear-encoded microsatellites was assayed among 967 red drum (Sciaenops ocellatus) sampled from four consecutive cohorts at seven geographic localities (=28 samples total) in the northern Gulf of Mexico (Gulf). Number of alleles per microsatellite ranged from 6 to 21; average direct-count heterozygosity values per sample (-SE) ranged from 0.560ǂ.018 to 0.903ǂ.009. Tests of Hardy-Weinberg equilibrium revealed significant departures from expected genotype proportions at one microsatellite, which was omitted from further analysis. Tests of genotypic equilibrium indicated that genotypes between pairs of microsatellites were randomly associated. Homogeneity tests of allele distributions across cohorts within localities were non-significant following correction for multiple tests executed simultaneously, and results from molecular analysis of variance indicated that the genetic variance component attributable to variation among cohorts did not differ significantly from zero. Homogeneity tests of allele distributions among localities (cohorts pooled) revealed significant differences both before and after correction for multiple tests. Neighbor-joining clustering of a pairwise matrix of Š values (an unbiased estimator of F_ST), spatial autocorrelations, and regression analysis revealed a pattern of isolation by distance, where genetic divergence among geographic samples increases with geographic distance between sample localities. The pattern and degree of temporal and spatial divergence in the nuclear-encoded microsatellites paralleled almost exactly those of mitochondrial (mt) DNA, as determined in a prior study. Stability of both microsatellite and mtDNA allele distributions within localities indicates that the small but significant genetic divergence among geographic samples represents true signal and that overlapping populations of red drum in the northern Gulf may be influenced by independent population dynamics. The degree of genetic divergence in microsatellites and mtDNA is virtually identical, indicating that genetic effective size of microsatellites and mtDNA in red drum are the same. This, in turn, suggests either that gene flow in red drum in the northern Gulf could be biased sexually or that red drum populations may not be in equilibrium between genetic drift and migration. If a sexual bias exists, the observation that divergence in mtDNA is considerably less than 4 times that of microsatellites could suggest female-mediated dispersal and/or male philopatry. The observed isolation-by-distance effect indicates a practical limit to dispersal. Approximate estimates of geographic neighborhood size suggest the limit is in the range 700-900 km. Although the genetic studies of red drum indicate significant genetic divergence across the northern Gulf, the genetic differences do not delimit specific populations or stocks with fixed geographic boundaries.     

广东省不同水库底泥理化性质对内源氮磷释放影响

采用分级浸取分离方法,分析了广东省10个典型水库底泥的氮磷营养形态分布和污染状况;并通过模拟覆水试验,研究了不同水库底泥氮磷形态及理化性质对内源氮磷释放的影响。结果表明：广东省10个水库底泥氮磷污染较为严重,全氮含量为0.33~3.31 g.kg^-1,平均值为1.70 g.kg^-1;全磷含量为0.14~2.63 g.kg^-1,平均值为1.31 g.kg^-1。底泥氮磷主要以可转化态形式存在,可转化态氮磷含量占总氮磷含量百分比分别为41.2%~71.4%和53.6%~93.2%。底泥内源氮磷的释放主要受氮磷的赋存形态和含量的影响,水库底泥总氮的释放量与离子交换态氮（IEF-N）、碳酸盐结合态氮（WAEF-N）、铁锰氧化物结合态氮（SAEF-N）呈极显著正相关关系,相关系数分别为0.931、0.814、0.807;总磷的释放量与碳酸盐结合态磷（WAEF-P）、铁锰氧化物结合态磷（SAEF-P）呈极显著正相关,相关系数分别为0.960、0.957;这几种氮磷形态是上覆水体中氮磷的重要来源。同时底泥内源氮磷释放还与底泥机械组成有关,其中总氮和总磷释放量与底泥黏粒质量分数呈显著正相关,相关系数分别为0.738、0.638;而总氮的释放量与底泥砂粒质量分数呈显著负相关,相关系数为-0.685。这可能与可转化态氮磷更多的分布在细粒级底泥中有关,细颗粒底泥氮磷释放是上覆水体氮磷的主要来源。     

Increase in Quantity and Quality of Suitable Areas for Invasive Species as Climate Changes

As climatically suitable range projections become increasingly used to assess distributions of species, we recommend systematic assessments of the quality of habitat in addition to the classical binary classification of habitat. We devised a method to assess occurrence probability, captured by a climatic suitability index, through which we could determine variations in the quality of potential habitat. This relative risk assessment circumvents the use of an arbitrary suitability threshold. We illustrated our method with 2 case studies on invasive ant species. We estimated invasion potential of the destroyer ant (Monomorium destructor) and the European fire ant (Myrmica rubra) on a global scale currently and by 2080 with climate change. We found that 21.1% of the world's landmass currently has a suitable climate for the destroyer ant and 16% has a suitable climate for European fire ant. Our climatic suitability index showed that both ant species would benefit from climate change, but in different ways. The size of the potential distribution increased by 35.8% for the destroyer ant. Meanwhile, the total area of potential distribution remained the same for the European fire ant (>0.05%), but the level of climatic suitability within this range increased greatly and led to an improvement in habitat quality (i.e., of invasive species’ establishment likelihood). Either through quantity or quality of suitable areas, both invasive ant species are likely to increase the extent of their invasion in the future, following global climate change. Our results show that species may increase their range if either more areas become suitable or if the available areas present improved suitability. Studies in which an arbitrary suitability threshold was used may overlook changes in area quality within climatically suitable areas and as a result reach incorrect predictions. Incremento de la Cantidad y Calidad de Áreas Idóneas para Especies Invasoras a Medida que Cambia el Clima     

