In a report by WM Air, the West Midlands Air Quality Improvement Programme at the University of Birmingham, the research team demonstrated that charcoal filters, which typically cost around £10-£20, can effectively remove NO2 from the air within vehicle cabins.
NO2 is a common air pollutant that can aggravate diseases such as asthma and increase the risks of respiratory infections. Traffic emissions are a dominant source of NO2, so road users inside vehicles are exposed as air circulates into vehicle cabins from outside through open windows and ventilation systems.
While ventilation systems do currently filter air, this is typically via a pollen filter. These prevent tiny particles and pollen getting inside the vehicle, but they have little effect on gases such as NO2. The activated carbon filters, in contrast, remove NO2 through a process called adsorption, in which the NO2 reacts with the carbon to stick to the surface area of the filter.
As with pollen...