Circadian rhythm, also known as the biological clock, basically governs the biological processes of life on earth, including humans. Our biological clock syncs with the world outside our body in order to control the inside processes including melatonin, which suppresses cancer. Interestingly, we produce this hormone when blue spectrum light enters our eyes. In other words, we need some darkness to maintain basic processes such as melatonin secretion.
It’s not only humans who aren’t able to enjoy the beauty of the night sky due to the city’s light. They also increase their chances of having cancer.
Cancer epidemiologists have conducted a number of observations of night shift workers as well as nurses and airline crews, noticing that breast cancer for women and prostate cancer for men have increased their chances of survival, decreasing humans’ lives. Additionally, depression, weight gain, slower thinking and impulsivity have been detected in animals which were exposed to more light and as a result, lacking melatonin.
As much as we need clean water, therefore invest in wastewater treatment industry, we need a good and dark night of sleep in order to survive. Many people cannot sleep without a table light being on. However, while they think they cannot sleep without light, they potentially shorten their life span.
Two thirds of our planet’s population lives under light-polluted sky. For example, in Australia there are over 1.94 million public lights installed all over the continent. While we rely on light so much, affecting our health there are also other disruptions of the light pollution.
It’s a problem when there is so much light almost everywhere that we cannot see the sky and struggle with space observation. It is clearly beneficial for the humankind to be able to keep an eye on cosmos.