Search

It has been shown that the exposure to airborne particulate matter is one of the most significant environmental risks people face. Since indoor environment is where people spend the majority of time, in order to protect against this risk, the origin of the particles needs to be understood: do they come from indoor, outdoor sources or both? Further, this question needs to be answered separately for each of the PM mass/number size fractions, as they originate from different sources. Numerous studies have been conducted for specific indoor environments or under specific setting. Here our aim was to go beyond the specifics of individual studies, and to explore, based on pooled data from the literature, whether there are generalizable trends in routes of exposure at homes, schools and day cares, offices and aged care facilities. To do this, we quantified the overall 24h and occupancy weighted means of PM10, PM2.5 and PN - particle number concentration. Based on this, we developed a summary of the indoor versus outdoor origin of indoor particles and compared the means to the WHO guidelines (for PM10 and PM2.5) and to the typical levels reported for urban environments (PN). We showed that the main origins of particle metrics differ from one type of indoor environment to another. For homes, outdoor air is the main origin of PM10 and PM2.5 but PN originate from indoor sources; for schools and day cares, outdoor air is the source of PN while PM10 and PM2.5 have indoor sources; and for offices, outdoor air is the source of all three particle size fractions. While each individual building is different, leading to differences in exposure and ideally necessitating its own assessment (which is very rarely done), our findings point to the existence of generalizable trends for the main types of indoor environments where people spend time, and therefore to the type of prevention measures which need to be considered in general for these environments. Keywords: Indoor particulate matter, Indoor aerosols, Indoor ultrafine particles, Home indoor particles, School indoor particles, Office indoor particles, Child care indoor particles, Aged care indoor particles

Porous graphene materials possess a unique structure with interconnected networks,high surface area, and high pore volume. Because of the combination of its remarkable architecture and intrinsic properties, such as high mechanical strength, excellent electrical conductivity, and good thermal stability, porous graphene has attracted tremendous attention in many fields, such as nanocomposites, lithium batteries, supercapacitors, and dye-sensitized solar cells. This chapter reviews synthesis methods, properties, and several key applications of porous graphene materials.

Open biomass burning from wildfires and the prescribed burning of forests and farmland is a frequent occurrence in South-East Queensland (SEQ), Australia. This work reports on data collected from 10 to 30 September 2011, which covers the days before (10–14 September), during (15–20 September) and after (21–30 September) a period of biomass burning in SEQ. The aim of this project was to comprehensively quantify the impact of the biomass burning on air quality in Brisbane, the capital city of Queensland. A multi-parameter field measurement campaign was conducted and ambient air quality data from 13 monitoring stations across SEQ were analysed. During the burning period, the average concentrations of all measured pollutants increased (from 20% to 430%) compared to the non-burning period (both before and after burning), except for total xylenes. The average concentration of O3, NO2, SO2, benzene, formaldehyde, PM10, PM2.5 and visibility-reducing particles reached their highest levels for the year, which were up to 10 times higher than annual average levels, while PM10, PM2.5 and SO2 concentrations exceeded the WHO 24-hour guidelines and O3 concentration exceeded the WHO maximum 8-hour average threshold during the burning period. Overall spatial variations showed that all measured pollutants, with the exception of O3, were closer to spatial homogeneity during the burning compared to the non-burning period. In addition to the above, elevated concentrations of three biomass burning organic tracers (levoglucosan, mannosan and galactosan), together with the amount of non-refractory organic particles (PM1) and the average value of f60 (attributed to levoglucosan), reinforce that elevated pollutant concentration levels were due to emissions from open biomass burning events, 70% of which were prescribed burning events. This study, which is the first and most comprehensive of its kind in Australia, provides quantitative evidence of the significant impact of open biomass burning events, especially prescribed burning, on urban air quality. The current results provide a solid platform for more detailed health and modelling investigations in the future. Keywords: Bushfire, Wildfire, Aerosol, Particle, Air pollutant, Aerosol mass spectrometry

1 Department of Civil & Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK 2Department of Civil Engineering, Indian Institute of Technology New Delhi, Hauz Khas, New Delhi 110016, India 3 School of Life Sciences, Heriot-Watt University, Edinburgh EH14 4AS, UK 4Nanotechnology and Molecular Sciences, School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, QLD 4001, Australia

