AIR POLLUTANTS
For the survival of the human race and other living things in the natural ecosystem, adequate measures have to be put in place to deal with air pollution. This may be through the introduction and development of clean technologies and widespread use of the renewable energy sources in almost all features of life. Investment in green energy may be used as a springboard for achieving real improvements in environmental conservation.
The objective of this paper is to look into the various aspects of air pollution and the possible negative effects of pollution on the human health, plants and animals life and the environment in general. In order to understand the subject of the paper, common types of air pollutants will be briefly discussed together with their effects. The cause and effects of global warming and ozone air depletion will also be highlighted in some sections of the paper. The paper then ends with a conclusion which suggests possible measures that could be adopted in the fight against air pollution.
Types of Air Pollutants and their Negative Effects
Generally, air pollutants are classified into two broad categories, namely, the primary and the secondary pollutants. Primary pollutants are those emitted directly into the air particulates, ash and gaseous emissions, such as sulfur dioxide, carbon monoxide, nitrogen oxides, and hydrocarbons from volcanic eruptions, factories, vehicle exhaust fumes etc. Secondary pollutants are those produced through reactions between primary pollutants and other atmospheric compounds, e.g., ozone. Other examples of pollutants may assume both the secondary and primary manifestations especially if they may either result from direct emissions or get their derivations from ordinary primary pollutants.
Airborne Particles as Air Pollutants
These particles may either be liquid in nature or tiny fragments suspended in the air. Particles may also be primary, i.e. if they are directly emitted into the atmosphere or secondary in situations where they are formed through interactions and reactions with primary emissions. The main sources of airborne particles include dust and fumes from road transport, power generation plants, factories and dust blown into the air from construction sites. The natural sources include soil erosion by wind, volcanic eruptions, forest and desert fires, living vegetation and evaporation of sea water causing suspension of salt crystals in the air (Breuer, 1980).
Air pollutants have various negative effects upon nature including the human health. For humans, inhalation of tiny dust particles and other fumes may lead to respiratory diseases such as lung cancer, asthma, and cardiovascular disorders, among others.
Gaseous Air Pollutants
The most pronounced group of air pollutants are different kinds of gaseous pollutants, namely, sulfur dioxide, nitrogen oxides and ozone. In this case, Nitric oxide and sulfur dioxide are the examples of primary pollutants whereas the ozone gas is a secondary type. Other types of gaseous pollutants may include carbon monoxide, ammonia, persistent and volatile organic pollutants.
Air pollution is said to have a harmful impact on human health (Len, 2009). Some of the negative effects include respiratory disorders such as asthma, bronchitis, lung cancer among other diseases. The air pollutants also have a negative impact on the environment and the natural ecosystem in that it leads to destruction of animal and plant life, and also causes substantial damage to property.
Effects of Ozone gas (O3)
This is a colorless toxic gas with a pungent, irritating smell. The ozone gas resulting from human activities is a secondary pollutant since its produced by reactions of various pollutants such as hydrocarbons and nitrogen oxides with the help of sunlight. Ozone in the atmosphere has got several negative effects on both the natural ecosystem and humans (including animals). Some of the health effects include vulnerability to respiratory disorders and infections, chest diseases, damage and inflammation to the lungs (Breuer, 1980).
For plants and agricultural crops, the presence of the ozone gas interferes with the process of photosynthesis and may to some extent inhibit the natural growth and development of some crop species. This has a general impact of reducing agricultural yields and thus may in the long run lead to hard economic times due to hunger and starvation.
Effects of Carbon Monoxide
This is an odorless, colorless gas which is highly poisonous to humans and is in most cases derived from incomplete combustion of carbon-based fuels. The most defined sources of this toxic gas are industries and motor vehicles. Carbon monoxide emission has got several health effects whereby continual exposure may lead to poisoning of the heart and the nervous system, dizziness and headaches, suffocation, and to some extent severe effects on the unborn children incase an expectant mother is exposed to high concentrations of the gas.
Chlorofluorocarbons (CFCs) and Sulfur
Sulfur dioxide gas is produced through combustion of fuels with some sulfur contents e.g. fuel oils and coal. This poisonous gas may also be produced in metallurgical procedures involving ores rich in sulfur and in the industrial manufacture of sulfuric acid. This gas is harmful to man, materials and plants. This gas has an overall effect of interfering with the respiratory system when one is exposed continually to high concentrations of this gas. This gas can travel long distances by wind to the clouds leading to formation of acid rains which are in effect destructive to plant life, human life and even property since they cause corrosion (Miller, 1990).
Chlorofluorocarbons on the other hand are said to lower the ozone concentration in the stratosphere. Under extremely high energy UV radiation, chlorofluorocarbons disintegrate and release chlorine particles which in turn speed up the disintegration and ultimate breakdown of O3 (ozone) into oxygen gas. This leads to an increased rate of depletion of the ozone layer and also enhances global warming (Miller, 1990). The dangers and negative effects of global warming and ozone layer depletion are quite severe and substantial precautionary measures need to be urgently put in place to minimize air pollution by chlorofluorocarbons.
