A groundbreaking study has revealed a concerning link between extreme rainfall events and an increased risk of death from all causes, as well as from heart and lung diseases. The findings highlight the urgent need for coordinated public health strategies to address the broad health effects of climate change-driven extreme weather patterns. Climate change is intensifying the frequency and severity of short-term rainfall events, and this study provides a global perspective on the impact of these extreme rainfall events on human health.
The Impact of Extreme Rainfall
More than 34 countries or regions from six continents contributed to daily rainfall data and cause-specific, mortality records for a combined 109,954,744 all-cause deaths, of which 31,164,161 were cardiovascular-related and 11,817,278 respiratory-associated deaths between the years 1980 and 2020 in The BMJ.
For the 14 days following a day of extreme rainfall with a five-year return period (i.e., the statistical point which defines the expected interval between such events), all-cause deaths increased by 8%, cardiovascular deaths increased by 5%, and respiratory deaths increased by an astonishing 29% [9]. The discovery of this relationship has important implications for the health of many people, particularly in vital populations.
The Weight of Intense Rainfall
The health impacts of most types of extreme rainfall conditions also differed based on the regional climate and vegetation, found the researchers. Roof slopes <20% showed the least risk of death after extreme rainfall events, while locations with rainfalls not as variable or contaminated by vegetation, and vertical wall development area eaves presented the highest risks. This indicates that the threat of devastating extreme rainfall impacts could be even worse in some areas, probably as a corollary of aid damage, water pollution, and infectious microorganisms.
But the researchers also discovered that moderate to high rainfall levels could be protective, partially due to a decrease in air pollution as people stay indoors. At the same time, the likelihood of injury became significantly more probable under extreme rainfall conditions, indicating a complex connection between rainfall patterns and health.
Getting Ready for A Wetter Tomorrow: Ways To Deploy Resilience
Our results suggest a prompt action is needed to establish public health strategies to combat the pervasive health impact of such heavy rainfall events, even more so in light of the increasing frequencies and magnitudes due to climate change.
In an accompanying editorial, John Ji from Tsinghua University in China writes that it serves health professionals to act as leaders for climate action and educate about the health implications of climate change and improving local resilience. Still, he says, there is no doubt that even though there might be absolute clarity around why what we are doing to the planet is so profoundly wrong, as “people forget the lessons of scarcity in times of abundance.”
Nonetheless, too much is at stake to ignore how more-intense rainfall affects public well-being. Critical and presciently as the authors of the study point out, “This is all too relevant given the long-recognised trend for a greater incidence of short-term rainfall events, driven by climate change”. More importantly, by becoming aware and taking early precautions toward building a future that is resilient to a changing climate.
