While indoor air contaminants affect each individual differently, there can be patterns amongst building occupants of symptoms or discomfort.

It may be more useful to look for patterns of symptoms rather than a specific contaminant. What are they and when do they happen?

The charts below can help you investigate your building. They provide common symptoms of unhealthy indoor air quality and what to check or look for should those symptoms occur.


Headache, lethargy, nausea, drowsiness, dizziness If symptoms are acute, arrange for medical evaluation, as the problem may be carbon monoxide poisoning.

·       Check combustion sources for uncontrolled emissions or spillage.

·       Check outdoor air intakes for nearby sources of combustion fumes.

·       Check overall ventilation; see if areas of poor ventilation coincide with complaints.

Congestion; swelling, itching, irritation of eyes, nose, or throat; dry throat


 May be allergies if only small number affected; more likely to be irritational response if large number are affected.

·       Check outdoor allergen levels.

·       Check for dust or microbial contamination due to sanitation problems, water damage, contaminated ventilation system.

·       Check closely for sources of irritating chemicals such as formaldehyde or those found in solvents such as toluene, ethanol, benzene etc.

Cough; shortness of breath; fever, chills and/or fatigue after return to the building May be hypersensitivity pneumonitis or humidifier fever. A medical evaluation can help identify possible causes.

·       Check for microbial contamination due to sanitation problems, water damage, or contaminated HVAC system.

Diagnosed infection May be Legionnaire’s disease or histoplasmosis, related to bacteria or fungi.

·       Contact your local or State Health Department for guidance.

Cluster of rare or serious health problems such as cancer, miscarriages Contact your local or State Health Department for guidance.

Info provided by the EPA


Symptoms begin and/or are worst at the start of the occupied period ·       Review HVAC operating cycles.

·       Emissions from building materials, or from the HVAC system may build up during unoccupied periods.

Symptoms worsen over course of occupied period ·       Consider that HVAC system may not be adequate to handle routine activities or equipment operation within the building.
Intermittent symptoms ·       Look for daily, weekly, or seasonal cycles, weather-related patterns, and other events in and around the building.
Single event of symptoms ·       Consider unrepeated events as sources such as spills.
Recent onset of symptoms ·       Ask staff/occupants about recent changes or events (remodeling, renovation, redecorating, HVAC system adjustments, leaks, spills).
Symptoms relieved on leaving the building, either immediately, overnight, or after extended periods away from the building ·       Consider that the problem is likely to be building-related, but may not necessarily be due to air quality. Other stressors could be lighting, noise, ergonomics/placement of office furniture etc.
Symptoms never relieved, even after extended absence from building ·       The problem may not be building-related.

Info provided by the EPA

If you have concerns about any contaminants that may be present in your home or work environment, don’t hesitate to contact us.

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