The world’s birds eat up to 550 million tons of insects annually, and every one of those bugs could be carrying around microplastic, according to a new study published in the journal Biology Letters.

A team of researchers came to this conclusion after feeding microplastic to mosquito larvae and then observing how the plastic remained in the insects throughout their lives. Since microplastics pervade bodies of water where mosquitoes form, it’s likely that the insects, and many others, are naturally consuming microplastics in the wild. And that means that creatures who eat bugs could be getting an extra dose of plastic in their already plastic-stuffed diets.

“It is a shocking reality that plastic is contaminating almost every corner of the environment and its ecosystems,” Amanda Callaghan, the study’s lead researcher, told the Guardian. “Much recent attention has been given to the plastics polluting our oceans, but this research reveals it is also in our skies.”

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In recent years, research into the prevalence and consequence of microplastics has grown. Scientists have determined that trillions of microplastics are in the world’s oceans, and the air is positively teeming with the stuff. In fact, a single cycle of a washing machine could release up to 700,000 plastic fibers into the air.

All of this microplastic is being digested by animals, including humans, and it could be causing to shorter life spans and other health problems. Microplastics are known to pick up bacteria and harbor chemicals, according to the Guardian, and these toxins are then likely passed onto animals.

A study from earlier this year found that humans consume around 70,000 microplastics per year and that both tap and bottled water contain microplastics.

Your one cup lid breaks UP, not down, from one piece of plastic to millions.
Walking along the beach in 25 years you may not see what is identifiable as a lid but these microplastics will be there.
A powerful image from @trashplanet_norway#microplastics#ausmap#reuseablepic.twitter.com/dyJPkzmZJy

— AUSMAP : microplastic (@AUSMAP_AU) September 11, 2018

Read More: Why Global Citizen Is Campaigning to Reduce Plastic Waste in the Oceans

Another recent study found that a single piece of normal-sized plastic ingested by a turtle increases its chance of death by 20%, and that 14 pieces of plastic consumed makes a turtle 52% more likely to die. More than 70% of turtles have plastic in their guts, and the United Nations found that ingesting plastic kills around 1 million marine birds and 100,000 marine animals each year.

“It’s totally depressing,” Callaghan told the Guardian. “These plastics are going to be around forever.”