| 1. |
- Alves, C. A., et al.
(författare)
-
Physical and chemical properties of non-exhaust particles generated from wear between pavements and tyres
- 2020
-
Ingår i: Atmospheric Environment. - : Elsevier Ltd. - 1352-2310 .- 1873-2844. ; 224
-
Tidskriftsartikel (refereegranskat)abstract
- A road simulator was used to generate wear particles from the interaction between two tyre brands and a composite pavement. Particle size distributions were monitored using a scanning mobility particle sizer and an aerosol particle sizer. Continuous measurements of particle mass concentrations were also made. Collection of inhalable particles (PM10) was conducted using a high-volume sampler equipped with quartz filters, which were then analysed for organic and elemental carbon, organic constituents and elemental composition. Tyre fragments chopped into tiny chips were also subjected to detailed organic and elemental speciation. The number concentration was dominated by particles <0.5 μm, whereas most of the mass was found in particles >0.5 μm. The emission factor from wear between pavements and tyres was of the order of 2 mg km−1 veh−1. Organic carbon represented about 10% of the PM10 mass, encompassing multiple aliphatic compounds (n-alkanes, alkenes, hopanes, and steranes), PAHs, thiazols, n-alkanols, polyols, some fragrant compounds, sugars, triterpenoids, sterols, phenolic constituents, phthalate plasticisers and several types of acids, among others. The relationship between airborne particulate organic constituents and organic matter in tyre debris is discussed. The detection of compounds that have been extensively used as biomass burning tracers (e.g. retene, dehydroabietic acid and levoglucosan) in both the shredded tiny tyre chips and the wear particles from the interaction between tyres and pavement puts into question their uniqueness as markers of wood combustion. Trace and major elements accounted for about 5% of the mass of the tyre fragments but represented 15–18% of the PM10 from wear, denoting the contribution of mineral elements from the pavement. Sulphur and zinc were abundant constituents in all samples.
|
|
| 2. |
- Amato, F., et al.
(författare)
-
A review on the effectiveness of street sweeping, washing and dust suppressants as urban PM control methods
- 2010
-
Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 408:16, s. 3070-3084
-
Forskningsöversikt (refereegranskat)abstract
- Given the absence of a definitive threshold for atmospheric particulate matter (PM)-induced adverse health effects and the evidence of road traffic as a main contributor to PM-urban levels, there is a general agreement in reducing PM-associated health risks by firstly focusing on vehicle traffic sector. Beside the reduction of primary exhaust emissions, recent potential measures are challenging to reduce emissions of particulate matter from abrasion and resuspension processes given the high potential health burden of heavy metals and metalloids sourced by vehicle-wear particles (brakes, tires, rotor, discs and catalysts) and of coarse particles (PM2.5-10). Some mitigating measures can be adopted in order to reduce road dust emissions from paved roads by removing or binding those particles already deposited and easy to be resuspended by traffic-generated turbulence. Sweeping, water flushing and use of chemical suppressants are usually more commonly employed to try to diminish emissions, but evaluating the effectiveness of preventive measures on improving air quality is a difficult task, consequently there is a general dearth of information about their effectiveness in reducing ambient PM concentrations. In particular, the scientific bibliography seems to be particularly scarce, whilst most of the information comes from local authorities committees. Consequently the existing reports are often aimed only to the municipalities and in the native language, with an objective difficulty for the international scientific community to access to them. For this review we have gathered contributions from some of major experts in this field, with the purpose of taking advantage of their background and personal awareness about any kind of related reports even not in English. Furthermore, the results we have gathered are often dissimilar, probably due to the different local conditions (weather, road pavement conditions etc.), therefore another objective of the review is to make a balance of actual knowledge and create a useful reference for future research studies and air quality management.
|
|
| 3. |
- Putaud, J. -P, et al.
(författare)
-
A European aerosol phenomenology-3 : Physical and chemical characteristics of particulate matter from 60 rural, urban, and kerbside sites across Europe
- 2010
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 44:10, s. 1308-1320
-
Tidskriftsartikel (refereegranskat)abstract
- This paper synthesizes data on aerosol (particulate matter, PM) physical and chemical characteristics, which were obtained over the past decade in aerosol research and monitoring activities at more than 60 natural background, rural, near-city, urban, and kerbside sites across Europe. The data include simultaneously measured PM10 and/or PM2.5 mass on the one hand, and aerosol particle number concentrations or PM chemistry on the other hand. The aerosol data presented in our previous works (Van Dingenen et al., 2004; Putaud et al., 2004) were updated and merged to those collected in the framework of the EU supported European Cooperation in the field of Scientific and Technical action COST633 (Particulate matter: Properties related to health effects). A number of conclusions from our previous studies were confirmed. There is no single ratio between PM2.5 and PM10 mass concentrations valid for all sites, although fairly constant ratios ranging from 0.5 to 0.9 are observed at most individual sites. There is no general correlation between PM mass and particle number concentrations, although particle number concentrations increase with PM2.5 levels at most sites. The main constituents of both PM10 and PM2.5 are generally organic matter, sulfate and nitrate. Mineral dust can also be a major constituent of PM10 at kerbside sites and in Southern Europe. There is a clear decreasing gradient in SO42- and NO3- contribution to PM10 when moving from rural to urban to kerbside sites. In contrast, the total carbon/PM10 ratio increases from rural to kerbside sites. Some new conclusions were also drawn from this work: the ratio between ultrafine particle and total particle number concentration decreases with PM2.5 concentration at all sites but one, and significant gradients in PM chemistry are observed when moving from Northwestern, to Southern to Central Europe. Compiling an even larger number of data sets would have further increased the significance of our conclusions, but collecting all the aerosol data sets obtained also through research projects remains a tedious task.
|
|
| 4. |
|
|
| 5. |
- Rodriguez-Merchan, E. C., et al.
