Light has always been associated with positivity. But too much of a good thing could be bad for us! Ever since the invention of the electric light bulb some150 years ago, the artificial light has revolutionised the way we spend our waking hours after dusk. From safer streets to prolonged working hours, this artificial light has brought many such positive transformations in the history of human civilisation. But like all things in life, this too has come with a price tag which has been negatively impacting the natural rhythms of humans and animals in equal measures!
When the presence of artificial light during night time becomes excessive, obtrusive or misdirected, it leads to light pollution which could have a whole raft of problems: from disrupting the natural biological cycles of nocturnal animals and human beings to washing out starlight in the sky and disturbing astronomical researches to wasting huge amount of electricity and in turn contributing to greenhouse gases emission and climate change. The light from the street lamps and poor light fixtures on buildings for outdoor lighting could lead to light trespass, glare, over-illumination and sky glow.
Light pollution could have far-reaching consequences. In some animals, which rely on natural sources of light such as moon and stars in the night for their growth and survival, light pollution can put their lives at risk. For instance, sea turtles after hatching from their eggs on the seashore follow moonlight to make their way to the oceans. However, as the artificial light from the buildings and surrounding areas in the cities wash away the light of the moon and the turtles may never find their way to oceans and most of them end up dying. Even for humans, the repercussions of light pollution have been detrimental. The excess exposure to artificial light can stimulate the photoreceptors of the retina which may lead to a loss of eyesight. Further, light affects the production of a particular pigment called melatonin — produced by the pineal gland in our bodies — which drives our sleep cycle. Exposure of light after dusk and before bedtime can hamper the production of melatonin and that can make sleep-cycle to go haywire. Sleep deprivation leads to a host of other health problems too, some as serious as cancer!
In the United States of America, about 30 per cent of the outdoor lighting is wasted due to poorly shielded fixtures. This wastage costs around USD 3.3 billion to the US and adds 21 million tonnes of carbon dioxide gas in the atmosphere, as well. By installing quality outdoor lighting with a design aimed at improving the efficiency of the light bulb, we could help save energy and reduce our monetary loss and carbon emissions; further, the outdoor lighting should be properly shielded and directed down where the need is and not towards the sky. Use of dimmers and motion sensors too can help in scaling down light pollution. With such small but effective steps, we can all contribute toward reducing light pollution and dream for a sight of a star-lit sky.
