How much exposure to asbestos dust does it take to cause mesothelioma?

When someone is diagnosed with mesothelioma, we know that invariably it is a disease caused by exposure to asbestos dust. Mesothelioma has a long latency period of typically between 20 and 50 years, meaning that when somebody has exposure to asbestos dust, it can then take quite some time before mesothelioma develops. 

There is currently no known “safe” level of exposure to asbestos, but when proceeding with a claim for compensation on behalf of a mesothelioma patient, we must do so on the basis of the standards and knowledge of the dangers of asbestos which applied at the time of their exposure. For example, when instructed by a carpenter who had exposure to asbestos dust in the 1960s cutting asbestos insulation board (AIB), we must apply the standards and regulations from the 1960s, rather than the standards which now apply to the use and disturbance of asbestos products such as AIB.

A recent case in the High Court, Bannister v Freemans Plc [2020] considered the extent and level of exposure which the deceased Mr Dennis Bannister suffered when he was working for Freemans Plc in the 1980s.

How was Mr Bannister exposed to asbestos?

The claim was pursued by Mr Bannister’s widow, Valerie, after he sadly died of malignant mesothelioma at 73 years old. 

The claim was pursued against his former employer Freemans Plc (“Freemans”) on the basis that they negligently exposed Dennis to asbestos more than 35 years ago during the course of his employment with them.

His case was that Freemans had negligently exposed him to asbestos dust over 35 years ago when he was their employee. It was his case that he was exposed to asbestos when working as a Manager in the Accounts Department at Freemans. 

Mr Bannister believed that he was exposed to asbestos dust when during his employment a partition wall in his office was removed over a weekend period, which resulted in a residue of asbestos which he then inhaled. Mr Bannister was not alleging that he was exposed to asbestos during the removal works, but instead to the aftermath of the removal works and the dust which had been produced. 

Mr Bannister’s evidence was supported by his friend and colleague Graham Ford who was also employed by Freemans at the time. Mr Ford remembered that the company had sent out a memo notifying them that asbestos would be removed and he believed that the exposure occurred in around 1983/1984.

What did the Judge have to consider?

When considering the claim, the Judge set out three issues which he needed to determine:

1. Was Mr Bannister exposed to asbestos dust during his employment with Freemans?
2. What was the extent of that exposure to asbestos dust?
3. Did the exposure constitute a “material increase in risk” of Mr Bannister developing mesothelioma?

Was Mr Bannister exposed to asbestos dust?

When considering whether or not Mr Bannister was exposed to asbestos during the course of his employment, the Judge considered in great detail his witness evidence and that of Mr Ford. 

Prior to his death Mr Bannister had taken part in an evidence on commission hearing.

What is an evidence on commission hearing?

The evidence on commission hearing gave the defendant’s legal team the opportunity to cross-examine Mr Bannister on his evidence in his lifetime. A video was taken of both Mr Bannister giving his evidence and the cross-examination. These “mini hearings” can take place at a claimant’s home or another location that is convenient for the claimant who may not be well enough to attend a Court. This was then presented to the Judge during the trial after Mr Bannister had sadly died.

The evidence

In addition to Mr Bannister’s video evidence, Mr Ford gave verbal evidence in the court hearing and the statements of both Mr Ford and Mr Bannister were available to the court.

The Judge scrutinised the evidence available to the Court. In his Judgment, the Judge commented that he felt that Mr Bannister’s evidence was prompted by Mr Ford’s recollection of events and that “the deceased had no significant independent recollection of being exposed to asbestos”.

The Judge concluded after assessing all of the evidence available that he was “not satisfied on the balance of probabilities that the deceased was exposed to asbestos dust when he returned to work on a Monday morning… However, on any view of the evidence the deceased was exposed to such other dust for a very short time”.

The Judge therefore found that the Claimant’s case could not be proven, as he did not consider that Mr Bannister had been exposed to asbestos dust in the way which he and Mr Ford described and therefore the claim would be unsuccessful. However, he then turned to consider the other two questions about the extent of Mr Bannister’s exposure and the increase in the risk of him developing mesothelioma. 

