The term light pollution is causing controversy because the community does not agree with its definition.
On the one hand, light pollution is defined as artificial light that degrades the ecosystem or the natural environment.
On the other hand, there are those who define it as the emission of artificial light at night at an inadequate intensity, direction, spectral range and time to carry out activities in the area where such lights are installed.
The main difference between these definitions is that with the first one (it is the scientific definition) all night lights cause light pollution and with the second one (it is the definition used in engineering) only those that are installed incorrectly do so.
In WellWo, we explain the possible consequences, how it is measured and its possible solutions.
What are the consequences of light pollution?
Society is still not sufficiently aware of the consequences of this type of pollution. There are many and they can be serious, that’s why it’s so important that we learn what they are and what we can do to reduce their impact. Here are some of them:
- A lot of energy is wasted and CO2 gases are emitted.
- It affects nocturnal ecosystems, alternating animal life. It causes changes in the environment and pests, because the animals are forced to move to other places where they can carry out their life without alteration.
- It can affect people’s health.
- It makes air and sea traffic difficult, but it also makes the work of astronomers difficult because it prevents them from observing the sky under the right conditions. It also makes it difficult for people who want to observe the stars.
The consequences of light pollution are not only where the source of the light is, but also extend for hundreds of kilometres.
How is light pollution measured?
Light intensity is measured in magnitude between arcsecond squared (mag/arcsec2). For example, a very dark night will have a maximum of 22 mag/arcsec2. If there is moonlight illuminating the sky, it will be 18 mag/arcsec2. In areas where the population is concentrated, it can be 17, that is, 100 times brighter. Imagine the consequences of sleeping under a light 100 times more powerful than it should be.
In Spain, the Valencian Community has the most light pollution, Madrid, Murcia and Cantabria also have a problem with night light.
Possible solutions to prevent or reduce light pollution
The aim of these measures is to regulate the lighting installation in cities so that light is emitted efficiently. Avoiding the pollution and that they illuminate what they have to illuminate without damaging the environment.
- Focusing the light so that it is directed only where it is necessary and preventing it from being scattered above the horizontal.
- Using low-polluting and more efficient lamps. For example the VSBO (Low Pressure Sodium Vapor) or VSAP (High Pressure Sodium Vapor), adapting their power to the use that we are going to give it.
- Try to illuminate only the areas that need to be illuminated, that the light goes from top to bottom and that it does not leave that area.
- Adjust the level of light output to those recommended by official bodies.
- Ornamental light signs, monuments and billboards should be turned off. They are one of the main sources of light pollution.
- The use of light cannons, spotlights or any device that emits light directly into the sky should also be prohibited.
- Turn off light signs that are not necessary, lower their intensity when there is less activity, or implement selective switching off.