One of the most common questions asked by people with mesothelioma is, “I was exposed to asbestos many times – How do I know which one caused my mesothelioma?”.
From a legal perspective, the short answer is (provided the exposure was not so small as to be insignificant, and provided it occurred within the latency period) each exposure caused the disease.
Expert evidence accepted by Courts in Australia is that each exposure that is not de minimis (A legal term meaning too small to be meaningful or taken into consideration) and which occurred in the latency period (at least 7-10 years prior to exposure) is a cause of any mesothelioma which later develops. The expert evidence accepted by the Court is the “single fibre theory”, the theory that there was one fibre that caused the disease, is wrong. Instead, the disease is caused by the cumulative effect of all exposures.
This theory was expressed in the High Court case of Amaca Pty Ltd v. Booth in the following terms:
“[W]hen there are multiple episodes of asbestos exposures and the individual concerned inhales increasing numbers of fibres on different occasions, that contributes to the total burden of asbestos fibres deposited in the lung and translocated to the pleura, and it is thought that mesothelioma develops because of an interaction between the asbestos fibres and the mesothelial cells by way of secondary chemical messengers[. A]and to simplify the answer, the point is that the more fibres there are, the greater number of fibres there will be interacting with mesothelial cells which themselves undergo proliferation and so the progress goes on with increasing numbers of mesothelial cells interacting with increasing numbers of fibres, so that the ultimate development of mesothelioma and its probability of development will be influenced by the numbers of fibres interacting with mesothelial cells over multiple periods of time and probably over multiple different generations of mesothelial cells[. A]nd I think this is a fairly well-accepted model now and it flies in the face of what used to be called the one fibre hypothesis that mesothelioma came about from a single fibre interacting with a single mesothelial cell which in biological terms is a ridiculous proposition.”
The practical effect in bringing claims is that a person can obtain full compensation in respect of any exposure that was causative of their disease. This means, for example, if you have been negligently exposed to asbestos in three different periods of employment, you can obtain compensation by suing in respect of any of the periods of employment. There is no requirement to sue in respect of all periods.
This does not mean that a person can double dip by first suing in relation to the first period of employment and obtaining compensation and then suing for in relation to the second period . Once compensation has been obtained in respect of one employment, you generally cannot make another claim.
It is also worth noting that the second system of “cross-claims” operates to share the cost of compensation among the defendants. In the example described above, if a claimant sued in respect of the first employment, it is common for that defendant to “cross-claim” in respect of the second and third employment. This cross-claim process generally occurs as a distinct process from the primary claim and does not create any work or risk to the primary claimant.