Often vague, symptoms commonly attributed to indoor air quality problems include headache, fatigue, difficulty breathing, sinus congestion, cough, sneezing, eye, nose, throat, skin irritation, dizziness, nausea, and increased infections. Indoor air pollution may also cause long term health problems like nervous system damage and cancer. Everyone is different. One person may react to an indoor air quality problem when others have no noticeable ill effects. Different degrees and different types of reactions can be triggered by the same problem or pollutant.
Some people appear to be more susceptible , yet have no known underlying health condition.
Moisture problems from condensation, leaks, drainage problems, and high humidity. Moisture causes or aggravates problems with dust mites, molds, insect infestations, and infectious organisms. Building occupants themselves convert oxygen to carbon dioxide when they breathe. Carbon dioxide can build up quickly in a crowded classroom without the introduction of adequate amounts of fresh air to the recirculating air. Carbon dioxide levels in an occupied classroom can be used as an indicator of indoor air quality because if it is not being diluted by fresh air, other contaminants are likely to be building up in the air as well.