Monsoon Health Alert: That Musty Smell After Rain Could Be Harming Your Lungs

Monsoon Health Alert: Why That Musty Smell After Rain Could Be Harming Your Lungs

That damp, musty smell lingering in your bedroom, wardrobe or living room after the rains may seem like a harmless part of the monsoon. However, health experts warn it could be an early sign of hidden moisture and mould growth—both of which can affect indoor air quality and increase the risk of allergies, asthma attacks and other respiratory illnesses.

According to the World Health Organization (WHO), people living in damp or mouldy indoor environments are more likely to develop respiratory symptoms, allergic reactions, asthma and respiratory infections. During the monsoon, indoor humidity often rises above the recommended 30-50%, creating ideal conditions for mould to grow on walls, furniture, curtains, carpets and inside wardrobes.

Simply masking the odour with air fresheners may hide the smell temporarily, but it does not address the underlying problem.

Why Mould Can Affect Your Lungs

Mould releases microscopic spores that become airborne and can be inhaled deep into the lungs. While healthy individuals can usually clear occasional exposure, prolonged or repeated exposure may trigger inflammation of the airways and breathing difficulties.

Symptoms often begin with:

• Sneezing
• Watery or itchy eyes
• Sore throat
• Nasal congestion

With continued exposure, people may develop:

• Persistent cough
• Wheezing
• Chest tightness
• Worsening asthma symptoms
• Increased risk of respiratory infections

People with asthma, chronic obstructive pulmonary disease (COPD), allergies or weakened immunity are especially vulnerable. In severe cases, long-term mould exposure has been linked to conditions such as hypersensitivity pneumonitis and aspergillosis.

A long-term study published in the American Journal of Epidemiology found that prolonged exposure to dampness and mould inside homes significantly increases the risk of severe respiratory infections, while reviews by the European Respiratory Society have associated chronic mould exposure with airway inflammation and worsening chronic lung diseases.

Early Signs Your Home Has Excess Moisture

Visible mould is usually a late warning sign. Interior designer Monica Chawla of Essentia Environments says homeowners should look for subtle indicators much earlier.

“Soft furnishings absorb moisture first. A musty smell or even curtains and upholstery feeling slightly heavier than usual are often the earliest signs that humidity is building up indoors,” she says.

Wooden furniture can also react to excessive moisture.

“Wood naturally expands during the monsoon and usually returns to normal once humidity drops. If it doesn’t, it may indicate prolonged moisture exposure. Furniture should be kept away from damp walls and allowed proper ventilation,” Chawla explains.

Areas Most Prone to Mould

Certain parts of a home are more susceptible to moisture buildup because of poor airflow. These include:

• Wardrobes and cabinets
• Storage rooms
• Bathrooms
• Kitchens
• Laundry areas
• Basements
• Dark corners with little ventilation

“Wardrobes often trap humid air. Using moisture absorbers or leaving wardrobe doors open for some time every day can help prevent mould and musty odours,” Chawla says.

Don’t Ignore Damp Walls

A musty smell is not the only warning sign. Damp patches, peeling paint, bubbling plaster and finishes that never seem to dry properly can all indicate moisture seeping into the building.

“A damp patch is not just a cosmetic issue. Ignoring it can lead to structural damage and higher repair costs over time. Preventive maintenance is an essential part of maintaining a healthy home,” Chawla adds.

Health experts say the best way to reduce mould-related health risks is to improve ventilation, keep indoor humidity under control, fix leaks promptly and address dampness before mould begins to spread. A dry, well-ventilated home not only protects interiors but also helps safeguard respiratory health during the monsoon.