When travelling overseas, do you buy water in plastic bottles or take your chances with tap water? Imagine you are wandering about on a Thai island or 26 the ruins of Angkor. It's hot so you grab a bottle of water from a local vendor. It's the safe thing to do, right? The bottle is 27 , and the label says “pure water”. But maybe what's inside is not so 28 . Would you still be drinking it if you knew that more than 90 percent of all bottled water sold around the world 29 microplastics?

That's the conclusion of a recently 30 study, which analysed 259 bottles from 11 brands sold in nine countries, 31 an average of 325 plastic particles per litre of water. These microplastics included a 32 commonly known as PET and widely used in the manufacture of clothing and food and 33 containers. The study was conducted at the State University of New York on behalf of Orb Media, a journalism organisation. About a million bottles are bought every minute, not only by thirsty tourists but also by many of the 2.1 billion worldwide who live with unsafe drinking water.

Confronted with this 34 , several bottled-water manufacturers including Nestle and Coca-Cola undertook their own studies using the same methodology. These studies showed that their water did contain microplastics, but far less than the Orb study suggested. Regardless, the World Health Organisation has launched a review into the 35 health risks of drinking water from plastic bottles.