Air pollution

Written by
Dr Ayub Macharia

The air in our atmosphere is composed of molecules of different gases. The most common gases are nitrogen (78%), oxygen (about 21%), and argon (almost 1%). Other molecules are present in the atmosphere as well, but in very small quantities.
Nitrogen – 78% – Dilutes oxygen and prevents rapid burning at the earth’s surface. Living things need it to make proteins. Nitrogen cannot be used directly from the air. The Nitrogen Cycle is nature’s way of supplying the needed nitrogen for living things.
Oxygen – 21% – Used by all living things. Essential for respiration. It is necessary for combustion or burning.
Argon – 0.9% – Used in light bulbs.
Carbon Dioxide0.03% – Plants use it to make oxygen. Acts as a blanket and prevents the escape of heat into outer space.
The atmosphere. Air pollution especially from industries is a growing problem. The public outcry against KEL Chemicals in Thika in 1991 is symbolic of the problem. Large concentrations are evident at Webuye where the paper and pulp factory emits sulfur compounds into the air turning trees yellow in the region. Vehicle emissions contribute significant volumes of carbon dioxide, one of the greenhouse gases causing global warming.
Urban outdoor air pollution is estimated to cause 1.3 million deaths worldwide per year. Children are particularly at risk due to the immaturity of their respiratory organ systems. Exposure to air pollutants is largely beyond the control of individuals and requires action by public authorities at the national, regional and even international levels.
Indoor air pollution is responsible for 2 million deaths annually. Acute lower respiratory infections, in particular pneumonia, continue to be the biggest killer of young children especialy in developing countries.
Air pollution can be harmful even when it is not visible. Scientific studies have shown that some pollutants can harm public health and welfare even at very low levels.
Air Pollution Challenges
Research has shown that emissions of carbon dioxide and other long-lived greenhouse gases that build up in the atmosphere endanger the health and welfare of current and future generations by causing climate change and ocean acidification. Long-lived greenhouse gases, which trap heat in the atmosphere, include carbon dioxide, methane, nitrous oxide, and fluorinated gases. These gases are produced by a numerous and diverse human activities.
Air pollution has been blamed for rapid climate change challenges. The global discussions on climate change under the auspices of UNFCCC have put a lot of emphasis on reduction of green house gas emissions.
What is Kenya doing to curb air pollution?
Kenya has taken several steps to address air pollution including
1. Removal of Lead in petroleum to reduce pollution from combustion engines including vehicles.
2. Prohibition of air pollution by the Environmental Management and Coordination Act (1999).
3. Gazettement of air quality regulations (2014)
4. Prohibition of importation of used vehicles older than 8 years to reduce vehicular air pollution.
5. Annual environmental audits requirements by EIA/EA regulations (2003) makes regulated facilities to declare their emissions and corrective action enforced.

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