Persistent, water-soluble polymers in the research spotlight

Persistent, water-soluble polymers like polyacrylamides (PAM) and polycarboxylates are not generally considered microplastic or even nanoplastic to many researchers and regulators, and therefore have not received as much attention. These persistent, water-soluble polymers have annual production volumes well into the millions of tonnes, with many uses associated with direct environmental emissions, such as in the water treatment sector and oil and gas. Though environmental behaviour of these polymers is complex, they will likely directly interact with organic matter and other colloids to form persistent composites of varying sizes, which themselves could be problematic for the environment. A potential consequence of oversight into their environmental behavior by researchers and regulators is that deeper insights into the fate and impacts of these persistent, water-soluble polymers remain unknown. This should not be the case, as many of the potential concerns of persistent, insoluble polymers overlap directly and indirectly with their soluble microplastic and nanoplastic counterparts.