The pollutant: Mold
Believe it or not, a little bit of mold can be beneficial: Outdoors, it helps organic stuff decompose, says indoor-air scientist Connie Morbach. “But when those mold spores are activated by indoor moisture, they can grow out of control,” she explains. Excess fungus can induce unpleasant symptoms like itchy eyes and breathing problems. And a few harmful strains can attack your immune system.
The solution: Indoor air that’s 30 to 50 percent humidity is comfortable for you but discouraging to mold (buy a $30 digital hygrometer at a hardware store to check your room levels). Spores love dark, damp corners, so once a week mop around your fridge, sinks, and toilets with a mild dish detergent or diluted hydrogen peroxide. Just be sure to dry everything thoroughly; mold can sprout in just 48 hours.