Indoor Air Quality has become an important human health and safety concern, clean air is essential for good health. Many studies demonstrate that air recirculation can reduce exposure to nanoparticles in vehicle cabins. However when people occupy confined spaces, air recirculation can lead to carbon dioxide (CO2) accumulation which can potentially lead to deleterious effects on cognitive function. It is known that in-vehicle CO2 concentration tends to increase due to occupant exhalation when the HVAC (Heating, Ventilation and Air Conditioning) air is in recirculation mode. This study establishes a major safety problem associated with automotive; Field experiments were conducted to measure CO2 concentration in a typical automotive cabin
