Reason to sample close to a source during a mold investigation

Below grade abandoned electrical outlet

SAS 180 air sampler

Air sample in control area

Air sample in room using DG-18 Outside air and hallway control on right

Air samples below the floor DG-18

Indoor air samples for 100 liters were taken in a below grade room.  Occupants in the space reported a musty odor.  Air samples in the breathing zone did not find a problem.   Air samples below the floor had elevated levels of Aspergillus spp. and Penicillium spp.  Outside air sample 50 liters.