A client who had lived in her house for more than ten years was concerned that her son who suffers from certain inflammation problems might be affected by poor air quality.
Investigation: The home is a well maintained twenty year old two story house with a forced hot air heating system with same duct central air. The HVAC system incorporated a merv 6 air filter with an ultra violet bacteria control light. Particulate measurements showed very low particle counts. Relative humidity was 50% or lower. Air quality appeared to be good. An interview with the homeowner revealed a history of small water leaks in two bathrooms and in one exterior window. Examination of these sites showed areas of residual mold growth which had not been removed or cleaned.
Analysis: Mold growth contains a variety of contaminants even after it has dried and moisture is no longer present. Disturbing these sites can cause a localized dispersal of mold products that can pollute the air in a room or portion of a house and become a health irritant.
Recommendations: Remove and replace affected areas of sheetrock, trim or insulation where mold has grown and clean all adjacent areas.