The World Health Organization warned Tuesday that the vast amount of waste produced in tackling the Covid-19 pandemic posed a threat to human and environmental health.

The tens of thousands of tonnes of extra medical waste had put a huge strain on healthcare waste management systems, the WHO said in a report.

The extra waste is "threatening human and environmental health and exposing a dire need to improve waste management practices", the UN health agency said.

As countries scrambled to get personal protective equipment (PPE) to cope with the crisis, less attention was paid to disposing of Covid-19 health care waste safely and sustainably, the WHO said.

The report looked at the 1.5 billion units -- approximately 87,000 tonnes -- of PPE procured between March 2020 and November 2021, and shipped out to countries via the United Nations system -- a small fraction of the global total.

Most of this equipment has likely ended up as waste, the WHO said.

"It is absolutely vital to provide health workers with the right PPE. But it is also vital to ensure that it can be used safely without impacting on the surrounding environment," said WHO emergencies director Michael Ryan.

Furthermore, over 140 million test kits have been shipped, with the potential to generate 2,600 tonnes of mainly plastic, non-infectious waste and 731,000 litres of chemical waste.

Approximately 97 percent of plastic waste from tests is incinerated, the report said.

And the first eight billion Covid-19 vaccine doses administered globally produced 144,000 tonnes of additional waste such as syringes, needles and safety boxes.

The WHO does not recommend using gloves for vaccine injections but the report said it appeared to be common practice.

Gloves, in terms of volume, constitute the greatest proportion of PPE waste of all items procured by the UN, the report said.

Practical solutions 

The 71-page report warned that safe management services for healthcare waste were lacking even before the pandemic added further pressures.

The latest available data, from 2019, suggested that one in three healthcare facilities globally did not safely manage healthcare waste -- and in the 46 least-developed countries, more than two in three facilities did not have a basic healthcare waste management service.

"This potentially exposes health workers to needle stick injuries, burns and pathogenic microorganisms, while also impacting communities living near poorly-managed landfills and waste disposal sites through contaminated air from burning waste, poor water quality or disease-carrying pests," the WHO said.

The report recommended practical solutions, such as using PPE more rationally; using less packaging; developing reusable PPE; using PPE made with biodegradable materials; investing in non-burn waste treatment technology; centralising waste management; and investing in local PPE production.

"Addressing environmental concerns does not necessitate compromising on safety," it said.