When it comes to New York City in the United States, it is difficult for people to associate this highly attractive international metropolis with a garbage city with sewage and foul odors. In fact, before the end of the 19th century, New York was one of the dirtiest cities in the world. At that time, the streets of New York were littered with garbage, mosquitoes and flies danced around, and the pungent odor made many residents afraid to open their windows. Poor sanitation conditions became a breeding ground for various diseases.

It wasn't until the appearance of health engineer George Welling that New York saw hope. In 1895, as a street hygiene commander, Weilin created the first garbage collection and classification system in New York's history, proposing a series of regulations and specific measures for using food waste to produce soap and agricultural fertilizer, and calling on the whole nation to pick up brooms to clean the streets

With the joint efforts of the whole nation, New York gradually got rid of its dirty and messy environment and established a relatively systematic and complete garbage classification and recycling system. According to the latest law in 1989, New York residents must sort and dispose of their garbage before discarding it. Recyclable waste is divided into two categories: paper and cardboard, and metal, glass, and plastic products, which need to be placed in different colored trash cans.