Degradation of bio-based and biodegradable plastics in a salt marsh habitat: Another potential source of microplastics in coastal waters.
Degradation of bio-based (polylactic acid [PLA] cups, Mater-Bi® [MB] bags) and biodegradable plastics (biodegradable extruded polystyrene [bioPS] plates, biodegradable high density polyethylene [bioHDPE] bags) were compared to conventional plastics (recycled polyethylene terephthalate [rPET] cups, HDPE bags, extruded PS plates) in a salt marsh over a 32-week period. Following 4 weeks, biofilm developed on all plastics, resulting in an increased weight and concomitant decrease in UV transmission for most plastics. All plastics produced microplastic particles beginning at 4 weeks, with single-use bags producing the most microplastics over the 32-week period. At 32 weeks, SEM revealed microcracks and delamination for all plastics except PLA and MB, the latter of which degraded through embrittlement. IR spectral analysis indicated degradation for all plastics except PLA. Results suggest that degradation rates of bio-based and biodegradable plastics vary widely, with MB bags and bioPS plates demonstrating the greatest degradation, while PLA cups demonstrated the least degradation.
['Weinstein|John E|JE|', 'Dekle|Jack L|JL|', 'Leads|Rachel R|RR|', 'Hunter|Rebecca A|RA|']
D063566:Biodegradable Plastics D017753:Ecosystem D004784:Environmental Monitoring D000080545:Microplastics D010969:Plastics D020959:Polyethylene D011137:Polystyrenes D014874:Water Pollutants, Chemical D053833:Wetlands
Microplastics Polylactic acid Polystyrene High density polyethylene Polyethylene terephthalate