The presence of plastics in natural waters has long been acknowledged as a threat to aquatic biota, and recent research on the persistence of nanoplastic particles now raises questions about implications for human health.

Washington State University researchers examined the relatively unexplored fate of polyethylene and Salt types and ionic strength had significant effects on the stability of both nanoscale plastic types, while pH had none. Source: Mehnaz Shams et al.Salt types and ionic strength had significant effects on the stability of both nanoscale plastic types, while pH had none. Source: Mehnaz Shams et al.polystyrene nanoscale plastics in a range of aquatic chemistries. Salt types and ionic strength were observed to exert significant effects on the stability of both types of nanoscale plastic, while pH had none. Polystyrene nanospheres proved more stable in the aquatic environment than polyethylene nanoscale plastics.

The health implications of nanoplastic ingestion via drinking water, estimated by the researchers as a few grams of plastic each month, are unknown. Almost eight trillion pieces of microplastics are believed to enter wastewater treatment plants daily and end up in aquatic environments, and more than 90% of tap water in the U.S. is thought to contain these invisible plastic pollutants.

Technology is needed to effectively remove micro- and nanoscale plastics from water treatment plants. The researchers also emphasize the need for reduced use of single-use plastics and increased plastics recycling.

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