Scientists in Mexico City have created a novel way to reduce diaper waste, using hay and mushroom seeds and recycling the plastic and gel found inside what is traditionally a wasteful, but essential, item for babies and mothers. Roselle Chen reports.
It's a quandary for all parents of young children - all those used diapers that end up in the landfill. But scientists from Mexico's Metropolitan Autonomous University have an answer. They've developed a technique to degrade diapers together with wheat hay to grow mushrooms. Scientists Alethia Vazquez and Rosa Maria Espinosa receive dirty diapers from nurseries in north-west Mexico City. They only use urine soaked diapers, as they're easier and safer to handle. After taking the diapers apart, the remains are placed with wheat straw in plastic bags. The bags are then sterilized to get rid of pathogens, which inhibit mushroom growth. Mushroom seeds are placed with the mixture, while cells from the diaper waste and a wood polymer called lignin - found in the hay - help them grow. Espinosa says mushrooms are one of the few organisms that degrade wood, specifically cellulose, which makes up most of a diaper's structure. (SOUNDBITE) (Spanish) ROSA MARIA ESPINOSA, SCIENTIST, SAYING: "The diapers come from cells extracted from the trees. When we think of something that could degrade them, we think of an organism capable of degrading wood. Within the few organisms in nature, we have mushrooms." To inoculate the mushrooms, sorghum seeds are used. The seeds, diaper waste, and hay are placed back into plastic bags and left in a dark room with controlled temperature and humidity so the mushrooms can grow and degradation begins. The mushrooms aren't meant for eating, but three recyclable sub-products are left. (SOUNDBITE) (Spanish) ROSA MARIA ESPINOSA, SCIENTIST, SAYING: "We have plastic, which can be separated, cleaned and sent to be recycled. We have the hay and the rest of the diaper which did not manage to degrade, which can be sent off for compost and we have the mushrooms, which is high in protein product and can be used to feed cattle, as a flavoring product or as a high quality protein." The bundles are moved to a bright room, so that sunlight can stimulate the mushrooms' growth. The degradation process takes about three months. The process degrades more than 70 percent of the diaper, significantly reducing the volume of waste generated. 500 tons of used diapers end up in Mexico City landfills every day. The scientists believe parents can be trained to perform the procedure at home, helping them generate less waste and easing their guilty conscience.