Magnetic Response of Soils and Vegetation to Heavy Metal PollutionA Case Study

Abstract

Fast and cost-effective detection of industrial pollution can significantly promote its ecological, economic, and social assessment. A magnetometric method, used for qualitative determination of anthropogenic contamination, meets these requirements but needs further development in more quantitative terms. It could be used successfully in numerous cases when the heavy metals coexist with strongly magnetic iron oxide particles in the source dust. We present an integrated magnetic and geochemical study that examines the utility of magnetometric techniques for rapid, qualitative detection of metallic pollutants in soils and vegetation. The new aspect of our approach, in comparison with previously published articles on this subject, is the combined investigation (magnetic and geochemical) of both soils and vegetation, thus using an additional medium for employing the magnetometry as a pollution proxy at a site. The study area is a small (approximately 3 km2) region in the suburbs of Sofia (Bulgaria), with the main pollution source being a metallurgical factory. Soil samples have been taken from the topmost 20 cm from private gardens, located at different distances from the factory. Vegetation samples were taken from ryegrass (both leaves and roots) and leaves from two kinds of deciduous trees (maple and acacia). The results show that both vegetation and soils are characterized by enhanced magnetic properties, compared to background material, which is due to the presence of magnetite particles of anthropogenic origin accompanying heavy metal emissions. SEM images and microprobe analyses reveal the presence of a significant amount of particles, containing heavy metals (including iron) in vegetation samples taken close to the main pollution source. Correlation analyses show a statistically significant link (correlation coefficients ranging from 0.6 to 0.7) between magnetic susceptibility and the main heavy metals (Cu, Zn, Pb) in soil samples, indicating that the magnetic susceptibility can provide a proxy method for identifying the relative contribution of industrial pollution in soils and vegetation, that is reliable, inexpensive, and less time-consuming than standard chemical analyses.

Vehicle-derived emissions and pollution on the road autovia 2 investigated by rock-magnetic parameters: A case study from Argentina

“…Magnetic mapping in magnetism has been well accepted for investigating industrial and urban pollution in different environments, such as soils, rivers/streams and lakes, different vegetative habitats, and roads (e.g., Hunt et al, 1984;Hoffmann et al, 1999;Matzka and Maher, 1999;Petrovský and Ellwood, 1999;Jordanova et al, 2003;Amereih et al, 2005;Lu et al, 2005;Zhang et al, 2006;Kim et al, 2007;Chaparro et al, 2007;Maher et al, 2008). A considerable number of studies have indicated relationships between magnetic parameters and heavy metal concentrations based on a genetic relationship from simultaneous production of both particle sources (e.g., Beckwith et al, 1986;Georgeaud et al, 1997;Petrovský et al, 1998;Knab et al, 2001;Spiteri et al, 2005;Chaparro et al, 2006Chaparro et al, , 2008.…”

Magnetic mapping of fly-ash pollution and heavy metals from soil samples around a point source in a dry tropical environment

“…In several studies, a significant correlation between magnetic susceptibility and heavy metal content in soils was found (e.g., Heller et al 1998;Dearing et al 2001;Lecoanet et al 2001;Hanesch et al 2003;Jordanova et al 2003). It has been well established that aerosols from varieties of industrial combustion processes possess a significant mineral magnetic component (Hunt et al 1984;Beckwith et al 1986), and that these minerals make significant contribution to the magnetic component of topsoil horizons, especially in urban areas and sites downwind of industrial centers .…”

Magnetic particulate matters in the ashes of few commonly used Indian cigarettes

“…Another possible source of magnetic property in vegetation is due to the deposition of atmospheric dust particles of different origins on plant leafs. Dust itself contains strongly magnetic iron oxide particles (Hunt et al 1984) and could be a reason for enhanced magnetic properties of vegetation (Matzka and Maher 1999;Jordanova et al 2003). At this point, it has to be noted that dry Tendu leaf is collected from forests and used to role the tobacco sample (U1) to prepare bidi.…”