KAIST study: algal bloom conditions speed early weathering of plastic bags

A KAIST team led by Professor Jaewook Myung reports that algal bloom conditions can make low-density polyethylene plastics, such as bags, more prone to early surface weathering and microscopic cracking, potentially speeding microplastic formation, phys.org wrote. In a six-week microcosm experiment using water from Duck Pond on the KAIST campus, researchers induced eutrophic bloom conditions and tracked biofilms on LDPE. Under those conditions cyanobacteria and other bacteria formed thicker surface biofilms, and microbes that produce sticky extracellular polymeric substances became more abundant. The team also saw more microbes carrying genes tied to plastic oxidation and early-stage degradation. FT-IR and SEM measurements showed rises in oxygen-containing surface groups and finer hairline cracks, phys.org said. The authors argue water pollution from blooms and plastic pollution should be managed together. The study appears in Water Research with DOI 10.1016/j.watres.2026.126183.