Revision Questions

Question 1

a. What is the likely distribution in the respiratory tract of powders which are 15 , 8 and 2 µm? (3)
b. For each particle describe the mechanisms that the body may use to defend itself(7)

Answer 1

a. Generally particles which are above 10 µm will be deposited in the nasal cavity trapped by nasal hairs and mucus membranes. Particles of 7 to 10 µm will be deposited in the conducting airways. Particles of 0;5 to 7 microns will be deposited in the respiratory units that is respiratory bronchioles and alveoli.
b. Nasal cavity - nasal hairs, sneeze reflex.
Conducting airways - mucocilliary escalator
Respiratory units - alveolar macrophages
If particles cannot be moved in this way then inflammation of the membranes may occur and this may lead to the formation of fibrous cross connection (scarring).

Question 2

Outline the strengths and weaknesses of using animal testing to investigate the carcinogenic properties of a substance that people may be exposed to at work(6)

Answer 2

The principal strengths of animal testing for carcinogenicity are that they are very well developed methodology is used for a variety of test animals backed up by good understanding of the ways in which the test data must be interpreted. Testing can be done relatively quickly and avoid the impossible issue of conducting prospective cohort studies on man. There are many weaknesses to the use of animal studies namely the response varies between species so the applicability of results to man may be questionable ; cancers may have a number of contributing factors in these synergistic effects in man may not appear in healthy laboratory animals and it takes time and can be expensive.

Question 3

a. Compare and contrast retrospective cohort studies and prospective cohort studies as epidemiological methods. (6)
b. Outline the issues that can affect the reliability of the 2 epidemiology study methods. (4)

Answer 3

a. Cohort studies are concerned with establishing a cause-and-effect relationship and use exposed and unexposed groups.
* Retrospective cohort studies build an historical cohort in the past from records of exposure history and disease outcomes. Historic exposures are then estimated and disease is looked for in the present day.
* Prospective cohort study starts in the present and follows cohort forward in time, that is , exposure and health outcomes being monitored as the study proceeds. This study involves selecting groups of exposed individuals who other wise are very similar and then looking for disease in the future.
b. * Cohort size - makes a difference to the statistical significance of results. Too small a cohort and the significance of the results may cease to have meaning.
* There are issues to do with the accuracy of historical records. This can mean that retrospective studies fail to find enough reliable evidence of exposure to make good predictions.
* Complications of non-occupational exposure and lifestyle factors such as smoking drinking and diet which will affect both types of study. Did a worker develop cancer because they were exposed to a certain toxic substance in a previous workplace or because they smoked for 20 years of their life?
* Most ill health diseases have a period of latency that is, effects may take a long time to appear.
* Prospective short studies may suffer from loss of members (people die, move away, no longer co-operate)..

Question 4

Outline a hierarchy of control measures which would be applied to carcinogens in the workplace. (10)

Answer 4

1. eliminate the carcinogen where reasonably practicable.
2. Prevent exposure preferably by substitution for a non-hazardous substance or a considerably less hazardous substance.
3. Design work processes, systems and engineering controls so as to minimise the amount of carcinogen is needed or produced as byproducts.
4. Control at source, by using totally enclosed systems or by the use of local exhaust ventilation systems.
5. Use organisational measures to control numbers exposed, ends level or duration of exposure and quantities used or stored in the workplace.
6. Control the working environment including using general ventilation.
7. ProHIBiT eating drinking or smoking in potentially contaminated areas.
8. Clean surfaces.
9. Designate potentially contaminated areas and use warning signs.
10. Use safe storage, handling and disposal methods.
11. PPE as a last resort in addition to all the above.
12. Health surveillance for exposed workers.
13. Develop emergency and spillage procedures
    

Question 5

Workers in a factory making furniture are potentially exposed to a range of solvents associated with adhesives, paints and varnishes. Outline the range of factors that should be considered when assessing the health risks associated with this potential exposure. (10)

Answer 5

• Hazardous properties: toxicity/ability to cause dermatitis.
• Level of exposure: depends on quantities used, volatility
• Task & work methods - to be assessed against relevant OELs.
• Number exposed
• Type & duration of exposure
• Frequency of exposure
• Effect of mixtures: info available on SDS.
• Thresholds of exposure
• Individual susceptibility
• Adequacy of existing controls
• Health surveillance & complaints from workers.

