How light pollution is a real health issue and five things you can do to reduce it
Hong Kong’s illuminated skyline is famous, but it could be bad for your health. Parts of the city at night are 1,000 times brighter than the global average. We share tips on how to lessen the unbearable brightness of being
Our world is a brighter place – and not in a good way. According to Dr Jason Pun Chun-shing from the University of Hong Kong’s Department of Physics, whose work involves gauging the level of light pollution, Hong Kong ranks among the worst on the planet. A 2013 study by the university’s scientists found the city’s urban night sky to be as much as 1,000 times brighter than international norms.
That brightness – estimated to be growing at 20 per cent a year in some parts of the world – may be doing significant harm to our health. Eighty per cent of the world’s population has never even seen the Milky Way.
While it’s clear that light at night is important, the value of darkness – true darkness – is often forgotten. As Steven Lockley of Harvard Medical School’s Division of Sleep Medicine reminds us, it is essential to the healthy biological function of most living things – the flick of a switch interferes with mating, moving and migrating patterns.
Pun agrees, referring to light pollution as “environmental degradation, which affects the natural environment and the ecosystem”.
In humans, light at night suppresses the production of melatonin, a hormone that helps promote healthy sleep patterns and is believed to protect against tumour growth. Being exposed to light at night has been linked with increased risk for diabetes, sleep disorders, and even obesity.