| MEL | metabolic equivalent level; mouse erythroleukemia |
|---|---|
| MPL | maximum permissible level; melphalan; mesiopulpolingual; myeloproliferative leukemia |
| MSV | maximum sustained level of ventilation; mean scale value; mean spatial velocity; Moloney sarcoma vir... |
| NARL | no adverse response level |
| NEDEL | no epidemiologically detectable exposure level |