PHOTO: Brice Laine/CNN
Now playing
03:55
'Extreme' amount of microplastics discovered in the North Atlantic
AURORA, CO - DECEMBER 15: (EDITORIAL USE ONLY) Rocky Mountain Regional VA Medical Center investigational pharmacy technician Sara Berech prepares a dose of the Johnson & Johnson COVID-19 vaccine for a clinical trial on December 15, 2020 in Aurora, Colorado. The Johnson & Johnson vaccine could be submitted for emergency use by late January and is the only vaccine among leading candidates given as a single dose. (Photo by Michael Ciaglo/Getty Images)
PHOTO: Michael Ciaglo/Getty Images
AURORA, CO - DECEMBER 15: (EDITORIAL USE ONLY) Rocky Mountain Regional VA Medical Center investigational pharmacy technician Sara Berech prepares a dose of the Johnson & Johnson COVID-19 vaccine for a clinical trial on December 15, 2020 in Aurora, Colorado. The Johnson & Johnson vaccine could be submitted for emergency use by late January and is the only vaccine among leading candidates given as a single dose. (Photo by Michael Ciaglo/Getty Images)
Now playing
02:46
FDA says Johnson & Johnson vaccine is safe and effective
AUGUSTA, GEORGIA - NOVEMBER 15: Tiger Woods of the United States looks on from the third tee during the final round of the Masters at Augusta National Golf Club on November 15, 2020 in Augusta, Georgia. (Photo by Patrick Smith/Getty Images)
PHOTO: Patrick Smith/Getty Images
AUGUSTA, GEORGIA - NOVEMBER 15: Tiger Woods of the United States looks on from the third tee during the final round of the Masters at Augusta National Golf Club on November 15, 2020 in Augusta, Georgia. (Photo by Patrick Smith/Getty Images)
Now playing
02:43
Tiger Woods' team gives an update on his condition
PHOTO: KCAL/KCBS
Now playing
01:37
Official details speaking with Woods in moments following accident
PHOTO: CNN
Now playing
04:15
Experts: Former CIA agent victim of microwave weapon in Moscow
Trump supporters clash with police and security forces as people try to storm the US Capitol on January 6, 2021 in Washington, DC. Demonstrators breeched security and entered the Capitol as Congress debated the 2020 presidential election Electoral Vote Certification.
PHOTO: Brent Stirton/Getty Images
Trump supporters clash with police and security forces as people try to storm the US Capitol on January 6, 2021 in Washington, DC. Demonstrators breeched security and entered the Capitol as Congress debated the 2020 presidential election Electoral Vote Certification.
Now playing
04:34
This is what we learned from Capitol riot hearing
Now playing
02:08
Cabinet secretary explains why he took on challenging role
Angelo Quinto
PHOTO: Law Offices of John Burris
Angelo Quinto
Now playing
02:00
Man dies after police kneel on his neck, family says
PHOTO: AFP/Getty Images
Now playing
04:54
Ocasio-Cortez rips Democrat's doubts about Biden nominee
Then-President Donald Trump addresses supporters during a Make America Great Again rally in Erie, Pennsylvania, October 20, 2020.
PHOTO: SAUL LOEB/AFP/Getty Images
Then-President Donald Trump addresses supporters during a Make America Great Again rally in Erie, Pennsylvania, October 20, 2020.
Now playing
02:44
What Trump's released tax records mean for DA's criminal case
From left, President Joe Biden, First Lady Jill Biden, Vice President Kamala Harris and her husband Doug Emhoff, bow their heads during a ceremony to honor the 500,000 Americans that died from COVID-19, at the White House, Monday, Feb. 22, 2021, in Washington. (AP Photo/Evan Vucci)
PHOTO: Evan Vucci/AP
From left, President Joe Biden, First Lady Jill Biden, Vice President Kamala Harris and her husband Doug Emhoff, bow their heads during a ceremony to honor the 500,000 Americans that died from COVID-19, at the White House, Monday, Feb. 22, 2021, in Washington. (AP Photo/Evan Vucci)
Now playing
05:45
Biden leads nation in mourning 500,000 US Covid-19 deaths
PHOTO: NASA
Now playing
01:15
Watch the Perseverance rover's first footage of Mars
donald trump juicio politico violencia capitolio presidente eeuu gobierno senado aristegui mexico roberto izurieta republicanos democratas_00002909.png
donald trump juicio politico violencia capitolio presidente eeuu gobierno senado aristegui mexico roberto izurieta republicanos democratas_00002909.png
Now playing
02:48
Supreme Court allows release of Trump tax returns
trump impuestos fiscal nueva york eeuu corte suprema investigacion dusa juan carlos lopez_00021006.png
trump impuestos fiscal nueva york eeuu corte suprema investigacion dusa juan carlos lopez_00021006.png
Now playing
04:06
Trump fires back at Supreme Court ruling in statement
Now playing
02:27
Bash: Cruz looking for Fox News sound bite at Garland hearing
Now playing
04:34
See what has happened to Trump's DC hotel after his loss
Merrick Garland emotional family story obligation vpx_00002927.png
Merrick Garland emotional family story obligation vpx_00002927.png
Now playing
01:16
Merrick Garland was asked why he wants the job. See his emotional response
(CNN) —  

They’re in our oceans, soil, air, snow – and even in your cup of tea.

Plastic tea bags are shedding billions of shards of microplastics into their water, according to a new study.

Researchers at McGill University in Canada analyzed the effects of placing four different commercial tea bags into boiling water.

They found that a single bag releases around 11.6 billion microplastic particles, and 3.1 billion even smaller nanoplastic particles, into the cup – thousands of times higher than the amount of plastic previously found in other food and drink.

The health effects of drinking these particles are unknown, according to the researchers, who called for further study into the area.

The team removed the tea from inside the bags to prevent it from interfering with the results, before boiling the bags in water to simulate the tea-making process.

Scientists have found microplastics in various foods, but less research has been done into whether they can be shed into water during the brewing of tea and other hot drinks.

Many tea producers use polypropylene to seal their bags.

Humans eat an average of 5 grams of plastic each week, according to a separate study earlier this year – the equivalent of a credit card’s weight in plastic.

In its first review of the health risks of plastic in tap and bottled water, the World Health Organization (WHO) said last month that microplastics “don’t appear to pose a health risk at current levels,” but the key finding came with a big caveat – the review said available information was limited and more research was needed on microplastics and how they affect human health.

“We urgently need to know more about the health impact of microplastics because they are everywhere – including in our drinking water,” said Dr. Maria Neira, director of the Department of Public Health, Environment and Social Determinants of Health at the WHO.