Data science has emerged as a new discipline and is transforming science and society. In this talk, I will focus on “big data”, or data science at scale, more specifically in the context of environmental policy and health policy. I will use two examples to show how research data platforms can be leveraged. The first example will be from air pollution epidemiology and the second one from the current COVID-19 pandemic. I will illustrate the legal and technical, but also cultural and ethical, challenges and opportunities that we find along the way.