(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.

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