Artificial light is an integral part of our daily lives. It allows us to function after dark, extends the day and improves safety. But over-intensive or poorly designed lighting can do more harm than good.

Light pollution is a phenomenon that is still not talked about enough - and it affects our health, environment and quality of life.

What exactly is light pollution?

This is a problem that affects the night. When there are too many sources of artificial light in an area - usually urban - it starts to disrupt the natural rhythm of day and night. This is when we speak of light pollution. This is most often the result of the ill-considered positioning of infrastructure - for example, lamps that shine too brightly, unshielded light sources or lighting directed upwards.

In Poland, we do not yet have legislation to regulate this problem. It is a global phenomenon that is increasing year on year - especially in densely populated and well-developed areas.

Negative impact on human health

Sunlight regulates our diurnal rhythm. When external lighting is too intense, our biological clock stops working properly. Artificial light, especially blue light (present in screens and many LED lamps), interferes with the production of melatonin, the hormone responsible for sleep. As a result, we do not feel the night, which leads to sleep problems, insomnia and sleep disorders. The long-term effects of light can lead to a deterioration of mood, as well as the development of lifestyle diseases such as depression.

Negative impact on animals and plants

Animals and plants have lived in harmony with the rhythm of day and night for millions of years. However, light pollution also has an adverse effect on them. Birds migrating at night often mistake city lights for stars, causing them to crash into buildings. Young sea turtles, instead of heading towards the ocean, head towards street lights. Insects attracted by artificial light die en masse by the lamps. Constant lighting also disrupts the natural rhythm of plants, affecting the length of growing seasons and flowering time.

A problem with astronomical observations

Light pollution is a major challenge for astronomy. The light emitted by cities and other sources of artificial lighting significantly hinders astronomical research. As a result of this phenomenon, astronomers have fewer and fewer opportunities to observe the cosmos. Even in places far from cities, their lights effectively interfere with visibility, making the sky almost constantly bright.

Light pollution is not just a problem for scientists, however. Fewer and fewer people have the opportunity to see the Milky Way with the naked eye. According to the 2023 Light Pollution Think Tank (LPTT) report, giving data for 2022, light pollution is intensifying in Poland. In 2022, the night sky was on average 147 per cent brighter than the natural one, and for 20 per cent of Poles it was too bright to feel like a real night. Moreover, there is no place in Poland that is completely free of pollution. The darkest sky is in the Bieszczady Mountains, but even there it is not completely free of light.

How can this phenomenon be combated?

Light pollution, especially through poorly directed lighting, is not only an aesthetic problem, but also a financial and environmental one. Cities spend millions on lighting that does not always do its job, lighting up spaces unnecessarily rather than areas that need lighting.

This is a problem that can be tackled effectively. The key is to manage the light wisely - its direction, intensity and timing.

Above all, it is worth using appropriately designed lighting that directs light only where it is needed - usually downwards. Warm coloured light is less harmful to the environment and human health. It is also a good idea to use motion sensors and limit the duration of lighting - both in private and public spaces.

Is anything being done in Poland to reduce light pollution?

In 2023, the Light Pollution Think Tank published the first report describing the scale of the phenomenon. Among other things, it includes maps of sky brightness and data on light emissions in different parts of the country. This is an important step towards raising the topic of artificial lighting as a real environmental problem. The report is available at: Report - Light Pollution Think Tank.

Some local authorities are beginning to take an interest in the problem. One example is Poznań, where the city council has addressed the problem of excessive lighting - considering, among other things, upgrading street lamps or limiting light in public spaces.

Dark Sky Parks are also being established in Poland to protect against excessive light and allow observation of the night sky in its natural form. This is not only a tourist attraction, but also an educational example of how darkness can be protected as a natural resource.

Light pollution is a problem that has serious consequences for human health, the environment and quality of life. It is worth taking action now to reduce artificial lighting where possible. Responsible light management will not only protect our planet, but also restore the night sky in its natural form.