Flux capacities and acclimation costs in Trichodesmium from the Gulf of Mexico

Phytoplankton function and acclimation are driven by catalytic protein complexes that mediate key physiological transformations, including generation of photosynthetic ATP and reductant, and carbon and nitrogen fixation. Quantitation of capacities for these processes allows estimation of rates for key ecosystem processes, and identification of factors limiting primary productivity. We herein present molar quantitations of PSI, PSII, ATP synthase, RuBisCO and the Fe protein of nitrogenase of Trichodesmium collected from the Gulf of Mexico, in comparison to determinations for a range of cyanobacteria growing in culture. Using these measurements, estimates were generated for Trichodesmium capacities for carbon fixation of 1–3.4 g C g chl a ⁻¹ h⁻¹ and nitrogen fixation of 0.06–0.17 g N g chl a ⁻¹ h⁻¹, with diel variations in capacities. ATP synthase levels show that ATP synthesis capacity is sufficient to support these levels of carbon and nitrogen fixation, and that ATP synthase levels change over the day in accordance with the ATP demands of nitrogenase and RuBisCO activity. Levels of measured complexes indicate that Trichodesmium manifests n-type diel light acclimation through rapid changes in RuBisCO:PSII, supported by significant investment of cellular nitrogen. The plasticity in the levels and stoichiometry of these core complexes show that changes in the abundance of core protein complexes are an important component of acclimation and regulation of metabolic function by Trichodesmium populations. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Relationship between growth rate and age at recruitment ofAnguilla japonica elvers in a Taiwan estuary as inferred from otolith growth increments

The growth history and recruitment dynamics of eel (Anguilla japonica) elvers were studied. Observations were based on growth increments in sagittal otoliths of elvers collected from Shuang-Chi River estuary off northeastern Taiwan, from November 1985 to February 1986. Total lengths of elvers upon arrival at the estuary were similar in most case; mean total lengths were from 55.99 to 59.06 mm. Daily ages of elvers at arrival ranged from 112.8±9.4 (±SD) to 156.5±13.5 d, indicating that migration of eel larvae from their oceanic spawning ground to the estuary requires 4 to 5 mo. Elver hatching dates, back-calculated from estimated daily ages, indicated that the spawning season lasted 5 mo (from late June to early October). Furthermore, the earlier eels spawned, the earlier elvers reached the estuary. The transition in growth history during the larval stage was obvious, as indicated from the change in increment width in elver otoliths. The inverse correlation between daily age and mean daily growth rates of fish length and otolith indicated that the age of elvers upon arrival at the estuary was susceptible to larval growth rate. In other words, the time taken on migration from oceanic spawning ground to the estuary was shorter for fast-growing larvae than for slowgrowing ones.     

Soils from abandoned shooting range facilities as contamination source of potentially toxic elements: distribution among soil geochemical fractions

Environmental Geochemistry and Health - Civilian and military shooting range facilities cause environmental issues in several countries due to the accumulation of Potentially Toxic Elements; as a...     

Fish as an indicator of aquatic environment: Multielemental neutron activation analysis of nutrient and pollutant elements in fish from Indian coastal areas

Fish is the main food in coastal areas and its analysis for toxic metals has been used as an indicator of the pollution status of the aquatic environment. Several different fish species from the three Indian coasts, Visakhapatnam in the east, Mumbai in the west and Mangalore in the south west and also inland freshwater fish from Nagpur in the central region for comparison were analyzed for up to 20 elements (As, Au, Ba, Br, Cl, Co, Cr, Cu, Fe, Hg, K, Mn, Na, P, Rb, Sb, Sc, Se, Sr, Zn) by instrumental neutron activation analysis (INAA). Dried fish samples in powdered form were irradiated with thermal neutrons in a nuclear reactor followed by high resolution gamma ray spectrometry at different intervals. Several Reference Materials (RMs) of biological origin were analyzed for quality assurance and data validation. Elemental contents in different fish species vary in a wide range depending on the species, its size, location, and aquatic environment. Fish from Mangalore showed highest mean contents of Cr (14.8?±?29.9?µg?g^?1), Cu (1005?±?643?µg?g^?1) and Sb (849?±?888?ng?g^?1) whereas those from Mumbai exhibited highest Hg (2066?±?2146?ng?g^?1) and P (20.3?±?4.63?µg?g^?1) but lowest Cu (6.30?±?3.10?µg?g^?1) contents. Fish from all the regions showed significant amounts of nutrient elements such as Na, K, P, Mn, Fe, Se and Zn as well as some pollutant elements (Br, Cr, Sb, Hg). No regularity in variation of elemental contents with the size was observed. Prawn (Panaeus latisulcatus), a popular fish species from four different regions showed wide variation in elemental contents of Cr, Mn, Fe, Zn, Se, P including toxic pollutants, Sb and Hg. An attempt has been made to calculate daily dietary intake (DDI) for some nutrient elements from Indian fish. Elemental data for Cr, Cu, Fe, Hg, Se, and Zn have been compared with those from other fish exporting countries.