Greenness and job-related chronic stress in young adults: a prospective cohort study in Germany

OBJECTIVES: We aimed to prospectively study the association between normalised difference vegetation index (NDVI) as a measure of greenness around homes and occupational stress. SETTING: A population-based cohort in Munich and Dresden cities was followed from age 16–18 years to age 20–23 years (n=1632). PARTICIPANTS: At baseline, all participants attended high-school while at follow-up some had started working and others studying at university. At baseline and in each follow-up, we assigned NDVI based on participants’ residential geocoded addresses and categorised it by quartiles. OUTCOME MEASURES: School-related, university-related or job-related self-reported chronic stress was assessed at the two follow-ups by the Trier Scale for Assessment of Chronic Stress using work discontent and work overload as outcomes. We modelled the association employing ordinal generalised estimating equations model accounting for changes in sociodemographics, non-job-related stress, job history and environmental covariates. Stratified analysis by each city was performed. RESULTS: NVDI at baseline was higher for participants from Dresden (median=0.36; IQR 0.31–0.41) than Munich (0.31; 0.26–0.34). At follow-up, it decreased only for participants in Dresden (0.34; 0.30–0.40). Higher greenness (quartile 4 vs quartile 1) was associated with less work discontent (OR 0.89; 95% CI 0.80 to 0.99) and less work overload (OR 0.87; 95% CI 0.78 to 0.96). In stratified analyses, results were more consistent for Munich than for Dresden. CONCLUSIONS: Our results suggest that residential green spaces, using the vegetation index as a proxy for exposure, are inversely associated with two types of job-related chronic stress in German young adults transitioning from school to university or working life.