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1.
Passive sampling of glycol ethers and their acetates in indoor air   总被引:1,自引:0,他引:1  
This study examined the performances of a thermal desorbable radial diffusive sampler for the weekly measurement of eight glycol ethers in indoor air and described the results of an application of this method carried out as part of HABIT'AIR Nord - Pas de Calais program for the air monitoring of these compounds in sixty homes located in northern France. The target compounds were the four glycol ethers banned from sale to the public in France since the 1990s (i.e. 2-methoxy ethanol, 2-ethoxy ethanol and their acetates) and four other glycol ethers derivatives of which the use have increased considerably (i.e. 1-methoxy-2-propanol, 2-butoxy ethanol and their acetates).A test program was carried out with the aim of validating the passive sampling method. It allowed the estimation of all the parameters of a method for each compound (calibration, analytical precision, desorption efficiency, sampling rate in standard conditions, detection limit and stability of sample before and after exposure), the examination of the influence of environmental factors on the sampling rate by some exposure chamber experiments and the assessment of the uncertainty of the measurements.The results of this evaluation demonstrated that the method has turned out to be suitable for six out of eight glycol ethers tested. The effect of the environmental factors on the sampling rates was the main source of measurement uncertainty. The measurements done in sixty homes revealed a relative abundance of 1-methoxy-2-propanol that was found in more than two thirds of homes at concentration levels of 4.5 microg m(-3) on average (a maximum value of 28 microg m(-3)). 1-methoxy-2-propanol acetate and 2-butoxy ethanol were also detected, but less frequently (in 19% of homes) and with the concentrations below 12 microg m(-3). The highest levels of these glycol ethers appear to be in relation to the emissions occurring at the time of cleaning tasks.  相似文献   
2.
Studies have shown that biogenic compounds, long chain secondary compounds and long lifetime anthropogenic compounds are involved in the formation of organic aerosols in both polluted areas and remote places. This work aims at developing an active sampling method to monitor these compounds (i.e. 6 straight-chain saturated aldehydes from C6 to C11; 8 straight-chain alkanes from C9 to C16; 6 monoterpenes: α-pinene, β-pinene, camphene, limonene, α-terpinene, & γ-terpinene; and 5 aromatic compounds: toluene, ethylbenzene, meta-, para- and ortho-xylenes) in remote areas. Samples are collected onto multi-bed sorbent cartridges at 200 mL min(-1) flow rate, using the automatic sampler SyPAC (TERA-Environnement, Crolles, France). No breakthrough was observed for sampling volumes up to 120 L (standard mixture at ambient temperature, with a relative humidity of 75%). As ozone has been shown to alter the samples (losses of 90% of aldehydes and up to 95% of terpenes were observed), the addition of a conditioned manganese dioxide (MnO(2)) scrubber to the system has been validated (full recovery of the affected compounds for a standard mixture at 50% relative humidity--RH). Samples are first thermodesorbed and then analysed by GC/FID/MS. This method allows suitable detection limits (from 2 ppt for camphene to 13 ppt for octanal--36 L sampled), and reproducibility (from 1% for toluene to 22% for heptanal). It has been successfully used to determine the diurnal variation of the target compounds (six 3 h samples a day) during winter and summer measurement campaigns at a remote site in the south of France.  相似文献   
3.
The performances and applicability of a diffusion tubesampler for the simultaneous measurements of NO2 andSO2 in ambient air were evaluated. SO2 andNO2are collected by the passive sampler using triethanolamine astrapping agent and are determined as sulphate and nitrite withion chromatography. The detection limit (2.3 g m-3 ofNO2 and 4.2 g m-3 of SO2 for two weekssampling) is adequate for the determination of concentrationsin urban and industrial areas. Precision of the method as RSDis in mean 5% for NO2 and 12% for SO2 at theconcentration levels in urban areas. Calibration of the methodwas performed in the field conditions by comparison between theresponses of sampler and the concentrations measured by thecontinuous monitors. High degree of linearity (correlationcoefficients > 0.8) is found between the passive sampler tubeand the continuous monitor data for both NO2 and SO2.To reduce the wind velocity influence on passive sampling ofdiffusion tubes, a protective shelter was tested in this study.The overall uncertainty of one measure for the optimised methodis estimated at 5 g m-3 for NO2 and 6g m-3 for SO2. Suitability of this passivesampling method for air pollution monitoring in urban areas wasdemonstrated by the results shown in this paper on a campaigncarried out in the French agglomeration.  相似文献   
4.
