There has been an ongoing debate within scientific cycles as to what is it about air pollution that damages the brain leading to cognitive decline. It is that air pollution damages the brain from limiting the amount of oxygen breathed in by the lungs or does air pollution itself damage the brain directly? A new study by German and Swiss scientists has suggested that it is latter namely poor quality air directly impairs the brain and is a potential cause of cognitive decline in the elderly. The team looked at data from over 800 elderly German women and believe that it is highly likely that particles polluting the air enter the central nervous system which may result in mild cognitive impairment. The researchers are calling for further research to confirm their findings and to help understand the exact mechanism of these changes in the brain.