A claim for compensation for leukaemia from benzene exposure
Leukaemia can be caused by prolonged exposure to benzene. There are a number of epidemiological studies that have been carried out in the downstream petroleum industry to investigate the risks from relatively low benzene exposures. Dr Brian Miller and other IOM scientists have been involved in reviewing the three key studies and have advised the industry about further research that should be undertaken to help understand the apparent differences in risk between studies. Benzene exposure also occurs in the upstream petroleum sector, including offshore oil and gas platforms, although there have been fewer epidemiological studies carried out in this part of the industry. However, a new study is being undertaken in the Norwegian industry and Dr John Cherrie, the IOM's Research Director, has been asked to provide advice to the study team on the estimation of benzene exposure.
IOM scientists have considerable experience in reconstructing exposure to hazardous substances for epidemiological studies and these techniques are also used to assist in the preparation of expert reports in connection with claims for damages from occupational disease. We recently acted for the Defendant in a case where an offshore oil technician alleged that exposure to benzene during his employment had caused his leukaemia.
Our expert was asked to provide an assessment of the Claimant's exposure to benzene throughout the seven years when he had worked with North Sea gas and gas condensate, both offshore and onshore. The report, which was based on the available witness statements, documentary information and the published scientific literature, provided quantitative estimates for benzene exposure levels during each task reportedly undertaken by the Claimant along with an assessment of the likely background benzene air concentrations on gas platforms. We concluded that it was likely that the Claimant was exposed to low background levels of benzene while he worked both offshore and onshore. In addition, when he undertook specific tasks involving condensate or other process streams he would have been exposed to higher levels, with the magnitude of the exposure dependant on the work activity, the proportion of benzene in the mixture and several other factors.
Using the exposure reconstruction methodology developed for use in occupational epidemiological studies it was estimated that the benzene exposure level during specific tasks could have ranged between <0.1 and 18.4 ppm. Background benzene exposure was judged to be less than about 0.009 ppm.
The Claimant's estimated cumulative benzene exposure, i.e. the product or the average level and the duration of exposure, was 5.7 ppm-years. This is comparable with the exposure experienced by many workers in UK onshore petroleum distribution.
Subsequent to finalising our report, a joint report was prepared with an occupational hygienist acting for the Claimant and this report, outlining the areas of agreement and disagreement, was submitted to the Court. The IOM expert also continued to provide advice to the solicitors acting for the Defendant to assist them in managing the case.
The case was settled with the Claimant receiving a substantial financial payment. IOM's impartial scientific assessment of the benzene exposure was an important contribution to resolving this case.