Evidence of causal association and mechanism has been slowly gathering since the late 1980s. The International Agency for Research into Cancer (IARC) has now published a position statement. Their conclusion: diesel exhaust is carcinogenic to humans.
http://download.thelancet.com/flatcontentassets/pdfs/S1470204512702802.pdf
Estimates for the UK indicate that up to 1000 lung cancers and around 100 bladder cancer cases each year could be a result of occupational exposure. There are no diesel exhaust exposure standards in the UK but standards exist in the USA and it is likely that these are regularly exceeded in some kinds of work.
Perhaps it would be a good time to undertake a thorough review of liability exposure and the barriers to liability exposure.
The next issue of the Radar journal will begin that process.
Evidence from:
Lancet June 15, (2012) DOI:10.1016/S1470- 2045(12)70280-2
and
DT Silverman et al. J Natl Cancer Inst (2012) Vol.104 p 1–14