In a somewhat unique factual circumstance, the plaintiff claimed for industrial asthma following exposure to green coffee bean dust at work for the defendant. The defendant’s business was coffee roasting and sales. The plaintiff worked in the warehouse. The plaintiff noticed breathlessness and was subsequently diagnosed with chronic obstructive pulmonary disease (COPD). The plaintiff claimed the green coffee bean dust aggravated her pre-existing asthma and COPD with emphysema. The plaintiff’s emphysema was caused by her long history of smoking.
In the plaintiff’s favour was that occupational hygienists agreed the green coffee bean dust was a ‘dangerous substance’ under the Dangerous Substances Act 2004 (ACT). There were no Australian standards or standards as to an accepted exposure level.
Associate Justice Mossop found that in the absence of a standard or safe level of exposure that the measures recommended by the hygienists of limiting exposure with ongoing monitoring would be appropriate.
Breach in favour of the plaintiff was based on the civil cause of action flowing from the Dangerous Substances Act. Unlike other legislation, express provisions were not included to remove it. Given the Act provided for implementation of a management system of handling dangerous substances and warnings, and the defendant did not have one, but subsequently implemented one, breach was satisfied based on the statutory regime.
Once this determination was reached, Associate Justice Mossop found that breach would also have been made out at common law, because the statutory duty informed the content of the duty of care in negligence.
In issue was whether the measures required under the Act would have avoided the plaintiff’s injury. In this respect, there was a conflict between the experts. In finding against the plaintiff, Associate Justice Mossop preferred the defendant’s expert, Associate Professor David McKenzie. The plaintiff relied on Professor David Barnes, a cardiothoracic physician.
The expert evidence turned on the pre-existing COPD, emphysema and ongoing sensitisation to allergens. In making the findings, Associate Justice Mossop applied the common law ‘but for’ and ‘material contribution’ test, because of the application of the statutory breach, whereas negligence was governed by the Civil Law (Wrongs) Act 2002 (ACT).
In applying the test, Associate Justice Mossop found it was only possible, but not probable that the exposure to the green coffee bean dust contributed to the aggravation of the plaintiff’s asthma.
- Underlying the requirement to establish causally related damage arising from the breach of statute or breach of duty of care is the onus lying on the plaintiff to prove on the balance of probabilities that the occupational exposure provided at least a material contribution to her asthmatic condition. I am not satisfied that the plaintiff has discharged that onus. In order for her to discharge that onus I would have to prefer the evidence of Prof Barnes to A/Prof McKenzie. I do not. Rather, if the opinion of one of the experts had to be preferred over the other I would have preferred that of A/Prof Mackenzie. That is because of the following matters:
(b) The absence of variability of her breathlessness condition during the period of employment, her condition during employment being consistent with the expected deterioration in her lung function due to COPD.
(c) The absence of any association between the severity of her symptoms and occupational exposure:
- (i) no daily pattern of symptoms;
- (ii) no rhinitis associated with exposure;
- (iii) no pattern of her symptoms improving when away from work;
- (iv) the severe event in Hawaii occurring when there was no exposure;
- (v) no recalled level of variability of symptoms during her period of employment consistent with asthma as opposed to COPD.
- (vi) the apparent gradual worsening of breathlessness over the 10-month period after leaving the employment of the defendant, most notably in the two months prior to seeing Dr Saburova in December 2012.
(d) The absence of evidence in the scientific literature referred to that green coffee beans had been demonstrated to either continue to have an asthmagenic effect beyond the period of exposure or a latent effect extending beyond the period of exposure (as distinct from the situation with Western Red Cedar referred to by Prof Barnes). Further, the absence of evidence would indicate that because of the nature of the asthmatic response it was likely that green coffee beans would produce a similar response to those asthmagens, the effects of which can continue beyond the period of exposure.
(e) The fact that Prof Barnes accepted that in the absence of exposure to green coffee bean dust he would not be looking for any other cause other than her emphysema condition for the symptoms of which the plaintiff complained.