The present study investigates into the link between people’s vulnerability in the face of coastal hazards and sustainable livelihoods. It focuses on the town of Borongan in the Philippines and draws on questionnaire-based surveys and focus group discussions. This research shows that local fishermen are often compelled to go out fishing despite pending typhoon or storm surge to sustain the daily needs of their family. Its also demonstrates that the capacity of these people to protect themselves from the threat is constrained by poor and fragile livelihoods. In the event of a crisis, the study argues that people resort to a range of adjustments on their daily life which is rooted in the strength and diversity of their livelihoods. To reduce people’s vulnerability and enhance capacities to face coastal hazards, the study fosters Community-Based Disaster Risk Reduction with special emphasis to sustainable livelihoods.  相似文献   
5.
There is a considerable interest in quantifying near-surface ozone concentrations and associated trends, as they serve to define the impacts on ozone of the anthropogenic precursors reductions and to evaluate the effects of emission control strategies. A statistical test has been used to the ozone air concentrations measured in the French rural monitoring network stations, called MERA, in order to bring out spatio-temporal trends in air quality in France over the 1995-2003 period. The non-parametric Mann-Kendall test has been developed for detecting and estimating monotonic trends in the time series and applied in our study at annual values: mean, 98th percentile and median based on hourly averaged ozone concentrations and applied to daily maxima. In France, when averaged overall 9 stations between 1995 and 2003, a slight increasing trend of the O(3) levels (+0.6 +/- 1.3% year( - 1)) is observed, which is strongly influenced by the concentrations of the high altitude stations. In stations below 1000 m a mean rate of -0.48% year( - 1) from annual average concentrations, of -0.45% year( - 1) for medians and of +0.56% year( - 1) for P.98 over the 1995-2003 period were obtained. In stations above 1,000 m a mean rate of +1.75% year( - 1) from annual averages values, of +4.05% year( - 1) for medians and of +2.55% year( - 1) for P.98 were calculated over the 1997-2003 period. This situation is comparable to the one observed in other countries. In Europe and in France a reduction of precursor emissions is observed whereas a slight increasing trend of the O(3) levels is observed over the 1995-2003 period. One reason is the non-linearity of chemical ozone production with respect to precursor emissions. Possible explanations are an increase in near-surface ozone values caused by a reduced ozone titration by reduced NO( x ), the meteorological parameters change, an increase in bio-geogenic compound concentrations, the intercontinental transport from North America and Asia and the influence of stratospheric-tropospheric exchanges. These possible explanations must be interpreted carefully as on the short time scales considered.  相似文献   
6.
The long-term monitoring of precipitation and its chemical composition are important for identifying trends in rain quality and for assessing the effectiveness of pollution control strategies. A statistical test has been used to the atmospheric concentrations measured in the French rural monitoring network (MERA) in order to bring out spatio-temporal trends in precipitation quality in France over the period 1990–2003. The non-parametric Mann–Kendall test which has been developed for detecting and estimating monotonic trends in the time series was used and applied in our study at annual values of wet-only precipitation concentrations. The emission data suggest that SO2 and NO x emissions decreased (−3.3 and −2.0% year−1, respectively) contrary to NH3 emissions that increased slightly (+0.2% year−1) over the period 1990–2002 in France. On the national scale, the pH values have a significant decreasing trend of −0.025 ± 0.02 unit pH year−1. and concentrations in precipitation have a significant decreasing trend, −3.0 ± 1.6 and −3.3 ± 0.6% year−1, respectively, corresponding with the downward trends in SO2 emissions in France (−3.3% year−1). A good correlation (R 2 = 0.84) between SO2 emissions and concentrations was obtained. The decreasing trend of was more significant (−5.4 ± 5.2% year−1) than that of (−1.3 ± 2.4% year−1). Globally, the concentration of the major ions showed a clear downward trend including marine and alkaline ions. In addition, the relative contribution of HNO3 to acidity precipitation increased by 51% over the studied period.  相似文献   
7.
