This research from Australia (2013) investigated whether indoor plants, under realistic office conditions, contribute to fungal/mold airborne concentration.

Trials were conducted using fifty-five single occupant offices. Offices were installed with either Spathiphyllum wallisii (Peace Lily) or Dracaena deremensis (Janet Craig) and allocated ‘treatments’ of 0, 1, 2, or 3 plants. Monitoring was conducted over two seasonal periods: autumn and spring.

The authors’ findings determined, that indoor plants:

• Made no significant difference to indoor mould spore counts or species composition
• That neither plant number or plant species influence significantly spore loads
• And, that there were no seasonal differences between autumn and spring measurement periods

Furthermore, indoor spore loads were significantly lower than outdoor levels, indicating the efficiency of the installed HVAC systems in the buildings sampled. The authors’ conclude that the inclusion of indoor plants did not increase exposure to the hazards of airborne fungi and mold spores.