While pollution masks vary in design, they all typically feature a nose and mouthpiece that covers the face, along with some type of filter material that removes pollution particles from the air. Some pollution masks also have an exhalation valve to help reduce heat and moisture build-up inside the mask, making them more comfortable to wear for extended periods of time. Whether you're an avid cyclist or simply looking for ways to protect your lungs from pollution, a pollution mask like one of these is a worthy investment. If you are thinking of safety, take a look at cycling armour, bike helmets, and bike light sets.