Another week another course finished. This time it was M101, "health effects of hazardous substances".

As usual, the exam was disappointing, in that the questions were not all of a high standard. One of the part B questions in particular, was of concern. Although the overall question was OK - it asked about the hazardous effects of four relatively important substances, it also asked about how the substances could be "detected" required the candidates to list the relevant occupational exposure limits.

First of all what was meant by "detected"? Do they mean how do the senses detect the substances, how they can be detected by biological monitoring or how they can be detected by air sampling? It is not clear at all. And if they mean any of these aspects, they are outside the scope of the syllabus. An example of poor question writing.

I also think that expecting candidates to list exposure limits is unreasonable. For a start, there is nothing in the syllabus that requires it (limits aren't even mentioned). If the examiners do think it is fair (I assume they do given that they set the question), then it would imply that the candidates must know all the limits in EH40 as there is nothing to indicate that only a small selection need to be memorised. This is not just unreasonable but I would contend that it is bad practice to attempt to remember the contents of EH40. First of all there are more important things that need to be held inside our limited memory banks. Secondly limits change and I think that it is much better to encourage hygienists to look them up and ensure that the most current one is applied. Its easy enough to do this - especially as the main reference source is the pdf file posted on the HSE website (now that they don't publish a hard copy every year).

We should be training candidates about what limits are, where to find them and how to locate them - but not expecting them to memorise them.

Featured on Slideshare

I just received an e-mail telling me that my presentation Pollution And Human Health is currently being showcased on the Slideshare 'Health & Medicine' page.

Pollution And Human Health

This is a slideshow of my lecture to MSc students at Manchester Unversity

Pollution And Human Health

View more presentations from mikeslater. (tags: pollution environment)

Intro To Occupational Hygiene

This presentation was originally intended as an introduction to occupational hygiene for oil industry personnel. I've modified it slightly so its more generally applicable (although it still has an oil industry "slant").

Intro To Occupational Hygiene

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Introduction To Toxicology

This is an introductory presentation on toxicology.

I'll be using a slightly expanded version on day 1 of the M101 course that we are running in Chester next week.

Introduction To Toxicology

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Cupola furnace

I took this picture recently of a cupola furnace at a small foundry. Scrap metal and coal are loaded into the top of the furnace and the coal set alight to melt the scrap and produce molten metal which is used to manufacture castings.

As there is insufficient oxygen for complete combustion, carbon monoxide is generated. Hydrogen sulphide can also be produced due to the presence of sulphur in the coal. Both of these gases are highly toxic and have to be extracted to minimise the risk to the operators. Some of the gases dissolve in the molten metal and can gas off as it cools, so there can be some risk during the casting operation itself.

This is a good example of how hazardous substances can be generated during a process and which are often forgotten by inexperienced or untrained people carrying out health risk assessments.

A number of years ago I got involved with a company (NOT the one shown in the picture, I should point out) where a worker had been exposed to high concentrations of carbon monoxide when inspecting the furnace when a leak occurred. The company concerned had employed a safety consultant to carry out COSHH assessments for them. Unfortunately he based his assessments on the material data sheets for the substances bought by the company. There were no data sheets for carbon monoxide or hydrogen sulphide as they aren't bought in so there was no mention of two of the most serious risks in he foundry - i.e. potential exposure to the gases. There were other hazards he didn't consider too - metal fume created during melting and casting and exposure to respirable crystalline silica during "fettling" (the grinding of the finished castings to remove rough edges) - because again, these substances are created by the process and are not bought in.

Although most people seem to think that COSHH requires an assessment to be carried out for substances, this isn't actually the case - the assessment should actually cover the "risks created by work" where workers can be exposed to hazardous substances. Its best to start by considering the process and what workers and others can be exposed to - both bought in substances and any that can be generated by the process itself. Quite often it is the latter that present the most significant risks, as is the case with the cupola furnace and other foundry operatons. Listing the substances bought in and using the supplier's data sheets as the basis of the assessment is likely to lead to significant risks being missed.

