2010-10-30 06:38:26
By Kate Kelland, Health and Science Correspondent Kate Kelland, Health And
Science Correspondent Fri Oct 29, 7:41 am ET
LONDON (Reuters) Putting the clocks back in winter is bad for health, wastes
energy and increases pollution, scientists say, and putting an end to the
practice in northern areas could bring major health and environmental benefits.
Countries across Europe, the United States, Canada and parts of the Middle East
mark the start of winter by ending Daylight Saving Time (DST) and putting their
clocks back by an hour -- often in late October or early November -- a move
that means it is lighter by the time most people get up to start their day.
But this also robs afternoons of an hour of daylight, and some experts argue
that in more northern regions, the energy needed to brighten this darkness, and
the limits it puts on outdoor activities are harming our health and the
environment.
Leaving clocks alone as winter approaches would allow an extra hour of daylight
in the afternoon and could boost levels of vitamin D as well as encourage
people to exercise more.
In some countries, such as Britain and Russia, politicians are being asked to
consider parliamentary bills suggesting it's time for a change.
"It must be rare to find a means of vastly improving the health and well-being
of nearly everyone in the population -- and at no cost," said Mayer Hillman of
the Policy Studies Institute in Britain, where a bill on DST is coming up for
consideration in parliament soon. "And here we have it."
Almost half of the world's population has lower than optimal levels of vitamin
D, often called the sunshine vitamin. Vitamin D deficiency is a well-known risk
factor for rickets and evidence suggests it may increase susceptibility to
autoimmune diseases.
BRIGHT IDEA?
Hillman conducted a study focused on Scotland, the northern-most part of
Britain, which found that switching to Central European Time -- to Greenwich
Mean Time plus one hour (GMT+1) in the winter and GMT+2 in the summer -- would
give most adults 300 extra hours of daylight a year.
A "lighter later" campaign in Britain has gained support from many of the
country's major sporting bodies.
Writing in the British Medical Journal on Friday, Hillman said research shows
people feel happier, more energetic and have lower sickness rates in the
longer, brighter days of summer, whereas moods and health decline during duller
days of winter.
Dr. Robert Graham of Lenox Hill Hospital in New York said leaving clocks alone
in winter should be considered to encourage people to get out more and get more
exercise.
High rates of chronic illnesses such as diabetes, heart disease and obesity are
caused in part by lack of exercise -- adults are advised to do 30 minutes
moderate or vigorous activity a day, and children at least an hour.
"As a society we are always looking for accessible, low cost, little-to-no harm
interventions," he said by telephone. "By not putting the clocks back and
increasing the number of accessible daylight hours, we may have found the
perfect one."
A study published earlier this year found that advancing clocks by an hour in
the winter would lead to energy savings of at least 0.3 percent of daily demand
in Britain.
Elizabeth Garnsey, one of the study's authors and an expert in innovative
studies at Cambridge University, said this was equivalent to saving 450,000
metric tons of CO2 during winter alone.
(Editing by Paul Casciato)