What is light pollution?
This is a problem that mainly affects cities and occurs when the level of light in the night environment is increased, a product of artificial lighting. This is generated when the light is not efficiently directed to illuminate the ground or buildings, but is dispersed towards the sky, affecting the possibility of seeing the stars and the night sky. This type of pollution has negative impacts, both for astronomical observation, and for people's health and biodiversity.
It is a global problem, which especially affects cities, but not exclusively. It is also one of the main factors that threaten quality for astronomical observation of the northern skies of the country.
Light pollution has as its most obvious manifestation the increase in the brightness of the night sky, by reflection and diffusion of artificial light in the gases and particles of urban air, so that the visibility of stars and other celestial objects is diminished.
The clearest manifestation of light pollution is the brightness or luminous halo in the sky, due to the dispersion (sky glow), which added to the spectral range and its intensity, can generate various impacts that include biodiversity, quality of life and people's health and also sustainable development.
Light pollution always involves a waste of light, either because:
- The objective is not illuminated: ground, construction, etc. and therefore the light escapes or disperses to the horizon or to the sky directly.
- It deals in unnecessary moments or in the unnecessary amount.
- It is emitted in a spectrum not useful for human vision, but which affects other living beings or activities such as astronomical observation.
Light pollution in the northern zone of Chile
The privileged conditions for astronomical observation of the northern part of Chile are increasingly at risk, due to the urban growth of the cities near the observatories. In the presence of emission lines from artificial light sources, observatories require more exposure time to perform spectroscopy 8 of dim objects.
Although since the late 1990s the country has sought to protect the quality of the skies through emission regulations, as well as through guidelines on outdoor luminaire installations, it has been necessary to increase these regulatory requirements, in order to ensure the care of this heritage.
The importance of astronomical observation for scientific progress has brought to the fore the places that still have the conditions to develop this work.
In this context, the idea of the International Astronomical Union (IAU, for its acronym) emerged at the 2007 light pollution conference in La Palma, Spain in English), to apply for astronomical sites as a World Heritage Site. This, given the impossibility of registering the "skies" for astronomical observation as part of said heritage.
Subsequently, the World Heritage Committee of UNESCO, at its 34th meeting held Brasilia (Brazil 2010), approved the study on the Astronomy and Archeological Astronomy Heritage Sites, prepared in the framework of the International Year of Astronomy 2009. This study identifies certain places in the world as astronomical heritage, among which are the North of Chile, the Canary Islands, Hawaii and Namibia, referred to as "Windows of the Universe".
In this context, the International Astronomical Union created the World Heritage Commission, which seeks to promote the protection of some of the most important astronomical observation sites. In August 2015, during the XXIX General Assembly of the International Astronomical Union, the participating countries were summoned to coordinate efforts to carry out this initiative. On that occasion, Chile announced the creation of a “Windows to the Universe” worktable, as a focal point of this international initiative. Likewise, during the assembly Chile was elected as Coordinator of the World Network of Astronomical Observatories of Patrimonial Value.
DS43. aka. Regulation of Light Pollution (D.S. No. 43/2012) / Dark Sky Compliance
Since 1998, Chile has an Emission Standard for the Regulation of Light Pollution, which applies to the Antofagasta, Atacama and Coquimbo regions.
This standard seeks to avoid the emission of light to the sky and promote the use of technologies that do not emit in the spectrum that is not useful for the human eye and that hinders astronomical observation. In 2012, the revision of this standard was promulgated in order to establish greater requirements, expand regulated sources and include new lighting technologies (DSN ° 43/2012 MMA).
The DSN n° 43/2012 is effective as of May 4, 2014. This rule restricts the emission of radiant flow to the upper hemisphere, in addition to restricting certain spectral emissions of the lamps, except for specific applications that are expressly indicated.
The emitting sources are the lamps, whatever their technology, that are installed in luminaires, in projectors or by themselves, that are used in what is called Outdoor Lighting.
Also included are notices, light signs, projectors or other lighting devices that may be moved while operating, and the like. The lighting produced by the combustion of natural gas or other fuels, vehicles and emergency lights necessary for public safety are not considered as outdoor lighting.
Regulated sources (luminaires) must have a certification, issued by a laboratory authorized by the SEC, Chile.
Sources installed as of May 4, 2014 must immediately meet the new requirements. On the other hand, the sources existing before the entry into force of this standard (that is, that were installed before May 4, 2014), have a period of 5 years to initiate compliance with the regulation, which means that as of May 4, 2019 the standard will be enforceable for all regulated sources in the regions of Antofagasta, Atacama and Coquimbo.
The supervision of the norm is carried out by the Superintendence of the Environment.
In the world
Switzerland and France turn off street lighting to warn of light pollution
Municipalities of Switzerland and France, in the Greater Geneva area, did not turn on their street lights and around 900,000 thousand people had the opportunity to see the stars again and enjoy the night landscape and its biodiversity.
The initiative called the Night is Beautiful, organized by the Great Geneva, the Natural History Museum of Geneva, the Astronomical Society of Geneva and the Maison du Salève in Présilly, he joined 152 communes of the Cantons of Geneva, Vaud and France. To this initiative, some companies and private institutions adhered, which turned off lights of luminous or ornamental signs, in order to contribute in this search of the night and show the population the problem of light pollution and its impacts on the environment and in people's health.
Although the darkness was not total, due to the illumination of shops, restaurants and buildings, the lack of street lighting allowed to arouse the reflection on the amount of light that illuminates the night and put into discussion the problem of light pollution.