Plastic Fibers are found in 83% of the world’s tap Water, a new study reveals

People may be ingesting between 3,000 and 4,000 microparticles of plastic from tap water every year, according to a study published Wednesday based on samples from 14 countries.

While the health risks are unknown, the researchers pointed to previous findings that plastic particles can absorb, and release, potentially harmful chemicals and bacteria.

Some 83% of tap water samples collected from over a dozen countries on five continents tested positive for microplastic, according to a study commissioned by data journalism outlet Orb.

Samples were collected in the first three months of the year in Kampala, New Delhi, Jakarta, Beirut, Quito, several cities in the United States and in seven European countries. All tested locations — from Europe to Jakarta and Beirut — saw plastic found in over 70% of tap water samples. The highest—found in the US—was 94-percent positive rate.

“We have enough data from looking at wildlife, and the impacts that it’s having on wildlife, to be concerned,” said Dr Sherri Mason, a microplastic expert at the State University of New York in Fredonia, who supervised the analyses for Orb. “If it’s impacting [wildlife], then how do we think that it’s not going to somehow impact us?”

The water testing was conducted by the University of Minnesota School of Public Health on behalf of Orb Media, a nonprofit media organization that focuses on global development issues. The data, first reported by The Guardian, didn’t include what kinds of plastics the researchers found.