Note: COSHH is an acronym for the British Control of Substances Hazardous to Health Regulations 2002

Evaluation

There's a management cliche that used to be quite popular a few years ago - "you can't manage what you can't measure". I'm afraid I couldn't agree less!

This may seem strange coming from an occupational hygienist, particularly as where anyone knows anything about what we do they assume we spend our time making measurements of dust, fumes, vapours noise and other hazardous agents. In fact evaluation is only part of what an occupational hygienist does and even then measurement is only one technique that we use to evaluate risk. Our prime objective is not to carry out measurements, but to control risk. In order to do that we need to know which hazardous agents present in the workplace are likely to present a significant risk - so risk evaluation is an essential prerequisite to control - but it is a means to an end, not an end in itself.

As many workplace hazards are not visible to the naked eye it s not always easy to recognise where a significant risk is present. In these situations, measuring worker exposure to the contaminants can help us to decisions on risk. However, sometimes it is obvious that a problem exists. Just take a look at the picture above. Its pretty obvious that the worker is exposed to a high concentration of fume and that improved controls are needed o protect his health (and possibly the health of others n the workplace). In such cases its better putting our time and effort into solving the problem rather than quantifying it.

Life at the Extremes

I was running the BOHS module on Thermal environment, non-ionising radiation and lighting last week. That's one hell of a course to teach. So many topics to cover and most of the attendees hadn't much experience of them.

For anyone wanting to know more about heat and cold stress, this book by Frances Ashcroft is a nice gentle introduction. It is very well written, easy to read and explains the basic principles very well with some good real life examples.

As well as heat and cold, it covers other challenging environments that might be of interest to occupational hygienists and physicians - high altitude and hyperbaric (high pressure).

Training professionals

Its been a tough week. I've been running BOHS module M201 this week with 15 delegates, none of whom have had any experience of the topics covered. The problem with the course is that there is so much to cover, particularly when the concepts are new. And as I discussed in a previous post quite a bit of the material we have to cover is not really relevant to modern practice.

M201 isn't the only BOHS module where we have this problem. Most of them have too much content for a one week course where the exam is taken at the end of the week. This is compounded by the examinations which concentrates on testing the candidates' memory rather than understanding of principles and their ability to apply them.

The modules are intended to allow trainee occupational hygienists and other people carrying out some aspect of occupational hygiene as part of their job to develop knowledge and skills they need to carry out the job competently. This requires more than just knowledge of facts.

"Bloom's taxonomy" is a well known concept used by educationalists. It was developed in 1956, by a group of educational psychologists led by Benjamin Bloom. Its a way of looking at the different types of learning, setting them out in a hierarchy with six levels, often set out in the form of a pyramid. The lowest level is "knowledge", involving learning facts which are then recalled or recognised and the highest level, is "evaluation", where judgements are made about the validity and quality of information.

The way the BOHS modules are currently set up we are mainly developing and testing knowledge with much less emphasis on the higher level skills. I would contend that in the modern world of work professionals need to absorb fewer facts and develop the ability to find the information they need, understand it (i.e. comprehensive) and then be able to apply it and use it effectively (i.e. application, analysis, synthesis and evaluation).

There are two dimensions to knowledge - breadth and depth. During a short duration course there is only so much we can expect learners to absorb. In simple terms, if we are aiming from breadth we can't expect knowledge to be too deep. Its only reasonable to expect depth of knowledge in a narrow range of topics. The BOHS syllabii require coverage of a lot of topics - i.e. breadth, but the exam questions are such that deep knowledge of each topic is required. This is a problems that needs to be addressed.

As I see it, there are a number of specific problems that need to be addressed. Currently, the module structure means that trainee operational hygienists are expected to have deep knowledge of:

• health effects of substances that are rarely, if ever, encountered in practice. How many hygienists in modern industry need to know that a symptom of excessive exposure to vanadium pentoxide is a green tongue? How many of us have actually seen one? Do we really need to know that arsene exposure can lead to “port wine urine”? How many of us have ever seen “wrist drop” caused by excessive exposure to lead? Just think of how much exposure to lead would be required for that to happen. These are things that candidates taking BOHS exams are expected to know. They are easy questions to write, but are they really relevant?

