Health Impacts of Flooding

by Kaylee Anderson

An effect of climate change is an increase in the occurrence of floods. Particularly, in Canada flooding is five times more frequent than the occurrence of the next most common natural disaster. In addition to the obvious risk of drowning, toxin and pathogen exposure, and stress increase during flooding. A past study by Nakamura, et al. (2012) revealed an association between acute cardiovascular disease and natural disasters, such as the Japanese tsunami in 2011. Vanasse et al. (2016) examines the effect of flooding on acute cardiovascular disease in Saint-Jean-sur-Richelieu.

Areas of flooding and control areas were assigned by using area codes. Health data were collected from Quebec Integrated Chronic Disease Surveillance System; these included hospitalizations, diagnoses, community visits, and emergency room visits during flooding years and the years before and after the disaster. Additionally, data were collected to determine comorbidity, which was used to adjust the collected data about cardiovascular disease (CVD) and exclude individuals with acute CVD caused by previous conditions.

Based on the tsunami data cited above, researchers expected to find a significant effect of flooding, but they did not. They did, however, determine that there is a 25-27% higher likelihood to be diagnosed with acute CVD during years with flooding than years without flooding.

Vanasse et al. had a few explanations for the lack of significance. Firstly, the nature of flooding is a slower progression of water and therefore, residents and hospitals have more time to prepare mentally and physically for the disaster. This would lower stress levels at an individual level, but it also would allow access to health care to remain more available. Those who were in need of help were able to get care in a timely manner. During the flood Vanasse et al. focused on, the city was able to provide housing and food to those who had to evacuate.

Another explanation for the lack of significance is that the flood was not sufficiently severe; other floods and natural disasters have been more distruptive.

Nevertheless, it is important to also look at the trend and understand that there is some association between the presence of acute cardiovascular disease and the occurrence of natural disasters since natural disasters are occurring more frequently due to climate change.


Vanasse, Alain, et al. 2016. “Association between Floods and Acute Cardiovascular Diseases: A Population-Based Cohort Study Using a Geographic Information System Approach.” Int. J. Environ. Res. Public Health 13, no. 2: 168. doi:10.3390/ijerph13020168


Nakamura, M., et al. 2012. Comparison of the Incidience of Acute Decompensated Heart Failure Before and After the Major Tsunami in Northeast Japan. Am. J. Cardiol. 110, 1856-1850.





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