New advances to assess biodegradation and toxicity of alternative environmentally friendly polymers

The inherent toxicity linked to plastic ubiquitous presence in the environment has received a growing interest in the last decades. Even though laws, policies and scientific projects addressing plastic pollution and its impact have recently flourished, very few concerned plastic risk assessment (i.e. linking plastic exposition and their effects on ecosystems) taking into account conventional or biobased, recycled or biodegradable polymers. Our objective was to develop new methods to assess plastic end-of-life on marine environment based on biodegradability assays and toxicity tests on marine organisms in order to develop environmental impact indexes relevant for Life Cycle Analysis.

On the basis of field and laboratory experiments, we tested different conditions to follow the biodegradation of polymers by natural marine bacterial communities (named “plastisphere”). We tested several media and conditions to measure the biodegradability of biosourced and petroleum based polymers comparatively to cellulose standard, in real marine and aquatic conditions. On the other hand, we developed methods to measure the impacts of plastics at different trophic levels of the marine environment, based on ecotoxicological studies on communities in their natural environment at the molecular, cellular, organ, individual and population levels. The methodological limits of toxicity tests, generating a partial assessment of the impact of microplastics on marine organisms were tested including several limits such as concentration, size, shape, chemical composition of plastics. Finally, relevant standards were tested to evaluate plastic toxicity to assess the effective risk of alternative and conventional plastics in marine biodiversity.