• sampling methods for a wide range of specific substances - even though this information can easily be looked up in the standard methods which have now been made freely available on the Internet by HSE and NIOSH. I think it is reasonable to expect operational hygienists to be familiar with the basic methods, but they should be encouraged to check specific details in the written method rather than rely on their memory with the consequent risk of making a mistake,
  details of analytical procedures. A long time ago the person taking a sample may have performed the analysis. With the exception of asbestos, that is rarely the case, yet our examination system persists in requiring trainee operational hygienists to learn details on analytical techniques. I can see the value in knowing what methods are appropriate for the main classes of substances we have to sample, but not for knowing the specific procedures adopted by the analyst,

• a large number of equations – is this really necessary in the real world of work? If an equation is needed for a calculation it is easy enough to look it up (if necessary BOHS provide handbook of common equations that can fit in a pocket or electronic version that could be downloaded onto a laptop, PDA or mobile phone.) They need to be able to select the appropriate equation (not as easy as it seems) and be able to use it. Wouldn't it be better to test that than the ability to memorise it. Most colleges and other bodies (including the Institute of Acoustics) provide equation sheets for exams these days.

• For some exams candidates are expected to be able to remember specific exposure limits for chemicals, and details from other standards (including remembering exposure limit values for non-ionising radiation and the TLVs for heat stress) and other similar information such as the wording of R phrases. All of these things can be easily located and looked up. Knowing where to find this information and being able to understand it is important but why does a trainee hygienist need to memorise it? In reality it will be forgotten a few days after the exam unless the information is used regularly. Again, surely it is more appropriate to expect the trainee to learn how to find information, understand it and use it.

In my working life I've seen major changes in the ability to access technical information. 30 years ago everything was printed and to obtain information you had to have access to books, journals, other documents. This meant you couldn't carry around information easily and important information which needed to be accessed quickly had to be memorised. Today things are different. Its much easier to access to information via the Internet or electronic documents that can be kept on mobile devices such as laptops, PDAs and even mobile phones. In addition, the amount of information we need to refer to continues to grow. Human memory has limited capacity, and our knowledge will rarely be completely up to date.

Currently we expect trainee hygienists to memorise large amounts of information and be able to reproduce it. There is little emphasis on interpretation, application and the higher level cognitive skills. In my view it would be much better if we changed our emphasis to a new approach where we required trainees to be able to :

• understand basic principles


• have knowledge of a smaller number of key facts


• know what information sources are available and which are relevant


• know how to search for information


• be able to interpret the information.

To support this the BOHS and Faculty could look at

• providing guidance on information sources


• making available reference material such as key equations and principles in a handbook/manual, probably in an electronic format that could be downloaded and which would be relatively easy to keep up to date.
  
  
  
  
  

Plants and indoor air quality

The TED conference has just started in California. It would be nice to be there enjoying some warm sunshine rather than shivering in the cold. At least Wigan hasn't been affected by the snow which has caused London and other parts of the country to grind to a halt!

I noticed the following posted on the TED blog - the slide show from a talk that took place today.

How to Grow Your Own Fresh Air - TED 2009 Talk

View more presentations from jaymeattle. (tags: plants greenhouse)

Plants are often proposed as a way of improving the indoor environment and there have been claims before about how they can remove air pollutants in "sick buildings". They can also, possibly, have other benefits by raising humidity in dry buildings, particularly in the winter in Britain when damp cold air is brought into the building and warmed up causing the relative humidity to plummet with consequent problems due to dry eyes, sore throats etc. The claims made in this presentation are pretty dramatic. I'll be interested to watch the video when its eventually posted on the TED site and would like to see more detail of their results to see whether the claims are justified.

