Hundreds of volunteers yesterday helped clear up the mass of plastic pellets washed ashore on Discovery Bay's beaches in the wake of Typhoon Vicente two weeks ago. For their part, environmental groups called for quicker action from the government. Green activists said the spill could introduce potentially harmful materials into the food chain and have a long-term impact on the public's health. They urged the authorities to step up contingency measures. The government has confirmed that 150 tonnes of the potentially toxic plastic pellets fell into the sea from a ship during the typhoon. Only about 60 tonnes of the pellets have been collected so far, including 13 tonnes from various beaches in the southern part of Hong Kong. Food and Health Secretary Ko Wing-man said the authorities did not intend to conceal the incident, adding that efforts were being made to retrieve the pellets from the sea and remove them from the beaches. Ko stressed that the pellets were harmless, but green groups said they could be harmful as they could absorb toxins before being consumed by marine animals. Greenpeace campaigner Ada Kong Cheuk-san said the government had failed to inform the public of the potential harm the plastic pellets pose. 'If people don't know what they are, children could pick them up from the beaches,' she said. Clean-up campaign organiser Tracey Read said millions of pellets, mixed with sand and rubbish, remained on the beaches and the sea tides could bring more ashore. 'It will be a problem for a long time,' Read said. It remains unclear how many of the plastic pellets, which were originally in bags stored in containers, have been washed ashore and how many remained at sea. Green Sense's Roy Tam Hoi-pong said clean-up activities would be conducted on Cheung Chau while the campaign at Discovery Bay would continue today. 150 tonnes of plastic pellets fell into the sea from a ship during Typhoon Vicente's onslaught last month.