How Driver Alertness Can be Affected by Poor Air Quality

Exhaust fumes are a major cause of air pollution in vehicles. (Image credit: Rasulov/

Exhaust fumes are a major cause of air pollution in vehicles. (Image credit: Rasulov/

Air pollution caused by cars has been discussed over the years in relation to its impact on the environment and health of people outside, such as cyclists and pedestrians. However, the impact it has on a driver’s alertness has not received much attention.

Numerous unwanted effects can occur when pollutants enter a car, hindering the performance of the driver. The air quality within cars is gaining a lot of interest in developed countries, as there are more vehicles and a great number of people use their cars for more than an hour daily.

Reasons for Poor Air Quality in Cars

The three main sources that cause a decline in air quality inside cars are described in the paragraphs below.

Exhaust Fumes

Exhaust fumes, including toxic gases such as carbon monoxide (CO), hydrocarbons (HC), and oxides of nitrogen (NOx), can enter the vehicle through heating ventilation and air conditioning (HVAC) systems. These gases are, in fact, present in vehicles at a level above the standard limits fixed by the World Health Organization (WHO).

They can lead to breathing problems in people with respiratory issues, such as asthma. In elderly people with cardiovascular issues, these gases can even cause heart attacks. They have also been known to cause dizziness, poor hand-eye coordination, headaches, and nausea, all of which can result in accidents.

Accidental poisoning could be the result of CO gas discharged by cars. Traffic jams are potential situations that raise the chances of drivers being exposed to unsafe exhaust fumes.

Car Interior Materials

Materials used in the making of vehicle interiors, such as the seats, dashboard, and steering wheel, can also affect air quality within the vehicle. This is due to the use of flame retardants made up of antimony and bromine, PVC to create the seats, and chromium to treat leather.

All of these can release volatile organic compounds (VOCs). When temperatures rise because of switching on the heating, or when cars are parked in the sun, the chances for VOC emissions grow. Symptoms such as dizziness, headaches, and nausea can happen because of exposure to VOCs.

Breathing in an Enclosed Environment

Poor air quality can also be due to the usual breathing process when it takes place in an enclosed setting. For example, in a car with the windows closed and HVAC being used in recycle mode to halt pollutants from entering the vehicle, oxygen is exhausted over time and displaced by carbon dioxide (CO2).

According to the Occupational Safety and Health Administration (OHSA) in the United States, an oxygen concentration below 19.5% is classified as dangerous. One study showed that in a car with two people, the oxygen levels were found to be only 19.1% after 15 minutes. Increased heart rate and weakened muscle coordination and judgment are experienced by drivers when oxygen levels fall.

Likewise, raised CO2 levels may cause drowsiness, resulting in fatigue. This is already one of the most critical concerns about road safety. Drivers’ reaction times can become sluggish, thus rendering them less alert.

Studies reveal that almost 20% of all accidents and a quarter of fatal or critical ones are caused due to fatigue. Another study revealed that in fatal single-vehicle crashes, the majority of cars had the windows closed and the heater on.

Improving Air Quality in Cars

Internationally, a lot of efforts have been taken to curb pollution from cars. Standards have been set in Europe to restrict the emission levels of exhaust gases such as NOx and HC. For example, in 1992, a Euro standard made it compulsory that all petrol cars have to be fitted with catalytic converters to lower CO emissions.

In recent times, some cars are designed with cabin filters often positioned under the glove compartment to avoid irritants, such as pollen, and pollutants from entering the car. This is intended to enhance driver comfort, as some gas fumes cause disagreeable odors.

Manufacturers, such as SGX Sensortech, are designing advanced devices to regulate air quality. However, these devices are yet to be incorporated as a standard component into cars. The Hyundai Genesis Sedan, launched in 2013, was the first car fitted with an internal CO2 monitor, which is engineered to reduce driver drowsiness by allowing fresh air in. CO2, which is more frequently used as a refrigerant gas in air conditioning, can lead to asphyxiation if it seeps into the vehicle.

Air quality monitors (AQMs) have also been created to avoid lethal gas accumulation in cars. The AQM’s default position is “open,” as their function is based on controlling the HVAC flaps. However, they shut in reaction to the detection of increased pollutant levels in the area. Some models of AQMs can provide audio and visual alerts when poor air quality is sensed.

Likewise, AQMs are also built to switch off the car engine when CO concentration touches harmful levels, thereby preventing suicides and accidental poisonings. In the future, AQMs may be integrated into cars as a standard safety feature, a lot like seat belts or airbags.

This information has been sourced, reviewed and adapted from materials provided by SGX Sensortech (IS) Ltd.

For more information on this source, please visit SGX Sensortech (IS) Ltd.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    SGX EUROPE SP. Z O.O.. (2020, March 13). How Driver Alertness Can be Affected by Poor Air Quality. AZoSensors. Retrieved on December 07, 2021 from

  • MLA

    SGX EUROPE SP. Z O.O.. "How Driver Alertness Can be Affected by Poor Air Quality". AZoSensors. 07 December 2021. <>.

  • Chicago

    SGX EUROPE SP. Z O.O.. "How Driver Alertness Can be Affected by Poor Air Quality". AZoSensors. (accessed December 07, 2021).

  • Harvard

    SGX EUROPE SP. Z O.O.. 2020. How Driver Alertness Can be Affected by Poor Air Quality. AZoSensors, viewed 07 December 2021,

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback