Even moderate temperature changes can lead to death
“The risk of extreme heat and extreme cold on health is well known,” says Chen, who is also an adjunct scientist at ICES. “However, we were surprised to find that even moderate changes in temperature had an impact on death rates in Ontario, with cold weather having a greater impact.”
These health impacts were seen even on winter days when average temperatures were 0°C and on summer days when temperatures were 23°C.
“This may be particularly important for homeless people and those who live in marginal housing,” notes Copes, PHO’s chief of environmental and occupational health. “We need to change our thinking about how temperature impacts health. There may be impacts even on days when temperatures are not considered extreme and no heat or cold alerts have been called.”
· In Ontario, each 5°C change in daily temperature was associated with approximately seven more non-accidental deaths per day in winter and about four more non-accidental deaths per day in summer.
· Cold-related effects are more strongly linked to cardiovascular-related deaths, especially in people under 65 years of age; heat increased respiratory-related deaths.
· Effects from cold lasted longer – over several days – compared to effects from heat, which were undetectable the day after exposure.
· Using data provided by ICES, the researchers analyzed records of 352,818 Ontario residents who died from non-accidental causes from 1996-2010. The study was funded by Heath Canada.
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