Nanosilver is said to fight bacteria, molds and fungi, so a few years ago, companies began incorporating nanosilver particles into fitness apparel. It seemed like a flashy way to keep sweaty gym clothes from smelling stale. But the antimicrobial benefits may not last long. Researchers at Arizona State University found that after about four or five washings, nanosilver-treated fabric lost about half its particles, which then washed out into the water. Although the long-term effects of these ingestible particles on wildlife is still unknown, environmental groups have started sounding the alarm on nanosilver's ability to neutralize positive bacteria in some ecosystems. Until conclusive studies are released, save the money you would have spent on anti-odor clothing and put it toward laundry detergent instead.