MANILA (REUTERS) - Virgilio Estuesta has picked through trash in the Philippines' biggest city for four decades, and is noticing an unusually large amount of plastics during his daily trawl of about 15km.

Tough curbs re-imposed to combat a surge in daily coronavirus infections are squeezing the 60-year-old's income, as many of the junkyards and businesses in Manila that buy his recyclables have been closed since March.

Plastic items, such as bottles and containers, dominate the contents of the rickety wooden cart Mr Estuesta pushes through the deserted streets, far more than metal and cardboard, yet the money they bring in is not enough to get by.

"It's been really hard for us, it's been difficult looking for recyclables that sell high," he said.

"Recently, we've been seeing a lot more plastics, but the problem is they don't really sell high."

Environmentalists say the Philippines is battling one of the world's biggest problems stemming from single-use plastics, and ranks among the biggest contributors to plastic pollution of the oceans.

It has no reliable data for its plastics consumption.

Greenpeace campaigner Marian Ledesma said consumers and businesses are now using yet more single-use plastics, in a bid to ward off virus infections.

"The pandemic has really increased plastic pollution," she added.

"Just because there's a lot more people using disposables now, due to misconceptions and fears around transmitting the virus."

Since March 16, Manila has experienced lockdowns of varying levels of severity, in some of the world's longest and tightest measures to curb the spread of the virus.

They are taking a toll on Mr Estuesta, who hopes to start earning soon.

"When you go out, the police will reprimand you," he said.

"I was stuck at home and had to rely on government aid, which was not enough. I had to resort to borrowing money from people."