Dynamics and origin of PM2.5 during a three-year sampling period in Beijing, China

Systematic sampling and analysis were performed to investigate the dynamics and the origin of suspended particulate matter smaller than 2.5 μm in diameter (PM(2.5)), in Beijing, China from 2005 to 2008. Identifying the source of PM(2.5) was the main goal of this project, which was funded by the German Research Foundation (DFG). The concentrations of 19 elements, black carbon (BC) and the total mass in 158 weekly PM(2.5) samples were measured. The statistical evaluation of the data from factor analysis (FA) identifies four main sources responsible for PM(2.5) in Beijing: (1) a combination of long-range transport geogenic soil particles, geogenic-like particles from construction sites and the anthropogenic emissions from steel factories; (2) road traffic, industry emissions and domestic heating; (3) local re-suspended soil particles; (4) re-suspended particles from refuse disposal/landfills and uncontrolled dumped waste. Special attention has been paid to seven high concentration "episodes", which were further analyzed by FA, enrichment factor analysis (EF), elemental signatures and backward-trajectory analysis. These results suggest that long-range transport soil particles contribute much to the high concentration of PM(2.5) during dust days. This is supported by mineral analysis which showed a clear imprint of component in PM(2.5). Furthermore, the ratios of Mg/Al have been proved to be a good signature to trace back different source areas. The Pb/Ti ratio allows the distinction between periods of predominant anthropogenic and geogenic sources during high concentration episodes. Backward-trajectory analysis clearly shows the origins of these episodes, which partly corroborate the FA and EF results. This study is only a small contribution to the understanding of the meteorological and source driven dynamics of PM(2.5) concentrations.     

Evaluating a Canadian regional air quality model using ground-based observations in north-eastern Canada and United States

The simulated concentrations from a numerical 3-dimensional regional air quality model (MC2AQ) are compared to those of ground-based observations in north-eastern Canada and the United States. The model has oxidant chemistry for both inorganic and organic species and deposition routines driven online by a mesoscale compressible community meteorological model (MC2). A standard emission inventory of anthropogenic, natural and biogenic sources for the year 1990 for 21 atmospheric trace species was used in the simulation. The model was run for July 1999, because of the occurrence of a high ozone episode and the availability of the monitoring data for surface O3, SO2, NO, NO2 and NOx. The comparisons during the episode show that the model performs quite well for predicting concentrations and diurnal variations of the surface ozone. The predictions for other gaseous species show some discrepancies with observations, but they are consistent with the results from other models evaluated in the literature. The uncertainties in the emission inventory for these species might be the main causes of the discrepancies. Further studies are needed to improve the predictability of SO and NOx, especially as the model is developed to include particulate matter formation as a result of these gaseous precursors.     

Integrating spatial support tools into strategic planning—SEA of the GMS North–South Economic Corridor Strategy and Action Plan

The GMS countries, supported by the Asian Development Bank, have adopted a holistic, multidimensional approach to strengthen infrastructural linkages and facilitate cross border trade through (i) the establishment of a trans-boundary road connecting two economic nodes across marginalised areas, followed by 2) facilitation of environmentally and socially sound investments in these newly connected areas as a means to develop livelihoods. The North–South Economic Corridor is currently in its second phase of development, with investment opportunities to be laid out in the NSEC Strategy and Action Plan (SAP). It targets the ecologically and culturally sensitive border area between PR China's Yunnan Province, Northern Lao PDR, and Thailand. A trans-boundary, cross-sectoral Strategic Environmental Assessment was conducted to support the respective governments in assessing potential environmental and social impacts, developing alternatives and mitigation options, and feeding the findings back into the SAP writing process. Given the spatial dimension of corridor development—both with regard to opportunities and risks—particular emphasis was put in the application of spatial modelling tools to help geographically locate and quantify impacts as a means to guide interventions and set priorities.     

Correlations between mutagenic activity of organic extracts of airborne particulate matter, NOx and sulphur dioxide in southern Germany: results of a two-year study

