Table 1.

Summary of potential toxic effects of micro- and nanoplastics on human health.

Toxic Effects	Characteristics of Plastic Particles	Particle Size	Details	References
Inflammation	Polystyrene particles	202 nm and 535 nm	Upregulation of IL-8 expression. Induced inflammation in human A549 lung cells.	[112]
	Unaltered/Carboxylated polystyrene nanoparticles	20 nm, 44 nm, 500 nm, and 1000 nm	Upregulation of IL-6 and IL-8 expression. Enhanced inflammation in multiple human malignancies.	[113,114]
	Carboxylated and amino-modified polystyrene particles	120 nm	Altered expression of scavenger receptors. M2 cells increased IL-10 production. Increased TGFβ1 (M1) and energy metabolism (M2).	[115]
	Unaltered polyethylene particles	0.3 μm, 10 μm	Increased the secretion of IL-6, IL-1β, and TNFα in murine macrophages.	[117]
	Polyethylene particles from plastic prosthetic implants	0.2 μm and 10 μm	Induced the expression of TNFα, IL-1, and RANKL. Resulted in periprosthetic bone resorption.	[121]
			Induced inflammatory response at the implant area.	[121,122,123]
	Polystyrene microplastics particles	5 μm and 20 μm	Induced inflammation in the liver. Induced adverse effects on neurotransmission.	[125]
Oxidative stress and apoptosis	Amine-modified polystyrene nanoparticles	60 nm	Strong interaction and aggregation with mucin. Induced apoptosis in all intestinal epithelial cells.	[126]
	Cationic polystyrene nanoparticles	60 nm	Induced ROS generation and ER stress Induced autophagic cell death of mouse macrophages and lung epithelial cells.	[127,128]
	Unaltered or functionalized polystyrene	20 nm, 40 nm, 50 nm, and 100 nm	Induced apoptosis of several human cell types.	[129,130,131,132]
	polyvinyl chloride (PVC) and poly (methyl methacrylate) (PMMA)	120 nm, 140 nm	Reduced cell viability with a reduction of ATP and increase of ROS concentrations.	[133]
Metabolic homeostasis	Pristine and fluorescent polystyrene microplastics	5 µm	Changes in amino acid and bile acid metabolism. Induced gut microbiota dysbiosis and intestinal barrier dysfunction.	[134,135]
	Anionic carboxylated polystyrene nanoparticles	20 nm	Altered ion channel function and ionic homeostasis Activated basolateral K+ channels. Induced Cl− and HCO3− ion efflux.	[136]
	Polystyrene nanoparticles	30 nm	Blocked vesicle transport and the distribution of cytokinesis-associated proteins.	[137]
	Cationic polystyrene nanoparticles	50 nm and 200 nm	Disrupted intestinal iron transport and cellular uptake.	[138]
	Pristine polystyrene microparticles	5 µm and 20 µm	Reduction in hepatic ATP levels. Impairment of energy metabolism.	[125,139,140]
	Microplastics	0.5 µm and 5 µm	Metabolic disorder associated with gut microbiota dysbiosis and gut barrier dysfunction. Increased the risks of metabolic disorder in the offspring.	[135,141]