Urban road dust comprises of a range of potentially toxic metal elements and plays a critical role in degrading urban receiving water quality. Hence, assessing the metal composition and concentration in urban road dust is a high priority. This study investigated the variability of metal composition and concentrations in road dust in 4 different urban land uses in Gold Coast, Australia. Samples from 16 road sites were collected and tested for selected 12 metal species. The data set was analyzed using both univariate and multivariate techniques. Outcomes of the data analysis revealed that the metal concentrations inroad dust differs considerably within and between different land uses. Iron, aluminum, magnesium and zinc are the most abundant in urban land uses. It was also noted that metal species such as titanium, nickel, copper and zinc have the highest concentrations in industrial land use. The study outcomes revealed that soil and traffic related sources as key sources of metals deposited on road surfaces., {"references":["Fergusson, J.E. and D.E. Ryan, The elemental composition of street dust from large and small urban areas related to city type, source and particle size. Science of the Total Environment, 1984. 34(1–2): p. 101-116.","Ball, J.E., R. Jenks, and D. Aubourg, An assessment of the availability of pollutant constituents on road surfaces. The Science of the Total Environment, 1998. 209(2-3): p. 243-254.","Liu, Y., et al., Source apportionment of ambient volatile organic compounds in the Pearl River Delta, China: Part II. Atmospheric Environment, 2008. 42(25): p. 6261-6274.","Al-Khashman, O.A., Heavy metal distribution in dust, street dust and soils from the work place in Karak Industrial Estate, Jordan. Atmospheric Environment, 2004. 38(39): p. 6803-6812.","Al-Momani, I.F., Trace elements in street and household dusts in Amman, Jordan. Soil and Sediment Contamination: An International Journal, 2007. 16(5): p. 485-496.","Mahbub, P., et al., The impacts of traffic and rainfall characteristics on heavy metals build-up and wash-off from urban roads. Environmental Science and Technology, 2010. 44: p. 8904-8910.","Kowalik, C. and J.W. Einax, Modern chemometric data analysis – methods for the objective evaluation of load in river systems. Acta hydrochimica et hydrobiologica, 2006. 34(5): p. 425-436.","Zhang, W., et al., Source diagnostics of polycyclic aromatic hydrocarbons in urban road runoff, dust, rain and canopy throughfall. Environmental Pollution, 2008. 153(3): p. 594-601.","Mas, S., et al., Application of chemometric methods to environmental analysis of organic pollutants: A review. Talanta, 2010. 80(3): p. 1052-1067.\n[10]\tGunawardana, C., et al., Role of solids in heavy metals buildup on urban road surfaces. Journal of Environmental Engineering, 2012. 138(4): p. 490-498.\n[11]\tSartor, J.D., G.B. Boyd, and F.J. Agardy, Water pollution aspects of street surface contaminants. Journal (Water Pollution Control Federation), 1974. 46(3): p. 458-467.\n[12]\tEgodawatta, P. and A. Goonetilleke, Characteristics of pollution build-up on residential road surfaces, in 7th International Conference on Hydroscience and Engineering, M. Piasecki, et al., Editors. 2007, Drexel University.\n[13]\tMostert, M.M.R., G.A. Ayoko, and S. Kokot, Multi-criteria ranking and source identification of metals in public playgrounds in Queensland, Australia. Geoderma, 2012. 173–174(0): p. 173-183.\n[14]\tLim, M.C.H., et al., A comparative study of the elemental composition of the exhaust emissions of cars powered by liquefied petroleum gas and unleaded petrol. Atmospheric Environment, 2006. 40(17): p. 3111-3122.\n[15]\tPalacios, M.A., et al., Assessment of environmental contamination risk by Pt, Rh and Pd from automobile catalyst. Microchemical Journal, 2000. 67(1–3): p. 105-113.\n[16]\t\tAdachi, K. and Y. Tainosho, Characterization of heavy metal particles embedded in tire dust. Environment International, 2004. 30(8): p. 1009-1017.\n[17]\tMostert, M., G. Ayoko, and S. Kokot, Application of chemometrics to analysis of soil pollutants. Trends in Analytical Chemistry, 2010. 29(5): p. 430-445.\n[18]\tHulskotte, J.H., et al., Brake wear from vehicles as an important source of diffuse copper pollution. Water Sci Technol, 2007. 56(1): p. 223-31.\n[19]\tThorpe, A. and R.M. Harrison, Sources and properties of non-exhaust particulate matter from road traffic: A review. Science of The Total Environment, 2008.400(1-3): p. 270-282."]}

Urban water quality can be significantly impaired by the build-up of pollutants such as heavy metals and volatile organics on urban road surfaces due to vehicular traffic. Any control strategy for the mitigation of traffic related build-up of heavy metals and volatile organic pollutants should be based on the knowledge of their build-up processes. In the study discussed in this paper, the outcomes of a detailed experimental investigation into build-up processes of heavy metals and volatile organics are presented. It was found that traffic parameters such as average daily traffic, volume over capacity ratio and surface texture depth had similar strong correlations with the build-up of heavy metals and volatile organics. Multicriteria decision analyses revealed that that the 1–74 μm particulate fraction of total suspended solids (TSS) could be regarded as a surrogate indicator for particulate heavy metals in build-up and this same fraction of total organic carbon could be regarded as a surrogate indicator for particulate volatile organics build-up. In terms of pollutants affinity, TSS was found to be the predominant parameter for particulate heavy metals build-up and total dissolved solids was found to be the predominant parameter for the potential dissolved particulate fraction in heavy metals buildup. It was also found that land use did not play a significant role in the build-up of traffic generated heavy metals and volatile organics.

While current research has demonstrated that the operation of some laser printers results in emission of high concentrations of ultrafine particles, fundamental gaps in knowledge in relation to the emissions still remain. In particular, there have been no answers provided to questions such as the following: (1) What is the composition of the particles? (2) What are their formation mechanisms? (3) Why are some printers high emitters, while others are low? Considering the widespread use of printers and human exposure to these particles, understanding the process of particle formation is of critical importance. This study, using state-of-the-art instrumental methods, has addressed these three points. We present experimental evidence that indicates that intense bursts of particles are associated with temperature fluctuations and suggest that the difference between high and low emitters lies in the speed and sophistication of the temperature control. We have also shown, for the first time, that the particles are volatile and are of secondary nature, being formed in the air from VOC originating from both the paper and hot toner. Some of the toner is initially deposited on the fuser roller, after which the organic compounds evaporate and then form particles, through one of two main reaction pathways: homogeneous nucleation or secondary particle formation involving ozone.

No Abstract.Nigerian Journal of Chemical Research Vol 5 2000: 61-64

No Abstract.Nigerian Journal of Chemical Research Vol 4 1999: 57-62