The average American could be consuming over 74,000 microplastic particles per year, the health effects of which are not yet known.
The new analysis made the estimates from published data on amounts of microplastics found in food, air and water and the average Americans' caloric intake.
Since the mass production of plastics began in the 1940s, the versatile polymers have spread rapidly across the globe.
The researchers estimate that the average American consumes 74,000- 121,000 particles of microplastics per year, and that this is likely an underestimation.
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Since the mass production of plastics began in the 1940s, the versatile polymers have spread rapidly across the globe. Researchers estimate that the average American consumes more than 74,000 particles of microplastics per year, the health effects of which are not yet known
Microplastics are tiny pieces of plastic that can arise from the degradation of larger plastic products in the environment.
They can also come from the shedding of particles from food and water containers during packaging.
Humans can inadvertently take in these materials, some pieces of which are small enough to enter human tissues, when eating food or breathing air.
The researchers reviewed 26 previous studies that analysed the amounts of microplastic particles in fish, shellfish, added sugars, salts, alcohol, tap or bottled water, and air.
Other foods were not included in the analysis because of lack of data.
The team then assessed approximately how much of these foods men, women and children eat from the recommended dietary intakes of the 2015-2020 Dietary Guidelines for Americans.
They estimated microplastic consumption ranged from 74,000 to 121,000 particles per year, depending on age and sex.
People who drink only bottled water could consume an additional 90,000 microplastics annually compared with those who drink only tap water.
Because the researchers considered only 15 per cent of Americans' caloric intake, these values are likely underestimates, they said.
Additional research is needed to understand the health effects, if any, of the ingested particles but the team said that they could trigger immune reactions or release toxic substances.
Dr Stephanie Wright, Research Associate, King's College London (KCL), said:
'There has been an awareness of microplastic contamination of dietary products and air for several years. This study reiterates what is already known of microplastic exposure, synthesising the existing evidence.'
Microplastics are tiny pieces of plastic that can arise from the