[Show abstract][Hide abstract] ABSTRACT: Knowledge of the human health impacts associated with airborne nanoparticle exposure has led to considerable research activity aimed at better characterising these particles and understanding which particle properties are most important in the context of effects on health. Knowledge of the sources, chemical composition, physical structure and ambient concentrations of nanoparticles has improved significantly as a result. Given the known toxicity of many metals and the contribution of nanoparticles to their oxidative potential, the metallic content of the nanoparticulate burden is likely to be an important factor to consider when attempting to assess the impact of nanoparticle exposure on health. This review therefore seeks to draw together the existing knowledge of metallic nanoparticles in the atmosphere and discuss future research priorities in the field. The article opens by outlining the reasons behind the current research interest in the field, and moves on to discuss sources of nanoparticles to the atmosphere. The next section reviews ambient concentrations, covering spatial and temporal variation, mass and number size distributions, air sampling and measurement techniques. Further sections discuss the chemical and physical composition of particles. The review concludes by summing up the current state of research in the area and considering where future research should be focused.
[Show abstract][Hide abstract] ABSTRACT: Civil aviation is fast-growing (about +5% every year), mainly driven by the developing economies and globalization. Its impact on the environment is heavily debated, particularly in relation to climate forcing attributed to emissions at cruising altitudes and the noise and the deterioration of air quality at ground-level due to airport operations. This latter environmental issue is of particular interest to the scientific community and policymakers, especially in relation to the breach of limit and target values for many air pollutants, mainly nitrogen oxides and particulate matter, near the busiest airports and the resulting consequences for public health. Despite the increased attention given to aircraft emissions at ground-level and air pollution in the vicinity of airports, many research gaps remain. Sources relevant to air quality include not only engine exhaust and non-exhaust emissions from aircraft, but also emissions from the units providing power to the aircraft on the ground, the traffic due to the airport ground service, maintenance work, heating facilities, fugitive vapours from refuelling operations, kitchens and restaurants for passengers and operators, intermodal transportation systems, and road traffic for transporting people and goods in and out to the airport. Many of these sources have received inadequate attention, despite their high potential for impact on air quality. This review aims to summarise the state-of-the-art research on aircraft and airport emissions and attempts to synthesise the results of studies that have addressed this issue. It also aims to describe the key characteristics of pollution, the impacts upon global and local air quality and to address the future potential of research by highlighting research needs.
[Show abstract][Hide abstract] ABSTRACT: Size-resolved composition of particulate matter (PM) sampled in the industrial town of Port Talbot (PT), UK was determined in comparison to a typical urban background site in Birmingham (EROS). A Micro-Orifice Uniform Deposit Impactor (MOUDI) sampler was deployed for two separate sampling campaigns with the addition of a Grimm optical spectrometer at the PT site. MOUDI samples were analysed for water-soluble anions (Cl(-), NO3(-) and SO4(2-)) and cations (Na(+), NH4(+), K(+), Mg(2+) and Ca(2+)) and trace metals (Al, V, Cr, Mn, Fe, Cu, Zn, Sb, Ba and Pb). The PM mass distribution showed a predominance of fine particle (PM2.5) mass at EROS whereas the PT samples were dominated by the coarse fraction (PM2.5-10). SO4(2-), Cl(-), NH4(+), Na(+), NO3(-), and Ca(2+) were the predominant ionic species at both sites while Al and Fe were the metals with highest concentrations at both sites. Mean concentrations of Cl(-), Na(+), K(+), Ca(2+), Mg(2+), Cr, Mn, Fe and Zn were higher at PT than EROS due to industrial and marine influences. The contribution of regional pollution by sulphate, ammonium and nitrate was greater at EROS relative to PT. The traffic signatures of Cu, Sb, Ba and Pb were particularly prominent at EROS. Overall, PM at EROS was dominated by secondary aerosol and traffic-related particles while PT was heavily influenced by industrial activities and marine aerosol. Profound influences of wind direction are seen in the 72-hour data, especially in relation to the PT local sources. Measurements of particle number in 14 separate size bins plotted as a function of wind direction and speed are highly indicative of contributing sources, with local traffic dominant below 0.5μm, steelworks emissions from 0.5 to 15μm, and marine aerosol above 15μm.
Science of The Total Environment 01/2014; 475C:29-38.
