Indoor Air Quality
What Are the Health Effects of Poor Indoor Air Quality?
Poor indoor air quality (IAQ) can affect your health in many ways, from mild discomfort to serious long-term conditions. Common indoor pollutants such as smoke, mold, vapors, and chemicals found in paints, furniture, and cleaning products can all have an impact on your well-being (NIEHS).
Short-term exposure can lead to symptoms like irritated eyes, nose, or throat, headaches, dizziness, fatigue, or worsened asthma (NEEF). Long-term exposure increases the risk of more serious health issues, including respiratory diseases, heart problems, cognitive delays in children, mental health concerns, infections, and even cancer.
There are at least sixty sources of household air pollution, and these vary from country to country. These include:
• Indoor tobacco smoking
• Building and construction materials
• Fuels used for cooking, heating, or lighting
• Incense and mosquito repellents
• Pesticides and household cleaners
• Artificial air fresheners
(World Health Organization, 2016)
- Control Pollution at the Source Eliminate or reduce pollutants where possible. For example, keep appliances well-maintained and properly adjusted to reduce emissions. Adjusting to a gas stove can lower the amount of harmful gases released into the air.
- Increase Ventilation Letting in fresh air helps reduce the concentration of indoor pollutants. Use exhaust fans, open windows, and ensure that your home’s ventilation system is working properly.
- Use Air Purifiers Air purifiers with HEPA filters can help remove particles such as dust, pollen, pet dander, and smoke. Make sure to clean or replace filters regularly to keep the purifier working effectively (Harvard Health).
- Control Humidity Keep indoor humidity levels between 30 and 50 percent to prevent mold growth and reduce dust mites. Dehumidifiers and air conditioners can help regulate moisture (EPA).
- Clean Regularly Vacuum with a HEPA filter and dust surfaces using a damp cloth. Choosing hard flooring over carpeting can help reduce the buildup of dust and allergens (American Lung Association and Harvard Health).
- Avoid Smoking Indoors Smoking indoors is a major source of air pollution. Avoiding it protects everyone in the home from secondhand smoke exposure.
- Test for Radon Radon is a colorless and odorless gas that can increase the risk of lung cancer. Test your home and take corrective steps if levels are too high (EPA).
- Use Appliances Safely Ensure fuel-burning appliances are vented outside and inspected regularly for leaks. Installing carbon monoxide detectors adds an extra layer of protection (American Lung Association).
The figure below shows a comparison of indoor air quality with and without filtration (Cheek et al., 2021). Interestingly, this data was collected from different countries, but there is an emerging trend.
Do Air Purifiers Really Work?
Yes, air purifiers can help improve indoor air quality, especially when used along with other clean-air habits. HEPA filters are particularly effective and can remove at least 99.97 percent of airborne particles as small as 0.3 microns (UMass Amherst EHS).
Studies have shown that air purifiers can reduce allergy and asthma symptoms and improve respiratory health overall (Healthline). However, they are most effective when used alongside practices like proper ventilation, regular cleaning, and limiting indoor pollutants.
The effectiveness of a purifier depends on factors such as:
• The size of the room
• The type and quality of the filter
• The kinds of pollutants present in the home
Choosing a purifier that fits your specific needs is important for the best results (Healthline).
The figure below shows a comparison of indoor air quality with and without filtration (Cheek et al., 2021). Interestingly, this data was collected from different countries, but there is an emerging trend.
Things to Know When Considering Indoor Air Purification
1. How Do Air Purifiers Work?
Air purifiers use different technologies to remove pollutants from the air. Here’s a quick overview of the most common types:
• HEPA Filters
Capture 99.97% of particles as small as 0.3 microns. This includes dust, pollen, pet dander, and some bacteria.
• Activated Carbon Filters
Absorb odors, gases, and volatile organic compounds (VOCs), such as those from cleaning products or paints. They do not remove particles like dust.
• UV-C Light
Destroys bacteria, viruses, and mold. However, it doesn’t capture particles from the air.
• Ionizers and Ozone Generators
Charge particles so they stick to surfaces or fall out of the air. Ozone generators, however, can produce harmful ozone and are not recommended for home use.
2. Do Air Purifiers Really Help?
Air purifiers can be effective, but their performance depends on what you’re trying to clean from the air. Keep these in mind:
• Great for Particles
HEPA filters work well for removing allergens like dust, pollen, and pet dander.
• May Help with Germs
Some air purifiers, especially those with UV-C or high-quality filters, can reduce airborne bacteria and viruses. However, they should not replace good ventilation or hygiene practices.
• Useful for Odors and Smoke
Activated carbon filters can reduce tobacco smoke, kitchen odors, and some chemical smells.
• Don’t Replace Cleaning
Air purifiers do not remove dust or mold that has settled on surfaces. Regular cleaning is still essential.
• Can’t Fix Poor Ventilation
Air purifiers do not bring in fresh air or reduce carbon dioxide levels. Good airflow is still necessary for healthy indoor air.
3. When Should You Use an Air Purifier?
Consider using an air purifier if:
a) You or someone in your home has allergies, asthma, or other respiratory issues.
b) Your home has poor ventilation or is exposed to pollution, wildfire smoke, or nearby traffic.
c) You’re concerned about VOCs from furniture, paints, or cleaning products.