Industrial Injuries Disablement Benefit 

One of the issues identified by the Judge which led to his finding that Mr Bannister was not exposed to asbestos, was the fact that Mr Bannister had denied being exposed to asbestos on three other occasions prior to pursuance of his legal claim. Although he accepted the medical expert’s position that people did not often recall their exposure to asbestos dust immediately following a diagnosis of mesothelioma, he felt that there was ample opportunity for him to have recalled this exposure at some point during the three separate occasions when he was asked. 

In addition, within the Mr Bannister’s application for Industrial Injuries Disablement Benefit, Mr Bannister had referenced potential exposure with another employer, which he later denied, and the Judge felt that there was insufficient detail about his exposure within his Industrial Injuries Disablement Benefit application form, which was completed four months before his witness statement. 

The Judge’s comments in respect of the application for benefits highlight the importance of this document in a mesothelioma claim. This document is often created before a witness statement has been drafted and in some circumstances is completed before a solicitor has been instructed. 

When acting on behalf of any asbestos disease client, we assist in making applications for government benefits which they may be entitled to. Any mesothelioma patient should therefore bear in mind the importance of the benefits application forms and seek advice from an expert mesothelioma and asbestos claims solicitor or support group. 

What was the extent of the exposure to asbestos dust?

To consider this point the Judge had to put to one side his finding that Mr Bannister was not exposed to asbestos dust. His comments are therefore an expression of his judicial opinion and do not form a part of the Court’s decision. 

On review of the expert engineering evidence, the Judge felt that the deceased’s exposure to asbestos dust had given rise to an accumulative dose in the region of no more than 0.00045/ml years. 

Did the exposure constitute a “material increase in risk” of Mr Bannister developing mesothelioma?

When considering whether the above level of exposure to asbestos dust constituted a material increase of Mr Bannister developing mesothelioma, the Judge was considering whether the “particular exposure is too insignificant to be taken into account, having regard to the overall exposure that has taken place”.

When considering the risk of the development of mesothelioma, the Judge considered the statistical evidence produced by the Defendant’s medical expert. The Defendant’s expert used the total fibre/ml years assessed by the engineers to then calculate the equivalent risk based on a study by Hodgson & Darnton and used this epidemiological evidence to assess an incident as 0.2 deaths per 100,000 which he regarded as not medically material.

Based on this evidence, the Judge found that the Claimant had not established to his satisfaction, on a balance of probabilities, that any exposure suffered by Dennis had caused a material increase in the risk of him developing mesothelioma.

So what does this mean for mesothelioma claims?

The Judge’s comments about material increase in risk did not form a part of the Court’s decision. What the comments do mean though is that even if the asbestos exposure had occurred in more recent times, say in the 1980s or 1990s when the dangers of low level asbestos exposure were more widely accepted, Freemans would not have been fixed with liability. The Bannister case could therefore impact on mesothelioma cases where there have been low levels of asbestos exposure, such as our successful case involving low level exposure.

Furthermore, Claimants who recall additional incidences of asbestos exposure after they have recounted their employment history to the doctors and to the DWP could also be penalised. We find it is not unusual for people who have just been diagnosed with a fatal condition (for which there is no cure), to recollect their employment history and asbestos exposure inaccurately. Once an employment history is received from HM Revenue and Customs it can prompt further memories, as can detailed questioning by expert solicitors. Our clients are understandably often in shock in those first few weeks. Anthony, for example was fixated on a one-off incident of asbestos exposure in a supermarket which was written on his benefits forms. He later recalled British Steel exposure and the case his widow brought was successful against them alone. He died soon after we were instructed and unlike Mr Bannister’s case there was no evidence on commission hearing. More can be found about this successful case here.

Defendants are likely to push for more evidence on commission hearings which can often be stressful and nerve –racking for the claimants involved. However, our clients can rest assured that we will support them and guide them through this process if necessary to make it as easy as possible for them like we did for Martin in this case.

Support for our clients

One client said

Laura explained everything to us as a family and made the process as simple as it could possibly be. She held our hands (figuratively), explaining, guiding and answering all of our questions, communication throughout was superb. The excellent support and service provided by Laura and her team wasn't held up or interrupted in any way, even through the difficult months of the Covid-19 Lockdown. Laura has been a pleasure to deal with. We will be forever grateful that Laura agreed to take on my father's case. We could not have been in safer hands