For many people, their biggest exposure to daily air pollution comes while they are driving their car.
Air quality inside a car can be significantly affected by heavy stop and start traffic, and over the course of a long drive, a car can accumulate levels of particulate matter (PM2.5) that are unhealthy to breathe.
The car cabin will filter the air, but vehicles differ in their ability to filter pollutants, and as it stands there is no universal test method.
Current cabin air filters are designed to remove relatively large particles like pollen and dust and are not very good at removing smaller, more harmful particles like PM2.5 and nitrogen dioxide (NO2).
Heejung Jung, a professor of mechanical engineering at the University of California has collaborated with consultancy firm Emissions Analytics to develop a more standard air pollution test method.
The researchers tested 100 vehicles and used this data to create a database that will help drivers to protect their respiratory health by including cabin air quality as something to consider when buying a new car.
The team of researchers have developed a way to open the recirculation flap door at specific angles so it can control the exchange of recirculated and fresh air.
According to the team, this method can reduce CO2 while also ensuring that PM2.5 is at an ‘acceptable’ level.
They hope that car manufacturers will incorporate this method into new and improved air filtration systems in order to benefit the health of the passengers.
Jung said: ‘When you see polluted road conditions such as congested road or lots of trucks in front of you, then you choose the recirculation mode.
‘This principle applies to all enclosed environments such as aeroplanes, buses, trains, subways and buildings.
‘We can significantly reduce exposure to air pollutants in some environments where people spend the most time with air circulation systems that include fractional recirculation.’
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