Indoor air quality is a critical factor in protecting health and well-being. In this article, Dr. Anna O’Donovan explains why many people underestimate the importance of indoor air quality compared to outdoor air pollution. With individuals spending up to 90% of their time inside homes, workplaces, and public buildings, poor indoor air quality can significantly impact comfort, respiratory health, cognitive performance, and overall productivity.
You can influence your indoor environment in three key ways:
• Source control – reducing pollutants at their origin
• Ventilation – bringing in fresh air and removing stale air
• Cleaning – eliminating particles and contaminants that accumulate indoors
1. Be Air Aware to Improve Indoor Air Quality
While we often think of pollution as an outdoor problem, indoor air can be even more polluted due to the accumulation of contaminants in enclosed spaces. Everyday activities, household products, and building materials can contribute to poor IAQ. Stay mindful of your indoor environment and consider IAQ monitoring devices to keep track of pollutants.
2. Maintain Ideal Humidity Levels for Healthy Indoor Air Quality
Relative humidity levels should be kept between 30% and 50% to minimize health risks. Low humidity can cause dry skin and eye irritation, while high humidity encourages dust mites and mold growth. A hygrometer can help you monitor humidity, and a dehumidifier or humidifier can help maintain optimal levels.

3. Choose Products Wisely to Protect Indoor Air Quality
Everything in your indoor space—from paint and flooring to furniture and household items—can release chemicals known as volatile organic compounds (VOCs). The “new car smell” is often a result of VOC emissions from plastics and adhesives. To reduce exposure, look for low-VOC or formaldehyde-free labels, and choose independently tested products to ensure they meet IAQ standards.
4. Enforce a No-Smoking Rule Indoors to Maintain Indoor Air Quality
Smoking indoors significantly degrades IAQ. A study in Scotland found that non-smokers living with a smoker inhale as much PM2.5 (harmful fine particulate matter) as those living in highly polluted cities like Beijing. Enforce a strict no-smoking policy at home to protect your indoor environment.
5. Reduce Candle and Incense Use
While candles create ambiance, burning them releases particulate matter and gaseous pollutants. Scented candles, even when unlit, can emit VOCs. If you choose to use candles, opt for unscented, natural wax alternatives and ensure proper ventilation.
6. Prioritize Ventilation
Modern homes and offices are built for energy efficiency, often reducing natural airflow. However, proper ventilation is crucial for maintaining good IAQ. Consider mechanical ventilation systems such as heat recovery ventilation (HRV) or mechanical ventilation heat recovery (MVHR) to introduce fresh air without excessive heat loss. If such systems aren’t available, opening windows periodically can help.
7. Control Cooking Emissions
Cooking, especially frying, produces airborne particles that can linger in indoor air. To minimize exposure:
- Use an effective exhaust hood over your stove and change the filters regularly.
- Use the back burners when possible to ensure better air capture by the hood.
- Open a window while cooking to increase ventilation.
8. Don’t Rely on Plants to Clean the Air
Despite popular belief, houseplants are not an effective solution for improving IAQ. Studies show that their ability to filter air pollutants is minimal in real-world settings. In fact, you would need about 680 plants to purify the air in a 1,500-square-foot home. Instead, focus on source control and ventilation for better results.
9. Choose a High-Quality Vacuum Cleaner
Regular vacuuming helps remove allergens and dust from floors, preventing them from being stirred into the air. However, not all vacuums improve IAQ. Some vacuums release dust, bacteria, and allergens back into the air. Look for vacuums with HEPA filters to ensure that particles are effectively trapped rather than recirculated.

10. Be Mindful of Cleaning Products
Cleaning is essential for good IAQ, but some cleaning products release VOCs and other pollutants. To clean effectively without compromising air quality:
- Use non-toxic, low-VOC cleaning products.
- Follow the manufacturer’s instructions to avoid overuse.
- Ventilate the area during and after cleaning to prevent chemical buildup.
Final Thoughts
Improving indoor air quality doesn’t require drastic changes—simple steps like reducing pollutant sources, increasing ventilation, and using the right cleaning methods can make a significant impact. As we become more aware of the importance of IAQ, prioritizing clean air indoors will contribute to a healthier and more comfortable living environment.
