The demands and pressures of modern life are precursors to two of the most deadly medical problems we face today: cardiac disease and stroke. Chronic exposure to stressful events can lead to long-term physiological dysfunction that puts people at higher risk for these serious conditions. Fortunately, there is mounting evidence that exposure to urban forests enhances the resources that allow people to more effectively manage their stresses.
Multiple studies have found that settings that include trees, grass, and open space reduce the psychological symptoms of stress. The amount of exposure to urban nature is associated with the number of visits to health care facilities, recovery time from surgery, and physiological recovery from stress. Although it is well established that exposure to urban forests has calming effects, the shape of the dose-response curve is entirely unclear. Lack of this knowledge prevents health care providers and public health officials from recommending exposure to urban forests as part of preventive health care or clinical treatment programs for the 252 million Americans who live in metropolitan areas.
Not understanding the shape and implications of the dose-response curve also costs landscape architects and urban forest managers the opportunity to make science-based management decisions that might improve the health and longevity of people in the communities they serve.
My central hypothesis is that moderate increases in exposure to urban forests result in measurable reduct ions in blood pressure, heart rate variability, electrical activity in the brain, and hormonal levels associated with stress. Therefore, through this study, I will examine the dose-response curve to determine the “dose of urban forest” necessary to reduce risk levels for cardiovascular disease and stroke, which are the number one and number three killers of Americans, respectively.