Table 1.
Specific conditions for MPs extractions.
| Facemasks | Impregnation | Shaking | Filtration | Drying | MPs release | References |
|---|---|---|---|---|---|---|
| Surgical or N95 face mask | A whole facemask, 100 mL Milli-Q water in glass bottle | Shaking rigorously for 3 min | A total of 1000 mL leachate per facemask | 100 μL leachate dropped onto silicon wafer and dried at room temperature | Over one billion of MPs ranging from 5 nm to 600 μm | Ma et al. (2021) |
| Surgical, KF-AD, and KF94 facemasks | A whole facemask, 200 mL Milli-Q water in glass flask | 150 rpm for 24, 48, and 72 h | Whatman nitrocellulose filter (pore size 0.45 μm), vacuum filtration | Drying at room temperature for 24 h. | Over 47 microfibers per mask per day | Dissanayake et al. (2021) |
| Ecoparksg disposable masks | Mask strips (1.5 × 14 cm), 50 mL deionized water in absence and presence of 20 sand | Shaking at 300 rpm for 24 h | Without filtration | / | Over 1.5 million MPs per weathered mask | Wang et al. (2021a) |
| Surgical masks | A whole facemask, 1 L artificial seawater in glass bottle | Stirring at 4000 rpm for 24 h | Sieving through 500 μm mesh and vacuum filtration through a Whatman nitrocellulose filter (pore size 0.45 μm) | Drying for 24 h | 173,000 microfibers per surgical mask per day | Saliu et al. (2021) |
| Medical surgical facemasks, disposal medical facemasks, normal disposal facemasks and N95 facemasks | A whole facemask, 200 mL deionized water in glass flask | Shaking at 120 rpm for 24 h | Filtration through a Millipore mixed cellulose esters membrane filter (pore size 0.8 μm | Drying at room temperature | MPs 183.00 ± 78.42 pieces per new mask, 1246.62 ± 403.50 pieces per used mask | Chen et al. (2021) |
| Surgical masks | A whole facemask, 250 mL of artificial seawater in glass bottle | Shaking at 200 rpm for 9 days | Vacuum filtration through a membrane filter (0.45 μm) | Drying at room temperature | Estimated 396 billion MPs per day. | Sun et al. (2021) |
| Common masks, surgical masks, and face filtering piece masks | Facemask (1 × 1 cm), 15 mL deionized water or 6 g sand with 10 mL water in glass tubes | Rotating at 60 rpm for 240 h | Filtration through a 1 μm glass fiber filtrate | Oven-drying at 60 °C for 3 h | MPs 272 ± 12.49 items/cm2 mask after sediment abrasion | Wu et al. (2022) |
| Surgical facemasks | Cut facemask, 500 mL of Milli-Q water in a glass beaker. | Kitchen chopper with a rotating blender blade | / | / | MPs thousands of microfibers and up to 108 submicrometric particles per facemask | Morgana et al. (2021) |
| N95 masks, medical surgical masks, and normal medical masks | A whole mask in 200 mL deionized water in conical flask | Shaking at 220 rpm for 24 h | Filtration with a 0.45 μm cellulose ester membrane | Drying at room temperature | MPs: 801–2667 particles/(piece·d) for N95 mask, 1136–2343 particles/(piece·d) for medical surgical mask, and 1034 −2547 particles/(piece·d) for normal medical mask |
Liao et al., 2021 |
| Surgical masks | A whole mask, 3 L of ultrapure water in a glass beaker | Stirring at 120 rpm for 24 h | Vacuum filtration through nitrocellulose membrane (pore size 0.45 μm) | Drying at 40 °C | MPs 360 items per mask in the static water | Shen et al. (2021) |
| Disposable face masks | 10 facemasks, 1.5 L deionized water | Gent stirring for 4 h | Vacuum filtration through a 0.1 μm Al2 O3 membrane filter | Drying for 2 h at 50 °C | / | Sullivan et al. (2021) |