Floods may carry hidden health risks that liner long after the waters recede, according to the world’s largest study on the long-term health impacts of flooding, led by Monash University.
The study, published in Nature Water, analysed more than 300 million hospital records from 747 flood-affected communities across 8 countries, including Australia.
It found a 26% overall increase in disease serious enough to require hospitalisation, with elevated risk persisting for up to 7 months after flood events.
Researchers observed flooding events led to increases in hospitalisation for:
- Cardiovascular disease (35%),
- Respiratory disease (30%),
- Infectious diseases (26%),
- Digestive diseases such as gastroenteritis (30%),
- Mental health disorders (11%),
- Diabetes (61%),
- Cancer (34%),
- Nervous system disorders (34%) and
- Renal diseases (40%).
Professor Yuming Guo, lead researcher, says the findings highlight how flooding has been an under-recognised driver of long-term health concerns.
“An escalation in the severity, duration and frequency of floods due to the more frequent extreme precipitation events and rising sea levels due to global warming [is expected],” says Professor Guo.
The study analysed data from flood-affected regions between 2019 and 2019, including the northeast region of NSW in Australia, the Amazon River and the southern region of Brazil, the Mekong Basin in Vietnam, and in the south region of Thailand.
While acute dangers like drowning or electrocution are widely recognised, this study highlights how flooding contributes to chronic health issues.
“[These findings] suggest “The health impact of floods may have been underestimated and will further exacerbate as climate changes,” says Professor Guo.
To read the study, visit nature.com/articles/s44221-025-00425-8.
