Hongkongers with mental disorders – especially dementia – most at risk of death in extreme weather, study shows

Study of more than 133,000 deaths finds ‘strong association between temperature and mortality associated with mental disorders’

Up to 8 per cent of residents aged over 65, and up to 30 per cent of those over 80, suffer from dementia, according to the Hospital Authority

3-MIN READ3-MIN

A woman seeks protection from the sun in Tuen Mun. There were nine days with an average temperature above 33 degrees in 1976 – there were 38 in 2016. Photo: K.Y. Cheng

Published: 8:00am, 30 Jun 2019Updated: 11:54pm, 30 Jun 2019

Hong Kong residents with mental or behavioural disorders – especially those with dementia – are most at risk of dying when temperatures reach 24.5 degrees Celsius or above, a study by local universities has shown.

After studying more than 133,000 deaths recorded in the summer months between 2007 and 2014, researchers from the University of Hong Kong and Polytechnic University found that Hongkongers with mental problems have a lower ability to adapt and prepare in environmental extremes, notably the summer heat.

“We conclude that critical health care is necessary for people with mental and behavioural disorders, especially for people with dementia,” the researchers wrote in a paper published in the scientific journal Environmental Science and Pollution Research.

Lead researcher Derrick Ho Hung-chak, of HKU’s department of urban planning and design, said the study showed how much temperature affects the risk of death.

Ho said additional factors – including high urban density, scarce green space and air pollution – also increase the death rate associated with mental disorders during hot summer days.

Possibly because of climate change, Hong Kong’s weather is getting hotter and more extreme. There has recently been an increase in the number of “very hot days” at 33 degrees or above.