it's going to assess the present day studies into the spread and impact of so-called microplastics - particles which can be small enough to be ingested.
It comes after journalism business enterprise Orb Media discovered plastic debris in many foremost manufacturers of bottled water.
there may be no proof that microplastics can undermine human fitness but the WHO desires to determine the state of information.
Plastic debris located in bottled water
Bruce Gordon, coordinator of the WHO’s international work on water and sanitation, instructed BBC news that the important thing query became whether or not an entire life of ingesting or consuming debris of plastic should have an impact.
"when we think about the composition of the plastic, whether there is probably pollution in it, to what extent they could deliver dangerous elements, what clearly the debris might do within the body – there's just not the studies there to tell us.
"We commonly have a 'safe' restrict however to have a secure limit, to outline that, we want to understand if this stuff are dangerous, and in the event that they occur in water at concentrations which might be dangerous."
'disgrace and anger' at plastic pollution
Earth is turning into 'Planet Plastic'
Plastic pollution in seven charts
Mr Gordon said that he did not need to alarm anyone, and additionally emphasised that a much extra waterborne danger is available in nations where components may be infected with sewage.
however he said he acknowledged that people hearing about the presence of microplastics in their drinking water would flip to the WHO for advice.
"the general public are glaringly going to be involved about whether or not that is going to cause them to sick inside the brief term and the long time."
The WHO initiative is in part in response to a study that screened greater than 250 bottles of water from eleven extraordinary brands sold in 9 nations - the biggest investigation of its type.
The assessments have been accomplished at the state college of new York in Fredonia as part of a assignment regarding original studies and reporting with the aid of the us-primarily based journalism corporation Orb Media.
the usage of a dye called Nile crimson, which binds to unfastened floating pieces of plastic, the university's Prof Sherri Mason determined a median of 10 plastic debris per litre of water, each large than the size of a human hair.
Smaller particles assumed to be plastic but not positively identified have been determined as well - a mean of 314 according to litre.
Of all the bottles examined, 17 were determined to haven't any debris at all even as many had counts ranging into the loads or even thousands, with large variations inside manufacturers and even the identical % of bottles.
We contacted the corporations at the back of the manufacturers and most spoke back, standing via the best and safety of their merchandise.
a few questioned why the study’s outcomes had been a lot better than their own internal research or pointed out that there are no rules on microplastics or agreed methods for testing for them.
The examine comes on top of in advance investigations which have discovered microplastics in tap water, beer, sea salt and fish, and Prof Mason informed me that researchers want if you want to answer the pressing query of whether or not microplastics may be dangerous.
"What we do recognize is that some of those particles are huge enough that, once ingested, they're probable excreted however along the manner they could launch chemical substances that purpose regarded human fitness impacts.
"some of these particles are so especially small that they can sincerely make their manner throughout the gastro-intestinal tract, across the liner and be carried during the body, and we don’t understand the implications of what that means on our various organs and tissues."
the United Kingdom's food requirements organization said it turned into not going that the degrees of microplastic stated in the bottles of water should purpose damage but it brought that, "it might examine any rising records concerning microplastics in food and drink".
For Dr Stephanie Wright of the King’s college Centre for surroundings and fitness, the priority is to understand how lots microplastic we are exposed to, and precisely what occurs to it inside us.
Researchers have hooked up that tiny debris of titanium dioxide can pass through the liner of the intestine so the same might be viable with plastic, raising the question of wherein it'd then emerge as.
Dr Wright informed me: "The debris should live within an immune mobile within the gut lining, or be handed into our lymphatic system ending up inside the lymph nodes, or there is a small ability for them to enter the blood stream and in all likelihood gather within the liver.
"these are overseas hard debris which our body will manifestly need to get rid of however it is able to’t because plastic is not degradable so in an effort to purpose damage to the local tissue.
"but in the meanwhile we do not know."
I cautioned to Michael Walker, a consultant to the workplace of the United Kingdom government Chemist and founder board member of the food requirements agency, that the jury become out on whether microplastics may want to motive damage.
He replied: "The medical literature says that now not only is the jury no longer but out on this query but the jury has no longer but been convened on it."