Asthma is a common lung disease that makes breathing difficult. When it is caused by breathing in hazardous substances in the workplace, it is called occupational asthma.

Baker’s asthma is an occupational asthma that bakery employees develop after being exposed to cereal grains such as wheat, rye and yeast. The allergy can be life-threatening and eventually affect their ability to work.

Globally, research shows between 12% and 26% of bakers suffer from allergic rhinitis (itchy eyes) or conjunctivitis (runny nose), and between 15% to 21% have bakers asthma.

In South Africa, between 17% and 31% suffer work-related respiratory and ocular-nasal symptoms, and about 13% eventually develop baker’s asthma.

But at least double the number of employees show symptoms of wheat flour sensitivity. With continued exposure this can lead to them developing baker’s asthma.

To tackle the challenge of flour dust, various countries have proposed exposure limits for flour dust. In the US industrial hygienists’ bodies have adopted a threshold of flour dust per cubic metre. In Holland, the Dutch Expert Committee of the Health Council also have a grain dust limit.

Although South Africa has a general dust standard level ten times higher than international norms for flour dust, it has no legislation with specific exposure limits for flour dust allergens such as wheat, rye and yeast.

The high sensitisation potential of grain dust makes the South African standard unacceptable in protecting the health of workers. It is a source of concern.

HOW THE ALLERGY DEVELOPS

If bakery employees who are sensitive to flour dust continue to be exposed to elevated levels of dust, they first develop eye or nose symptoms before they develop asthma.

The frequency of the sensitisation to wheat flour and yeast or other raising agents increases with the intensity of their exposure. The longer the person is exposed or the higher the dust levels, the greater the risk of developing allergy and asthma due to allergens in the flour dust.

International reviews show that between 5% and 28% of bakery workers have a wheat flour sensitivity while between 2% and 16% have a reaction to yeast or other raising agents.

In South Africa, 26% are wheat-flour-sensitive; about 24% are also sensitive to rye flour; and another 4% show a yeast reaction.

Workers with bakers asthma and/or allergic symptoms require medical treatment and workplace remediation. They are treated in the same way as non-occupational asthma sufferers. The most important medication is inhaled bronchodilators and regular use of inhaled corticosteroids. Nasal and eye symptoms are similarly treated with antihistamine medication and local corticosteroid.

Symptoms can be controlled with the appropriate medication and less exposure, but some workers require chronic treatment.

In addition, redeploying workers to minimise further exposure to bakery allergens is strongly advised. Preventative measures should be aimed at reducing workplace exposure and reducing airborne dust generated by baking processes.

CHANGING PRACTISES

International research shows there is a direct relationship between occupational asthma and exposure to airborne allergens. The intensity of the exposure to sensitising agents is the most important risk factor for occupational asthma.

This suggests that reducing allergen exposure levels may reduce the number of sensitised bakery workers.

Despite the overwhelming evidence that workplace exposures to flour dust should be controlled, there are sub-optimal prevention strategies in bakeries.

Primary prevention strategies aimed at reducing workplace exposure to sensitising agents would be the most rational approach for reducing the burden of occupational asthma.

Our study introduced various interventions to reduce the possibility of baker’s asthma. It includes introducing lids on mixer tubs, dust masks for “dusty” tasks, and better housekeeping routines to minimise flour dust exposure.

As part of our study we introduced techniques for bakery employees that would reduce flour dust. These formed part of dust control manual and a training DVD that was developed to educate bakers on how to reduce the dust levels in their workplaces. These included:

using a sieve instead of throwing flour around;

using oil instead of flour to prevent dough sticking to the kneading board during bread baking; and

using a vacuum cleaner or sprinkling the floor with water when sweeping, to prevent the flour dust becoming airborne.

The overall effect of the intervention – evaluated one year later – revealed a 50% decrease in mean flour dust, wheat allergen and rye exposures in bakeries.

It also resulted in a supermarket chain implementing the use of mixer tub lids as a standard feature in bakeries, and using the DVD to train all new bakers as part of their induction programme.

