What are the common causes of IAQ problems?

IAQ problems result from interactions between building materials and furnishing, activities within the building, climate, and building occupants. IAQ problems may arise from one or more of the following causes: •Indoor environment - inadequate temperature, humidity, poor air circulation, ventilation system issues. •Indoor air contaminants - chemicals, dusts, moulds or fungi, bacteria, gases, vapours, odours. •Insufficient outdoor air intake.