Table 1.

Overview of polyhydroxybutyrate (PHB) and polymethylmethacrylate (PMMA) microplastic particle (MPP) properties and visual comparison of particles under the microscope.

MPP	PHB	PMMA
Density	1.24 g cm−3	1.19 g cm−3
Color	white, opaque	transparent
Form before grinding	pellets (3 mm)	pellets (3 mm)
MPP sizes after grinding	32–64 µm	32–64 µm
	64–125 µm	64–125 µm
	125–250 µm	125–250 µm