Aircraft emissions and local air quality impacts from takeoff activities at a large International Airport

Real time number concentrations and size distributions of ultrafine particles (UFPs, diameter <100 nm) and time integrated black carbon, PM_2.5 mass, and chemical species were studied at the Los Angeles International Airport (LAX) and a background reference site. At LAX, data were collected at the blast fence (∼140 m from the takeoff position) and five downwind sites up to 600 m from the takeoff runway and upwind of the 405 freeway. Size distributions of UFPs collected at the blast fence site showed very high number concentrations, with the highest numbers found at a particle size of approximately 14 nm. The highest spikes in the time series profile of UFP number concentrations were correlated with individual aircraft takeoff. Measurements indicate a more than 100-fold difference in particle number concentrations between the highest spikes during takeoffs and the lowest concentrations when no takeoff is occurring. Total UFP counts exceeded 10⁷ particles cm⁻³ during some monitored takeoffs. Time averaged concentrations of PM_2.5 mass and two carbonyl compounds, formaldehyde and acrolein, were statistically elevated at the airport site relative to a background reference site. Peaks of 15 nm particles, associated with aircraft takeoffs, that occurred at the blast fence were matched with peaks observed 600 m downwind, with time lags of less than 1 min. The results of this study demonstrate that commercial aircraft at LAX emit large quantities of UFP at the lower end of currently measurable particle size ranges. The observed highly elevated UFP concentrations downwind of LAX associated with aircraft takeoff activities have significant exposure and possible health implications.     

Combining polar organic chemical integrative samplers (POCIS) with toxicity testing to evaluate pesticide mixture effects on natural phototrophic biofilms

Polar organic chemical integrative samplers (POCIS) are valuable tools in passive sampling methods for monitoring polar organic pesticides in freshwaters. Pesticides extracted from the environment using such methods can be used to toxicity tests. This study evaluated the acute effects of POCIS extracts on natural phototrophic biofilm communities. Our results demonstrate an effect of POCIS pesticide mixtures on chlorophyll a fluorescence, photosynthetic efficiency and community structure. Nevertheless, the range of biofilm responses differs according to origin of the biofilms tested, revealing spatial variations in the sensitivity of natural communities in the studied stream. Combining passive sampler extracts with community-level toxicity tests offers promising perspectives for ecological risk assessment.     

Long-term environmental monitoring of persistent organic pollutants and metals in a chemical/petrochemical area: human health risks

Organic pollutants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and polycyclic aromatic hydrocarbons (PAHs), as well as some metals are periodically monitored in soil and vegetation samples collected in Tarragona County (Spain). We here report the temporal trends of the concentrations of the above pollutants between the initial survey (2002) and that recently (2009) performed. The area under evaluation was divided into 4 sections (chemical, petrochemical, urban/residential and unpolluted). In general terms, urban soils presented the highest concentrations of PCDD/Fs, PCNs and PAHs, confirming that traffic is a very important emission source of these pollutants. In addition, substantially higher levels of PAHs and some metals were found in vegetation samples from the petrochemical complex. The assessment of health risks of these contaminants indicated that the current concentrations of micropollutants did not mean additional non-carcinogenic or cancer risks for the population living in the zone.     

Removal of emulsified fuel oils from brackish and pond water by dissolved air flotation with and without polyelectrolyte use: pilot-scale investigation for estuarine and near shore applications

In coastal areas, estuaries, and inland waters, dispersant use after oil spills is not allowed due to sensitivity of the ecosystems. The purpose of this study was to investigate the removal of emulsified fuel oils from brackish and pond water by dissolved air flotation (DAF) with and without use of coagulants. Experiments were conducted with a 60 L DAF system. Fuel oil-water emulsions were prepared with regular unleaded gasoline, jet fuel, and diesel fuel mixed at 1:1:1 (v/v/v) ratio. Batch and continuous runs were conducted at air pressurization of 354.6 kPa. During both batch and continuous modes, significant petroleum hydrocarbon (PHC) removal was achieved within 10 min. Coagulant addition initially increased the PHC removal by about 5-15%. However, effectiveness of the coagulant was not significant after 20 min due to breakage of the aggregates. In general, the pond water had higher PHC removal than the brackish water. With longer run times, PHC removal improved slightly and the effluent contained increasing fractions of higher molecular weight compounds indicating that PHC removal was due to both DAF and stripping processes. Results indicate that DAF process can be effective both with and without the use of coagulants for removing PHCs from brackish and pond waters.     

A rapidly equilibrating, thin film, passive water sampler for organic contaminants; characterization and field testing

Improving methods for assessing the spatial and temporal resolution of organic compound concentrations in marine environments is important to the sustainable management of our coastal systems. Here we evaluate the use of ethylene vinyl acetate (EVA) as a candidate polymer for thin-film passive sampling in waters of marine environments. Log K_EVA−W partition coefficients correlate well (r² = 0.87) with Log K_OW values for selected pesticides and polychlorinated biphenyls (PCBs) where Log K_EVA−W = 1.04 Log K_OW + 0.22. EVA is a suitable polymer for passive sampling due to both its high affinity for organic compounds and its ease of coating at sub-micron film thicknesses on various substrates. Twelve-day field deployments were effective in detecting target compounds with good precision making EVA a potential multi-media fugacity meter.     

