Not only is air pollution bad for our lungs and heart, it turns out it could actually be making us less intelligent, too. A recent study found that in elderly people living in China, long-term exposure to air pollution may hinder cognitive performance (things like our ability to pay attention, to recall past knowledge and generate new information) in verbal and maths tests. As people age, the link between air pollution and their mental decline becomes stronger. The study also found men and less educated people were especially at risk, though the reason why is currently unknown.