Ultra Violet Radiation And The Ozone Layer
Ultra- Violet Radiation is that part of the sun’s light and energy which causes some adverse effects to human beings if they overexpose themselves to it. It is generally not visible through human naked eyes. It is divided into three regions according to the wavelength and energy emanated by each. There is the near ultra violet (NUV), the extreme ultra violet (EUV) and the far region (FUV). The near region is also abbreviated as UV-A, while the extreme region is also abbreviated as UV-B, and the far region as UV-C. These regions are divided depending on how long or how shorter the wavelength is, and the shorter the wavelength the stronger and damaging it is to the living things in the earth. The wavelength is measured in nanometers. The UV-A lies between 320 and 400 nanometers, the UV-B lies between 280 and 320 nanometers and the UV-C lies between 200 and 280 nanometers. Hence, the UV-C is the strongest and the most adverse to the earth.
The shorter the wavelength the more it causes damage to the earth if it reaches there. These effects are harmful to the living things in the earth, especially if human beings overexpose themselves to it. Fortunately enough, UV-C rays are absorbed by the ozone layer and hence have never reached the earth. The UV-A rays are not absorbed by the ozone layer and hence they reach the earth in a very large quantity that has continued to affect the earth, though compared to the UV-B and the UV-C it causes the least damages. Ultra Violet is of help to the people if it is small quantities because it helps in generating vitamins needed by human body. (Bogue, 1998) says that, URV is the strongest electromagnetic radiation.
The adverse effects of the UV are that, it causes extremely great and prolonged health effects on the skin. It can also cause sunburns, which is medically termed as ‘erythema’. Overexposure causes the body cells, body tissues and blood vessels to deteriorate in the long term. The very most serious effect of overexposure to the UV is that it can cause cancer of the skin. There is also the cataract that can be caused by the UV. A cataract is a clouding around the lens of the eye that may cause visual degradation and can also lead to blindness. (Anonymous, 2009).
(Sid, 2005) indicates that, the ozone layer is the most helpful in blocking the UVR from reaching the earth’s surface. However, it only absorbs the shortest wavelength which is the UV-C, but it is not able to absorb the longest wavelength which is the UV-A. Therefore, the largest quantity of the UVR that reaches the earth is that emanated by the nearer ultra violet radiation, especially in summer time and at midday when the sun is very hot. Hence, though the ozone layer has played a very major and helpful role in absorbing some of the radiation, it is not able to prevent the longest wavelength. Man on the other side, has contributed in damaging the ozone layer, through his adverse activities that have gradually damaged the ozone layer, for example, the release of harmful gases such as carbon monoxide. It is feared, overtime the ozone layer will not be unable to absorb even the UV-A.
As a measure to prevent overexposure to ultra violet, the public should avoid sun-bathing or sun basking for longer hours and especially between when the sun is very hot, that is, at midday. The strongest UV rays reaches the earth at around 11am and 3pm; hence, it is advisable to avoid the sun between these hours. It is also important to avoid both direct sunlight and reflected sunlight. Reflected sun light is such as that reflected by water, snow, sand. Wearing long sleeved clothes for the skin and hats for the head and the eyes can be other preventive measures. This helps in blocking direct sunrays to the skin, the head and the eyes that can cause damages and other long term effects such as discussed above. There is also the need to plant many trees that will offer shade where people can shelter when the sun is very hot. Man made shades can also be set up in places such as the bus stops.
The information on this issue can be given out to the members of public through open forums held in social centers and through the public health department website.
|Anonymous. (2009). Climate-Warming-Ozone-UV. Financial Post. Emerald.|
Sid, Perkins. (2005). Ozone Hole Might Not Recover Until The Year 2065. Emerald.
Robert, Bogue. (2008). Sensing With Electromagnetic Radiation: a review: Short