From The Guardian:
The average person eats at least 50,000 particles of microplastic a year and breathes in a similar quantity, according to the first study to estimate human ingestion of plastic pollution.
The true number is likely to be many times higher, as only a small number of foods and drinks have been analysed for plastic contamination. The scientists reported that drinking a lot of bottled water drastically increased the particles consumed.
The health impacts of ingesting microplastic are unknown, but they could release toxic substances. Some pieces are small enough to penetrate human tissues, where they could trigger immune reactions.