Negative correlation between concentration of iron oxides and particulate matter in atmospheric dust: case study at industrial site during smoggy period

Abstract

Background Environmental magnetism, focusing on ferrimagnetic iron oxides, provides useful additional information on pollution of different environments. Magnetic methods have been applied to studies of atmospheric dust, namely PM10 (particulate matter smaller than 10 µm) in, e.g., industrial or urban areas. Until now, positive correlation was reported between concentration of iron oxides (expressed in terms of either magnetic susceptibility, saturation remanent or saturation induced magnetization) and concentration of PM10 or smaller. Purpose of this study was to verify the relationship between iron oxides and PM at monitoring site close to source of emissions rich in iron oxides during period of smoggy conditions. Results We examined 24-h PM10 and PM1 samples, collected during 10 days of smoggy winter period at a site close to steel plant, which represents a significant source of atmospheric emissions in industrial region of Northern Moravia (Czech Republic), known for generally high degree of air pollution. Magnetic hysteresis loops were measured to obtain parameters reflecting the concentration and grain-size distribution of iron oxides. Our data show unexpected negative correlation between saturation magnetization (concentration of ferrimagnetic iron oxides) and both PM1 and PM10 concentrations, to the best of our knowledge the trend not being reported yet. Conclusions Our finding may seemingly disqualify magnetic methods as useful proxy in air pollution studies. However, we suggest that this is an exceptional case, specific to this region and monitoring site, as well as to synoptic conditions during the smoggy period. Although the significant dust emissions are presumably rich in iron oxides, the overall air quality at the monitoring site is determined by the general environment, controlled by many other sources of different character in the region, and by the specific climatic conditions. Thus, the steel plant, presumably emitting dust rich in ferrimagnetic iron oxides, dominates the deposited dust at the nearby monitoring site only during few days of suitable weather (namely wind speed and direction).

A Fuzzy-Based Analysis of Air Particle Pollution Data: An Index IMC for Magnetic Biomonitoring

“…This fine magnetic fraction comprises the ubiquitous anthropogenic magnetite and adsorbed potentially toxic elements (PTE), which may cause genotoxic and mutagenic impacts. Several studies proved a relationship between PTE and magnetic parameters in soils [9], sediments [10,11], biomonitors [12][13][14], and atmospheric dust [15][16][17]. This association between the AMP and PTE in magnetic fractions of PM generated from industrial or vehicle emission was shown by [18][19][20].…”

Measuring magnetic susceptibility of particulate matter collected on filters

“…The successful use of magnetic monitoring for soil contamination in industrial areas led to the adoption of magnetic methods for monitoring air pollution in urban environments. A significant contribution of Fe-rich particles to urban dust was clearly demonstrated by detailed studies of PM collected by municipal monitoring networks (e.g., Muxworthy et al 2003 ; Sagnotti et al 2006 ; Górka-Kostrubiec et al 2012 ; Mantovani et al 2018 ; and Petrovský et al 2020 ). Contrary to studies reporting a positive correlation between the concentration of ferrimagnetic iron oxides and particulate matter, Petrovský et al ( 2020 ) reveal a negative correlation between the concentration of PM and saturation induced magnetization.…”

“…A significant contribution of Fe-rich particles to urban dust was clearly demonstrated by detailed studies of PM collected by municipal monitoring networks (e.g., Muxworthy et al 2003 ; Sagnotti et al 2006 ; Górka-Kostrubiec et al 2012 ; Mantovani et al 2018 ; and Petrovský et al 2020 ). Contrary to studies reporting a positive correlation between the concentration of ferrimagnetic iron oxides and particulate matter, Petrovský et al ( 2020 ) reveal a negative correlation between the concentration of PM and saturation induced magnetization. It is crucial to note that magnetic monitoring is site-specific and predominantly reflects local factors such as the nature of emission sources and weather conditions.…”

“…Research teams studying environmental magnetism have shown promising results in the study of environmental pollution. Magnetometry (magnetic techniques or methods), which is widely used for rock-magnetic studies, is an inexpensive, fast, and precise technique for assessing and monitoring pollution in different environmental systems (Kapper et al 2020 ), including soil (e.g., Xia et al 2014 ; Szuszkiewicz et al 2015 ; Rachwał et al 2017 ; Wang et al 2018a , b ; Magiera et al 2021 , 2023 ); sediments of streams, rivers, lakes, and estuaries (e.g., Prajith et al 2015 ; Zhang et al 2018 ; Wang et al 2018a , b ; Harikrishnan et al 2018 ; Szczepaniak-Wnuk et al 2020 ); and air (e.g., Saragnese et al 2011 ; Petrovský et al 2020 ). Magnetic methods have been used to estimate atmospheric air pollution levels by applying them to airborne particles collected on filters (e.g., Muxworthy et al 2002 , 2003 ; Sagnotti et al 2006 ; Górka-Kostrubiec et al 2012 ; Mantovani et al 2018 ), dust captured on vegetation (e.g., Hofman et al 2017 ; Mantovani et al 2018 ; Winkler et al 2020 ), and the dust settled on the surface of roads, soil, and snow-covered road sites (e.g., Bućko et al 2011 ; Gonet and Maher 2019 ; Gonet et al 2021 ).…”

Nitrate formation and iron dissolution in the heterogeneous reactions of NH3 on nano α-Fe2O3

“…35,36 Industrial processes such as steelmaking and Fenton-like wastewater treatment inevitably release Fe 2 O 3 particles into the atmosphere. [37][38][39] Previous studies have found that it can promote the heterogeneous reaction of SO 2 through a REDOX process during the conversion between Fe 2+ and Fe 3+ , allowing SO 2 oxidation to SO 4 2− even under dark conditions. 40 In addition, it has been found that the dissolution of Fe 2 O 3 particles can be induced with the addition of oxalic acid.…”