Her daughter, 17, and younger son, 13, live with their grandparents in her hometown.

The eldest son works on construction sites in Shenzhen, Guangdong province, with her husband.

"They're there because construction workers are paid more highly than they are here," she says.

Yuan says she opted to stay in Hangzhou because her pay is satisfactory.

"To collect waste paper you need to know everything about office buildings and apartment complexes in your area. I have built up that knowledge in Hangzhou, and it would take up too much time to start from scratch in another city."

Being separated from her family is no big deal, she says, because the long work hours leave her little time to think about loneliness.

"Making money is more important."

Yuan hopes her husband and herself can make enough money to build a house in their hometown.

"We cannot afford an apartment in the city, but we should have our own house back home," she says, staring at a nearby high-rise apartment block.

As night falls and the rush hour is in full swing, Yuan takes care of her last batch of work for the day. She flattens cardboard cartons, piles them together and then fastens them with string.

Nearby is the city's largest shopping center, teeming with shoppers decked in the latest fashion, many carrying swish shopping bags stuffed with their expensive purchases.

It is something Yuan can only dream of - something she will have ample time to do on the two-hour bus ride home.