Most of us wear synthetic fabrics like polyester every day. Shirts, yoga pants, sweatshirts and even underwear are all more and more often produced from synthetic materials - in fact, plastic. But these synthetic fabrics, from which 60 percent of all clothing on earth is made, have a big problem: When washed, they release tiny pieces of plastic -- called microfibers -- that flow into our canals, through water treatment plants, and on into rivers, lakes and oceans.