People continuously exposed to air pollution are at increased risk of dementia, especially if they also suffer from cardiovascular diseases, reports a new study from the Karolinska Institute in Sweden, published in the JAMA Neurology. Researchers examined nearly 3,000 adults with an average age of 74 living in the Kungsholmen district in central Stockholm for up to 11 years. Of those, 364 people developed dementia. The district’s annual average level of particulate matter 2.5 microns or less in width is high by Swedish standards, but low compared to international standards. Heart failure and ischemic heart disease both enhanced the dementia risk, and stroke explained almost 50 percent of air pollution-related dementia cases, according to the researchers.