• Epidemiology
• occupational health practice
• benzene

Readers of Occupational and Environmental Medicine (OEM) are quite familiar with reports that highlight clinical cases or workplace incidents that may represent sentinel events or exposures. There is a storied history of these in the field and there are countless examples of their utility and importance to doctors and researchers. Recently, when I was reviewing the archives of OEM online ((http://oem.bmj.com/contents-by-date.0.dtl); browsing this archive is an activity I highly recommend to all) I was struck by the considerable evidence of the active evolution of medicine and science. The archive is replete with published descriptions of occupational disease that, in retrospect, offer striking evidence of the incremental advance in the understanding of mechanism, diagnosis and prognosis in a large number of complex medical conditions. I was particularly attracted to two descriptions of the potential adverse effects of benzene exposure; the first presented in 1966 by the then 32-year-old Finnish occupational doctor and epidemiologist Sven Hernberg,1 and the second, a paper authored in 1971 by a group of Turkish haematologists headed by Muzaffer Aksoy.2 In 1966 benzene was suspected to be acutely toxic to the blood-forming tissues and the American Conference of Governmental Hygienists threshold limit value for benzene exposure in the workplace was 25 ppm, having been lowered from 35 ppm in 1963.

The report of …