Global Warming
Green house gases have the ability to stay in the atmosphere for extremely long periods of time, ranging from few decades to several hundreds of years. Based on this argument, the global warming resulting from such emissions will in the long run have an impact on the Earth. Some of the negative effects of global warming are already being experienced in various parts of the world.
Global warming will also lead to an increase in the intensity and probability of heat waves and droughts. In as much as other parts of the globe may become wetter, other regions (especially Africa and certain parts of Europe) will experience serious heat waves and droughts. The consequences of global warming such as water shortage are already being experienced in most parts of Africa.
One major effect of global warming is the spread of diseases. The spread may be brought about through regular migrations of disease carrying insects such as mosquitoes from one part of the globe to another. To clearly illustrate this argument, warming of northern countries may have the general effect of causing insects to migrate towards the north. Some of these insects bring with them diseases and plague to such northern countries. For this reason, the fight against malaria has been negatively affected by global warming in this domain. ( HYPERLINK httpwww.environmentalgraffiti.comoffbeat-newsmalaria-no-longer-eradicated-thanks-to-global-warming402 httpwww.environmentalgraffiti.comoffbeat-newsmalaria-no-longer-eradicated-thanks-to-global-warming402 ).
Global warming would also result in the melting of polar ice caps. This will in turn lead to an increase in the sea levels and thus leading to an imbalanced situation of the global ecosystem. The melting of the ice will lead to desalination of most salty oceans leading to an interference with some of the aquatic lives. With all the white ice caps melt and gone, the terrestrial radiation from the earth would be highly reduced since ice which previously acted as a reflector would have gone. This will lead to increased temperatures.
Increase in the frequency andor magnitude of hurricanes is also another anticipated long term effect of global warming. It is argued that as the ocean temperatures rise due to the warming effect, the chances of increased hurricanes will also be high. These effects have a disastrous economic effect in that fighting diseases and dealing with destructions caused by hurricanes are quite expensive.
Ozone Layer Depletion
The ozone layer is part of the upper atmosphere. It is made up of an extremely high concentration of ozone (a form or type of oxygen) that absorbs harmful ultraviolet radiation from the sun. This absorption ends up purifying and deodorizing the atmosphere. In addition, the ozone sterilizes the rain water reaching the earth surface (EPA, 1998).
Depletion of the ozone layer is said to indirectly or directly endanger human life and survival of other living organisms and plants. Minor cases of ozone depletion can result in major harmful effects. Scientific research shows that for 2 percent more of the harmful radiations are able to reach the earths surface for every 1 percent of the ozone layer depleted ( HYPERLINK httplibrary.thinkquest.org26026Environmental_Problemsenvironmental_problems.html httplibrary.thinkquest.org26026Environmental_Problemsenvironmental_problems.html ). Depletion of the ozone layer has many negative effects on the environment namely disruption of the food chain, interference with the normal life cycles of animals and plants.
The unforeseen impacts of the ozone depletion on animals may be severe. Oceans and other large water bodies will not be spared either with the ongoing destruction of the ozone layer. Tiny and microscopic organisms e.g. the plankton may fail to survive which in effect implies that all other animals above the plankton in the food chain would definitely die out. Depletion of the ozone layer could also lead to climate changes leading to changes in wind patterns and in turn affecting other ecosystems including forests, deserts and other vegetation cover ( HYPERLINK httplibrary.thinkquest.org26026Environmenta_Problemsenvironmental_problems.html httplibrary.thinkquest.org26026Environmenta_Problemsenvironmental_problems.html ).
Ozone depletion is also associated to various forms of skin cancer in humans. This is attributed to the fact that exposure to high levels of ultra violet radiations destroys the skin cells DNA composition thus increasing the risk of contracting skin cancer (non-melanoma or melanoma cancer). Immuno-suppression is said to be caused by ozone depletion since the Ultra Violet (UV-B) emissions have the overall effect of damaging the immune system of both animals and humans (Nilsson, 1996). More health dangers and illnesses such as Cataracts and blindness will arise since increased exposure to the UV-B radiations have the ability do distort the proteins and other cells within the eye.
Studies have been conducted by many scientists to establish the relationship between crop yields, ozone depletion and effects of increased exposure to UV-B radiations. Results of such studies have in the recent past indicated that increased exposure to UV-B radiations to plants has the effect of decreasing the crop yields (Nilsson, 1996). Critics of this postulation may however argue that certain plants have a natural mechanism that shields them from ultra violet damage.
There are several strategies that could be adopted with an aim of reducing air pollution and the dangers associated with climate change. Some of the measures could heavily rely on individual discipline and regulation of government policies in order to yield results. Some of the strategies may include restricted use of un- roadworthy vehicles, use of alternative means of transport such as cycling, walking or use of public transport. At domestic level, use of environmentally friendly energy appliances such as gas cookers in place of charcoal burners, fluorescent tubes instead of ordinary incandescent bulbs may also play a critical role in minimizing air pollution. Planting trees and implementing laws that illegalize deforestation may also come in handy in ensuring clean environment.
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