Is Your Building Making Your Team Less Sharp?

Think about the last time you had a foggy afternoon at work. You couldn't focus, your decisions felt slow, and by 3pm you were running on fumes. You probably blamed a bad night's sleep or too much coffee. But here's a question worth sitting with: what was the air like in the room?

Over the last decade, a growing body of research has been quietly making a case that the air inside our buildings — the stuff we all breathe 90% of our day — has a direct and measurable impact on how we think, how we feel, and how well we perform. For facility managers and EHS professionals, this isn't just interesting science. It's a workplace risk hiding in plain sight.

Let's break down what we know, why it matters, and what you can actually do about it.

The Air-Brain Link: What Does the Research Say?

The connection between air quality and brain function isn't fringe science anymore. Researchers at Harvard's T.H. Chan School of Public Health have been studying this for years through their COGfx studies^[1] — and the findings are hard to ignore. In green buildings with better ventilation and lower pollutant levels, workers scored significantly higher on cognitive function tests covering areas like crisis response, information usage, and strategy.

In the first COGfx study^[2], 24 participants worked in simulated office environments under different air quality conditions. Those in the green-certified, better-ventilated setting scored 61% higher on cognitive performance tests. In a follow-up controlled condition with doubled ventilation rates, crisis response scores more than doubled — a 101% improvement.

The most recent phase of the COGfx Study^[3], expanded this across 302 office workers in 42 buildings spanning six countries. It found a direct relationship between PM2.5 and CO₂ exposure levels and cognitive function — with no threshold below which cognitive performance wasn't affected.

More recently, a 2024 comprehensive review published in Indoor Air confirmed that poor IAQ leads directly to symptoms that erode performance: headaches, mental fatigue, difficulty concentrating, and slower information processing. And emerging research is linking long-term exposure to indoor pollutants — particularly VOCs and fine particulate matter — to increased risk of anxiety, depression, and cognitive decline.^[4]

The Usual Suspects: Which Pollutants Affect The Brain?

Not all air quality problems affect cognition equally. Here are the key culprits that facility and EHS managers should have on their radar:

• CO₂ (Carbon Dioxide): In crowded meeting rooms and poorly ventilated spaces, CO₂ accumulates quickly. The COGfx Global study found every 500 ppm increase in CO₂ slowed response times by 1.4–1.8% and reduced throughput by 2.1–2.4%.^[3] In many offices, the 1,000 ppm mark is hit routinely — and it gets worse from there.
• VOCs (Volatile Organic Compounds): Off-gassing from furniture, cleaning products, and building materials, VOCs have been linked — independently of CO₂ — to reduced cognitive performance and mood disruption. A 2025 study in Frontiers in Psychiatry draws direct lines between VOC exposure and risk of psychiatric symptoms.^[5]
• Fine Particulate Matter (PM2.5): Indoor PM2.5 from printers, cooking, candles, and outdoor infiltration is a growing concern. Neurological research increasingly links fine particle exposure to cognitive decline and depression risk. The COGfx global study confirmed that for every 10 µg/m³ increase in PM2.5, response times slowed by 0.8–0.9%.^[3]
• Temperature and humidity: Thermal comfort is tightly bound to cognitive performance. 2025 findings using WHO-SAGE data show stronger associations between depression risk and elevated wet-bulb temperatures — with clear implications for facility management.^[6]

This Is Invisible — And That's the Problem

• Establish a baseline. Deploy continuous monitoring across your spaces to understand where CO₂, VOCs, PM2.5, temperature, and humidity sit throughout the day. Pay special attention to conference rooms, high-occupancy zones, and areas with known off-gassing sources.
• Act on the data. Real-time monitoring lets you respond proactively — adjusting ventilation before a large meeting, flagging elevated VOC readings after cleaning cycles, or identifying problem zones that need attention.
• Optimize HVAC settings. Many buildings run ventilation at minimum code levels as a cost-saving measure. The Harvard data suggests that doubling ventilation rates more than doubles performance scores — a compelling return on a modest operational change.^[2]
• Connect the dots for leadership. Frame IAQ improvements in terms of cognitive performance and mental wellbeing — not just compliance. When your C-suite is investing in mental health benefits, helping them see the physical environment as part of that equation opens budgets and builds your profile as a strategic partner.

Want to see what monitoring your facility's air looks like in practice?

Explore TSI's indoor monitoring solutions




References

[1]Harvard T.H. Chan School of Public Health — COGfx Study overview: healthybuildings.hsph.harvard.edu/cogfx 
[2]Allen JG et al. (2015). Associations of cognitive function scores with carbon dioxide, ventilation, and VOC exposures in office workers. Environ Health Perspect. DOI: 10.1289/ehp.1510037. Also covered: Harvard Gazette 
[3]COGfx Study 3: Global Buildings — findings and results: thecogfxstudy.com/study-3 
[4]Deng et al. (2024). Impact of indoor air quality and multi-domain factors on human productivity and physiological responses. Indoor Air. Wiley Online Library 
[5]Torres et al. (2025). From air to mind: unraveling the impact of indoor pollutants on psychiatric disorders. Frontiers in Psychiatry. PMC / PubMed 
[6]Nature (2025). Humid heat increases mental health risks in a warming world. nature.com