A US study suggests many lung cancers are routinely misattributed to smoking, when workplace and other exposures are to blame. Scientists have concluded much of the known much higher lung cancer rates in workers with less education cannot be explained by smoking.

JNCI media briefing. Gwenn Menvielle  and others. The role of smoking and diet in explaining educational inequalities in lung cancer incidence, JNCI, volume 101, pages 321-330, 2009. Risks 396.