One of the possible adaptive costs of coping with stress is diminished capacity to respond to subsequent adaptive demands. This paper examined the complex interplay between major life events and one source of chronic strain. Residents of the greater Los Angeles metropolitan area exposed to higher levels of smog, who had also experienced a recent stressful life event, exhibited poorer mental health than those exposed to pollution who had not experienced a recent stressful life event. There were, however, no direct effects of smog levels on mental health. These patterns of results were replicated in both a cross-sectional and a longitudinal study. The interplay of psychosocial vulnerability and environmental conditions is discussed.