A team of investigators at France's state food agency has discovered that some glass bottles have more microplastics in them than other containers, including those made of plastic.
The "surprising finding" came about in tests carried out by the Anses Laboratory for Food Safety, whose researchers fingered paint on bottle caps as the likeliest culprit for the counterintuitive outcome.
"The level of microplastics was found to be higher in glass bottles than in other containers," the team said, with glass bottles of cola, lemonade, iced tea and beer having at least five times the amount of particles than plastic bottles or cans.
"We were expecting the opposite result when we compared the level of microplastics in different drinks sold in France," said Iseline Chaïb of the Aquatic Food Safety Unit in Boulogne-sur-Mer, which carried out the study at the Anses Laboratory for Food Safety.
The researchers aimed to figure the levels of "microplastic contamination" in drinks and to assess the effects of container or bottle type on the amount of pollution.The team said they did not look into "toxicological reference data," meaning they could not determine any health risk related to the amounts of plastics found in the bottles.
But they advised people to reduce the amount of plastic being washed into a drink by rinsing caps before putting them back on a bottle.
The team said that during their research they hit upon clues such as the microplastics found in drinks being "mostly the same colour and had the same composition as the paint on the caps."
"Caps were suspected to be the main source of contamination, as the majority of particles isolated in beverages were identical to the colour of caps and shared the composition of the outer paint," the team explained in a paper published by Anses. – dpa
