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"I think it is coming through the process of bottling the water," Mason told AFP. "I think that most of the plastic that we are seeing is coming from the bottle itself, it is coming from the cap, it is coming from the industrial process of bottling the water."

So, is it dangerous to drink bottled water? 

Researchers caution that it's unclear what effect microplastics can have on the human body. And, microplastics have been found in everything ranging from fish and shellfishfound at the super market to tap water. 

"There are connections to increases in certain kinds of cancer to lower sperm count to increases in conditions like ADHD and autism," said Mason. "We know that they are connected to these synthetic chemicals in the environment and we know that plastics are providing kind of a means to get those chemicals into our bodies."