Eisenring said: "Waste management and pollution is a topic the government is following more closely now. It's being discussed in public and more people know what can be done to reach the goal of blue skies, clean water and vegetation."

She added that Chinese people prefer the concept of "doing things together", whereas Westerners focus more on solo activities.

"That's why we always go for drinks and food together after a run," she said.

The group's collective ethos helps to maintain momentum because ploggers encourage one another during activities, and working together helps to reduce the embarrassment factor when passers-by stare at them.

Some skeptics have complained that the ploggers' efforts are just a drop in the ocean because China produces a huge amount of domestic waste.

In fact, the problem remains acute, even though a large proportion of waste is collected and not just dumped on the side of the road.

Zhang said every plogger collects about two bags of waste during their runs, but some discarded materials can't be collected.

Sometimes the job requires a strong stomach, too. Zhang recalled one time when her group came across kitchen residue that looked as though someone had vomited over it.

Despite their bamboo tongs, the ploggers were reluctant to deal with the mess. Nevertheless, they cleaned it up.

"We could have left the dirty trash for the street cleaners, but that moment made us realize how great those cleaners are," she said.

For Sogor, the plogger from Hungary, that moment encapsulated the meaning of the activity - raising awareness.

Ploggers will never be able to clean up all the waste on the nation's streets, but they can show people how much trash is produced in urban areas and provide a way for everyone to play their part in environmental protection.

"Let the people see and maybe, next time, they will think twice before littering the streets," she said.