When Chinese journalist Chai Jing took a PM particle filter sampler with her during an ordinary working day in Beijing in 2012, it registered 305.91mg/m3 . The filter turned from pure white to pure black. To find out what the stuff was, she invited Dr Xinghua Qiu from Peking University to chemically analyse her sample. It contained 15 carcinogens, including biphenyl, acenaphthene, benzo(e)pyrene (one of the most potent known carcinogens) and fluorene (one of the key pollutants during the 1948 Donora disaster).
Carcinogens in PM
