Water and Soil Pollution Implications of Road Traffic

Abstract

Rising vehicle ownership around the world has resulted in greater traffic volume on roads and associated traffic generated pollutants. Vehicular traffic and by implication road surfaces are among the most important sources of pollutants to the environment, particularly the urban environment which can pose significant human and ecosystem health impacts. Research studies have confirmed the vulnerability of the population living near high traffic areas, particularly the elderly. An equal concern is the uptake of trace metals by plants near road environments. Road surfaces also act as a repository for pollutants from other sources which can react with traffic generated pollutants leading to changes to pollutant characteristics influencing their solubility, reactivity, bioavailability, mobility, toxicity, and persistence. Pollutants deposited on road surfaces are incorporated in road dust. The primary sources of traffic pollutants are, exhaust emissions, fuel and lubrication system leakages, component wear such as tyres, brakes and chassis and road surface wear. Traffic and road surface factors play a significant role in influencing the type, amount and rate of pollutant generation. It has been found that traffic congestion is more significant than traffic volume in terms of pollutant generation. The pollutant emissions from heavy duty vehicles which use diesel are different compared to light vehicles which use gasoline. A very wide range of trace metals and hydrocarbons are emitt…