Results of a new study by environmental health scientists at the University of Massachusetts Amherst suggest that inexpensive cloth masks worn by people who hope to reduce their exposure to air pollution vary widely in effectiveness and could be giving users a false sense of security, especially in highly polluted areas.Researchers Richard Peltier, Kabindra Shakya and colleagues believe theirs is the first study to rigorously test disposable surgical masks and washable cloth masks, which are widely used in Asia and Southeast Asia for personal protection against airborne particulate matter. Their study shows that "wearing cloth masks reduced the exposure to some extent," but "the most commonly used cloth mask products perform poorly when compared to alternative options available on the market."