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L.I. Nieto-Gligorovski S. Net S. Gligorovski H. Wortham H. Grothe C. Zetzsch 《Atmospheric environment (Oxford, England : 1994)》2010,44(40):5451-5459
This work intends to quantify the variation in optical properties of aerosol by in-situ spectroscopic monitoring the ozonolysis of a mixture of typical biomass burning compounds. The reaction occurs on silica and glass particles in the presence of simulated sunlight.Fused silica particles (Aerosil) were coated with a thin film of a 1:1 mixure of 4-phenoxyphenol with 4-carboxyphenone as a photosensitizer. UV–VIS spectra of dichloromethane extracts from the particles recorded before and after treatment, show development of a new band after prolonged ozone and light exposure.Changes in optical properties are reported, and variations of spectroscopic features are discussed. We show that the ozone-induced heterogeneous photochemical reaction does produce species absorbing light in the solar spectral range. Further, we demonstrate that the heterogeneous photosensitized reactions at 200 ppb ozone (strongly ozone polluted regions) for a time period of 7 h aging process, can increase light absorption of atmospheric aerosols in the tropospheric actinic window (>290 nm) by 0.4 absorption units ng-C?1 O3 ppm?1 in the region 290–358 nm and by 1.0 absorption units ng-C?1 O3 ppm?1 in the region 360–448 nm.Chemical changes of such surface films were identified by diffuse reflectance infrared Fourier transform spectroscopy of coated glass spheres, and we suggest formation of humic-like substances comparable to those reported in continental aerosol. 相似文献
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Die von REACH ausgel?sten Ver?nderungen im Hinblick auf die neu definierte Verantwortung von Hersteilern und industriellen
Nutzern werden beschrieben. Die Datenerfassung für Altstoffe und die damit einhergehende Verbesserung der Risikobewertung
werden ab 2007 beginnen, aber mehr als zehn Jahre in Anspruch nehmen. Der erfasste Datenumfang l?sst Lücken im Bereich Arbeitsschutz
offen. Der Schurz der Verbraucher vor Stoffen in Erzeugnissen bleibt unzureichend. Dennoch ist REACH ein gro?er Schritt nach
vorn für die Chemiepolitik. 相似文献
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The changes initiated by REACH towards the newly defined responsibility of producers and industrial users are presented. The data acquisition for ‘old chemicals’, and hereby the improvement of risk assessment, will start in 2007, though will take more than ten years. The data material shows gaps in the area of occupational health and safety. The protection of consumers from substances in products remains insufficient. Nevertheless, for chemicals policy, REACH is a big step forward. 相似文献
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Aim and Background
In 1999, under German Presidency, the European Council asked the European Commission to set up an approach with new instruments for a new European strategy on chemicals management. In 2001, the Commission subsequently published a White Paper called ‘Strategy for a future European chemicals policy’. After intensive discussions with all involved parties, a proposal for a new Regulation, called REACH, was brought in to Council and Parliament (co-decision procedure) in October 2003. Different impact assessments concerning the strategy of the White Paper presumed dramatically increasing costs for the chemical industry. Due to these discussions, the Government of North Rhine-Westphalia decided to conduct a pilot project on workability of the new requirements in the second half of 2003. The parties involved were administrations, producers, industrial associations, unions and NGOs. The focus was not to test the entire Regulation, but to analyse the practicability of selected processes, evaluations, and communication processes connected with the registration of substances.Results
Examining the requirements and processes with regard to their realization in practice, resulted in a list of well-founded proposals. These proposals concern modification in the Regulation itself, implementation tools required, and guidelines which will need to be available before the REACH system is launched. The pivot questions of the pilot testing were the acceptance of data of substance-effects and their evaluation in different application areas. The registration Agency (played by the German Competent Authorities) checked the presented documents concerning completeness and plausibility. For all presented papers inquiries were needed In summary, the simulation has provided concrete evidence of where and why REACH may cause problems. Lack of simple instruments and corresponding knowledge for conducting exposition scenarios were noticed. The simulation process facilitated a new communication of all parties along the supply chain. In addition, the development of new networks could be observed to ease co-operation between authorities and those active on the market. These networks continue to exist even after cessation of the pilot trial. 相似文献9.
Luc Int Panis Bas de Geus Grégory Vandenbulcke Hanny Willems Bart Degraeuwe Nico Bleux Vinit Mishra Isabelle Thomas Romain Meeusen 《Atmospheric environment (Oxford, England : 1994)》2010,44(19):2263-2270
Emerging evidence suggests that short episodes of high exposure to air pollution occur while commuting. These events can result in potentially adverse health effects. We present a quantification of the exposure of car passengers and cyclists to particulate matter (PM). We have simultaneously measured concentrations (PNC, PM2.5 and PM10) and ventilatory parameters (minute ventilation (VE), breathing frequency and tidal volume) in three Belgian locations (Brussels, Louvain-la-Neuve and Mol) for 55 persons (38 male and 17 female). Subjects were first driven by car and then cycled along identical routes in a pairwise design. Concentrations and lung deposition of PNC and PM mass were compared between biking trips and car trips.Mean bicycle/car ratios for PNC and PM are close to 1 and rarely significant. The size and magnitude of the differences in concentrations depend on the location which confirms similar inconsistencies reported in literature. On the other hand, the results from this study demonstrate that bicycle/car differences for inhaled quantities and lung deposited dose are large and consistent across locations. These differences are caused by increased VE in cyclists which significantly increases their exposure to traffic exhaust. The VE while riding a bicycle is 4.3 times higher compared to car passengers. This aspect has been ignored or severely underestimated in previous studies. Integrated health risk evaluations of transport modes or cycling policies should therefore use exposure estimates rather than concentrations. 相似文献
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