WordNet (r) 3.0 (2006):

blackdamp
    n 1: the atmosphere in a mine following an explosion; high in
         carbon dioxide and incapable of supporting life [syn:
         chokedamp, blackdamp]

Moby Thesaurus II by Grady Ward, 1.0:

26 Moby Thesaurus words for "blackdamp":
   afterdamp, breath, chokedamp, cloud, coal gas, damp, effluvium,
   exhalation, exhaust, exhaust gas, fetid air, firedamp, flatus,
   fluid, fume, malaria, mephitis, miasma, puff of smoke, reek, smoke,
   smudge, steam, vapor, volatile, water vapor