An article published on April 18, 2018 in the peer-reviewed journal Environmental Sciences Europe addressed environmental risks arising due to the persistency of marine litter plastics, with a particular focus on their toxic chemicals components. The article is authored by Frederic Gallo from the Barcelona Convention for the Protection of the Marine Environment and the Coastal Region of the Mediterranean, Stockholm Convention Regional Activity Centre in Spain, Barcelona, Spain, and several other scientists and consultants belonging to the working group of Regional Centers of the Stockholm and Basel Conventions and/or active in the field of persistent organic pollutants (POPs).

The authors emphasize that the degradation of persistent plastics into micro- and nanoplastic fragments facilitates their uptake by marine biota, likely resulting in the accumulation in the food chain. Some of the chemical additives and contaminants present in the polymers are known to have endocrine disrupting properties and hence “may be harmful at extremely low concentrations for marine biota, thus posing potential risks to marine ecosystems, biodiversity and food availability.”

Most of these chemicals “may not qualify as ‘persistent’ under the strict criteria of the Stockholm Convention.” However, “when present in a polymeric matrix in marine conditions, they may be potentially as harmful as officially recognized POPs in terms of behavior and consequences in the marine environment,” the authors claim. This is due to the “continuous flow of ‘fresh’ plastic waste,” enhanced persistence in marine systems because of “their adsorption to microplastics, combined with the harsher environmental conditions of low temperature and salinity, combined also with low light and low oxygen content in subsurface waters and sediments,” along with further inhibition of degradation due to “sorption of contaminants in nanopores of plastics.”

The authors identify several knowledge gaps still to be filled with regard to the real-life impacts of plastics and their components on the marine ecosystems and human health. However, regardless of further research needs, “existing scientific evidence and concerns are already sufficient to support actions by the scientific, industry, policy and civil society communities to curb the ongoing flow of plastics and the toxic chemicals they contain into the marine environment,” the authors conclude. Invoking the precautionary principle, they call for “immediate strong preventive measures” and “a fundamental rethink of the ways in which we consume plastics.”

Commonly advocated solutions rely on a “global fully fledged efficient waste collection, management, recycling and environmentally sound disposal systems that would guarantee an almost zero plastic release to the environment.” However, this is a “financially challenging and possibly decades-long endeavor,” the authors warn. Instead, they call for more extended producer responsibility (EPR)-based schemes and point to the need for “strong policy actions” such as “the ban on free single-use plastic bags,” “deposit-refund schemes for plastic beverage bottles,” and “the ban on plastic microbeads in cosmetics and personal care products” as part of waste management strategies. Further, “designers and producers should avoid creating products that are inherently single use or inevitably destined for landfill,” and packaging materials should be optimized “to avoid unnecessary use of persistent plastics and toxic chemicals.”

The now-published article served as a “background document for discussion in the 2017 Conference of the Parties (COP) of the Basel Convention on hazardous wastes and the Stockholm Convention on persistent organic pollutants (POPs).” As a result, the COP approved that its Regional Centers could deal with the issue of plastic waste and “consistently report their activities on the matter to next COP’s meetings.”


Gallo, F., et al. (2018). “Marine litter plastics and microplastics and their toxic chemicals components: the need for urgent preventive measures.Environmental Sciences Europe (published April 18, 2018).