According to the WHO , climate change is expected to cause about 250,000 additional deaths per year between 2030 and 2050. When we think about climate change, we usually think about temperature rise. However, the frequency and intensity of extreme temperatures has also increased. Studies have found that difference between daily minimum and maximum temperatures was an independent risk factor for mortality. Sudden temperature change might cause extra environmental stress which can lead to adverse effects on health, especially to people with pre-existing conditions.
In a study we recently published, the authors sought to investigate whether a sudden temperature change between neighbouring days had significant impact on morality in the town of Maanshan in East Anhui Province of China). The study recorded daily death counts, causes of mortality as well as daily meteorological data from 2008 to 2012. There were 8,111 deaths during this period. The mean temperature was 17.75 degrees Celcius (max. temperature -12.5 to 13.8, minimum temperature -13.2 to 8.7).
The main results of the study can be summarised as follows:
– Large temperature drops between neighbouring days were found to be significantly linked with decreased non-accidental and cardiovascular mortality
– Temperature increases, on the other hand, were associated with elevated risk of mortality from non-accidental and cardiovascular diseases.
– People with cardiovascular diseases were more vulnerable to temperature changes compared to those with respiratory diseases.
– Males and people over 65 years of age were more likely to be affected
These results highlight the importance of focusing on sudden temperature change and not only temperature rise.
* *This study was written by Jian Cheng, Rui Zhu, Zhiwei Xu, Xiangqing Xu, Xu Wang, Kesheng Li and Hong Su