Eric Kim, a research fellow in the Department of Social and Behavioral Sciences at Harvard T.H. Chan School of Public Health, recently led the first study to look at a possible link between volunteering and health care use in older adults.Why did you decide to study volunteering from a public health perspective?There is a growing body of research showing that volunteering is associated with better physical health and mental health outcomes, as well as better health behaviors.Another important reason is that the number of older adults in the U.S., and other countries, is rapidly rising. Over the next 35 years, the number of 65-year-olds is going to double. As a result, the number of chronic illnesses will likely rise causing at least two outcomes: First, there will be a large increase in the number of people suffering. Second, the rising number of illnesses is going to put a huge burden on our health care system. If volunteering does affect health care use, these findings could be used to inform new strategies for increasing preventive health screenings, lowering emergency room use and health care costs, and also enhancing the health of older adults.