In-vehicle carbon dioxide and adverse effects: An air filtration-based intervention study

Area of Science:

• Environmental Health
• Occupational Safety
• Human Physiology

Background:

• High carbon dioxide (CO2) levels in vehicles are linked to driver fatigue and drowsiness, increasing traffic accident risks.
• The impact of reducing in-vehicle CO2 via air filtration on driver physiological responses and alertness remains under-investigated.

Purpose of the Study:

• To evaluate the effectiveness of a CO2 filtration system in mitigating adverse physiological and psychological effects associated with elevated in-vehicle CO2 during driving.

Main Methods:

• Eighty-four healthy participants drove for one hour in a vehicle equipped with a CO2 filtration system under three conditions: Control (open windows), Off-mode (AC with false filter), and On-mode (AC with true filter).
• Measurements included heart rate (HR), blood pressure (BP), CO2, total volatile organic compounds (TVOCs), PM2.5, and subjective drowsiness ratings.

Main Results:

• Increased in-vehicle CO2 levels correlated with decreased HR, systolic BP (SBP), diastolic BP (DBP), and increased drowsiness.
• The most significant adverse effects were observed in the Off-mode, indicating higher CO2 impact.
• The On-mode demonstrated a reduction in HR, SBP, and DBP, alongside a slight increase in drowsiness compared to control.

Conclusions:

• Utilizing a CO2 filtration system effectively reduces in-vehicle CO2 concentrations.
• CO2 filtration can mitigate the negative effects of elevated CO2 on heart rate, blood pressure, and drowsiness in drivers.