Americans generate about 254 million tons of trash and recycle and compost ( 制成肥料 ) about 87 million tons of this material, which adds up to a 34.3 percent national recycling rate. Recycling and composting prevented the release of approximately 186 million metric tons of carbon dioxide ( CO 2 ) in 2013, comparable to taking over 39 million cars off the road for a year. In recent years, however, recycling companies are struggling with higher processing costs, due in part to newer, larger recycling bins that don’t require user sorting ( 分类 ) and thus become increasingly contaminated with garbage. When the District of Columbia replaced residents’ 32-gallon bins with ones that were 50 percent larger last year, the extensive amount of non-recyclable material put into the bins drove up the city’s processing cost for recyclables and cut profits from selling recyclables by more than 50 percent. “Our biggest concern and our biggest challenge today is municipal solid waste and contamination in our inbound stream,” said James Delvin, CEO of ReCommunity Recycling, which operates 31 facilities in 14 states. “It’s an economic issue if you think about we go through all this effort to process this material, and roughly 15 to 20 percent of what we process ends up going back to the landfill ( 垃圾填埋场 ) . It’s incredibly inefficient to do that.” In a 2014 survey by the National Waste and Recycling Association, nearly one in ten Americans admitted to throwing their waste in recycling bins when trash cans were full; one in five said they will place an item in a recycling container even if they are not completely sure it is recyclable. “People refer to this as ‘wishful recycling,’ that’s just when in doubt, put this in the bin because there’s an outside chance they might be able to recycle it,” Delvin notes. “So you see Styrofoam ( 聚苯乙烯泡沫塑料 ) . You see PVC. You see batteries and those types of things ...” This mixing of waste with recyclables, he says, makes it very difficult to extract the true recyclable commodities that have value. Improved education regarding the proper materials to recycle is needed to allow recycling plants to remain economically feasible. The pros and cons of recycling are heavily debated, but there’s never an argument over the environmental benefits of limiting disposable packaging and utilizing more durable reusable goods, like shopping bags, coffee thermoses and water bottles, to name a few, in daily life.