LED consumes less energy than traditional HID lamps, which should reduce greenhouse gas emissions. But at the same time, LED lighting threatens the health of residents and destroys local ecosystems in cities and villages.
0000 1 December 2013 Researchers from Belgium and neighboring countries, blue fluorescent lamps and mercury vapor street lamps
University of Exeter (England) studied the spectrum of night lighting in Europe and came to a disappointing conclusion: converting street lamps to LEDs does not seem to justify their environmental wiseness. Artificial light becomes bluer, which is worsening the quality of sleep in humans and the reduction in insect populations at night. Therefore, environmentalists wrote in the journal "Scientific Advances " that the accumulated harm exceeds the benefits of energy saving.
Since 2014, many European countries have been actively introducing street lighting using white LEDs instead of the previous sodium and fluorescent lamps. Such LEDs generate 200-300 lumens of light output per watt of energy, while sodium lamps produce 100-150 lumens per watt, while fluorescent lamps produce only 50-100 lumens per watt ( incandescent lamp : 12-16 lumens per watt). Meanwhile, LED resources reach 100,000 hours (usually 300,000-50,000 hours), while sodium lamps are 160,000-180,000 hours and fluorescent lamps are 100,000-20,000 hours (incandescent lamps can work about a thousand hours).
Because of this, LED lamps are much cheaper to run, although the LEDs themselves are usually more expensive than gas discharge lamps. High energy efficiency reduces the demand for lighting energy, thus reducing greenhouse gas emissions from power plants. This is completely in line with Europe's route toward "green" energy and climate change.
However, the spectrum of the white LED changes from yellow (characteristics of sunlight and gas discharge lamps) to blue. Research shows that this is not very good. blue light inhibits the production of melatonin, which is responsible for the sleep-wake cycle (circadian rhythm) in humans and animals. Naked Science reported on this, for example, here. Furthermore, LEDs strongly attract insects, preventing them from finding food and breeding partners.
From 2012 to 2020, the nocturnal light of European cities shifted to the blue part of the spectrum
British ecologists decided to evaluate the scale of the problem and analyzed the night lighting spectrum of European cities obtained with the help of International Space Station . They clearly show that due to sodium lamps, street lights in European cities were mainly white and yellow in 2012-2013. From 2014 to 2020, the spectrum of urban and rural light has indeed turned blue. The strongest are Italy, Romanian , Ireland , Spain and the United Kingdom, causing the decline in melatonin production in people and animals in these countries. While most street lamps in Austria and Germany still use sodium lamps with yellow light.
Newcastle University ecology and conservation professor Darren Evans was not involved in the study, but confirmed his colleagues' concerns. His own work shows that the number of nocturnal animals in British cities has dropped drastically, where more than half of the street lights are powered by LEDs. This will disrupt the food chain and potentially completely reshape urban and rural ecosystems. According to Darren Evans, the British authorities did not well predict the consequences of switching to white LED lighting. Especially for the health of those who sleep worse and suffer more often from blue street lights.
Ecologists provide several ways to solve this problem. For example, you can dim the lights at night. Or change the bandwidth of the LED lamp to make the emission spectrum return to the yellow area. Some British cities do this, and according to Darren Evans, the practice should be extended to other regions and countries.
