Indoor Air Quality Standards for Public Buildings

Great to see a paper calling for indoor air quality in public buildings in the August edition of Science. The article can be downloaded by clicking here but it is not open access.

The key points raised in the article are summarised below as an infographic and a longer text version.

Written Summary

The article argues that indoor air quality (IAQ) standards should be legally mandated in public buildings, similar to outdoor air pollution controls. Despite decades of research, few countries have enforceable IAQ standards, even though people spend more than 90% of their time indoors and the COVID-19 pandemic highlighted the risks of airborne disease.

Key Points:

• Current gaps:
  • No harmonised global IAQ standards.
  • Most building codes focus on energy efficiency/thermal comfort, not airborne infection.
  • IA pollution sources include outdoor pollutants, indoor emissions (combustion, building materials, cleaning products), and human respiratory aerosols
• Challenges:
  • Difficulties monitoring pathogens in real time.
  • Cost and complexity of widespread IAQ monitoring.
  • Political, legal, and industrial resistance to new regulations.
• Recommended measurable indicators:
  • PM2.5: 15 µg/m³ (1-hour average).
  • CO: 100 mg/m³ (15 min), 35 mg/m³ (1 hr), 10 mg/m³ (8 hrs).
  • CO₂: ≤800 ppm (absolute value) or ≤350 ppm above outdoor levels as a proxy for ventilation.
  • Ventilation rate: 14 L/s per person when spaces are occupied.
• Implementation strategies:
  • Incorporate standards into existing legal frameworks (e.g., workplace, school, hospital regulations).
  • Use CO₂ monitoring to assess ventilation adequacy.
  • Apply natural, hybrid, and displacement ventilation where possible.
  • Support ventilation with filtration, air cleaning, and disinfection technologies.
  • Use demand-controlled ventilation to adjust during outbreaks or seasonal surges.
• Benefits of regulation:
  • Reduced airborne disease transmission.
  • Improved health, wellbeing, and productivity.
  • Long-term cost savings outweigh initial investments (example: indoor air pollution contributed to 14.1% of China’s DALYs, costing 3.45% of GDP between 2000–2017).

Conclusion:

Mandatory IAQ standards for public buildings are scientifically feasible, technically achievable, and economically beneficial. Although short-term costs and political barriers exist, global leadership and national legislation could normalise clean indoor air as a public health standard, comparable to safe drinking water.