title: Heavy metal contamination in the Delhi segment of Yamuna basin.
abstract: Concentration of heavy metals (Cd, Ni, Zn, Fe, Cu, Mn, Pb, Cr, Hg and As) in the waters of River Yamuna and in the soil of agricultural fields along its course in Delhi are reported from 13 sites, spread through the Delhi stretch of Yamuna, starting from the Wazirabad barrage till the Okhla barrage. Varying concentration of heavy metals was found. Peaks were observed in samples collected downstream of Wazirabad and Okhla barrage, indicating the anthropogenic nature of the contamination. The Wazirabad section of the river receives wastewater from Najafgarh and its supplementary drains, whereas the Shahdara drain releases its pollution load upstream of the Okhla barrage. Average heavy metal concentration at different locations in the river water varied in the order of Fe>Cr>Mn>Zn>Pb>Cu>Ni>Hg>As>Cd. The river basin soil shows higher level of contamination with lesser variation than the water samples among sampling locations, thereby suggesting deposition over long periods of time through the processes of adsorption and absorption. The average heavy metal concentration at different locations in soil varied in the order of Fe>Mn>Zn>Cr>Pb>Ni>Hg>Cu>As>Cd.
authors.affiliation: Centre for Environmental Studies, The Energy and Resources Institute, India Habitat Centre, New Delhi, 110003, India. meenas@teri.res.in
authors.forename: Meena
authors.initials: M
authors.lastname: Sehgal
authors.forename: Ankur
authors.initials: A
authors.lastname: Garg
authors.forename: R
authors.initials: R
authors.lastname: Suresh
authors.forename: Priya
authors.initials: P
authors.lastname: Dagar
mesh_terms: D002947:Cities; D004784:Environmental Monitoring; D007194:India; D019216:Metals, Heavy / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
chemical_list: D019216:Metals, Heavy; D012987:Soil; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical