The printing of newspapers by the letterpress process produces, in the vicinity of the printing press, a relatively stable aerosol composed of small droplets of printing ink, known as ink mist. Many methods are available for collecting and quantifying the ink mist; these are evaluated and shown to be comparable and reproducible. Letterpress newspaper inks of U.K. origin are shown to contain 3,4-benzpyrene, b(a)p. typically at levels of up to 10 mg kg −1 . The levels of ink mist determined in newspaper press-rooms are expressed in terms of typical b(a)p content, giving the level of b(a)p in the press-room atmosphere. This was found to vary between 5.2 and 18.0 μg 1000 m −3 .