Checking Indoor Air Quality (IAQ)
1. Who Should Conduct IAQ Checks?
• Certified Professionals
Industrial hygienists, environmental health consultants, or IAQ specialists can conduct thorough assessments.
• Building Managers or Maintenance Teams
Often handle air quality checks in commercial buildings.
• Homeowners and Small Business Owners
Can use affordable air quality monitors to check basic conditions like CO₂ and humidity.
• Government Agencies
May carry out assessments in schools, hospitals, or workplaces, especially after complaints or incidents.
2. How Are IAQ Checks Done?
• Start with Observations
Look into any reports of odors, allergy flare-ups, or respiratory problems.
• Measure Key Pollutants
Use indoor air quality monitors to check levels of CO₂, VOCs, humidity, and particulate matter.
• Take Samples if Needed
For serious concerns like mold or formaldehyde, lab testing may be required.
• Check for Moisture and Mold
Tools like moisture meters and thermal imaging can identify hidden damp areas.
• Evaluate Ventilation Systems
Make sure HVAC systems are working properly and filters are clean.
• Compare with Standards
Match your results with indoor air guidelines from the EPA, WHO, or OSHA.
3. When Should IAQ Be Checked?
a) If people in the building report ongoing symptoms like coughing, headaches, dizziness, or allergies.
b) After home renovations, new furniture installations, or fresh paint.
c) In high-risk spaces like hospitals, classrooms, or poorly ventilated offices.
d) After any flooding or water damage, to check for mold or bacteria growth.
4. How Often Should You Check IAQ?
Homes: At least once a year, or more often if you notice problems.
Workplaces: Every 6 to 12 months, depending on occupancy and use.
Schools and Healthcare Settings: Every quarter, or as required by health regulations.
High-Risk and Industrial Areas: Monthly or continuous monitoring with sensors.
To help address air quality challenges in Saint Lucia, the Saint Lucia Bureau of Standards (SLBS) has already adopted relevant international standards from the International Organization for Standardization (ISO).
ISO 16000-1:2004 Indoor air — Part 1: General aspects of sampling strategy
ISO 16000-19:2012 Indoor air — Part 19: Sampling strategy for moulds
ISO 16000-20:2014 Indoor air — Part 20: Detection and enumeration of moulds — Determination of total spore count
ISO 16000-30:2014 Indoor air — Part 30: Sensory testing of indoor air
ISO 16000-32:2014 Indoor air — Part 32: Investigation of buildings for the occurrence of pollutants
ISO 16000-40:2019 Indoor air — Part 40: Indoor air quality management system
ISO 16813:2006 Building environment design — Indoor environment — General principles
ISO 16814:2008 Building environment design — Indoor air quality — Methods of expressing the quality of indoor air for human occupancy
ISO 20581:2016 Workplace air — General requirements for the performance of procedures for the measurement of chemical agents
These standards will soon be available for purchase on the SLBS website at www.slbs.org.
Sources of Information
This information is based on guidelines, research, and recommendations from reputable organizations, including:
1. World Health Organization (WHO) – Indoor air quality guidelines for pollutants like carbon monoxide, formaldehyde, and VOCs.
2. U.S. Environmental Protection Agency (EPA) – Extensive resources on indoor air pollutants, air purifiers, and ventilation.
3. Occupational Safety and Health Administration (OSHA) – Workplace safety standards, including indoor air quality.
4. American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) – Standards for ventilation and IAQ monitoring.
5. National Institute for Occupational Safety and Health (NIOSH) – Research on indoor air safety in work environments.
6. Building Science and Environmental Health Research – Studies on mold, allergens, and air quality impacts.
7. Air Purifier and IAQ Equipment Manufacturers– Product testing data and technical specifications.
For Further Reading:
If you’d like to explore the topic further, these official publications are excellent starting points:
WHO Guidelines for Indoor Air Quality: Selected Pollutants
Offers health-based recommendations on pollutants like benzene and carbon monoxide.
EPA Indoor Air Quality Resources
Covers practical steps for improving air quality in homes and businesses.
OSHA Indoor Air Quality Overview
Focuses on workplace air quality, ventilation, and exposure standards.
California Air Resources Board (CARB) Standards
Provides state-level air quality standards with public health focus.
Other Specific References
1. World Health Organization. (2016). Household air pollution and health. Frontiers in Public Health. Retrieved from https://pmc.ncbi.nlm.nih.gov/articles/PMC5089137/
2. National institute of Environmental Health Sciences Retrieved from https://www.niehs.nih.gov/health/topics/agents/indoor-air
3. National Environmental Education Foundation. (n.d.). Health impacts of indoor air quality. Retrieved from https://www.neefusa.org/story/health-and-environment/health-impacts-indoor-air-quality?
4. What can be done to prevent/improve indoor air quality at home? https://www.epa.gov/indoor-air-quality-iaq/improving-indoor-air-quality?
5. https://www.health.harvard.edu/blog/have-a-gas-stove-how-to-reduce-pollution-that-may-harm-health-202209072811?
6. https://www.health.harvard.edu/staying-healthy/easy-ways-you-can-improve-indoor-air-quality?
7. https://www.lung.org/blog/appliance-use-indoor-air-quality?
