Magnetic susceptibility of road deposited sediments at a national scale – Relation to population size and urban pollution (original) (raw)
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Magnetic properties of road dusts from 26 urban sites in Bulgaria are studied. Temporal variations of magnetic susceptibility (c) during eighteen months monitoring account for approximately 1/3rd of the mean annual values. Analysis of heavy metal contents and magnetic parameters for the fraction d < 63 mm reveal significant correlations (p < 0.05) between c and Fe, Mn and PLI index. The highest negative correlation (R 2 ¼ À0.84) is observed between the ratio ARM/c and Pb content. It suggests that Pb is related to brake/tyre wear emissions, releasing larger particles and higher Pb during slow driving e braking. Bulk c values of road dusts per city show significant correlation with population size and mean annual NO 2 concentration on a log-normal scale. The results demonstrate the applicability of magnetic measurements of road dusts for estimation of mean NO 2 levels at high spatial density, which is important for pollution modelling and health risk assessment.
Magnetic properties of road dusts from 26 urban sites in Bulgaria are studied. Temporal variations of magnetic susceptibility (c) during eighteen months monitoring account for approximately 1/3rd of the mean annual values. Analysis of heavy metal contents and magnetic parameters for the fraction d < 63 mm reveal significant correlations (p < 0.05) between c and Fe, Mn and PLI index. The highest negative correlation (R 2 ¼ À0.84) is observed between the ratio ARM/c and Pb content. It suggests that Pb is related to brake/tyre wear emissions, releasing larger particles and higher Pb during slow driving e braking. Bulk c values of road dusts per city show significant correlation with population size and mean annual NO 2 concentration on a log-normal scale. The results demonstrate the applicability of magnetic measurements of road dusts for estimation of mean NO 2 levels at high spatial density, which is important for pollution modelling and health risk assessment.
2009
The application of mineral magnetic concentration parameters (χ LF , χ ARM and SIRM) as a potential particle size proxy for urban road deposited sediment collected from Scunthorpe, North Lincolnshire, U.K. has been investigated. Correlation analyses between each magnetic parameter and traditional particle size classes (i.e. sand, silt and clay) and respiratory health related size classes (i.e. PM 10 , PM 2.5 and PM 1.0) are reported. Significant relationships (p <0.01; n = 35) exist between clay content and two of the magnetic concentration parameters (χ ARM and SIRM). This is also the same for each PM 10 , PM 2.5 and PM 1.0 sizes. Of the three magnetic parameters, χ ARM displays the strongest correlation (r = 0.45; p <0.01; n = 35) values and is the most significant parameter, which is consistent with class sizes of each approach. In doing so, these associations indicate mineral magnetic measurements have considerable potential as a particle size proxy for determining urban roadside particulate matter concentrations. Given the speed, low-cost and sensitivity of the measurements, this suggests magnetic techniques could potentially be used as an alternative and/or complementary exploratory technology for pilot particulate pollution investigations. Furthermore, in certain instances, it could be useful for examining linkages between respiratory health and particulate pollution and vehicle emissions.
Air Pollution XIX, 2011
Road deposited sediments (RDS) are a recognised pollution problem and a worrying public health concern of many urban environments. Linkages between the magneto characteristics of RDS and their particle size properties have been explored to determine the extent to which magnetic technologies can be utilised as a proxy for proffering insights to address pollution challenges. Samples (n = 60) were collected (May, 2008) along both sides of a busy urban road (Marylebone Road) in central London, UK. Magnetic concentration parameters (LF, χARM and SIRM) reveal high levels of magnetic material, when compared to previous urban RDS studies. Correlation analysis between the magnetic parameters and textural parameters (LF, χARM, SIRM and PM1.0, PM2.5, PM10) show significantly strong relationships but, unlike earlier studies, the trends display negative correlations. Despite this kinship not adhering to previously identified trends, this does not mean that mineral magnetic measurements cannot be used as a proxy. Moreover, it simply implies that the nature of any trends needs to be established for specific places before it can be reliably applied as a proxy.
International Journal of Environmental Science and Technology, 2017
The use of mineral magnetic techniques as pollution proxy for road deposited sediment was explored using various statistical approaches. Standard techniques were adopted for measurement of mineral magnetic and geochemical parameters. The analyses of magnetic parameters revealed that the samples were dominated by ferrimagnetic minerals and multidomain grains. This implied that the magnetic fractions in the samples might be of anthropogenic origin. Results also indicate that the samples were dominated by low coercive, magnetically soft minerals. Thermomagnetic curves confirmed magnetite as the remanence bearing magnetic mineral having a Curie point temperature of *580°C. The strong association observed between magnetic susceptibility, susceptibility of anhysteric remanent magnetization and saturation isothermal remanent magnetization and aluminum, titanium, manganese, iron, chromium and lead demonstrated that these metals occurred as ferrimagnetic particles of technogenic origin resulting from vehicular sources. Assessment of pollution status of the road deposited sediment identified silicon and lead as the priority pollutants of concern. Generally, pollution load index was \1 (mean, 0.66 ± 0.14), indicating that the samples were not polluted in the overall, but the metals were in the buildup stage requiring constant monitoring. The sources of pollutants from principal component and cluster analyses identified the sources of pollution to be mainly from vehicular emissions such as brake linings, exhaust materials, tire wear, corroded metal parts, abrasion of lubricating oil and road construction materials. This study found that mineral magnetic techniques offer great potential as pollution proxy for soil pollution studies.
