Virtually all the world’s tap water is contaminated by microscopic plastic fibers, a new study claims, raising fresh concerns about the implications of rampant plastic pollution on human and planetary health.

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. The specific rate of prevalence in different locales varied, but all tested locations — from Europe to Jakarta and Beirut — saw plastic found in over 70% of tap water samples.

In the U.S., researchers found that 94% of all water samples — including tap water from places like Trump Tower and the Environmental Protection Agency’s headquarters — were contaminated by plastic.

These microscopic fragments enter the water system in multiple ways, reports Orb, from synthetic fiber clothing to tire dust and microbeads, as well as the fragmenting of larger pieces of plastic, which for the most part is non-biodegradable.

With about 300 million tons of plastic produced annually, the worsening contamination problem it brings to oceans and rivers has attracted increasing concern.

Attention has previously focused on plastic pollution’s effect on marine life, seabirds and the human food chain, but effects of microplastic’s presence in the human body remain to be studied.

“There are certain commons that connect us all to each other, air, water, soil, and what we have universally found time and time again is if you contaminate any of those commons, it gets in everything,” Sherri Mason, an expert on plastic pollution at the State University of New York in Freedonia, told Orb.