Air pollution is responsible for 40,000 premature deaths in the UK. More than half of these are attributed to diesel fumes. Breathe London gives advice about pollution and how to reduce exposure to it. To avoid pollution in the home they advise: “Insulating your home will not only prevent heat escaping, reducing heating bills, but also help to reduce the amount of outdoor air pollution entering”. Having an open chimney is like leaving a window open all the time.