Vehicle-Generated Heavy Metal Pollution in an Urban Environment and Its Distribution into Various Environmental Components

Abstract

Pollution caused by vehicles and its rapidly growing number is a serious concern all over the world. Vehicular pollution is primarily known for emitting various kinds of organic and inorganic gaseous pollutants in to the atmosphere, but recent studies show that vehicles are one of the chief sources of creating heavy metal pollution in an urban environment via processes like exhaust of diesel and petrol, corrosion of metallic parts, engine wear, tyre and brake pad wear and road surface degradation due to vehicular movement. Studies show that apart from fuel burning, tyre and brake wear particles lead the contribution of heavy metals into an urban environment. Due to easy availability and low cost, two wheelers dominate the road traffic and become a major source of air pollution in most of the developing countries. Heavy metals emitted in ambient air ultimately get deposited on other environmental component like hydrosphere and lithosphere which ultimately affect flora and fauna living in it. Some heavy metals are able to create toxicity at low level of exposure, and metals like nickel, cadmium and chromium are able to produce carcinogenicity in humans. Meteorological and geographical conditions of an area play a major role in distribution and deposition of heavy metals. There is an urgent need to make an effective environmental management plan for urban areas which include promotion of new technologies, adaption of biofuels, green belt development and public participation.