Selected ion chromatograms and tandem mass spectrometry for detection of trace polycyclic aromatic hydrocarbons in diesel exhaust

Polycyclic aromatic hydrocarbon (PAH) measurements are essential for scientists and engineers who investigate these anthropogenic compounds. Diesel engines contribute to the problem, so analysts are measuring PAHs from these sources. However, diesel exhaust presents special problems for precise analytical measurements. The exhaust matrix is very complex; consequently, PAH detection sensitivity deteriorates, especially for trace PAHs in the exhaust. Yet, these are conditions and amounts that exist in real samples. Nonetheless, selected ion chromatogram (SIC) and tandem mass spectrometry (MS/MS) techniques improve trace PAH detection; ion trap technology makes both mass techniques possible. The purpose of this investigation was to evaluate SIC and MS/MS for applications to measure PAHs in diesel exhaust samples. The signal-to-noise ratio for accurate quantitation improves, relative to traditional mass techniques, because these techniques ignore or eliminate interfering components. On a VF-5MS chromatographic column, these techniques improve sensitivity and reproducibility. They produce a superior limit of detection in the useful range for PAH samples extracted from actual engine exhaust, 10-30 pg for the smaller PAHs and 1-6 ng for the larger PAHs. The results with SIC and MS/MS are reproducible, so analysts can report PAH amounts with defined statistical confidence intervals. SIC and MS/MS improve detection for trace PAHs in convoluted diesel exhaust samples.     

Evaluation of the flexibility of protective gloves.

Two mechanical methods have been developed for the characterization of the flexibility of protective gloves, a key factor affecting their degree of usefulness for workers. The principle of the first method is similar to the ASTM D 4032 standard relative to fabric stiffness and simulates the deformations encountered by gloves that are not tight fitted to the hand. The second method characterizes the flexibility of gloves that are worn tight fitted. Its validity was theoretically verified for elastomer materials. Both methods should prove themselves as valuable tools for protective glove manufacturers, allowing for the characterization of their existing products in terms of flexibility and the development of new ones better fitting workers' needs.     

2,3,7,8,-四氯苯噁英对NIH小鼠早期妊娠和生殖激素的影响

用不同剂量的2,3,7,8 四氯苯二英(2,3,7,8 tetrachlorodibenzopdioxin,TCDD)对小鼠胚胎附植数量和生长发育情况进行剂量反应评估,分析TCDD对假孕小鼠子宫蜕膜生长状况的影响以及比较胚胎种植前后染毒效果.所有样本采集血液,测定母体血清雌二醇和孕酮的浓度变化.结果表明,50和100ng·(kg·d)-1TCDD处理的孕鼠,胚胎附植数量明显减少(P<0 05),着床后胚胎出现发育迟缓,质量减轻(P<0 05);同等剂量TCDD处理的假孕小鼠,子宫蜕膜生长受到了极显著的抑制(P<0 01);种植前后染毒效果比较发现种植前期染毒的小鼠胚胎对TCDD更为敏感.母体血清雌二醇浓度随剂量和染毒时段有不同程度的升高,而孕酮浓度则极显著下降(P<0 01).由此表明低剂量TCDD可能通过对生殖激素的干扰,强烈影响NIH小鼠妊娠早期生殖生理状态和着床后胚胎的发育.实验同时证明小鼠也可作为早期妊娠毒物研究的供试动物,用以筛选动物和人类早期妊娠的有害化合物.     

Integration of ozonation and an anaerobic expanded granular sludge bed reactor for micropollutant removal from sewage

Environmental Science and Pollution Research - Conventional sewage treatment systems are generally not designed to remove micropollutants, requiring the development of new technologies, such as the...     

Of timelines and timeliness: lessons from Typhoon Haiyan in early disaster response

Typhoon Haiyan struck the Philippines on 8 November 2013 with maximum sustained winds of 235 kilometres per hour, adversely affecting at least 11 million people and displacing some 673,000 in the central regions of the country. The disaster clearly overwhelmed the Philippine government despite its seemingly well‐crafted disaster management plan. Using timelines of different organisations, this paper identifies gaps in the government's response, mainly due to its failure in coordinating and managing relief operations, which adversely affected its effectiveness and efficiency in the delivery of critical goods and services following the disaster. The paper also demonstrates how non‐governmental organisations (NGOs), the United Nations, foreign governments and other organisations provided assistance, mainly through aid niching, to cover the government's shortcomings. The paper recommends a paradigm shift in the government's disaster response by integrating collaborative arrangements between government agencies and NGOs, and giving local governments the lead role, with the national government as support, in disaster planning and response.     

