Microplastics, teeny bits of plastic pollution less than 5 millimeters thick, are literally everywhere. They’re in America’s rainwater and the Arctic’s snow. They’re in seafood, table salt, and the water we drink. They’re even in our poop. We can’t avoid consuming them, so how do they affect our health?

According to a new report by the World Health Organization (WHO), the effects of microplastics on our bodies probably aren’t too severe. Researchers trawled through data on the effects of microplastics in drinking water from both taps and bottles and found that at present, “there is no evidence to indicate human health concern.”

However, research into microplastics’ effects on health is limited, so there may well be more to discover. The team looked at the three aspects of microplastics that might harm our bodies: the physical particles themselves, the chemicals they might release, and the bacteria they can harbor on their surface.

“Based on the limited information we have, microplastics in drinking water don’t appear to pose a health risk at current levels,” explained Dr Maria Neira, director of the WHO’s Department of Public Health, Environmental and Social Determinants of Health. “But we need to find out more. We also need to stop the rise in plastic pollution worldwide.”

The researchers concluded that microplastics bigger than 150 micrometers in width are unlikely to be absorbed by the body and that absorption of even smaller particles is probably fairly limited. However, super-tiny nanoparticles might be absorbed more readily, just as our lungs can absorb air pollution nanoparticles, but the data is incredibly limited. Essentially, at present, we still don’t really know.

The WHO notes that there is a need to conduct more research into the potential connections between microplastics in drinking water and human health. They point out that wastewater and drinking-water treatment systems that filter out chemicals and poop also remove up to 90 percent of microplastics from water, with filtration being the most effective method.

The researchers say that since microplastics currently don’t seem to pose a significant risk to human health, removing chemicals and microbes from drinking water remains the priority. Much of the world’s population still doesn’t have access to clean, properly treated water and is therefore at risk from harmful chemicals and diseases such as cholera, which spreads via consumption of contaminated water and causes severe – and sometimes lethal – diarrhea.

“In these places, microplastics may exist in greater concentrations in freshwater sources of drinking water; however, the health risks associated with exposure to pathogens present in untreated or inadequately treated water will be far greater,” the report states. “By addressing the bigger problem of exposure to untreated water, communities can simultaneously address the smaller concern related to microplastics in surface water and other drinking-water supplies.”

Future research may shed more light on the impacts of microplastics inside our bodies, and determine whether they harm the wildlife contaminated by them too. Regardless of whether microplastics damage health, larger pieces of plastic pose a serious threat to the planet and its non-human inhabitants. Plastic in the ocean is set to outweigh fish by 2050, so swift action must be taken to reduce the amount of plastic being discarded in our seas.