A study of cancer risk in workers exposed to metalworking fluids suggests common study approaches systematically under-estimate the true extent of the problem. Harvard University researchers say failure to take adequate account of the time lag between exposure and development of an occupational cancer – the latency period – means a significant proportion of work-related cancers can be missed.

Elizabeth J Malloy, Katie L Miller and Ellen A Eisen. Rectal cancer and exposure to metalworking fluids in the automobile manufacturing industry, Occupational and Environmental Medicine , volume 64 , pages 244-249, 2007 [abstract]. Related editorial. Risks 302.