Skip to main content

Why night light pollution is bad for health

Why is sleep important?

Sleep plays an essential role for health and well-being. Short sleep and poor sleep quality can affect mental health, learning, memory, and performance at school and at work.

Sleep disturbances are frequent in both children and adults. In adulthood around 30% of people suffer from disturbed sleep. The most common sleep disorder in adulthood is insomnia, which is defined by symptoms such as difficulty falling or staying asleep at night.

Sleep duration has decreased by more than 1 hour in the last 100 years. This is paralleled by an increase in stress and mental health problems, particularly depression.

What is the role of light for sleep?

Light is an important environmental cue for our biological clock. Light “sets” our biological clock. When we are exposed to light in the evening or at night it can disturb sleep. In particular, exposure to blue light in the evening delays the secretion of melatonin. Therefore, exposure to screens in the evening can disturb our sleep. However, for vulnerable people light pollution may also disturb sleep.

Dr Sakari Lemola, Assistant Professor, Psychology

If you would like to interview Dr Lemola please get in touch with

Nicola Jones, Media Relations Manager 07920531221 or
N.Jones.1@warwick.ac.uk