ॐ असतो मा सद्गमय ।
तमसो मा ज्योतिर्गमय ।
मृत्योर्मा अमृतं गमय ।
ॐ शान्तिः शान्तिः शान्तिः ॥
(O God, lead me/from falsehood to truth. From darkness to light/from death to immortality, let there be peace.)
‘Light’ finds deep reverence in almost all cultures and civilizations around the world, as symbolising knowledge and wisdom, whereas darkness or absence of light is considered synonymous with ignorance. For ages, we have idolised light and demonised darkness. However, the time is ripe for us to realise that light is not always good and that darkness is not always bad. Wondering what the reason is behind this philosophical re-calibration? It’s ‘light pollution.’
Defined as unwanted or excessive artificial light in our surroundings at night, light pollution is one among many modern-day forms of pollution. Mostly observed in densely-populated, affluent and industrialized cities, it is now entering semi-urban areas at an alarming rate. While light pollution has already started affecting the ecosystems and human health, there is very little awareness of this environmental hazard.
Light pollution manifests itself in various forms, affecting different components of the environment in different ways:
- Night sky: The most popular understanding of light pollution comes from ‘sky-glow’ seen over the mega-cities around the world at night. Sky-glow is the phenomenon in which the night sky does not appear dark but instead displays hues of dawn or dusk. It results from excessive bright artificial light from the cities diffusing into the atmosphere above. Sky-glow severely affects sky gazing, with fewer than a dozen stars visible in the night sky.
- Animals and birds: Light pollution creates confusion about time/period of the day/night among animals and birds alike, affecting their daily routine. Nocturnal creatures suffer the worst as light pollution disturbs predator-prey relationship, driving many of them into extinction. Night-migratory birds when flying over the cities get confused and distracted from their paths.
- Human beings: Light pollution affects us in outdoor as well as indoor environments. Streetlights and advertisement panels contribute the most to outdoor light pollution. Also, the excessively bright headlights of the vehicles on roads add to our worries while driving. Light from high-mast floodlights, installed in playgrounds and gardens, often intrudes adjoining residential areas causing sleep deprivation to fellow residents.
Most of us are now aware that persistent exposure to bright television/computer/mobile screens can damage our eyesight. However, it must also be noted that indoor ambient light of excessive brightness and poor specifications, especially during late-night hours, can severely affect the circadian rhythm of the human body resulting in sleeplessness and other psychological disorders. Students often study at night, especially during exams. While it is indeed an encouraging sight, it must be ensured that their health and well-being aren’t affected due to the use of light for long hours.
While it is true that light pollution is still in its infancy, efforts towards its mitigation must start early lest the situation runs out of control, as has happened in case of air and water pollution. Fortunately, light pollution can be reduced by some simple and inexpensive interventions like minor design modifications and standardising the specifications of light sources. But, the first and the most important step in this direction is awareness.
Recently, we all celebrated Diwali, a ‘festival of lights’ with much fanfare. Considering the impact that ‘light pollution’ can have on our environment, if left unchecked, time is not far that one day we will have to celebrate a ‘festival of darkness’! Light and darkness are like two sides of the same coin. One cannot exist without the other. None of the two should be deemed either good or bad. What we should do is study, understand and respect both light as well as darkness, equally.