Scientists have conducted a study according to which the amount of blue light from artificial sources is increasing, which may have negative consequences for human health and the environment, reports The Guardian. The study itself was published by Science Advances.

Today, much of the orange radiation from old sodium lamps is quickly being replaced by the white radiation produced by LEDs. Such lamps are used, in particular, to illuminate the streets at night. This was discovered by scientists from the University of Exeter using images from the International Space Station.

Researchers believe that the increased emission of such blue light is causing “significant biological impacts” across the continent. Although LED lighting is more energy efficient and costs less, it can promote the production of melatonin, a hormone that regulates sleep patterns in humans and other organisms. Increased amounts of artificial blue light can impair people’s sleep habits, which can lead to a variety of chronic diseases over time. The study also claims that previous work on the effects of light pollution underestimated the effects of blue light radiation.

The increase in its abundance in Europe has also affected the visibility of stars in the night sky, which, according to the study, “may affect people’s perception of nature”. Blue light changes the behavior patterns of animals, including bats and butterflies, because it can change their movements towards or away from light sources.

The UK is one of the countries most affected by the transition to LED night lighting: in 2019, 51% of street lights in the UK were powered by LEDs.

Italy, Romania, Ireland and Spain were also identified as countries vulnerable to the effects of blue light radiation due to their recent switch to LED night lighting. The consequences were felt much less in Austria and Germany, where the majority of lighting is still done with old gas and fluorescent lamps.