[Show abstract][Hide abstract] ABSTRACT: Use of brominated flame retardants (BFRs) in soft furnishings has occurred for over thirty years with the phase out of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) only relatively recently begun. As products treated with BFRs reach the end of their lifecycle they enter the waste stream, thereby constituting an important and increasing reservoir of these chemicals. This review highlights the dearth of data on the extent and potential mechanisms of BFR emissions from waste soft furnishings. However, insights into what may occur are provided by scrutiny of the larger (though still incomplete) database related to BFR emissions from electronic waste (e-waste). In many countries, municipal landfills have historically been the primary disposal method of waste consumer products and therefore represent a substantial reservoir of BFRs. Published data for BFR emissions to both air and water from landfill and other waste disposal routes are collated, presented and reviewed. Reported concentrations of PBDEs in landfill leachate range considerably from < 1 ng L− 1 to 133,000 ng ΣPBDE L− 1. In addition to direct migration of BFRs from waste materials; there is evidence that some higher brominated flame retardants are able to undergo degradation and debromination during waste treatment, that in some instances may lead to the formation of more toxic and bioavailable compounds. We propose that waste soft furnishings be treated with the same concern as e-waste, given its potential as a reservoir and source of environmental contamination with BFRs.
[Show abstract][Hide abstract] ABSTRACT: Single particle analysis of an industrially polluted atmosphere in Port Talbot, South Wales, United Kingdom was conducted using Aerosol-Time-of-Flight Mass Spectrometry (ATOFMS). During the four week sampling campaign, a total of 5,162,018 particles were sized in the size range 0.2–1.9 μm aerodynamic diameter. Of these, 580,798 were successfully ionized generating mass spectra. K-means clustering employed for analysing ATOFMS data utilized 96% of the hit particles to generate 20 clusters. Similar clusters were merged together and 17 clusters were generated from which 7 main particle groups were identified. The particle classes include: K-rich particles (K–CN, K–NO3, K–EC, K–Cl–PO3 and K–HSO4), aged sea salt (Na–NO3), silicate dust (Na–HSiO2), sulphate rich particles (K–HSO4), nitrate rich particles (AlO–NO3), Ca particles (Ca–NO3), carbon-rich particles (Mn–OC, Metallic–EC, EC, EC–NO3 and OC–EC), and aromatic hydrocarbon particles (Arom–CN, Fe–PAH–NO3 and PAH–CN). With the aid of wind sector plots, the K–Cl–PO3 and Na–HSiO2 particle clusters were related to the steelworks blast furnace/sinter plant while Ca-rich particles arose from blast furnace emissions. K–CN, K–EC, Na–HSiO2, K–HSO4, Mn–OC, Arom–CN, Fe–PAH–NO3, and PAH–CN particles were closely linked with emissions from the cokemaking and mills (hot and cold) steelworks sections. The source factors identified by the ATOFMS were compared with those derived from multivariate analysis using Multilinear Engine (ME-2) applied to filter samples analysed off-line. Both methods of source apportionment identified common source factors including those within the steelworks (blast furnace, sinter, cokemaking), as well as marine, traffic and secondary particles, but quantitative attribution of mass is very different.
[Show abstract][Hide abstract] ABSTRACT: Use of the Chemical Mass Balance (CMB) model for aerosol source apportionment requires the input of source profiles of chemical constituents. Such profiles derived from studies in North America are relatively abundant, but are very scarce from European studies. In particular, there is a lack of data from European road vehicles. This study reports results from a comparison of road traffic source profiles derived from (1) US dynamometer studies of individual vehicles with (2) a traffic profile derived from measurements in a road tunnel in France and (3) new data derived from a twin-site study in London in which concentrations at an urban background site are subtracted from those measured at a busy roadside to derive a traffic increment profile. The dynamometer data are input as a diesel exhaust, gasoline exhaust and smoking engine profile, or alternatively as just a diesel exhaust and gasoline exhaust profile. Running the CMB model with the various traffic profiles together with profiles for other sources of organic carbon gives variable estimates of the contribution of traffic to organic carbon and to PM2.5 concentrations. These are tested in two ways. Firstly, unassigned organic carbon in the output from the CMB model, assumed to be secondary organic carbon, is compared to secondary organic carbon estimated independently using the elemental carbon tracer method. Secondly, the estimated traffic contribution to organic carbon and PM2.5 is compared with an estimate derived simply from the measured elemental carbon concentrations, and the effect on aerosol mass closure is investigated. In both cases the CMB model results correlate well with the independent measures, but there are marked differences according to the traffic source profile employed. As a general observation, it appears that the use of dynamometer data with inclusion of a smoking engine profile has a tendency to over-estimate traffic emissions at some sites whereas the tunnel profile shows a tendency to under-estimate. Overall, the traffic profile derived from the twin-site study gives probably the best overall estimate, but the quality of fit with independent estimates of secondary organic carbon and traffic particle mass depends upon the site and dataset for which the test is conducted.
