Scientists from around the world have warned this Tuesday that the excess artificial light at night it can cause negative health effects, from sleep disturbances and anxiety to increased risk of cancer.

One of the main problems is melatonin suppression, a hormone that is secreted in the dark of the night and is essential in regulating sleep, Luc Schlangen of the Eindhoven University of Technology warned during a virtual forum on light pollution organized by the UN in Vienna.

According to Schlangen, “it is necessary too little light to completely suppress“this hormone, a process that also happens very quickly.

In cities, where there is often a lot of artificial lighting at night, melatonin secretion is delayed, reducing the sleep cycle and causing a ‘jet-lag social’Since on weekends people tend to go to bed much later than usual.

This sleep disturbance can cause anxiety, emotional disorders, or obesity.

Cancer risk

According to Mario Motta, a cardiologist at the American Medical Association, there are numerous studies that associate overexposure to artificial light with the development of breast and prostate cancers.

“There are higher rates of breast and prostate cancer among people who live in environments where there is artificial light in the streets“, has pointed out.

“There are higher rates of breast and prostate cancer among people who live in environments where there is artificial light on the streets”

Motta has also explained that if you have breast cancer and there is excessive exposure to artificial light at night, cancer develops further and faster.

The problem lies in the blue light that produce LED bulbs, which are more efficient but also more harmful to health. “In medicine we have a saying: ‘do no harm’. I think lighting manufacturers should do the same,” he lamented.

Threat to biodiversity

Another unexpected victim of this nocturnal ‘overlighting’ is the biodiversity: almost half of insects and 93% of amphibians need darkness to thrive.

Furthermore, according to Sibylle Schroer, from the Leibniz Institute in Berlin, pollination cycles they can be affected by artificial light, as many night pollinators are more attracted to light sources than to flowers.

In the last ten years, the rate of increase in the power of artificial light was 2% per year, twice the rate of population growth.

According to Motta, these harmful effects derived from artificial light can be reduced with “good engineering”. Something that Schroer confirms: “Not only should the blue light be reduced but the light should be directed.”