A deflated football – $16,000 (£10,760). A broken computer with wires showing – $60,000. A cracked, yellow plastic chair – $16,000. An old, stained backpack – $8,000.

The items may not actually be for sale in the luxury shopping mall in Rio de Janeiro where they are displayed, but the prices reflect the environmental cost of waste thrown into the city's picturesque Guanabara Bay.

As project director Fernanda Cortez explained, the exhibition Achados da Guanabara, or Found in Guanabara, seeks to personalise the pollution of the bay to force people to take responsibility for the waste that is thrown into the water.

"The rubbish that we see here comes down to the citizens' responsibility. They were discarded in incorrect ways and ended up being disposed of in the bay, even if they were not directly thrown away there. A lot has been said about the Guanabara Bay as a polemical area, which is why we chose to do Found In Guanabara instead of Found In another bay, another sea, another river.

"This is to show that we are facing a great structural problem in terms of sanitation, but also that there is a big problem in terms of educating the population that water is not rubbish," Cortez told Reuters at the designer Shopping Leblon mall in Rio's wealthy South Zone.

As part of its Olympic bid, Rio promised to clean up 80% of the bay in time for the Games in 2016 but local government officials have already admitted this goal is no longer achievable.

Despite millions of dollars of investment over the years, the bay where the Olympic sailing and windsurfing will take place still stinks of sewage and sailors who visited the city for test events complained of a floating sofa and a dead dog in the water.

For Cortez and the Menos1Lixo (one less piece of rubbish) project, the clean-up of the bay needs greater public awareness as well as government support.

The prices for the pieces of rubbish were calculated by biologist Marcelo Szpilman who estimated that for every year it takes an item to decompose its costs the environment $320. Cortez said Menos1Lixo is in discussions with the International Olympic Committee to work together to raise awareness of the damage caused by disposing of waste in the bay.