The Science Behind the Smell
That distinct monsoon smell is primarily caused by a combination of high humidity and the resulting growth of mould and mildew. During the rainy season, the air becomes saturated with moisture, often reaching humidity levels of 80-90% in many parts of India.
This moisture seeps into porous surfaces like walls, wooden furniture, carpets, and fabrics. Such damp, often dark environments are the perfect breeding ground for microscopic fungi like mould and mildew. As these fungi grow and digest organic materials, they release gases known as microbial volatile organic compounds (MVOCs), which produce the characteristic earthy or musty odour we associate with dampness.
Know Your Enemy: Mould vs. Mildew
Though often used interchangeably, mould and mildew are slightly different. Mildew is a type of mould that tends to grow on flat surfaces, appearing as a powdery patch of grey or white. Its smell is typically musty but milder, sometimes compared to damp socks. Mould, on the other hand, can be fuzzy or slimy and appear in various colours like green, blue, or black. It often has a stronger, more pungent smell because it penetrates deeper into the materials it grows on. Both thrive in high humidity and contribute to that unwanted house smell, but addressing the root cause—moisture—tackles them both.
Strategy 1: Ventilate and Let the Sun In
The most effective and simplest strategy is to improve air circulation. Trapped moisture allows odours to linger and mould to grow. Whenever the rain stops, even for a short while, open your windows and doors to allow for cross-ventilation. This helps to flush out the stale, humid air and replace it with fresh air. Sunlight is a natural disinfectant, so on the rare sunny days, make sure to draw back the curtains and let sunlight into every possible corner. This is especially important for airing out heavy curtains, rugs, and bed linens that can trap moisture.
Strategy 2: Actively Dehumidify Your Space
When ventilation isn't enough, you need to actively remove moisture from the air. An electric dehumidifier is highly effective at pulling excess water from the air, making the environment less hospitable for mould. For a more natural and localised approach, use moisture absorbers. Bowls of rock salt or activated charcoal are excellent at absorbing ambient moisture in enclosed spaces like cupboards and bathrooms. You can create small pouches of these materials and place them in drawers and corners, replacing them every few days or when they become saturated.
Strategy 3: Harness Natural Odour Absorbers
Instead of masking the smell with artificial air fresheners, which can sometimes make the air feel heavier, use natural ingredients to neutralise odours. Placing open bowls of white vinegar or baking soda in rooms can effectively absorb musty smells. To tackle odours on fabric surfaces like sofas or mattresses, sprinkle baking soda liberally, let it sit for about 30 minutes, and then vacuum it up thoroughly. Boiling a pot with lemon slices, cloves, and a cinnamon stick can also cut through smells, particularly in the kitchen, and leave a pleasant, natural fragrance.
Strategy 4: Focus on Wardrobes and Fabrics
Wardrobes are notorious hotspots for musty smells, as poor airflow and damp clothes create a perfect storm. Never store clothes that are even slightly damp; ensure everything is bone-dry before putting it away. To help, don’t over-pack your closets, as this restricts air circulation. Place moisture absorbers like silica gel packets, neem leaves, or camphor inside to protect your clothes. Camphor is a traditional choice that also acts as a natural pest repellent. Keeping a low-wattage bulb on inside a wardrobe can also generate enough warmth to prevent dampness from settling in.
