625,000 is the number of plastics makeshift housing units that were built in Sichuan province after the magnitude 8.0 earthquake in 2008. As reconstruction progresses, these plastic structures have fulfilled their duties and are being taken down.

It costs 260 yuan (US$38.1) to dissemble a 20-square-meter (215.3-square-foot) unit and another 400 yuan (US$58.6) to reassemble it elsewhere, plus transport expenses, local authorities were quoted as saying in a report by the Chengdu Business Newspaper. It's also costly to warehouse and manage the unneeded ones. Therefore, it makes good sense to recycle the plastic homes.

Philanthropist Chen Guangbiao, who runs a recycling business -- Huangpu Group - in Jiangsu province, recently announced in Mianyang city that he has invested 30 million yuan (US$4.4 million) and put in place 20 mobile recycling stations, which combined can process 5,000 plastic housing units every day. Chen said the recycling service is free of charge.