The World Health Organization estimates that around 7 million people die every year from the air they breathe. Air pollution is a major killer around the globe and one that disproportionately affects low and middle income countries.    There are two kinds of air pollution. The first is called ambient air pollution, and that is basically the air we breathe when we are outside. The second is called household air pollution, and this is air pollution driven by the use of dirty burning  stoves inside the home.    The WHO recently released a report about the global burden of air pollution, and what communities around the world are doing to combat it. Here to discuss that report and the challenge of air pollution more broadly is Dr. Maria Neira, director of the department of public health, environment and social determinants of health at the WHO.    We talk through some of the big data and root causes of air pollution and have a longer conversation about global and local strategies to improve air quality around the world.