The general consensus is that air pollution is bad for the environment and harmful to our overall health. But did you know that studies also suggest that it's making us less intelligent? Air quality in some cities is five times higher than what the World Health Organisation recommends. With evidence suggesting that pollution, even the smallest particulates, causes damage to human and animal brains. A recent study conducted with elderly people in China, found that long-term exposure to air pollution might be hindering intellectual performance. The brain samples of people exposed to high levels of pollution showed the typical signs of Alzheimer’s disease. When mice were exposed to the same kind of pollution, they showed similar signs of reduced brain functionality and inflammation. It's still unknown what aspects of air pollution contributes the most to brain deterioration but the abnormal clumps in these brain samples contained hazardous substances that cause kidney and liver damage and cancer. This study shows a correlation between air pollution and mental decline, which grows more apparent as people age. Traffic pollution has also been linked to dementia, antisocial behaviour and stunted brain growth in children who attend schools in a highly polluted area. At the other end of the age spectrum our children are among the most vulnerable to air pollution because their brains are not fully developed. The study also identified that those less educated and men were more at risk, although the reason demographic group has yet to be determined.

Here are some ways of protecting yourself from air pollution exposure:

• Avoid short journeys to reduce your own pollution contribution
•  Avoiding rush hour traffic
• Driving more smoothly
• Keeping car windows closed and using AC to recirculate air

Driving less, walking and cycling instead will reduce overall pollution but without a concerted effort it simply means those who are trying are out in the pollution created by others. Since 2009 it has been compulsory that new cars be fitted with DPFs (Diesel Particulate Filters) to protect the environment from harmful emissions. Diesel engines favour longer journeys and by using them for shorter trips, the risk of the DPF blocking increases. Choosing to only drive when necessary would minimise the need for a DPF clean and decrease your emissions overall. The findings linking air pollution and declining intelligence, with evidence proving the link between pollution and dementia, are examples of why global air pollution levels must be reduced. Changes in car technologies and regulations provide practical ways to reduce the health risks associated with air pollution globally. Even though it is virtually impossible to protect yourself 100% from air pollution, making healthy choices and reducing exposure can minimise the effects.