- Air-pollution is among the top ten health risks faced by people and is also carcinogenic.
- New study states that pollution levels inside cars idling in traffic can be 40% higher compared to cars moving unabated.
- Sitting inside cars with closed windows but with fans switched on causes the fan to suck dirty air from outside to inside the vehicle, resulting in an accumulation of pollutants in the car.
- Changing the fan settings in such a manner that it re-circulates the air within the car without drawing in pollutants from outside and keeping windows closed is the best way to beat pollution.
The study, led by an Indian researcher, has found that pollution levels inside cars stuck in traffic can be 40% higher compared to when cars are freely moving down the road. Previous studies have shown that drivers stuck at traffic lights were exposed up to 29 times more harmful pollution particles than those driving in free flowing traffic. The World Health Organization has classified air pollution as being carcinogenic to humans and is among the top ten health risks faced by humans especially by those residing in the urban areas.
‘One of the best ways to limit exposure to pollutants while in traffic jams or stationary traffic lights is to keep car windows rolled up, fans turned off and to try and increase the distance between your vehicle and the one in front.’
AdvertisementThe findings showed that when vehicles stop at traffic signals, they go through different driving cycles such as idling, acceleration and deceleration and emission of toxic fumes. High concentration of vehicles in one area spewing pollutants leaves a cloud of emissions that take more time to disperse and they end up accumulating in the air at traffic signals, through which the drivers must navigate.
This exposure is not limited to traffic jams. Pollution exposure increases at traffic lights as well which feature idling vehicles throughout the day.
When people sit inside cars with closed windows but with fans switched on, they can be at an increased risk of exposure to the outdoor pollutants, the researchers said as the fan sucks the polluted air from outside to the inside, resulting in an accumulation of pollutants in the car.
Changing the fan settings to where they re-circulate air within the car without drawing in polluted air from outside and leaving the windows closed is the best way to beat pollution. The researchers found that this practice showed a 76% reduction in the "in-cabin" exposure to PMI (particulate matter of 1 micron or less in diameter and thought to be the most harmful).
"Where possible and with weather conditions allowing, it is one of the best ways to limit your exposure by keeping windows shut, fans turned off and to try and increase the distance between you and the car in front while in traffic jams or stationary at traffic lights," said Prashant Kumar from the University of Surrey. "If the fan or heater needs to be on, the best setting would be to have the air re-circulating within the car without drawing in air from outdoors," Kumar added.
The study published in the journal Environmental Science: Processes and Impacts, recommends the windows-closed-fan-off combination for the best reduction of exposure.
The new research has found that pedestrians are also exposed to increased air pollution around traffic signals.