Magnetic properties of air suspended particles in thirty eight cities from south India

Özet

Air pollution is a basic problem nowadays and it requires special concern. In India, the air pollution is agrowing problem because of the enhanced anthropogenic activities such as burning fossil fuels involvingindustrial processes and motor vehicles. We study airborne dust particles collected at the height of 7 m inroadside and land area from thirty-eight cities in the state of Tamil Nadu. The collection involves a total of111 samples concerning vehicular, industrial and residential areas, and allows us to assess the spatialdistribution of magnetic particles produced and emitted on a short period of time (about one month).Magnetic properties of these air suspended particles were determined by techniques of environmentalmagnetism, revealing the presence of magnetite and hematite. We found the overall average of massspecificmagnetic susceptibility c of 589.0 108 m3 kg1 and saturation of remanent magnetizationSIRM of 68.1 103 A m2 kg1; as well as c and SIRM values higher than 900.0 108 m3 kg1 and700.0 103 A m2 kg1, respectively, corresponding to the most impacted zones in industrial/vehicularareas and in cities located in the central/eastern region respectively (e.g.: Hosur, Krishnagiri, Salem,Dharapuram, Ranipet, Ayanavaram, Cuddalore and Chidambaram). We analyzed the relationship betweenmagnetic parameters, between areas and possible grouping of cities using multivariate statisticalanalysis. The SEM-EDS observations and grain size estimations reveal the presence of trace elements (Sb,Zn, Co, Ni, As and V) and fine particles (1e5 mm) that can be inhaled and therefore are dangerous tohuman health.