PUBLIC HEALTH RISK DUE TO URBAN AIR POLLUTION: A CASE STUDY OF SOME MAJOR CITIES

Abstract

Increasing amounts of potentially harmful gases and particles are being emitted into the atmosphere as a result of urbanization and industrial activities resulting in damage to human health and environment. This has made the air pollution as a major environmental problem affecting both developed and developing countries around the world. The scientific evidence on the health effects of ambient air pollution has been growing in recent years. It has been evident that air pollution principally affects the respiratory, circulatory and olfactory systems. Health effects data from various clinical and epidemiology studies have shown that air pollution is associated with wide spectrum of respiratory and cardiovascular effects including decreased lung function, asthma attacks, chronic obstructive bronchitis disease, lower respiratory illness in children and mortality. These evidences have prompted the World Health Organization (WHO) to include air pollution and its health effects in its agenda (WHO, 2000). In the 1952 London air pollution episode it was estimated that about 4000 extra deaths occurred as a result of smog largely consisting of high concentrations of SO2 and particulate matter. Since 1950s, a great deal of evidence has accumulated showing that air pollutants have damaging effects on human health (WHO, 2000). In an attempt to study the effects of ambient air pollution on public health, many epidemiologic studies have been undertaken to date in several settings demonstrating air pollution as risk factor for mortality and morbidity. For several health endpoints, the association has been quantified and Concentration-Response (C-R) relationships have been characterized for different pollutants like particulate matter (PK° and PM25; particulate matter with aerodynamic size less than 10 I.A.m and 2.5 lam respectively), SO2 and NO2.