AIR POLLUTION A CONTINUING HEALTH THREAT IN WORLD’S CITIES

AIR POLLUTION A CONTINUING HEALTH THREAT IN WORLD’S CITIES
 
CHAPTER ONE
INTRODUCTION
1.1      Background of the study
Air is one of the most important elements of man’s environment. An average human being requires about 12kg of air each day, which is nearly 12 to 15 times greater than the amount of food consumed. Clean and pure air is very essential for human health and survival. Any change in the natural and normal composition of air that may adversely affects the living system, particularly the human life invariably causes air pollution. Air pollution is generally defined as the presence in the outdoor atmosphere of one or more contaminants such as fumes, dust, gases, mist, odour, smoke, smog or vapours in considerable quantities and duration of which is injurious to human, animal and plant life or which unreasonably interferes with the comfortable enjoyment of life and property. Thus air pollution is generally disequilibrium condition of air caused due to the introduction of foreign elements from natural and manmade sources to the air so that it becomes injurious to biological communities. The World Health Organization (WHO) defines air pollution as limited to situations in which the outer ambient atmosphere contains materials in concentrations which are harmful to man and his environment.  A substance in the air that can cause harm to humans and the environment is known as an air pollutant and air pollutants are expressed as a ppm or ug/m3 which is subjected to change to variations of temperature and pressure.
The predominance of respiratory unhealthiness such as bronchial asthma, emphysema, lung cancer and chronic bronchitis appear to have heightened in recent years. A change in the genetic predisposition can snowball into allergic symptoms. Consequently this change in gene can be influenced by change in the environmental components. The average adult may require about 14 Kilograms of air each day compared with less than 1.4 Kilogram of food and about 2 Kilograms of water. Compared with the other necessities of life, obligatory continuous consumption is a unique property of air. The insensible intimate inter-penetration of air which of course flows in and out from the lungs gives to all pollution its essential importance. One of the major components of particulate matter which is the crystalline Silica has also been classified as a known human carcinogen and is associated with systemic autoimmune disease. The relationship between Silica and pneumoconiosis has been reported in the Azandarian Area. The occurrence of a pneumothorax was associated with complaints of pleuretic chest pain, resting dyspnea, respiratory distress, paroxysmal nocturnal dyspriea, orthopnea crackle Air pollution is a problem that is directly related to the number of people living in an area and the kinds of activities they engaged in. In a place where the population is low and their energy usage is also low, the impact of people in creating pollution is minimal. However where the population is high, the area urbanized and industrialized with high energy usage large quantities of pollutants are released into the environment. It is clearly obvious that the greater the concentration of people in one area, the greater the amount of pollution and the greater the sophistication of a society the more intricate and poignant its pollution. It is based on the above fact that this paper examines air pollution and control measures in urban centres of Nigeria. Nigeria is located on the west coast of Africa between the Bight of Benin to the fringes of the Sahara desert (between Benin Republic and Cameroun).  Air pollution may be taken as the contamination of air by discharge of harmful substances, which can cause health problems including burning eyes and nose, itchy irritated throat and breathing problems (USEPA, 1994). Air pollution is a major part of the overall atmospheric pollution and the motor vehicle emissions usually constitute the most significant source of ultrafine particles in an urban environment (Zhu and others, 2002). Important chemical pollutants emitted by land vehicles are Carbon monoxide (CO), Sulphur dioxide (SO2), Nitrogen dioxide (NO2) and Total Suspended Particles (TSP) (Najeeba and Saleem, 1997). Ambient air is one of the environments that human beings have to live in throughout their lives. The quality of the environment is therefore very important to the quality of life. It seems fitting and proper to examine the problem of air pollution from the view point of public health. An average man breathes 22,000 times each day. The air is the main link to life. It far exceeds one’s consumption of food and water. Hence, there is a general interest in air pollution studies (Subramani, 2012). In recent years many African countries have experienced significant economic growth leading to increased urbanization, motorization and energy use. Air pollution generated by motor vehicular exhaust has become a major cause of public concern worldwide. The rapid and the marked increase in motor vehicular traffic and its associated gaseous pollutants in the urban areas have caused a sharp increase in the prevalence of respiratory allergies (Polosa and Salvi, 1999). The net effect of this increase in population and cars is the drastic increase in environmental pollution including air pollution (Jackson, 2005) Nigeria is the most populous country in Africa accounting for approximately one-sixth of Africa’s people. Based on the 2006 National Population Census Nigeria has a population of 140,431,790 people and the population is exploding with current estimates of over 170 million and a growth rate of more than 2% per annum.
1.2      STATEMENT OF THE PROBLEM
 
In modern times and societies, there is a complex relationship between the environment, broadly defined, and human health. Poor air quality has been linked to respiratory health effects, especially among sensitive groups such as young children, elderly, and those with respiratory problems. The lack of a framework for the review, assessment and management of air pollution in the city implies that residents are exposed to significant ambient air pollution and therefore subject to attendant public health risks. It is on this note that the researcher intends to investigate the impact of air pollution and the continuing health threat in Nigeria.