"As a result of age-related declines in health and functioning, older adults are particularly vulnerable to the hazards of exposure to unhealthy air," Ailshire said. "Air pollution has been linked to increased cardiovascular and respiratory problems, and even premature death, in older populations, and there is emerging evidence that exposure to particulate air pollution may have adverse effects on brain health and functioning as well."This is the first study to show how exposure to air pollution influences cognitive function in a national sample of older men and women. It suggests that fine air particulate matter - composed of particles that are 2.5 micrometers in diameter and smaller, thought to be sufficiently small that if inhaled they can deposit deep in the lung and possibly the brain - may be an important environmental risk factor for reduced cognitive function