A study of the atmosphere in London underground trains before and after the ban on smoking.

Measurements of the ambient atmosphere in London Underground train compartments were made before and after a ban on smoking. Levels of nicotine and carbon monoxide and estimates of airborne particulates are given. This paper describes the analytical techniques used in measuring constituents of tobacco smoke in the ambient air of public environments. Levels observed were all found to be far lower than recommended OSHA limits for safe exposure.