Studies of Chemical Contamination and Toxic Pollutants in West Delhi-India

Abstract

The high urbanization and industrial growth rate in Delhi city have made it one of the most densely populated regions of India. This has resulted in an increase in the levels of environmental pollution from uncontrolled industrial effluents. The field investigation of chemical contaminants (Hg, Cd, Cr, Pb, Ni, Fe and Zn) and pesticides parameter were determined in underground water,
drains, Yamuna river, aquatic plants and soils during the seasons
(July–December) of 2001-2002. Nine samples of each reference
sample and underground water samples, soils attached aquatic plant
samples were collected from Yamuna river, near industrial effluent
discharges along 35 km of located surface streams and drains which
receive effluents from three major industrial areas. Contents of most
parts of metals in soils, water and aquatic plants significantly correlated
with each other and either a significant stimulatory or inhibitory
effect on seedling plants. A variety of inorganic and organic
analytes were detected in river soils and aquatic plants. Toxicity
occurred downstream at 5 of the 6 sampling stations based on
phytotoxivity and physical appearance of plants and invertebrate
survival. The concentration of Hg is higher in drains and underground
water found to be 21.5 and 1.5 μg/L respectively.