NEW LAWS ARE NEEDED

The challenge with many of the measures introduced internationally are that they are not totally protective and there has been very little implementation beyond general requirements.

Considering South Africa’s high levels of flour dust a guideline on the workplace management of baker’s allergy and asthma should be adopted.

But South Africa’s National Department of Labour should also consider revising the “grossly inadequate” flour dust exposure standard to bring it in line with international best practice.

*First published in the The Conservation at http://theconversation.com/how-bakers-can-get-itchy-eyes-and-asthma-if-flour-dust-is-not-contained-63310

Image courtesy of stockimages at FreeDigitalPhotos.net

Recently at a major German Research facility a talk relating to the micro-, meso- and macro- scales of research in Earth Science was delivered. It was interesting to note how we as geoscientists are integrating multiple tools in order to better understand the world around us and thus in turn improve society as a whole. Possible future projects were also outlined and these delved into the unknown. The real personal question which arose is “Where did all of this thinking originate?”

In order to properly understand geoscience one has to delve into the past and see where the thinking originates from, how it has developed and consequently what has moulded our thinking. It is critical to note that great geoscientists of the past were not necessarily geoscientists by classification and looked at problems from a holistic viewpoint. These great minds were keen observers, thinkers and in many cases philosophers and mathematicians with an interest in the world around them.

The Pyramids at Giza, in Egypt, are a prime example of the applied geosciences. The stones were sourced from another location, due to the fact that the designers knew of the ability of the material to withstand the elements. Furthermore the exact design, orientation and location of these ancient wonders allows one to believe that applied geological science was in existence some 3000 years before Christ, but nobody had the nomenclature in order to classify it.

When standing in the presence of these structures, armed with this knowledge, one can only stare in awe and only imagine how, when and where the idea for these magnificent structures came about. Everything about these three large pyramids is amazing. This leads you to question whether the deeper understanding of the magnificent history of science could guide our future applications.

When one looks into the annals of history we find that as early as 300 BC in Ancient Greece Theophrastus, who was a student of Aristotle and Plato, was examining concepts relating to geological science.

He was a philosopher and deep in thought about processes on earth. His ideas were guided by those of Aristotle who made critical observations of the slow rate of geological change. Furthermore his teacher also hypothesised what happens to water below the subsurface. It is interesting to note that the basis for earth science as we know it was deep thought observation and critical analysis.

Approximately 1300 years later Ibn Sina commented on the work of Aristotle and further delved into these surface processes, mountain formation, sources of water, formation of minerals and the origin of earthquakes. Thereafter Shen Kou, who was also a naturalist, proposed the modern theories of Geomorphology.

This Chinese scientist, who dabbled in many fields, observed surface processes and the erosion of mountains as well as the consequent deposition of materials in the ocean. From a better understanding of these processes we have learnt to understand the formation of offshore mineral resources and thus extract them.

The initial applied use of geological science related to the extraction of resources, as previously mentioned. This can be seen from the oldest gold mine in the world in Georgia, which supposedly dates back to the third millennium B.C. This application in turn affected where we situate our dwellings, the materials used to construct these dwellings, as well as the relationship/impact we had with/on the immediate (surrounding) environment. It is a known fact that settlements were located along rivers in order to minimise the amount of time spent on collecting water. This life source also caused destruction when flooding occurred, yet we persisted in living on the floodplain.

More recently and closer to home, due to the groundwater resources supplying the majority of the country’s freshwater, Henry Darcy became the father of hydrogeology in 1856. He examined flow in saturated porous media in the water supply of Dijon, France and then announced a law named after him.

Thus heralded an era of French Mathematics, particularly applied to the earth sciences, which we have never seen before. Charles Matheron, Benoit Mandelbrot and Pierre Gy all looked at problems related to understanding the earth.

Thus it is clearly evident that a rich history of geoscience has lead to the point whereby we are at the cutting edge of great discoveries and integration of knowledge. The future is so bright I have to wear shades!

Dr. Gaathier Mahed (Pr.Sci.Nat)
Senior Lecturer
Department of Environmental and Occupational Studies