Positive and negative aspects of GRI reporting as perceived by Brazilian organizations

This paper aims to identify the positive and negative aspects in the sustainability reporting framework proposed by the Global Reporting Initiative (GRI). The research was conducted through content analysis of 27 companies’ responses to three questions: “Why does the company where you work prepare a sustainability report?” “What are the positive aspects you identify in the framework for GRI reporting?” and “What are the negative aspects you identify in the framework for GRI reporting?” The questionnaire was sent to all Brazilian companies that published sustainability reports using the GRI guidelines between 2011 and 2013 related to the base year 2010. We found that respondents viewed the GRI guidelines and the reports they created as management tools for sustainability and that they assist in benchmarking sustainability performance and legitimizing the sustainability actions of the organization. Furthermore, some respondents indicated that the reports themselves are marketing tools. On the other hand, the respondents reported difficulties in understanding the proposed GRI guidelines. They considered the guidelines complex, ambiguous, and too flexible, which undermined both the standardization of the reports and the ability to compare reports. Based on these comments, it is recommended that the GRI develop a simpler and less flexible reporting methodology.     

The natives are restless, but not often and mostly when disturbed

The argument that the threat posed by introduced species is overblown is often buttressed by the observation that native species sometimes also become invasive. An examination of the literature on plant invasions in the United States shows that six times more nonnative species have been termed invasive than native species, and that a member of the naturalized nonnative pool is 40 times more likely than a native species to be perceived as invasive. In the great majority of instances in which a native plant species is seen as invasive, the invasion is associated with an anthropogenic disturbance, especially changed fire or hydrological regime, livestock grazing, and changes wrought by an introduced species. These results suggest that natives are significantly less likely than nonnatives to be problematic for local ecosystems.     

Key factors in levels of public satisfaction with urban waste collection in a northern Spain city

Journal of Material Cycles and Waste Management - Levels of public satisfaction among the inhabitants of Burgos with their urban waste collection service are analyzed by comparing satisfaction...     

Hazardous Air Pollutants (HAPs) and their Effects on Biodiversity: An Overview of the Atmospheric Pathways of Persistent Organic Pollutants (POPs) and Suggestions for Future Studies

Atmospheric change comprises many phenomena, namely climate change, acidic deposition, stratospheric ozone depletion, SMOG, increasing trend of suspended particulate matter, and hazardous air pollutants (HAPs). Among HAPs, a particular group of Persistent Organic Pollutants (POPs), such as some organochlorine pesticides, has shown a variety of toxic effects, altering the biodiversity of many ecosystems. Because of their persistence in the environment, and of their long range transport, the study of the global cycle of POPs is important in understanding how they can affect biodiversity. This can be accomplished by coupling different approaches: toxicity and ecological studies, emission estimates, and the use of global models.     

Secondary organic aerosol formation from ozone-initiated reactions with nicotine and secondhand tobacco smoke

We used controlled laboratory experiments to evaluate the aerosol-forming potential of ozone reactions with nicotine and secondhand smoke. Special attention was devoted to real-time monitoring of the particle size distribution and chemical composition of SOA as they are believed to be key factors determining the toxicity of SOA. The experimental approach was based on using a vacuum ultraviolet photon ionization time-of-flight aerosol mass spectrometer (VUV-AMS), a scanning mobility particle sizer (SMPS) and off-line thermal desorption coupled to mass spectrometry (TD-GC-MS) for gas-phase byproducts analysis. Results showed that exposure of SHS to ozone induced the formation of ultrafine particles (<100 nm) that contained high molecular weight nitrogenated species (m/z 400–500), which can be due to accretion/acid–base reactions and formation of oligomers. In addition, nicotine was found to contribute significantly (with yields 4–9%) to the formation of secondary organic aerosol through reaction with ozone. The main constituents of the resulting SOA were tentatively identified and a reaction mechanism was proposed to elucidate their formation. These findings identify a new component of thirdhand smoke that is associated with the formation of ultrafine particles (UFP) through oxidative aging of secondhand smoke. The significance of this chemistry for indoor exposure and health effects is highlighted.