The World Health Organization (WHO) is set to launch a review into the potential health risks of microplastics found in bottled drinking water.
The review comes after a study found most of the world's leading brands of bottled water were contaminated with small plastic particles, likely seeping in during the packaging process.
Co-ordinator of the WHO's global work on water and sanitation Bruce Gordon told BBC News on Thursday the key question was whether a lifetime of eating or drinking particles of plastic could have an effect on a person's health.
"When we think about the composition of the plastic, whether there might be toxins in it, to what extent they might carry harmful constituents, what actually the particles might do in the body – there's just not the research there to tell us."
"We normally have a 'safe' limit but to have a safe limit, to define that, we need to understand if these things are dangerous, and if they occur in water at concentrations that are dangerous."
A study published on Wednesday found there was "widespread contamination" of microplastics across 250 bottles of water in Brazil, China, India, Indonesia, Kenya, Lebanon, Mexico, Thailand and the United States.
The research - conducted by US-based non-profit Orb Media - found a type of plastic in 93 per cent of the samples analysed.
'This is everywhere'
Lead researcher Sherri Mason told BBC News: "We found [plastic] in bottle after bottle and brand after brand."
"It's not about pointing fingers at particular brands; it's really showing that this is everywhere, that plastic has become such a pervasive material in our society, and it's pervading water - all of these products that we consume at a very basic level," she said.
Ms Mason also told AFP that most of the plastic particles were likely coming from the bottle itself, including the cap.
"It is coming from the cap. It is coming from the industrial process of bottling the water," she said.
Previous research by Orb Media found plastic particles in tap water, too, but on a smaller scale.
"Tap water, by and large, is much safer than bottled water," Ms Mason said.
Doubt over claims
Representatives from the bottled water industry took issue with the findings, saying they were not peer-reviewed and "not based on sound science," according to a statement from the International Bottled Water Association.
"A recent scientific study published in the peer-reviewed journal Water Research in February 2018 concluded that no statistically relevant amount of microplastic can be found in water in single-use plastic bottles," it added.
"There is no scientific consensus on the potential health impacts of microplastic particles. The data on the topic is limited and conclusions differ dramatically from one study to another."
Additional reporting: AFP
