With an ever-increasing number of elderly individuals in the world, a better understanding of the issues associated with aging and the environment is needed. The respiratory system is one of the primary interfaces between the body and the external environment. An expanding number of studies suggest that the aging pulmonary system (> 65 years) is at increased risk for adverse health effects from environmental insult, such as by air pollutants, infection, and climate change. However, the mechanism (s) for increased susceptibility in this subpopulation are not well understood. In this review, we provide a limited but comprehensive overview of how the lung ages, examples of environmental exposures associated with injury to the aging lung, and potential mechanisms underlying the increased vulnerability of the aging lung to injury from environmental factors.