Air Pollution XV, 2007
The use of mineral magnetic concentration parameters (χ LF , χ ARM and SIRM) as a potential particle size proxy for urban street dust collected from Southport (Merseyside, UK) is explored. Correlation analyses between each magnetic parameter and traditional particle size classes (i.e. sand, silt and clay) and respiratory health related size classes (i.e. PM 10 , PM 2.5 and PM 1.0) are reported. Significant relationships (p <0.001; n = 50) exist between sand, silt and clay content with at least one or all of the magnetic concentration parameters. This is also the same for each PM 10 , PM 2.5 and PM 1.0 sizes. Of the three magnetic parameters, χ LF displays the strongest correlation values (r = 0.701, P <0.001, n = 50) and is the most significant parameter, which is consistent with all class sizes of each approach. In doing so, these associations indicate mineral magnetic measurements have considerable potential as a particle size proxy for determining urban roadside particulate matter concentrations. Given the speed, low-cost and sensitivity of the measurements, this suggests magnetic techniques could potentially be used as an alternative and/or complementary exploratory technology for pilot particulate pollution investigations. Furthermore, in certain instances, it could be useful for examining linkages between respiratory health and particulate pollution and vehicle emissions.
Atmospheric Environment, 2005
This study demonstrates significant correlations between the organic matter content of urban street dust and certain mineral magnetic properties, which accords with previous work that indicates magnetic parameters offer potential as a proxy for organic content. However, sitespecific data demonstrate the relationship can be different for particular roads, even within the same area. This indicates the association may be more complex than previous work proposes and a cautionary note is required. It is recommended that the nature of the relationship between magnetic and organic properties should be fully explored for particular urban environments and individual field settings, before using magnetic measurements as a proxy for organic matter content. Furthermore, whilst soil is believed to significantly contribute to urban street dust, magnetic values in this study are much higher than those previously reported for top-soils and indicate the influence of other sources, such as anthropogenic pollutants. This suggests that using magnetic measurements to discriminate sources of urban particulates has considerable potential for development.
Environmental magnetism: Measuring, monitoring and modelling urban street dust pollution
Urban street dusts have been monitored monthly for one year (May 2000 to April 2001), their magnetic properties measured and their multivariate relationships modelled by Simultaneous R-and Q-mode Factor Analysis, so as to differentiate dusts from three urban roads (two in Wolverhampton and one in Dudley) in the West Midlands (U.K.). Results show the street dusts contain a large range of magnetic concentrations, magnetic mineralogy and magnetic domain sizes, which has enabled significant differences (p < 0.001) to be identified between individual roads. Whilst soil is proposed as a notable provenance for the dust, magnetic values in this study are much higher than those previously reported for topsoils and thus, indicate the influence of other sources, such as anthropogenic pollutants. This indicates the potential of magnetic methodologies as a valuable means of contributing to local and national road pollution monitoring schemes. Furthermore, Factor Analysis aided the interpretation of dust variations and simplified the interrelationships between magnetic parameters, which highlights its potential for classifying and discriminating urban street dust sources.
Magnetic properties of road dusts from 26 urban sites in Bulgaria are studied. Temporal variations of magnetic susceptibility (c) during eighteen months monitoring account for approximately 1/3rd of the mean annual values. Analysis of heavy metal contents and magnetic parameters for the fraction d < 63 mm reveal significant correlations (p < 0.05) between c and Fe, Mn and PLI index. The highest negative correlation (R 2 ¼ À0.84) is observed between the ratio ARM/c and Pb content. It suggests that Pb is related to brake/tyre wear emissions, releasing larger particles and higher Pb during slow driving e braking. Bulk c values of road dusts per city show significant correlation with population size and mean annual NO 2 concentration on a log-normal scale. The results demonstrate the applicability of magnetic measurements of road dusts for estimation of mean NO 2 levels at high spatial density, which is important for pollution modelling and health risk assessment.
Potential linkages between mineral magnetic measurements and urban roadside soil pollution (part 2)
Environmental Science: Processes & Impacts, 2014
Use of mineral magnetic concentration parameters (χ LF , χ ARM and SIRM) as a potential pollution proxy for soil samples collected from Wolverhampton (UK) is explored. Comparison of soil-related analytical data by correlation analyses between each magnetic parameter and individual geochemical classes (i.e. Fe, Pb, Ni, Zn, Cd), are reported. χ LF , χ ARM and SIRM parameters reveal significant (p <0.001 n = 60), strong (r = 0.632-0.797), associations with Fe, Cu, Zn and Pb. Inter-geochemical correlations suggest anthropogenic influences, which is supported by low FD % measurements that infer an influence of multidomain mineralogy are indicative of anthropogenic combustion processes. Results indicate mineral magnetic measurements could potentially be used as a geochemical indicator for soils in certain environments and/or specific settings that are appropriate for monitoring techniques. The mineral magnetic technique offers a simple, reliable, rapid, sensitive, inexpensive and non-destructive approach that could be a valuable pollution proxy for soil contamination studies.