Air pollution occurs when gaseous substances are released into the atmosphere. Industrialization is the major source of air pollution. An alteration in the gaseous composition of the atmosphere is called air pollution. Air pollution is caused by the release of gaseous elements into the atmosphere (Schwartz 7). The gaseous substances contaminate the atmosphere and causes harm to living and nonliving things.
The chemical composition of the atmosphere can be seen below:
|Water vapor||H2O||0.004 to 4 (Variable)|
The composition table shows that gaseous elements can combine to cause adverse effect on humans and the atmosphere. Gaseous emissions from the atmosphere can cause short and long-term hazards. Air pollutants can be divided into primary and secondary pollutants.
Classification of Air Pollutants
Air pollutants can be classified into two types namely: Primary and secondary pollutants
Primary Pollutants: Gaseous substances released into the atmosphere are called primary pollutants. These substances have direct access to the atmosphere and can cause great danger to human health and the environment. When these gases are released in large quantities they combine to form a harmful product. These substances include compounds of carbon, Nitrogenous compounds, compounds of sulphur, compounds of halogen and solid particles (koop 4).
Secondary Pollutants: Primary pollutants react to form secondary pollutants. The accumulation of gaseous elements produces secondary air pollutants. Secondary pollutants include acidic oxides which are formed from the release of nitrogen oxides.
Characteristics of Air pollutants
- Particles of matter: Pollutants in this category consist of residues from bush burning, construction sites, combustion engines, dust particles, soot or smoke and heavy metals. When this particulate suspensions are inhaled there cause harm to the respiratory system.
- Nitrogen oxides: Oxides of nitrogen are released from heavy-duty engines. Accumulation and deposition of this substance can damage the ozone layer and affect the visibility of the environment.
- Oxides of sulphur: The emission of this substance produces a pungent smell. Oxides of sulphur are released into the atmosphere during gas flaring. Sulphur dioxide cause irritation of the skin and affects the lungs.
- Oxides of carbon: This gas is not visible; it is a colorless gas and has an adverse effect on human health. Oxides of carbon are produced from the combustion engines. High volumes of this substance can cause brain damage and immediate death.
- Depleted Ozone: when gaseous substances are released into the atmosphere, they cause depletion of the ozone layer. Ozone depletion is caused by the emission of primary pollutants into the atmosphere. The ozone becomes depleted and causes damage to the central nervous system.
- Lead particles: The burning of crude oil produces huge deposits of lead. The accumulation of this pollutant in the atmosphere can cause severe damage to the reproductive organs, lungs and the central nervous system.
- Toxic and radioactive pollutants: Toxic pollutants are found in products containing gasoline. Toxic substances increase the mortality rate in children and affect the female reproductive organs. Radioactive pollutants can cause breast cancer and other respiratory diseases (Wai 4).
The table below shows a list of some common pollutants and their sources
|Particulate matter suspensions||Heavy industries, cement plants, power plants, automobile industries.|
|Fluoride||Components of fertilizer, aluminium chippings, heavy metals.|
|Chlorine||Deposits from water plants.|
|Sulphur dioxide||Petroleum plants, heavy metals, power plants.|
|Lead||Battery manufacturing plants, Ore plants.|
|Peroxyacetyl nitrate||Indirect pollutant.|
|Oxides of nitrogen and its compounds||Heavy metals, power plants, automobiles|
|Carbon monoxide||Combustion engines.|
|Hydrogen sulphide||Power plants, paper industries.|
|Ammonia||Fertilizer, deposits from fertilizer plants.|
|Hydrocarbons||Crude oil plants, automobiles.|
Effects of Air Pollution on Human Health
Previous literatures indicate that air pollution is a major source of health problems globally (Daly and Zannetti 3). Air pollution has short and long term effect; it affects the climate and human beings. Depletion of the ozone layer is a long-term effect of air pollution. Health workers believe that the rate of gaseous emission has increased geometrically, this account for the health hazards and death of children.
Children are more vulnerable to air pollutants because the accumulated chemical substance would reduce the metabolic rate in the body (Daly and Zannetti 5). Health workers argue that the high rate of infant mortality and abnormalities is caused by the accumulation of gaseous substances in the atmosphere. Children have been diagnosed with lung cancer, a trend that began with industrialization. There are many other ailments associated with air pollution.
The table below summarizes the effects of air pollution on human health.
|Pollutants||Effects on human health|
|Particles of matter||Cause heart diseases, affects the lungs, and causes premature death due to prolonged exposure and cardiac arrest.|
|Ozone depletion||Affects the respiratory organs, induces symptoms such as cough, breath disorders, lung infection.|
|Lead||Causes renal failure, affects the memory of children, can lead to anemia, causes nervous breakdown.|
|Oxides of Nitrogen||Causes renal failure in children, affects the lungs.|
|Oxides of sulphur||Can lead to asthma, causes chest pain in children and the aged. Reduces the lifespan of children, can cause serious respiratory problems in pregnant women.|
|Carbon monoxide||Affects oxygen circulation in the body, causes respiratory disorders.|
|Ammonia||Associated with heart failures and low blood pressure.|
|Organic compounds||Volatile compounds cause cancer, affects the metabolic breakdown of the body. Causes renal failure and respiratory infections.|
|Mercury||Induces brain damage, causes liver and kidney failures, affects the growth of children.|
|Toxic wastes||Causes lung cancer, affects the reproductive organs, can lead to death of the victim.|
The table below summarizes the effects of air pollutants on the environment
Effect of Air Pollutants in the Environment
|Pollutants||Effects in the environment|
|Particles of matter||Affects visibility and the ecosystem, distorts the pattern of rainfall, damages the soil structure and affects plant growth.|
|Ozone depletion||Affects vegetation cover, affects leaves and flowering plants, reduces photosynthesis, reduces crop yield, affects carbon dioxide uptake in plants. Causes stunted growth in plants.|
|Lead||Harmful to aquatic life, reduces the availability of trace elements in the soil.|
|Oxides of Nitrogen||Causes climate change, increases ozone depletion, affects soil nutrients when the accumulated in higher amounts.|
|Oxides of sulphur||Reduces the vegetation cover, damages soil structure.|
|Carbon monoxide||Influences the formation of carbon dioxide and affects greenhouse compounds.|
|Ammonia||Influences the eutrophication of soil water, leads to contamination of ground water, and affects climate change.|
|Organic compounds||Influence the ozone process, affects the greenhouse process.|
|Mercury||Distorts aquatic life and the deposits in rivers affects the vegetative cover.|
|Toxic wastes||Affects wildlife and reduces the growth of livestock, affects the ecosystem.|
Finally, air pollution must be controlled in order to guarantee a safe environment. Burning of fuels must be controlled and proper care must be taken to ensure proper management of these air pollutants.
Daly, Arter and Zannetti Paker 2007, Introduction to Air Pollution. PDF file. Web.
Koop, Gary 2002, Measuring the Health Cost of Air Pollution. PDF file. Web.
Schwartz, Joel 2006, The Health Effects of Air Pollution. PDF file. Web.
Wai, Wong 2008, Air Pollution and Health Studies in China: A Literature Review. Web.