Characterising sources and sinks of rural VOC in eastern France   总被引:2,自引:0,他引:2  
Fifty non-methane hydrocarbons (NMHC) and seventeen carbonyl compounds were measured at a French rural site from 1997 to 2001, as part of the EMEP programme. Data handling was based on an original source-receptor approach. First, the examination of the levels and trends was completed by the comparison of the seasonal distribution of rural and urban VOC/acetylene ambient ratios. This analysis has shown that most of the compounds derived from mixing and photochemical transformation of mid-range transported urban pollutants from the downwind urban area. Then, identified sources and sinks were temporally apportioned. Urban air masses mixing explains, at least, 80% of the wintertime levels of anthropogenic NMHC and isoprene. In summer, photochemistry dominates the day-to-day distribution of anthropogenic NMHC whilst summertime isoprene is also controlled by in-situ biogenic emissions. Then, the results of C(1)-C(3) carbonyls were discussed with respect to their direct biogenic and anthropogenic emissions and photochemical production through the [carbonyl/auto-exhaust tracers] emission ratio. Diluted vehicle exhaust emissions mainly contribute to the total content of lower aldehydes in winter while other processes control lower ketones. Secondary production is predominant in summer with at least a 50% high intensity. Its dependence upon temperature and radiation is also demonstrated. Finally, the importance of the primary and secondary biogenic production of acetone and formaldehyde is assessed. In particular, biogenic contribution would explain 37 +/- 25% of acetone levels in summer.  相似文献   
8.
Nowadays there are approximately 80 Anglophone journals that deal primarily with disaster risk reduction (DRR) and allied fields. This large array signals a sustained, if uneven, growth in DRR scholarship but also competition between the offerings of different publishers and institutions. The purpose of this article is first to summarise the development of academic publishing on DRR from its early beginnings to the present day. The paper then evaluates the current state of publishing in this field and discusses possible future trends. Next, it identifies some possible opportunities, challenges, expectations, and commitments for journal editors both within DRR and academia more broadly, including those that refer to changes in the use of terminology, the relentless increase in the number of papers submitted, the expansion and dangers of predatory journals, different peer review models, open access versus paywalls, citations and bibliography metrics, academic social networks, and copyright and distribution issues.  相似文献   
9.
Since 1990, the MERA (MEsure des Retombées Atmosphériques, French acronym for background air pollution monitoring) network has been focused on the composition of the lower troposphere within the EMEP program. In particular, 46 non-methane hydrocarbon (NMHC) concentrations have been measured between 1997 and 2006 at three MERA sites.The analysis of temporal trends using Mann-Kendall and Sen methods showed a global decrease of anthropogenic NMHC. These results are in accordance with the trends observed on other sites in Europe and follow the decrease of VOCs emissions in France. Nevertheless the concentrations of long-life species like ethane seem to remain steady showing the growing influence of most distant source areas. In addition isoprene concentrations are typically higher in France than in other countries in Europe and slightly rising. Data analysis was performed using positive matrix factorization (PMF). Five similar PMF factors are identified as aged profiles for the three sites. The examination of factor contributions made it possible to determine a hierarchy in source influence. A higher contribution of evaporative sources was observed on the southern site while residential heating was the main factor for the other two. This work was completed by a clustering analysis (K-means) of air mass trajectories in order to apportion source contribution depending on air mass origins. Two main groups have been distinguished: (1) older and diluted air masses from an oceanic origin; and (2) anthropogenic and closer sources indicating continental influence.  相似文献   
10.
JC Gaillard 《Disasters》2019,43(Z1):S7-S17
Disaster studies is faced with a fascinating anomaly: frequently it claims to be critical and innovative, as suggested by the so‐called vulnerability paradigm that emerged more than 40 years ago, yet often it is perpetuating some of the core and problematic tenets of the hazard paradigm that we were asked to challenge initially. This paper interrogates why such an anomaly persists. In so doing, it employs Antonio Gramsci's concept of hegemony to unpack why disaster studies is still dominated by Western epistemologies and scholars that perpetuate an orientalist view of disasters. Ultimately, it suggests a research agenda for the 40 years to come, which builds on the importance of local researchers analysing local disasters using local epistemologies, especially in the non‐Western world. Such subaltern disaster studies are to be fuelled by increasing consciousness of the need to resist the hegemony of Western scholarship and to relocate disaster studies within the realm of its original political agenda.  相似文献   
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