We work by day and sleep at night; except when we don't or can't. And right now, about 30 per cent of Canadians work well into the night when many of them would rather be asleep. They are nurses, emergency room doctors, oil-rig workers, miners, autoworkers, office cleaners, police officers, prison guards, factory workers, salespeople and service personnel. They all face rotating shift work – and the problems that this causes.
One of these problems is called “light pollution,” and it is caused by exposure to a proliferation of artificial night light.
A growing concern
There is mounting evidence that such pollution not only affects human health but also the health of the entire planet.
Night workers are exposed to light when their bodies expect darkness. This causes changes to their circadian rhythm, which governs the natural rise and fall in body temperature, respiratory rate, urinary excretion, cell division and hormone production.
A circadian rhythm that is out of sync can lead to things such as chronic fatigue or jet lag. Other health effects include an incidence of peptic ulcer disease, which is eight times that of the general population, and increased cardiovascular mortality. These are documented in a policy paper developed by Dr. Harold Thomas, chair of the wellness section of the American College of Emergency Physicians.
Other research points to an increased risk of breast cancer, a risk that grows the longer a woman works at night. Why there's an increased risk is open to research, but many in the field theorize that it's the artificial light at night that is to blame.