Goals, Scope and Background Among other substances, sulphur dioxide (SO2), nitric oxide (NO) and nitrogen dioxide (NO2) are parameters which are routinely measured to describe basic air quality. Organic extracts of airborne particulate matter contain mutagenic chemical compounds of different origins. The aim of the study was to find correlations between routine monitoring data and mutagenic activity of organic extracts of simultaneously drawn samples.Methods Specimens were collected over a period of two years at 8 sampling sites in south-west Germany. Simultaneously, concentrations of NO, NO2, and SO2 were measured on-line within the framework of the official air monitoring network of Baden-Württemberg, Germany. Dust samples were collected for biotesting using high volume air samplers equipped with glass fibre filters. After sampling was completed, filters were extracted and samples were prepared for biological testing. Mutagenic activity was tested by means of the plate incorporation assay (Ames test) using S. typhimurium TA98 and TA100 tester strains. During the first year of the study, all tests have been performed with and without metabolic activation. Additionally, a series of tests has been performed in parallel with TA98 and TA98NR.Results and Discussion Comparison of Ames test data obtained with and without metabolic activation indicates no statistically significant difference between both methods. Therefore, during the second year of the study, all tests have been performed without metabolic activation. Average yearly activities at the sampling sites were between 1 und 27 Revertants per m³ (Rev/m³). High activities were preferably found at congested sites (Karlsruhe, up to 95 Rev/m³). However, peak values of over 100 Rev/m³ were found in other places where pollution by traffic is significantly lower. The reason for these high level values is not evident. Tests performed using TA98NR tester strain indicate a significant share (average 31%) of compounds requiring activation by nitroreductase for mutagenic activity. Average mutagenic activity can be correlated to routine monitoring parameters. Comparison of averaged data for particular sampling sites indicates significant correlation between nitric oxide and mutagenic activity in TA98 (r²=0.90), while correlation between nitrogen dioxide (0.84) or sulphur dioxide (0.52) and mutagenic activity is weaker. For TA100, correlations are generally weaker than for TA98. Comparison of data for mutagenic activity and routine monitoring data of distant sites being sampled simultaneously shows parallel behaviour.Conclusions Results from this study show that mutagenic activity can be compared to seasonal and local variations of gaseous indicator air pollutants. Tester strain TA98 generally shows the best correlations. Although pollution by particle-bound mutagenic substances is significantly higher during the cold season than during summer on average, mutagenic activity of airborne dust is not a continuous effect. During winter, peak levels as well as low pollution periods can occur. Even during winter time mutagenic activity can reach very low levels typical for summertime. Comparison of results for distant sampling sites where samples have been collected simultaneously indicate that “classical” indicators of air pollution and bacterial mutagenicity of organic extracts from airborne particulate matter are influenced by connected effects. Seasonal trend of mutagenic activity, in particular, is similar to the concentrations of nitrogen oxide. NO is a strong indicator for vehicle exhaust gases. It is concluded that the average mutagenic activity at particular sites can be estimated using NO concentrations as an indicator.     

Hazardous Waste Minimization: Part VII (A) Hazardous Waste Minimization within the Department of Defense

This article is a series of representative case studies of Department of Defense hazardous waste minimization. Each Military Department and the Defense Logistics Agency describe actual accomplishments. Areas covered range from production line modification to product specification change. These efforts are part of a Department of Defense plan composed of individual programs executed independently by each military service and defense agency.

Part VII of the hazardous waste minimization series appears in two separate installments: this installment, Part VII (A), deals with Department of Defense waste minimization efforts in vehicle repair operations, explosives manufacturing, and abrasive blasting processes; Part VII (B) will cover shipboard mercury wastes, industrial chemical control, solvent reclamation, and hazardous property sales efforts.     

Heavy Metals in Urban Soils of East St. Louis,IL, Part I: Total Concentration of Heavy Metals in Soils

ABSTRACT

The city of East St. Louis, IL, has a history of abundant industrial activities including smelters of ferrous and non-ferrous metals, a coal-fired power plant, companies that produce organic and inorganic chemicals, and petroleum refineries. A protocol for soil analysis was developed to produce sufficient information on the extent of heavy metal contamination in East St. Louis soils. Soil cores representing every borough of East St. Louis were analyzed for heavy metals—As, Cd, Cu, Cr, Hg, Ni, Pb, Sb, Sn, and Zn. The topsoil contained heavy metal concentrations as high as 12.5 ppm Cd, 14,400 ppm Cu, ppm quantities of Hg, 1860 ppm Pb, 40 ppm Sb, 1130 ppm Sn, and 10,360 ppm Zn. Concentrations of Sb, Cu, and Cd were well correlated with Zn concentrations, suggesting a similar primary industrial source. In a sandy loam soil from a vacated rail depot near the bank of the Mississippi River, the metals were evenly distributed down to a 38-cm depth. The clay soils within a half-mile downwind of the Zn smelter and Cu products company contained elevated Cd (81 ppm), Cu (340 ppm), Pb (700 ppm), and Zn (6000 ppm) and displayed a systematic drop in concentration of these metals with depth. This study demonstrates the often high concentration of heavy metals heterogeneously distributed in the soil and provides baseline data for continuing studies of heavy metal soil leachability.     

