Light pollution is harmful to our health!

As the nights became brighter, the list of health problems associated with artificial lighting became longer: from insomnia to cancer.

It was only a moment in the history of mankind when people spent nights in the dark, doing housework in the moonlight, by the light of a fire or, much later, with kerosene lamps. Today, about 80 percent of the world's population faces a high level of illumination at night: from bright street light bulbs to lamps and screens in homes. Scientists are increasingly aware that excessive light pollution can have serious health consequences: from poor sleep to breast cancer, stroke and other diseases.

The full scale of the problem and who is most susceptible to it is not yet clear. Scientists know that just as artificial light disrupts biological processes in the wild at night, it similarly affects the circadian system in humans.

(These fish eggs don't hatch. The culty? Light pollution.)

"Most of human evolution consisted of bright days, dim evenings and dark nights, and we really changed the difference. Some people will be satisfied with this, but others will not," says George Brainard, director of the light research program at Thomas Jefferson University in Philadelphia.

Outdoor lighting has increased significantly in recent decades. In recent years, well-lit areas have become brighter by more than two percent per year. Here's what we know about its impact on health and what you and your community can do to avoid it.

How does light pollution affect the body?

Several mechanisms can explain the effect of artificial light on health. At night, light can cause insomnia, which in itself is a risk of developing many diseases. It also reduces the body's production of melatonin, a sleep hormone secreted by the pineal gland in the dark, which has anti-inflammatory and antitumor properties. And this interrupts the daily cycles of the community of microbes living in the intestine.

The eye perceives light through rods and cones of the retina, as well as specialized neurons called retinal ganglion cells, which are light-sensitive by nature. These nerve cells synchronize circadian rhythms, promote the release of melatonin and interact with neurotransmitters throughout the brain.