I recently attended the Lane lecture, an annual event hosted by Manchester University’s Centre for Occupational and Environmental Health (COEH), held in honour of Ronald Lane, the first Professor of Occupational Medicine at the University. This year’s lecturer was Professor Paul Cullinan, Professor in Occupational and Environmental Respiratory Disease, National Heart and Lung Institute, Imperial College, London and Honorary Consultant Physician in Respiratory Medicine, Royal Brompton Hospital, London. The title of his talk was “Occupational Asthma: Too much of a bad thing” and was based around two case studies – one about exposure to enzymes in the detergent industry and the second about in-store bakers. The detergent cases study was reasonably well known but it was interesting to have the overview. It was the second one that I found particularly interesting.
According to the Health and Safety Executive, exposure to flour dust and additives such as amylase are the second most common cause of occupational asthma in Great Britain. And the numbers of workers affected is increasing.
Apparently 18% of all bread sold in the UK is made in supermarket in-store bakeries. There are 1500 of these "scratch" bakeries in the UK with a total of around 15,000 employees. Having had a number of cases of asthma referred to them from one supermarket, Professor Paul Cullinan and his colleagues managed to get funding for a study covering 20 supermarkets inside the M25. They found that 15% of the workers employed as bakers were sensitised to either flour dust or amylase (used as a flour improver) or both.
Extensive exposure measurements for flour dust had been undertaken during the study. The geometric mean total dust exposure for bakers was 1.2 mg/m3 (the paper reporting the findings gives a range two standard deviations either side of the geometric mean of 0.9 to 1.6 mg/m3 ) which means that exposures were well below the current UK Workplace Exposure Limit for flour dust, which is 10 mg/m3 . Given the proportion of the bakers suffering from asthma, this strongly suggests that the limit WEL is far too high.
Although the HSE advise that regular health surveillance is needed for bakers, we were told that of the big 4 supermarkets in the UK, only Sainsbury’s and Morrisons have any health surveillance in place. And there is little evidence that they have implemented measures to control the dust, even though solutions are available that could be applied in supermarket bakeries. Wearing a mask should be the last resort – other measures are possible and preferable – but the supermarkets won’t even allow that as the bakery staff can be seen by customers.
Bakers asthma in the UK is increasing, and it isn’t surprising given what we were told during the lecture. But the problem could be reduced significantly if well known measures are applied to control dust exposures.