Comparative chemical analysis of some traditional Omani-made kohl

Fourteen different types of Omani-made kohl were collected from different locations in Oman. The kohl samples were analyzed using different analytical techniques including X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray microanalysis, and inductively coupled plasma mass spectroscopy after sample digestion. The results show that six kohls (kohls 1–6) are mineral-based, four of which, namely lasif, cold ethmid, hot ethmid, and original ethmid, contain very high levels of Pb (basically galena). The other two kohls (red ethmid and black ethmid) contain mostly iron (hematite, magnetite, and goethite). The other kohl samples (kohls 7–14) are basically amorphous carbons, one of which is made by charring date stones while the rest are basically soot collected from burning different materials. Compared to the results obtained by inductively coupled plasma mass spectroscopy, energy-dispersive X-ray microanalysis yielded higher concentrations of major elements while some minor elements were not detected; this is probably related to some limitations in the latter technique. Based on this study, carbon-based kohls possess much lower levels of toxic elements than mineral-based kohls; consequently, the former can be considered as the less hazardous kohls. However, concerns about the use of soot in cosmetics are rising because of the presence of some carcinogenic compounds such as polyaromatic hydrocarbons in soot.     

Evaluation of residue risk and toxicity of different treatments with diazinon insecticide applied to mushroom crops

ABSTRACT

This work describes the phytotoxic effect of different doses of diazinon and different application times on Agaricus bisporus mycelium, and determines the residue levels in mushrooms from the first three flushes. Mushroom cultivation is a widespread commercial activity throughout the world. The application of insecticide diazinon to the compost or casing layer is a common practice to control two mushroom pests, the phorid Megaselia halterata and the sciarid Lycoriella auripila. Application to the compost does not result in any appreciable fall in yield or quality, and does not delay the harvest time. In contrast, application to the casing led to a slight fall (6.2%) in production and a smaller number of mushrooms although they are larger in size. Residue levels of more than 0.01 ppm are detected in many of the samples analyzed, and raising the question whether the product should continue to be used in mushroom cultivation in the conditions in which it is currently applied.     

宁东能源化工基地工业固体废物综合利用现状分析、预测及建议

宁东能源化工基地目前以及将来都是宁夏回族自治区工业固体废物主要产生源,因此做好宁东能源基地工业固体废物污染防治工作就相当于解决了宁夏地区大部分工业固体废物问题。通过对基地在工业固体废物方面存在的问题进行剖析,提出宁东能源化工基地固体废物污染防治对策,旨在为减少宁东基地工业固体废物的产生量,提高工业固体废物的综合利用率。做好工业固体废物贮存、处置工作,提供科学指导,保证基地的高水平建设,为可持续发展提供科学依据。     

糎T] "7.16"大连新港石油管道爆炸事故中的热红外溢油监测

利用有效的监测手段、降低溢油事故的风险是海洋环境保护和社会经济节约的关键问题。"7.16"事故中使用3.0～5.0μm红外热像仪作为机载监测的一种手段,对事故海域进行常规监测,识别海面油膜,利用热红外油膜厚度模式分析油膜的相对厚度,并且结合其他遥感数据,在GIS系统中绘制每日的事故海域溢油分布图,为清污指挥部门提供决策依据。     

Heavy metal pollution status in surface sediments of Swan Lake lagoon and Rongcheng Bay in the northern Yellow Sea

The national ‘Shandong Peninsula Blue Economic Zone Development Plan’ compels the further understanding of the distribution and potential risk of metals pollution in the east coast of China, where the rapid economic and urban development have been taken off and metal pollution has become a noticeable problem. Surface sediments collected from the largest swan habitat in Asia, the Swan Lake lagoon and the surrounding coastal area in Rongcheng Bay in northern Yellow Sea, were analyzed for the total metal concentrations and chemical phase partitioning of five heavy metals (Cu, Zn, Pb, Cd, and Cr). Metal contents in the studied region have increased significantly in the past decade. The speciation analyzed by the sequential extraction showed that Zn and Cr were present dominantly in the residual fraction and thus of low bioavailability, while Cd, Pb and Cu were found mostly in the non-residual fraction thus of high potential availability, indicating significant anthropogenic sources. Among the five metals, Cd is the most outstanding pollutant and presents high risk, and half of the surface sediments in the studied region had a 21% probability of toxicity based on the mean Effect Range-Median Quotient. At some stations with comparable total metal contents, remarkably different non-residual fraction portions were determined, pointing out that site-specific risk assessment integrating speciation is crucial for better management practices of coastal sediments.