- On the evidence I am readily able to accept that it is possible that exposure triggered a recurrence or aggravation of asthma (or at least was a material contribution to the recurrence or aggravation), but I do not accept that the plaintiff has established that on the balance of probabilities.
Associate Justice Mossop considered the alternative, namely if the defendant had complied with the Act would it have avoided the occurrence or aggravation of the plaintiff’s asthma? In finding against the plaintiff, his Honour found that it would not have changed the plaintiff’s COPD. His Honour also found by the nature of the green coffee dust that it was not possible to determine if the exposure was linear.
Because the expert evidence did not establish a relationship between the aggravation of asthma and overall cumulative exposure, it was distinguished from that in Bonnington Castings. Hence, it could have been a short period of exposure or long term, but the evidence did not assist and neither did the application of the “common sense” approach.
Hence, in the alternative, even if the plaintiff established that the exposure to green coffee bean dust was a cause of her asthma, the plaintiff failed because she did not establish on the balance of probabilities that measures which ought to have been taken, would have avoided her injury.
- If the plaintiff had established on the balance of probabilities that her occupational exposure caused or contributed to the recurrence or aggravation of her asthmatic condition she would have also been required to establish that the position would have been different in the absence of a breach of statutory duty or breach of duty of care. In other words she would be required to prove on the balance of probabilities that compliance with the statute or the absence of a breach of duty of care would have led to a different situation.
- That would have involved a comparison between the situation which in fact existed and the situation which would have existed if there was no breach of statutory duty or breach of duty of care.
- Clearly enough, having regard to the medical evidence, the plaintiff would still have suffered from COPD. The essential question would be whether compliance with the statute or the absence of a breach of duty would have avoided the recurrence or aggravation of her asthma. The difficulty for the plaintiff is that even if the evidence established, on the balance of probabilities, that her asthma had been aggravated by the occupational exposure, the relationship between the following levels of exposure is not clear:
(b) the level of occupational exposure actually experienced by the plaintiff;
(c) the level of occupational exposure that would have been experienced by the plaintiff in the absence of breach of duty.
- In relation to (a) it could be said (on the hypothesis that causation had been established) that the level in (a) was less than the level in (b). That is because the exposure did in fact cause the aggravation. It could also be said that the level in (c) would be lower than the level in (b). That is because the measures would reduce overall exposure to green coffee bean (or castor bean) dust. However, those postulates do not demonstrate that the level in (c) is less than the level in (a). It is clearly possible that the level in (a) is less than the level in (c) so that even with a reduced level of exposure the plaintiff would still have had her asthma aggravated.
- The expert evidence did not provide a basis for determining the level that would be reached if the measures that the plaintiff says should have been adopted were adopted. It is notable in this regard that there is no accepted standard identifying acceptable levels of exposure that might have been adopted. Also, both the common law and statutory duties are qualified by the concept of reasonableness and would not have involved complete elimination of exposure.
- The expert evidence did not establish that the relationship between risk of aggravation of asthma and overall cumulative exposure was a linear one. Further, it did not establish that any such relationship was applicable to the plaintiff. Thus the situation was distinguishable from that in Bonnington Castings where the expert evidence established that the cause of pneumoconiosis was caused by “gradual accumulation” of silica particles in the lungs and hence it could be said that where those particles came from two sources, one source could be said to constitute a material contribution to the plaintiff’s disease. If, in the present case, it was not a linear relationship then the basis for saying that the measures contended for would have made a difference to the aggravation of asthma in the plaintiff’s case is not established. It may instead have been long term (or short term) exposure to even very low levels of the antigen that provoked the recurrence of asthma. I do not consider that, in an area like this, it is possible to reach a conclusion based upon “common sense” that less dust would make it more likely than not the aggravation of asthma would have been avoided.
- As a consequence, even if the plaintiff had discharged the onus upon her to establish that exposure to green coffee bean dust was the cause of her asthma, her claim would still have failed because of the absence of proof to the relevant standard that the measures that the plaintiff alleges should have been taken would have avoided the aggravation of her asthma.
David Cormack – Brisbane Barrister and Mediator