The neglected defender? Rethinking biofilms on plastics

Plastics contain a wide range of additives for desired functions. Once exposed to natural environments, the plastic experiences physiochemical aging, leading to undesired leaching of additives. Wherever conditions allow, biofilms may form on plastic surfaces. A key question is, what is the actual role of biofilm in the complex processes? Most of current scientific work tends to ignore the high potential of biofilms in adsorbing and metabolizing chemicals in the framework of plastic leachates, as if the additives can leach out freely without a barrier. But with the existence of biofilms, additives could potentially be captured and metabolized by such bio-barriers while leaching, thus protecting the environment from chemicals. It hence becomes critical and essential to rethink the role of biofilms on plastics. This could challenge, or even reshape the current understanding on risk assessment of plastics interacting with the environment. It could thereby pave the way for a more realistic evaluation on plastic’s ultimate impact on and fate in the environment.