Macrozoobenthos diversity in an oxygen minimum zone off northern Namibia

A benthological survey in the Benguela upwelling area off northern Namibia (located at 17.3°S and water depth ranging between 26 and 117 m) showed the concentration of dissolved oxygen and the accumulation of organic-rich sediments to control macrozoobenthic community patterns. In contrast to highly biodiverse nearshore areas with well-structured shell deposits of the brachiopod Discinisca tenuis (Sowerby 1847), the benthic community in the oxygen minimum zone (OMZ) decreased strongly in species numbers. Nevertheless, a well-established community ranging from 13 to 31 species persisted. Species densities (300–3,350 ind m⁻²) and biomass (4–109 g afdw/m²) were surprisingly high for areas with near bottom oxygen concentrations from 0.06 to 0.88 ml l⁻¹. In contrast to OMZ’s of other upwelling areas, where the benthic macrofauna is generally dominated by small-bodied polychaetes, off Namibia larger key organisms like the bivalve Nuculana bicuspidata (Gould 1845) and the snail Nassarius vinctus (Marrett 1877) accounted for a large proportion of the macrozoobenthos >1 mm. This is supposed to have a distinct effect on the functional properties of the sediments.

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Ecotoxicological Assessment of Sediment, Suspended Matter and Water Samples in the Upper Danube River. A pilot study in search for the causes for the decline of fish catches (12 pp)

Goals, Scope and Background Fish populations, especially those of the grayling (Thymallus thymallus), have declined over the last two decades in the upper Danube River between Sigmaringen and Ulm, despite intensive and continuous stocking and improvement of water quality since the 1970s. Similar problems have been reported for other rivers, e.g. in Switzerland, Great Britain, the United States and Canada. In order to assess if ecotoxicological effects might be related to the decline in fish catch at the upper Danube River, sediment, suspended matter and waste water samples from sewage treatment plants were collected at selected locations and analyzed in a bioanalytical approach using a battery of bioassays. The results of this pilot study will be used to decide if a comprehensive weight-of-evidence study is needed. Methods Freeze-dried sediments and suspended particulate matters were extracted with acetone in a Soxhlet apparatus. Organic pollutants from sewage water were concentrated using XAD-resins. In order to investigate the ecotoxicological burden, the following bioassays were used: (1) neutral red assay with RTL-W1 cells (cytotoxicity), (2) comet assay with RTLW1 cells (genotoxicity), (3) Arthrobacter globiformis dehydrogenase assay (toxicity to bacteria), (4) yeast estrogen screen assay (endocrine disruption), (5) fish egg assay with the zebrafish (Danio rerio; embryo toxicity) and (6) Ames test with TA98 (mutagenicity). Results and Discussion The results of the in vitro tests elucidated a considerable genotoxic, cytotoxic, mutagenic, bacteriotoxic, embryotoxic and estrogenic burden in the upper Danube River, although with a very inhomogeneous distribution of effects. The samples taken from Riedlingen, for example, induced low embryo toxicity, but the second highest 17β-estradiol equivalent concentration (1.8 ng/L). Using the fish egg assay with native sediments, a broad range of embryotoxic effects could be elucidated, with clear-cut dose-response relationships for the embryotoxic effects of contaminated sediments. With native sediments, embryotoxicity was clearly higher than with corresponding pore waters, thus corroborating the view that – at least for fish eggs – the bioavailability of particle-bound lipophilic substances in native sediments is higher than generally assumed. The effect observed most frequently in the fish egg assay was a developmental delay. A comparison of our own results with locations along the rivers Rhine and Neckar demonstrated similar or even higher ranges of ecotoxicological burdens in the Danube River. Conclusions The complex pattern of ecotoxicological effects caused by environmental samples from the Danube River, when assessed in an in vitro biotest battery using both acute and more specific endpoints, showed that integration of different endpoints is essential for appropriate hazard assessment. Overall, the ecotoxicological hazard potential shown has indeed to be considered as one potential reason for the decline in fish catches at the upper Danube River. However, based on the results of this pilot study, it is not possible to elucidate that chemically induced alterations are responsible for the fish decline. Recommendations and Perspective . In order to confirm the ecological relevance of the in vitro results for the situation in the field and especially for the decline of the grayling and other fishes, further integrated investigations are required. For linking the weight of evidence obtained by in vitro assays and fish population investigations, the application of additional, more specific biomarkers (e.g. vitellogenin induction, EROD and micronucleus assay) has been initiated in fish taken from the field as well as in situ investigations.