[Show abstract][Hide abstract] ABSTRACT: Air quality models include representations of pollutant emissions, which necessarily entail spatial averaging to reflect the model grid size; such averaging may result in significant uncertainties and/or systematic biases in the model output. This study investigates such uncertainties, considering ozone concentrations in idealised street canyons within the urban canopy. A photochemical model with grid-averaged emissions of street canyons is compared with a multiple-box model considering each canyon independently. The results reveal that the averaged, ‘one-box’ model may significantly underestimate true (independent canyon mean) ozone concentrations for typical urban areas, and that the performance of the averaged model is improved for more ‘green’ and/or less trafficked areas. Our findings also suggest that the trends of 2005–2020 in emissions, in isolation, reduce the error inherent in the averaged-emissions treatment. These new findings may be used to evaluate uncertainties in modelled urban ozone concentrations when grid-averaged emissions are adopted.
[Show abstract][Hide abstract] ABSTRACT: This review summarizes the different receptor models that have been adopted at industrial and urban sites to apportion the sources of particulate matter (PM) from industries. Industrial processes and those associated with industry (such as transportation) are an important source of airborne PM which includes trace elements, organic and elemental carbon, and PAHs. Industry also emits gaseous pollutants which form secondary aerosol in the atmosphere. Most published studies have employed chemical mass balance (CMB), positive matrix factorization (PMF) and/or principal component analysis (PCA) models as source apportionment tools. These receptor models were mostly applied to fine particulate matter (PM2.5) and PM10 compositional data, particularly the inorganic constituents. Some studies have combined two or more of these receptor models, which provides useful information on the uncertainties associated with different models. Industry has been reported to contribute from 0 to 70% of PM mass at industrial sites. It appears that some studies are unsuccessful in apportioning PM from industry, e.g., unable to distinguish industrial emissions from other sources. A critical evaluation of the literature data also showed that the choice of appropriate tracers for industry, both generically and for specific industries, varies between different PM source apportionment studies. This is not surprising considering the significant difference in source profiles of PM from different types of industry, which may compromise source apportionment of industrial emissions using CMB with non-local source profiles. It may also affect the attribution of industrial emissions in multivariate statistical models (e.g. PMF and PCA). It is concluded that a general classification of the source “industry” is rarely appropriate for PM source apportionment. Indeed, such studies may even need to consider the different processes within a particular industry, such as a steelworks, which emit PM with significantly different chemical signatures. It is suggested that future source apportionment studies should make every effort to measure source profiles of PM from different industrial processes, and where possible, use multiple models in order to more accurately apportion the source emissions from industry.
[Show abstract][Hide abstract] ABSTRACT: This paper examines recent literature on achieving sustainable cities that incorporate a combined mitigation–adaptation approach towards improved urban resilience as a way of future-proofing. A multidisciplinary approach, which integrates scientific as well as ecopolitical frameworks, is found to benefit this sustainability discourse.
[Show abstract][Hide abstract] ABSTRACT: A greenhouse experiment was carried out to investigate the single effect of benzo[a]pyrene (B[a]P) or chromium (Cr) and the joint effect of Cr-B[a]P on the growth of Zea mays, its uptake and accumulation of Cr, and the dissipation of B[a]P over 60 days. Results showed that single or joint contamination of Cr and B[a]P did not affect the plant growth relative to control treatments. However, the occurrence of B[a]P had an enhancing effect on the accumulation and translocation of Cr. The accumulation of Cr in shoot of plant significantly increased by ≥ 79 % in 50 mg kg(-1) Cr-B[a]P (1, 5, and 10 mg kg(-1)) treatments and by ≥ 86 % in 100 mg kg(-1) Cr-B[a]P (1, 5, and 10 mg kg(-1)) treatments relative to control treatments. The presence of plants did not enhance the dissipation of B[a]P in lower (1and 5 mg kg(-1)) B[a]P contaminated soils; however, over 60 days of planting Z. mays seemed to enhance the dissipation of B[a]P by over 60 % in 10 mg kg(-1) single contaminated soil and by 28 to 41 % in 10 mg kg(-1)B[a]P co-contaminated soil. This suggests that Z. mays might be a useful plant for the remediation of Cr-B[a]P co-contaminated soil.
Environmental Science and Pollution Research 11/2013;
Information provided on this web page is aggregated encyclopedic and bibliographical information relating to the named institution. Information provided is not approved by the institution itself. The institution’s logo (and/or other graphical identification, such as a coat of arms) is used only to identify the institution in a nominal way. Under certain jurisdictions it may be property of the institution.