How to Overcome The Health Risks Associated With Light Exposure at Night

Almost all forms of life on earth depend on light from the sun for energy and growth. In the natural world, sunlight dictates when animals wake up and when they go to sleep and when plants photosynthesise and when they rest. However, in the modern world, humans are no longer bound by the cycle of night and day in the same way that other living things are. Indeed, in towns and cities across the world, people take for granted the ability to use artificial light to create ‘daytime’ at night.

The advantages of artificial lighting are obvious

Manmade lights are important for road safety, personal security against criminal activity, and evening and nighttime social and commercial activities. Artificial lighting enables businesses to stay open later than ever before and a variety of important industries, such as health, transport and engineering, rely on artificial lighting to keep people alive and on the move during the night time period.

Artificial outdoor lighting is also taken for granted in many towns and cities, allowing people to travel great distances after dark and enjoy evenings out without feeling vulnerable to attack.

Human desire for convenience has created cities full of 24-hour supermarkets and round-the-clock trains and buses. Such conveniences depend on artificial light sources to operate. In short, manmade light could be said to have changed human behaviour, enabling people to carry on doing at night what they do during the day.

Despite the obvious benefits of artificial lighting at night, it has been recognised for some time that there are drawbacks too. By taking away the darkness of night, we trick living organisms into thinking it is daytime, which disrupts normal physiology and the production of melotonin (a hormone which is present in all living things and is known to protect the human body from the proliferation of human breast cancer cells).

In fact, the American Medical Association (AMA) has recently adopted recommendations based on a report co-authored by a University of Connecticut researcher, which asserts that excessive light – including light from televisions and other electronic media – at night can have a serious effect on health, and is linked to sleep disorders (especially in children and teens) and even cancer. Other studies suggest a correlation between exposure to light at night and weight gain, although further research is required to confirm this.

Although, ideally, it is recommended that people spend their nights sleeping in complete darkness, we recognise that this is not always feasible. During the winter months, for example, many people living in the UK get home from work and school after dark and depend on artificial lighting to help them cook and eat food, do homework and enjoy socialising with friends and family. For many other people, such as hospital and factory night shift workers, night is a time when they have to get up and go to work. To reduce exposure to light at night however, it is advisable to invest in dimmer switches and to use red lights where possible.  

http://articles.courant.com/2012-06-20/health/hc-light..board-member

http://www.huffingtonpost.com/2012/06/22/light-night...5.html

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/228832/9780108508547.pdf