On Pollution by Light

Whenever we think or voice our concerns on pollution, rarely do we mean pollution caused by light. But the hard fact is that light pollution is pervasive and adversely affects not only human beings but all living organisms which in turn effects the larger environment.

Light pollution rarely, if ever, raises the same level of concern as air, water, or noise pollution and is generally mistakenly perceived to be harmless. A direct result is that there are few guidelines or safety standards in place in many parts of the world on what constitutes “light” pollution.

Listing the myriad ways in which light pollution affects us and our environment is interesting and quite an eye-opener of its myriad adverse consequences.

It is said that charity begins at home, so let us first try and appreciate how excessive amounts of light affects human health. First and foremost, it can cause retinal damage and it disrupts sleep patterns. Disrupted sleep patterns in turn has various psychological and physiological effects, such as, continuous feelings of tiredness, confusion, excessive anger, disturbed inter-personal relationships, headache, indigestion etc. That is one reason physicians advise that one should always sleep in a darkened room.

Moving out of our homes, we are confronted by bright lights emanating from street lights, advertising and decorative lights, oncoming headlights of vehicles, flood-lights illuminating places of tourist, commercial, or historical interest etc.

I am sure all of us have encountered being blinded by the headlights of oncoming vehicles. This is extremely disconcerting, especially for the driver, and major contributor to road accidents. It also contributes to road kills of wild animals on highways.

If for nothing other than enlightened self-interest, we should show some responsibility towards other life forms. It is well known and understood that human beings are critically depended on their well-being and survival on their natural surroundings. Unnecessary artificial illumination poses a threat to our natural environment by disrupting the natural life cycle of insects, animals and birds. Trees provide shelter to various kinds of animals, birds, and insects all of whom need the night cycle as much as they need the sun.  Excessive street light confuses and changes their behaviour patterns.

Bright lights disrupt animal navigation at night and is a significant threat to migratory birds. Birds are often unable to migrate when confronted with light pollution, because they get disoriented, fall prey to predators and travel the wrong way, among other things. This should worry us, because India offers important pathways for migrating birds. It also induces changes in their natural behaviour patterns and is confusing for night pollinators.

At the 13th Convention on Migratory Species in Ahmedabad, in 2020, it was recognised that “artificial light is an emerging issue for the conservation of wildlife, astronomy and human health and it adversely affects many species and ecological communities by disrupting critical behaviours in wildlife, stalling the recovery of threatened species and interfering with a migratory species’ ability to undertake long distance migrations integral to its life cycle”.

With various state governments deciding to facilitate nightlife in our cities and towns in their pursuit of “development”, there has been a steady increase in the use of artificial lighting which is an additional source of light pollution.

At present, there are no international or national guidelines to curtail light pollution. Doctors said the amount of light the human eye can adjust to and finds useful is between 400 and 500 microns. However, the current LED lights or those installed on advertising hoardings and even some street lights are well beyond 500 microns.

Researchers say that the growing transition from high-pressure orange sodium lamps to energy-efficient and cost-saving white Light Emitting Diodes (LED) for street lights has become counter-productive since governments are installing more LEDs which in turn are making the skies significantly brighter.

While everybody would agree that some amount of artificial lighting is essential to ensure the safety of citizens, the question arises as to how much is excessive lighting. Moreover, from a climate change perspective too, excessive use of artificial lighting is not only a waste of energy, but also contributes to global warming.

The big question is therefore how could we contribute to the serenity of our beloved County by reducing light pollution within our campus.

Written largely based on inputs by my dear friend Vijayvardhan Reddy, to whom I am eternally grateful for introducing me to this very important subject.