- Report from University of Hong Kong studied impact of cold snap in 2016
- Author calls for better public health education for vulnerable residents
A new study has suggested jobless and unmarried Hongkongers are most at risk of dying during a cold snap, as temperatures plummet across the city.
There should be a better protocol on public health education to target vulnerable residents with these two high-risk factors, who were up to 60 per cent more likely to die when there was a drop in temperatures, the report warned.
Tuesday was officially the coldest day of the year, with temperatures dropping to 10.8 degrees Celsius (51.44 degrees Fahrenheit).
With the winter monsoon bringing cooler weather to the region, the Hong Kong Observatory predicted the cold snap would last for a couple more days, with temperatures gradually rising over the weekend.
"Even though it seems Hong Kong is getting hotter in general and we may be seeing less of a cold front, it is all the more important to have a protocol in place to minimise the health hazards for the public," said lead author, Derrick Ho Hung-chak, a research assistant professor in the Department of Urban Planning and Design at the University of Hong Kong.
Ho's report, published in Science of the Total Environment in October, concluded a particularly cold spell which hit East Asia in January 2016 had pushed up the mortality rate in the region for about five weeks.
A significantly higher daily death rate in Hong Kong occurred between January 22 and 24 in 2016. The temperature dropped to 3.1 degrees on January 24 " the coldest day for the past 59 years. At Tai Mo Shan the temperature fell to a low of 6 degrees.
There were 67 people sent to the hospital with hypothermia as all kindergartens and junior schools closed because of a lack of heating.
Studying the prolonged cold effect in 2016, researchers looked into the cause of 9,047 deaths between January 22 and March 31 in Hong Kong that year.
Cold snap in Hong Kong comes with health warning
The weekly mortality in the following 9 weeks after the cold snap ranged from 848 to 986 deaths, with an average of 911 deaths " significantly higher than around 800 deaths when compared to the same period between 2007 and 2015.
Unmarried people were 29 to 61 per cent more at risk of dying by week two to five after the cold spell, the report said.
As for the unemployed, they were 43 per cent more likely to suffer such consequences by week four.
"Interestingly, the effect of the cold wave affected these specific groups of residents across the city, and it did not restrict to which district or community they lived," Ho said.
Other factors, such as age or gender, did not seem to pose a significant risk.
These groups of residents were most likely to be at risk of dying from respiratory diseases, but cardiovascular diseases did not enhance the fatal effect.
Extreme cold could weaken lung function, leading to damage over the longer term such as lung infection.
Although the spread of flu was not included in the study, the report suggested it could be one of the causes behind the surge.
Changes in global temperature means the world is seeing more extreme weather. Although hot weather has been a global threat, cold weather events have also had considerable influence on daily mortality, especially in subtropical cities, because of a lack of adaptability of the local people and lack of preparedness, the report added.
Ho said the results could help us understand which subpopulations are more vulnerable during extreme cold weather, to establish better public health surveillance and disaster risk planning.
Hong Kong getting hotter, as climate change makes its presence felt
"Disaster education, as well as social and health services, should be provided to all local people for an extended period in order to minimise the prolonged, fatal effects from future cold waves," he said.
Almustafa Lee Lap-hong, general secretary of the Hong Kong Elderly Rights Association, believed the homeless were most vulnerable under the two risk factors, and said they should be targeted to provide help.
"The (social welfare groups) should visit the homeless people more often to deliver suppliers, such as warm clothes, blankets, food, hot water, and simple first aid tools," Lee said, who was not involved in the study.
As of 2016, there were 12.38 homeless people per 100,000 residents in Hong Kong, according to the Hong Kong Council of Social Service.
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