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S B Chavan

Publications and source records attributed to S B Chavan.

6 recordsLinked to original sources
PubMed2003

Geochronology of Pb and Hg pollution in a coastal marine environment using global fallout 137Cs.

Global fallout 137Cs was used for dating sediment cores and estimation of recent sedimentation rates (up to 1 cm/y) in the Thane Creek, which lies in the southern part of the Deccan belt of India. The residence time of 210Pb in the Thane Creek water was calculated to be 0.7 years. Further, the concentrations of Pb (up to 70 microg/g) and Hg (up to 10 microg/g) in sediment profiles were measured to assess the anthropogenic input of contaminants due to large-scale industrialization, which has taken place in this area over the last two decades. The depth-wise concentration profile of Hg shows positive evidence of continued fresh input into the Creek.

Ecosystem↗
PubMed2002

Atmospheric dust loads and their elemental composition at a background site in India.

Air particulate samples collected during 1995-96 at a background site situated on the east coast of Thar Desert in Rajsthan State of India were analysed for atmospheric dust loads (Suspended Particulate Matter) and elemental composition. The values of SPM ranged from 9 microg M(-3) to 97 microg M(-3) with an average of 43 microg M(-3) except a few episodic values, which were 3 to 5 times higher than the average during summer months. The results for elemental composition of the particulate samples showed that the concentrations of anthropogenic toxic trace elements viz. Br, Cr, Pb, Sb, Se and Zn are lower by a factor of 2 to 10 as compared to urban areas. The high enrichment factors for anthropogenic elements viz. Br, Pb, Sb and Zn show an input from coal/wood fuel burning and vehicular pollution at the sampling site. The depletion of Si in SPM samples shows long distance transport of dust to the sampling site.

Air Pollutants↗
PubMed2002

Behaviour and fluxes of trace and toxic elements in creek sediment near Mumbai, India.

Studies on marine sediments are extremely important since they act as ultimate sink of anthropogenic pollutants. The present study was conducted near Mumbai city of India to understand and assess the behaviour and fluxes of trace and toxic elements in creek sediment. Seven sediment core samples were collected and analysed for trace and toxic elements such as Fe, Cu, Pb, Zn, Rb and Sr in different sections of the core using EDXRF technique. The fluxes of the elements in each section of the core were calculated using the mass sedimentation rates derived from 210Pb dating technique and the sediment density at each location. The estimated depositional fluxes of Fe, Rb and Sr in Zone-1 and Zone-3 are in the ranges of 0.4-0.5% cm(-2) yr(-1); 4-6 microg cm(-2) yr(-1) and 10-20 microg cm(-2) yr(-1) respectively, where as they were about 3-4 times higher in zone-2 for the same elements. The depositional fluxes of elements Cu (40-60 microg cm(-2) yr(-1)), Zn (35-43 microg cm(-2) yr(-1)) and Pb (6-12 microg cm(-2) yr(-1)) were also found to be higher in zone-2 compared to zone-1 and zone-3 which can be attributed to the release from the newly developed chemical zone of Thane-Belapur industrial belt.

Environmental Monitoring↗
PubMed2002

Heavy metal concentration and distribution in a dated sediment core of Nainital Lake in the Himalayan region.

The concentrations and distribution of the elements, including heavy metals such as As, Ba, Br, Co, Cr, Cs, Fe, Ga, K, Mn, Na, Rb, Sc, Sr, Th and Zn, were investigated in dated sediment cores of Nainital Lake located in the Himalayan region, in Uttar Pradesh state of India, which is considered as a remote background area. The concentrations of the elements were measured by instrumental neutron activation analysis using the k0 method. The International Atomic Energy Agency certified reference material SL-3 was used to evaluate the accuracy of the method. The normalized data for a series of elements were used to understand the source of loading. Elements like Br, Co, Cr, Fe, K, Mn and Zn show a negative correlation with increasing depth whereas elements like As, Ba, Cs, Na and Rb show a positive correlation with increasing depth. By considering the concentration for the bottom segments of the core as close to the baseline concentration, recent flux values for different elements were calculated. An increase in the flux value was observed for Br, Cr, Fe, K, Mn and Zn, which can be attributed to anthropogenic contribution in recent years.

Environmental Monitoring↗