Clean Up Australia volunteers copped a blast from the past when a Coke can from Expo 88 was discovered in an exclusive inner-city suburb of Brisbane. The bright-red beacon of bicentennial fun, spotted by a Queensland state MP, was just the tip of an estimated 15,600-tonne iceberg of rubbish collected by volunteers in this year's campaign. Almost 700,000 people took part in the 26th instalment of the environmental event held at more than 7000 locations across the country. Clean Up Australia Day founder Ian Kiernan said the ever-increasing presence of plastics, drink vessels and single-use packaging proved waste management was an ongoing challenge. "So long as we are prepared to get involved ... Clean Up events such as those of this last week will continue to make a difference," he said. In NSW, more than 246,800 volunteers collected 6110 tonnes of rubbish. The NSW Labor opposition has used the annual event to renew calls for a statewide ban on single-use plastic bags.