Poor IAQ is the consequence of insufficient ventilation performance that facilitates the progressive build-up and/or transmission of microbials, pollutants and allergens on the indoor air.
When we are indoors we are constantly breathing the indoor air and its contents so if there is poor IAQ there is heightened risk that we are breathing in harmful things that can affect or health, wellbeing and productivity.
Health and Wellbeing
Poor IAQ is linked to a wide range of adverse effects on health and wellbeing, from immediate discomfort to severe, chronic diseases and even premature death. The World Health Organization (WHO) estimates that household air pollution is responsible for millions of deaths annually worldwide.
Health and wellbeing effects can be broadly categorized into short-term and long-term impacts, with children, the elderly, and those with pre-existing conditions being particularly vulnerable.
Short-Term Effects
Immediate symptoms of poor IAQ, which often disappear when the person leaves the building, are sometimes referred to as "sick building syndrome" and include:
- Sensory irritation: Irritation of the eyes, nose, and throat.
- Neurological symptoms: Headaches, dizziness, nausea, fatigue, and lethargy.
- Cognitive effects: Difficulty concentrating, mental fatigue, and reduced performance in work or learning environments.
- Respiratory issues: Coughing, wheezing, chest tightness, and shortness of breath.
Long-Term Effects
Prolonged exposure to indoor air pollutants, such as particulate matter (PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO), radon, and volatile organic compounds (VOCs), is associated with serious, long-term health conditions:
- Respiratory Diseases: Increased risk of developing asthma, exacerbation of existing asthma symptoms, chronic bronchitis, and Chronic Obstructive Pulmonary Disease (COPD).
- Cardiovascular Diseases: Higher risk of heart disease, heart attacks, strokes, hypertension (high blood pressure), and hardening of the arteries.
- Cancer: Increased risk of lung cancer (radon is the second leading cause of lung cancer after smoking).
- Neurological & Mental Health Impacts: Emerging evidence links poor IAQ to cognitive decline, dementia, anxiety, depression, and other psychiatric disorders.
- Reproductive & Developmental Harm: Exposure during pregnancy is associated with adverse outcomes such as low birth weight and impaired lung function in infants. It can also negatively affect children's neurological and lung development.
Vulnerable Populations
Certain groups are at a higher risk, including children (whose lungs are still developing and who have higher respiration rates), the elderly, pregnant women, and people with pre-existing heart or lung conditions. Socio-economic factors and poor housing quality can also exacerbate these risks.
Key Pollutants and Their Impacts
| Pollutant | Key Health Effects | Source(s) |
|---|---|---|
| Particulate Matter (PM) | Respiratory and cardiovascular diseases, lung cancer, cognitive decline, premature death | Cooking, heating (solid fuels), smoking, dust, outdoor infiltration |
| Carbon Monoxide (CO) | Headaches, dizziness, nausea; high levels can be fatal | Malfunctioning combustion appliances (boilers, heaters, stoves) |
| Nitrogen Dioxide (NO₂) & Oxides (NOx) | Airway inflammation, respiratory infections, reduced lung development | Gas stoves/appliances, vehicle exhaust infiltration |
| Volatile Organic Compounds (VOCs) | Eye/throat irritation, headaches, potential cancer risk, cognitive effects | Paints, cleaning products, furnishings, building materials, air fresheners |
| Radon | Lung cancer (primary risk for non-smokers) | Naturally occurring radioactive gas from the ground |
| Biological Pollutants | Allergies, asthma, respiratory infections (pneumonia, flu) | Mould, damp, bacteria, viruses, dust mites, pet dander |
Productivity Effects
Poor IAQ) significantly reduces productivity by impairing cognitive function, increasing fatigue, causing physical discomfort, and raising rates of absenteeism and presenteeism.
Cognitive Function and Performance Decline
Studies consistently show that poor IAQ, often linked to high levels of carbon dioxide (CO2), volatile organic compounds (VOCs), and particulate matter (PM10,2.5,1), directly impacts mental acuity.
- Reduced Decision-Making & Focus: Research from Harvard T.H. Chan School of Public Health found that employees in well-ventilated offices with low pollutant levels scored 61% to 101% higher on cognitive function tests compared to those in conventional buildings.
- Slower Task Performance: High pollutant concentrations are associated with slower response times, more errors in tasks (like typing or addition), and difficulty concentrating.
- Impaired Creativity: Poor air quality can stifle creativity and problem-solving abilities, which are critical to workplace innovation.
Health Issues and Morale
Poor IAQ leads to various health symptoms, commonly grouped under "Sick Building Syndrome" (SBS), which in turn impact work capacity.
- Physical Symptoms: Occupants frequently experience headaches, fatigue, dizziness, nausea, and irritation of the eyes, nose, and throat.
- Increased Illness: Poor ventilation facilitates the spread of airborne illnesses like colds, flu, and COVID-19, leading to higher rates of sickness.
- Absenteeism and Presenteeism: The resulting illnesses lead to more sick days (absenteeism) and reduced efficiency when employees do come to work while feeling unwell (presenteeism).
- Lower Morale: A workplace that neglects employee well-being can lead to reduced job satisfaction, low morale, and increased staff turnover.
Economic Impact
The cumulative effect of reduced performance and increased health costs translates into significant financial losses for businesses. Improving IAQ has been shown to boost productivity by an estimated 8% to 11% and can result in substantial economic gains for companies and the wider economy.
