Year-round daylight time will cause 'permanent jet lag,' sleep experts warn in letter to government

A group of sleep experts have sent a letter to the provincial government asking itto stand down on paving the way for permanent daylight time in the province.

On Thursday, the B.C. government is introducing legislation that gives the province the power to usher in the change sometime in the future.

The letter, signed by six experts in sleep and biological rhythms, advises the government against the decision, saying it could have adverse long-term implications for public health and safety.

The letter says if daylight time is kept year round, the sun will rise later in the winter, leading to decreased exposure to morning sunlight, which humans need to wake their internal biological clock.

It notes that when exposure to morning sunlight is reduced, it makes it harder to wake up in the morning and more difficult to fall asleep at night.

The letter says sleep deprivation can lead to mental and physical health problems and increase risk of vehicle and workplace accidents. In December, the sun will not rise until around 9a.m. in southern B.C. and later further north if daylight time becomes the norm.

"It will be permanent jet lag," said Myriam Juda, a researcher at Simon Fraser University's Circadian Rhythms and Sleep Lab, on CBC's The Early Edition.

Juda said it might seem appealing to have more light exposure in the evening, as will happen with permanent daylight time, but said it will cause increased fatigue and decreased morning productivity.

Children will be particularly affected, Juda said, explaining that they would be woken up earlier when their melatonin levels arehigh and sleep should not be interrupted.

Juda said inadequate sleep can affect children's developing brains and mental health. There will also be safety risks for them commuting to school in the dark for at least one-third of the school year.

Judaand the letter's other signatories say they would prefer permanent standard time, which their research says is the best option for public health and safety.

Read the complete letter asking the B.C. government to reconsider moving to permanent daylight time: