Excess lighting in public spaces, associated with the false idea of development in large cities and the idea of citizen security, is causing energy waste, problems in people’s health and negative effects on biodiversity, among others .
The economic growth of the last 50 years has been accompanied by the development of cities, giving rise to a new type of little-known pollution. It is about light pollution , a phenomenon that progresses silently and that is having serious repercussions.
Over-lighting and the use of inefficient public lighting systems cause light to be emitted into the sky, and airborne particles propagate photons beyond where they are needed. This pollution of the sky by artificial light is a global problem, and it has been shown to have negative effects on the economy, biodiversity, the landscape of the night sky and also on people’s health .
According to the statistics of the Ministry of Industry, Energy and Tourism, the consumption of electrical energy for lighting has increased almost constantly since the 1960s. Currently, the inefficient management of public lighting goes against the austerity policies applied by governments since the beginning of the economic crisis.
Light pollution is affecting nocturnal flora and fauna. This is the case of some species of birds that lose their way in their migratory movements , due to the disorientation suffered by the loss of landmarks during the flight. For its part, the over-illumination of coastal areas is affecting marine life.
The effects of this phenomenon on people are reflected in the alteration of the circadian rhythms and the alteration in the secretion of melatonin, which can alter the normal cellular and organic function. It has also been shown that the lack of coordination between physiological rhythms and the natural light-dark cycle can cause sleep disturbances, attention and concentration problems, and are often associated with accelerated cellular aging processes .
Astronomers were the first to warn of the problem. The artificial light that emanates from the cities alters the light that comes from the celestial stars. To counteract the effects of light pollution, astronomers use filters that block certain wavelengths and allow only the light coming from the stars to be captured . It is increasingly difficult to find a place where the luminous halo of cities does not affect the quality of the night sky.
In Spain there are several platforms that are doing very important informative work, raising awareness among institutions and the general public of the need to reduce the excessive emission of artificial light. This is the case of the Cel Fosc Association or the Spanish Network of Studies on Light Pollution, in which several universities participate.
LED bulbs
In recent years, incandescent bulbs are being replaced by LED bulbs. Although this technology is more efficient than traditional lighting systems, it is not without harmful effects. The white light emitted by LEDs can also affect human health and biodiversity. On the other hand, astrophysicists from all over the world have raised the alarm about the impossibility of blocking the light from this type of lighting by means of filters, preventing research activity.
Light pollution is a global problem, therefore, to reduce its effects, measures must be applied from different areas and jointly. The development of less permissive regulations, ensuring their compliance, the installation of intelligent lighting systems that adapt the intensity of light to the needs of each moment or the application of energy efficiency criteria are some examples of the measures that should be adopted.
Amadeo Aznar, Isaac Aznar Observatory, CAAT-Alto Turia Astronomical Center.