(TED is an annual conference that defines its mission as "ideas worth spreading". The lectures, called TED Talks, cover a wide range of topics. The talks from past events are gradually being published via their website from where they can be viewed directly or downloaded)

Thermal stress

I'm absolutely shattered this evening. I've just got home after finishing day 2 of a BOHS module course - M201 covering thermal environment, lighting and non-ionising radiation. Its a lot of content to cover. I've had to try to compress thermal environment into two days for an audience who have had little previous involvement with the subject.

As usual with BOHS modules there is far too much content. It is particularly frustrating in that the thermal environment section of the syllabus includes a lot of material which is well out of date, does not have much relevance to current practice and is of historical interest only.

Covering some of the older, outdated material can reinforce understanding by showing how modern approaches evolved, but that is a luxury when time is limited. It means that I can't really devote enough time to teaching and reinforcing the material that is really relevant to today's practice. It also means that I haven't much time available for practical exercises that would really reinforce learning. The outdated material needs to be weeded out so that proper emphasis can be given to the information and skills that hygienists need to carry out their jobs.

I'm afraid this is par for the course with BOHS modules.

Making training stick

I've just finished reading "Made to stick" by Chip and Dan Heath - a book widely recommended on various blogs on presentation and management. Its about how to get ideas to "stick", and the principles outlined can be applied in various contexts, but the one I'm interested in is teaching and training.The core idea in the book is that to make ideas stick the message need to have a number of attributes, summed up by the acronym SUCCES. They should be

• Simple


• Unexpected


• Concrete


• Credible


• Emotional


• use Stories

The last of these is particularly important as stories usually involve concrete examples, can get to the core of the idea and can be framed to include unexpected and emotional aspects. The Heath's practice what they preach with stories (lots of examples) forming the basis for the book.The occupational hygiene profession is not very good at making things "sticky" - the very name we use for our discipline is perhaps a good example of this!

Although we often can work out what our core ideas and principles are, we are not always very good at using the other aspects discussed by the Heath's to put them across to an uninterested audience we are trying to influence, whether management, workers or regulators. For example, I was discussing the COSHH principles of good control practice with Adrian Hirst a few days ago, and we both agreed that while the principles are good and sensible, they are anything but "sticky" and its perhaps not surprising that very few people, including many general safety practitioners, have not really heard of them. From a training and teaching perspective, making ideas "sticky" is important if the learners are to remember what you've tried to get across, and the SUCCES principles can be applied to make the instruction more memorable.

Making things "simple" doesn't mean "dumbing down" but making sure ideas, however complex, are put across in a way that can be understood by learners new to the principle. Things that seem obvious to an expert need to be carefully explained. This can be made easier if the ideas are illustrated by concrete examples. Every good trainer will have "war stories" that can be used to illustrate application and implementation of the principles. Case studies too are types of stories and can be based on concrete examples and are a good way of getting the learners to think through the principles. The stories and case studies clearly need to be credible if they are to be seen as relevant by the learners.

The idea of using emotion might seem a bit airy fairy but is really about making the ideas relevant to the learners by showing them that what they are learning is relevant to them, either as individuals or as part of a group. Unexpectedness is probably the most difficult principle to apply - I think that it can only be used sparingly - you can't make everything unexpected. However its a good way of waking up the audience and grabbing attention and can be particularly useful during awareness type training, particularly where the audience might be uninterested, and can help to get the emotional "buy in" you are trying to achieve.

One thing isn't covered in the book, which is particularly important in making training and teaching "sticky". The book focuses on getting a message across and making it stick by presenting people with information i.e. by presenting the information verbally or in writing. Learning isn't just about listening and reading- quite the contrary. People learn best by doing - sometimes finding things out for themselves or reinforcing the points put across in presentations and written material. Perhaps some of the ideas in the book could be applied to practical exercises. As I've already mentioned above, they can be applied to designing effective case studies.

So all in all, a useful book. The ideas it contains have certainly stuck with me!