Europe chokes under freezing smog

Heavy pollution enveloping much of Europe prompted emergency measures across the continent on Tuesday. A toxic cocktail of extreme cold, no wind and heavy burning of coal and wood for heating has left many regions shrouded in smog. In many countries, including Britain, France and Brussels, officials have cautioned against physical exertion for children and the elderly, and for people with respiratory problems. Officials in Paris have ordered older, more polluting vehicles off the road since Monday, and cut the price of public transport.