"European policy making is hampered by considerable uncertainty about the magnitude and nature of the impacts of long term exposure to air pollution on human health. ESCAPE is a collaboration of more than 30 European cohort studies including some 900,000 subjects. It is aimed at quantifying health impacts of air pollution and at reducing uncertainty. ESCAPE will also test new hypotheses on specific health effects of air pollution. ESCAPE will focus on effects of within-city, within-area and within-country contrasts in air pollution, and so will enable Europe to remain at the cutting edge worldwide for further development and application of methods which have been largely pioneered here. ESCAPE will make measurements of airborne particulate matter and nitrogen oxides in selected regions in Europe. It will measure the chemical composition of the collected particles and it will store samples for future chemical and toxicological analyses. Escape will focus on four categories of cohort studies: 1. Pregnancy outcome and birth cohort studies; 2. Studies on respiratory disease in adults; 3. Studies on cardiovascular disease in adults; 4. Studies on cancer incidence and mortality. ESCAPE responds to a specific FP7 call for a large collaborative project in the Environment and Health program. The call asks for research within existing cohorts among children as well as elderly adults as sensitive groups, and it asks to consider the role of other environmental exposures such as noise, and of biomarkers and gene-environment interactions. Whereas ESCAPE will focus, as requested, on air pollution and to a lesser extent traffic noise exposures, studies have been included which contain a wealth of data on other exposures (e.g., drinking water contaminants), on biomarkers and on genetics. ESCAPE will actively engage stakeholder organisations and policy makers so that results can be swiftly translated to support policy development and implementation."