At least three times a week, Herman Felani and five other volunteers collect medical waste from Indonesia’s Cisadane River in West Java.

He said medical waste including masks, used intravenous lines and medicine packets have increasingly found their way into the waters since the pandemic began.

“We alerted the authorities and police about the issue, but we still haven’t found the source of the waste,” he told the ABC.

Mr Felani’s volunteer efforts against the mammoth task of cleaning waterways — a problem exacerbated by the pandemic — highlights a challenge faced by citizens and governments across Asia.

“Globally, the impending surge in the waste volume has already threatened the existing waste management infrastructures and proved to be incapable in dealing with this sudden surge,” wrote several scholars in the Journal of Environmental Chemical Engineering in November.

According to a separate study published in the journal Environmental Science and Technology earlier this year, an estimated 129 billion face masks and 65 billion gloves have been used around the world every month.

In Indonesia, more than 1,000 tonnes of extra hazardous waste — roughly the weight of 200 elephants — is being produced every day, Indonesia’s Ministry of Environment was cited by local media as saying.

Meanwhile, in China’s Hubei province, hazardous waste is thought to have increased by 600 per cent during the pandemic.