Light has always been associated with the positive side of life. Even today it continues to be the same but merely as a saying. As a fact, it has now become a source of pollution. Light pollution is one of the latest members in the large family of types of pollution. Light pollution can be largely defined as alteration in the levels of natural light due to human interference. Use of excessive and inappropriate lighting is termed as light pollution.
Light pollution can be attributed as a side-effect of our present day lifestyle. Apart from the normal illumination needed inside houses and offices, exterior lightings, commercial lightings, street lights, sport complexes, factories are the chief reasons for this kind of pollution. It consists of issues like over illumination, sky glow, glare and light trespass. These all not only lead to energy wastage but, also have ill effects on human and animal life.
Over illumination refers to excessive use of lighting i.e. even at places where it is not needed. Using outside lights even in the day time, keeping offices and other official buildings illuminated overnight, neglecting the possible use of sunlight in the interiors and so on. Not only does this lead to higher cost bearing by the owner but is also a health hazard. People who have been constantly exposed to the conditions of over illumination have been reported to have faced health issues such as headaches, fatigue and anxiety. Better planning at the design stage by using good architectural designs may help.
Sky glow refers to the glow or illumination that appears in the sky above highly populated areas. It appears partially due to light reflected from the ground and partially due to badly directed light in the area. This glow causes obstruction for the astronomical observations. Even the brightest of stars become difficult to spot as contrast between the stars and sky gets highly reduced. Using lighting fixtures which reduce reflection of light upwards or sideward might help. Cutting the excessive usage always helps though.
Decreased visibility in the night, entering of light in areas where it is not needed and disturbing the natural night landscape is also a part of light pollution. The world energy consumption has been highly increased due to the factors leading to light pollution. Apart from stress, fatigue and anxiety, people working in the night shifts have been reported to be at a higher risk of increased blood pressure as well as some types of cancer. It also leads to the impairment of normal night vision. Animal life has also been highly affected by this kind of pollution. Many ecosystems contain missing food chains as a result. Migratory birds are disoriented due to lights on tall structures which is fatal for most of them.
The lifestyle that we people have adopted is, undoubtedly, quintessential for our existence. But, a little bit of sense of responsibility can help in a great way. The intensity of light maintained at a place should be kept to minimum required. A timely check should be kept to switch off the lights when not in use. Even sensors can be employed to automatically turn off unused lightings. The lighting plans in the buildings should be revised in order to minimize the light pollution. Although all these measures require an extra human effort, yet the results are also for the sake of a safer and better human existence.
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