The LifeLines Cohort Study: a resource providing new opportunities for environmental epidemiology

Background: Lifelines is a prospective population-based cohort study investigating the biological, behavioral and environmental determinants of healthy ageing among 167,729 participants from the North East region of the Netherlands. The collection and geocoding of (history of) home and work addresses allows linkage of individual-level health data to detailed exposure data. We describe the reasons for choosing particular assessments of environmental exposures in LifeLines and consider the implications for future investigations. Methods: Exposure to ambient air pollution and road traffic noise was estimated using harmonized models. Data on noise annoyance, perceived exposure to electromagnetic fields, perceived living environment, and neighborhood characteristics were collected with questionnaires. A comprehensive medical assessment and questionnaires were completed in order to assess determinants of health and well-being. Blood and urine samples were collected from all participants and genome wide association data are available for a subsample of 15,638 participants. Results: Mean age was 45 years (standard deviation (SD) 13 years), and 59 % were female. Median levels of NO2 and PM10 were 15.7 (interquartile range (IQR) 4.9) mu g/m(3) and 24.0 (IQR 0.6) mu g/m(3) respectively. Median levels of daytime road traffic noise were 54.0 (IQR 4.2) dB(A). Conclusions: The combination of harmonized environmental exposures and extensive assessment of health outcomes in LifeLines offers great opportunities for environmental epidemiology. LifeLines aims to be a resource for the international scientific community.