Two separate studies have identified additional risks for Alzheimer's disease. Preliminary results from an investigation performed at Washington University School of Medicine in St. Louis, Mo., suggest that disrupted sleep may be linked to Alzheimer's. After monitoring the sleep patterns of 100 men and women between the ages of 45 and 80, half of whom had a family history of Alzheimer's, the researchers found that those who awakened more than five times per hour were more likely to have the accumulations of amyloid plaque characteristic of the disease, than those who had fewer sleep disruptions. The results will be presented at the annual meeting of the American Academy of Neurology in April. Another study, published in the February 13, 2012 issue of the Archives of Internal Medicine, found a faster, long-term decline in thinking and memory skills in women living in highly polluted areas although some of these geographic locations were considered "generally safe" by the U.S. Environmental Protection Agency. The researchers compared the results of cognitive tests given to nearly 20,000 women, most of them in their seventies, and estimated air pollution around the women's homes through the EPA monitoring system.