Which of the following is considered an indoor air quality (IAQ) hazard?

Mould is recognized as an indoor air quality (IAQ) hazard due to its potential to thrive in damp environments and release spores into the air. These spores can trigger allergic reactions and respiratory issues in exposed individuals, particularly among sensitive populations such as those with asthma or weakened immune systems. Additionally, mould can produce mycotoxins, which are harmful to health when inhaled or ingested, further highlighting its status as an IAQ hazard.

In contrast, while high temperatures can create discomfort and influence overall health, they are not classified as an IAQ hazard in the same way mould is. Natural sunlight, although beneficial for promoting mood and vitamin D production, does not pose an IAQ hazard; rather, it can help reduce mould growth through ultraviolet exposure. Oxygen is essential for human life and does not represent a hazard in indoor air quality discussions. Hence, mould stands out as a significant concern in the context of indoor air quality assessments.