(författare)
-
Joint protection in haemophilia
- 2011
-
Ingår i: Haemophilia. - : Wiley. - 1351-8216. ; 17, s. 1-23
-
Tidskriftsartikel (refereegranskat)abstract
- Haemarthroses (intra-articular haemorrhages) are a frequent finding typically observed in patients with haemophilia. Diagnosis and treatment of these bleeding episodes must be delivered as early as possible. Additionally, treatment should ideally be administered intensively (enhanced on-demand treatment) until the resolution of symptoms. Joint aspiration plays an important role in acute and profuse haemarthroses as the presence of blood in the joint leads to chondrocyte apoptosis and chronic synovitis, which will eventually result in joint degeneration (haemophilic arthropathy). Ultrasonography (US) is an appropriate diagnostic technique to assess the evolution of acute haemarthrosis in haemophilia, although magnetic resonance imaging remains the gold standard as far as imaging techniques are concerned. Some patients experience subclinical haemarthroses, which eventually tend to result in some degree of arthropathy, especially in the ankles. Nowadays, the most effective way of protecting these patients is primary prophylaxis, which in practice changes severe haemophilia into moderate haemophilia, preventing or at least minimizing the occurrence of haemarthrosis. If primary prophylaxis is, for whatever reason not an option, secondary prophylaxis and enhanced on demand treatment should be considered. Two alternatives are available for inhibitor patients: (i) control of haemostasis using by-passing agents (rFVIIa or aPCCs) either as enhanced on demand treatment or secondary prophylaxis, as appropriate, following the same basic principles used for non-inhibitor patients and (ii) immune tolerance induction (ITI) to eradicate the inhibitor.
|
|
| 6. |
- Rodriguez-Merchan, E. C., et al.
(författare)
-
Prevention of haemophilic arthropathy during childhood. May common orthopaedic management be extrapolated from patients without inhibitors to patients with inhibitors?
- 2008
-
Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 14:Suppl. 6, s. 68-81
-
Tidskriftsartikel (refereegranskat)abstract
- We recommend prophylaxis in haemophilic children with an inhibitor as a way of preventing the musculoskeletal impairment that is likely to affect them. This approach has been used for children without inhibitors with excellent results. If prophylaxis is not feasible, we suggest that intensive on-demand treatment should be given. Two agents, recombinant activated FVII (rFVIIa) and activated prothrombin complex concentrates (aPCC), are currently used to control haemostasis either for prophylaxis or intensive on-demand treatment. As it is recombinant, rFVIIa would seem more appropriate to be employed in children. aPCC could be used in adults, or in the event of an unsatisfactory response to rFVIIa. We recommend prophylaxis or, at least, intensive on-demand treatment in haemophilia children with inhibitors. Both rFVIIa and aPCC are being used for this purpose. It would seem that rFVIIa might be more appropriate for children as it is a recombinant product. Nevertheless, after skeletal maturity (in adults), both agents could be used indistinctively (taking into consideration that FEIBA is a plasma-derived product). We still need more well-designed comparative studies in order to be able to assert that our consensus-based conclusion is evidence based. In orthopaedic surgery, both aPCC and rFVIIa have been reported to be effective in controlling perioperative haemostasis, although in practice most centres have so far used rFVIIa for their orthopaedic procedures. We recommend rehabilitation programmes for all patients with inhibitors in order to mitigate the disabling and handicapping impact of their condition and thereby enable them to achieve social integration. Programmes for haemophilic children without inhibitors can be applied to children with inhibitors but should be individually tailored.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Viana, M., et al.
(författare)
-
Source apportionment of ambient PM2.5 at five Spanish centres of the European Community Respiratory Health Survey (ECRHS II)
- 2007
-
Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 41:7, s. 1395-1406
-
Tidskriftsartikel (refereegranskat)abstract
- Fine particulate matter (PM2.5) was sampled at 5 Spanish locations during the European Community Respiratory Health Survey II (ECRHS II). In an attempt to identify and quantify PM2.5 sources, source contribution analysis by principal component analysis (PCA) was performed on five datasets containing elemental composition of PM2.5 analysed by ED-XRF. A total of 4-5 factors were identified at each site, three of them being common to all sites (interpreted as traffic. mineral and secondary aerosols) whereas industrial sources were site-specific. Sea-salt was identified as independent source at all coastal locations except for Barcelona (where it was clustered with secondary aerosols). Despite their typically dominant coarse grain-size distribution, mineral and marine aerosols were clearly observed in PM2.5. Multi-linear regression analysis (MLRA) was applied to the data, showing that traffic was the main source of PM2.5 at the five sites (39-53% of PM2.5, 5.1-12.0 mu g m(-3)), while regional-scale secondary aerosols accounted for 14-34% of PM2.5 (2.6-4.5 mu g m(-3)), mineral matter for 13-31% (2.4-4.6 mu g m(-3)) and sea-salt made up 3-7% of the PM2.5 mass (0.4-1.3 mu g m(-3)). Consequently, despite regional and climatic variability throughout Spain, the same four main PM2.5 emission sources were identified at all the study sites and the differences between the relative contributions of each of these sources varied at most 20%. This would corroborate PM2.5 as a useful parameter for health studies and environmental policy-making, owing to the fact that it is not as subject to the influence of micro-sitting as other parameters such as PM10. African dust inputs were observed in the mineral source, adding on average 4-11 mu g m(-3) to the PM2.5 daily mean during dust outbreaks. On average, levels of Al, Si, Ti and Fe during African episodes were higher by a factor of 2-8 with respect to non-African days, whereas levels of local pollutants (absorption coefficient, S, Pb, Cl) showed smaller variations (factor of 0.5-2).
|
|
