According to the scientists, further research in the field of environmental magnetism will enable the development of precise, cheaper and less time-consuming tools for the analysis and monitoring of environmental quality.

'Our research focuses on the magnetic properties of street dust in Warsaw. As part of the experiment, we analysed samples taken from 149 locations and examined their magnetic susceptibility and other magnetic parameters. Granulometric separation of particles allowed us to determine which dust fractions were characterized by the strongest magnetic properties and how they differed between areas with different land use structures', emphasizes Sylwia Dytłow, PhD, from the Department of Magnetism of the Institute of Geophysics PAS, the first author of the publication on this subject in the prestigious journal Scientific Reports.

Road dust - one of the main carriers of harmful substances, including polycyclic aromatic hydrocarbons (PAHs) - is a mixture of particles originating from both natural processes and anthropogenic activities, which settle on road surfaces. These pollutants are created, among other things, as a result of fuel combustion, exhaust emissions, tire wear and brake pad friction.

Dust samples collected by scientists from the streets of Warsaw were divided into five fractions of different sizes - from particles larger than 0.8 mm to those below 0.2 mm. 'The results show that the smallest dust fractions (0.2 mm) have the highest magnetic susceptibility, which may indicate their origin from anthropogenic sources of pollution, such as car traffic or industrial processes', we read in a press release sent by the Institute of Geophysics PAS.

'Interestingly, despite the smallest amount in the samples, they contain the highest concentration of polycyclic aromatic hydrocarbons - compounds particularly dangerous to both human health and the environment. Such particles are more mobile and can penetrate the body more easily, increasing the risk of serious diseases', the scientist says.

According to Sylwia Dytłow, her research provides new data on the use of magnetic properties in the analysis of urban dust from locations representing various land use categories. 'Thanks to this, we can better understand the mechanisms of pollution spread in cities and develop more effective strategies for its monitoring', she emphasises.

In the vicinity of heavily frequented places - such as the Vilnius Railway Station - researchers recorded the highest values of magnetic properties, which indicates a higher concentration of pollution associated with road traffic.

'Despite this, our research shows a weak correlation between traffic intensity and magnetic susceptibility, which suggests that other environmental factors, such as land use, also play an important role in the distribution of these properties. Therefore, the study determined 19 different land use categories, including density and height of buildings, which affect the conditions of spreading road dust, and magnetic particles contained in it', the authors of the publication report.

Sylwia Dytłow leads a project financed by the National Science Center, in which she is developing an innovative method for rapid assessment of PAH concentrations in road dust using magnetic parameters.

'In Poland, there is still a lack of comprehensive studies on the spatial distribution of PAHs in road dust. So far, the assessment of the environmental risk of these pollutants requires the concentrations of individual PAHs obtained using chemical methods (gas and liquid chromatography). These are very accurate methods, but they are also time-consuming and expensive. Our project, thanks to a wide measurement database, will enable precise - and cheaper - determination of the level of pollution in various parts of the city', she says.

In her opinion, the conclusions from this research will be of key importance for improving air quality and protecting public health. 'Magnetic methods of dust analysis can help quickly identify sources of pollutant emissions, which may be particularly important in the context of increasing requirements for air quality in the European Union', the scientist concludes. (PAP)

PAP - Science in Poland

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