London Mayor Sadiq Khan wants to tax more cars that don’t meet emissions standards as part of his ULEZ expansion scheme. He says this is to improve air quality, but critics say it’s a money-generating scheme. Recently, though, some Londoners have noted that the air quality on the underground is far worse than above ground. NTD’s Malcolm Hudson followed a motoring journalist known as the Brown Car Guy through the underground to see how much pollution there is.
