When floodwaters recede, most people breathe a sigh of relief. But according to new research, the real health risks might only be just beginning.
A major study led by Monash University, analysing over 300 million hospitalisation records across eight flood-prone countries (including Australia), revealed a 26% increase in serious health conditions in the seven months following a flood. These include respiratory diseases, infections, cardiovascular issues, and even mental health disorders.
It’s a wake-up call that the aftermath of a flood isn’t just about property damage — it’s about the air you breathe and the health of your home long after the storm has passed.
What happens to your home after a flood?
Even when your floors are dry and the rain has stopped, your home could still be hiding serious environmental hazards.
Flooding creates the perfect storm for:
- Mould and mildew growth
- Contaminated air from bacteria, VOCs and fungi
- Dust mite outbreaks due to damp fabrics and furnishings
These issues thrive in high humidity and water-damaged spaces — often lingering behind walls, under floorboards, and inside insulation where they’re hard to detect but easy to inhale.
If you’ve ever wondered why your home feels musty or why you’re coughing more after a flood, poor indoor air quality is likely the culprit.
The real health risks of post-flood living
The Monash study, published in Nature Water, uncovered the wide-reaching health effects of flooding — even in developed countries with healthcare access. Increases in hospital admissions were recorded for:
- Respiratory diseases (+30%)
- Cardiovascular diseases (+35%)
- Digestive issues (+30%)
- Renal and nervous system diseases
- Mental health disorders (+11%)
Much of this stems from poor living conditions after a flood. Damp homes are ideal environments for mould spores, bacteria, and dust mites — all of which are known to trigger asthma, allergies, and infections.
Access to healthcare may also be delayed post-flood, leading to complications in chronic conditions.
According to the Australian Department of Health, exposure to mould and dampness is particularly harmful to those with asthma and allergic conditions as well as those with weakened immune systems. This includes infants and elderly individuals.
How to protect your home and health after flooding
You can’t stop a flood — but you can take steps to safeguard your home environment. Here's how:
Dry your home fast
Time matters. The longer water lingers, the more likely mould and bacteria will spread. Focus on ventilation and remove wet materials as soon as possible.
Use a dehumidifier
A dehumidifier helps pull moisture from the air and surfaces, creating an environment where mould can’t thrive.
Dehumidifiers have been proven to reduce humidity in homes and inhibit the growth of mould and mildew after floods or heavy rain.
Desiccant models like the Ionmax Vienne are ideal after floods in the Australian weather as they work effectively in cooler, high-humidity spaces, even during winter.
For moisture removal in warmer climates, Ionmax recommends the use of refrigerant or compressor units. Learn about the differences between the two in our blog Desiccant vs Compressor dehumidifiers.
Improve air quality
Floods often introduce airborne pollutants and mould spores. A HEPA air purifier, like the Ionmax Breeze Plus, can filter these out and restore cleaner, breathable air.
For more on this, read 5 commonly used air filters in air purifiers.
Disinfect and clean thoroughly
Don’t just wipe down visible surfaces. Clean soft furnishings, curtains, carpets, and HVAC systems. Where possible, replace insulation and wall linings exposed to water.
Monitor humidity long-term
Even after the flood, dampness can linger. A hygrometer helps you track indoor humidity (aim for 40–60%). Most Ionmax dehumidifiers include built-in hygrometers for easy monitoring.
You can’t stop the rain — but you can protect your health
The long-term effects of flooding go well beyond soggy carpets. Poor air quality, hidden mould, and lingering dampness can affect your health for months after the flood, especially for families with kids, elderly relatives, or chronic health conditions.
By using trusted tools like dehumidifiers and air purifiers, you can take control of your indoor environment — and start breathing easier again.
