Guardian: On the 5 and 6 March air pollution reached the maximum value of 10 on the UK's air pollution index levels where the public are advised to reduce strenuous outdoor physical activity. The easterly air flow that bought cold weather to the UK during March also brought particulate air pollution from traffic and industry across Europe which combined with local air pollution from our own cities. Yorkshire, Warrington and Birmingham were the worst areas affected on 5 March. The area with index level 10...