Question 6

a. Describe the anatomical structure of the skin and describe how hazardous substances enter the body via this route. (6)

Answer 6

Skin has 3 layers:

• Epidermis - outer tough layer which has horny zone, germinal zone
• Dermis - true living skin which has blood vessels, sweat glands & nerve endings.
• Subcutaneous adipose tissues - fatty tissues used for storage purposes.
• skin is semi-permeable and some chemicals in liquid/solution form go straight through it. Examples are phenol, carbon tetra chloride. Once through the skin, the chemicals can permeate the tissues beneath the skin and enter blood vessels.
• Cuts/ abrasions allow substances to enter body tissues into bloodstream.
• Direct physical injection through the skin, by puncture of the skin with sharp objects, such as a hypodermic needle or by high-pressure gas of fluid injection e.g. from a burst hydraulic pipe.

Question 7

Explain how primary contact dermatitis occurs. Work is in a hair salon I experiencing skin irritation on their hands which in one case has been formally diagnosed as contact dermatitis. (4)

Answer 7

Primary contact dermatitis arises as a result of primary cutaneous Irritants. PCI can be chemicals such as a strong acids, strong alkalis but also physical agents such as hot or cold conditions. Frequent contact with water is a major cause of contact dermatitis. These irritants degrease or defat the skin, this results in drying out, cracking and inflammation or reddening. Dermatitis may not develop immediately. It might take a while or might arise from frequent exposure to quite mild irritants.

Question 8

a. Describe the anatomical structure of the skin and describe how hazardous substances enter the body through this route(6)
b. Explain how primary contact dermatitis occurs(4)

Answer 8

a. Describe the anatomical structure of the skin and describe how hazardous substances enter the body through this route(6)
a. skin has 3 layers:
* Epidermis - outer tough layer which has horny zone, germinal zone
*Dermis - true living skin which has blood vessels, sweat glands & nerve endings.
* Subcutaneous adipose tissues - fatty tissues used for storage purposes.
* skin is semi-permeable and some chemicals in liquid/solution form go straight through it. Examples are phenol, carbon tetra chloride. Once through the skin, the chemicals can permeate the tissues beneath the skin and enter blood vessels.
* Cuts/ abrasions allow substances to enter body tissues into bloodstream.
* Direct physical injection - from a hypodermic needle(e.g. a needle stick injury) or by high pressure gas/fluid injection (e.g. from a high pressure hydraulic pipe).
b. Explain how primary contact dermatitis occurs(4)
Arises as a result of skin contact with Primary Cutaneous Irritants. PCIs can be chemicals(solvents, strong acids) & also physical agents(hot/cold conditions).
Frequent contact with water (wet working) is a major cause of contact dermatitis. Irritants de-grease the skin, resulting in drying out, cracking and inflammation. may take a while to develop.

Question 9

Workers driving vehicles on a large construction site have reported back pain caused by exposure to whole body vibration (WBV).

(a) Outline control measures that could minimize their exposure to WBV. (7)
(b) Outline other possible work-related causes of the back pain being experienced by these workers. (3)

Answer 9

requirements of the vehicles, particularly with regards to seating and conditions of roads.
* health and safety aspects of the training the drivers receive.
* vehicle suspension or seat suspension. Job rotation : breaks from driving the vehicles could minimize exposure to WBV.
Candidates were awarded good marks for part (b) with a high proportion of candidates achieving the full three marks with good coverage of all points.
*The ergonomics of the controls in the vehicle cab and how the layout could possibly cause back pain.

Question 10

A large manufacturing organization operates from several temporary workplaces in various locations.

(a) Outline what should be considered when assessing the basis of the first-aid provision at the temporary workplaces. (5)
(b) Outline the arrangements for the provision of first aid at the temporary workplaces. (5)

Answer 10

• The nature of the work
• The numbers of the workers involved and attention to the workforce with associated risk factors.
• The addition of the workplaces being in various locations required consideration of remote working and travelling between the sites.
• Provision of adequate numbers of suitable first aiders
• The provision of training
• First-aid room to be easily identifiable.

Question 11

Sailing instructors at a freshwater sports center are at increased risk of contracting leptospirosis.

(a) Identify ill-health effects associated with leptospirosis. (2)
(b) Outline the mode of transmission of Leptospira for these sailing instructors. (2)
(c) Outline control measures the sailing instructors could take to minimize the risk of contracting leptospirosis. (6)

Answer 11

a. The disease starts with a flu-like illness with a persistent and severe headache, which can lead to vomiting and muscle pains and ultimately to jaundice, kidney failures and even death.
b. The disease can be found in the water from the urine of animals to the instructors through cuts, abrasions, and mucous membranes.
c. the instructors can:
Minimize the amount of time spent in the water.
Report any signs of rats.
Cover open cuts and abrasions with waterproof dressing.
Good occupational hygiene practices should be followed, especially washing with warm water and soap.
Shower after each shift
Ensure that sports/diving equipment and clothing is rinsed and decontaminated.

Question 12

Glass blowers use furnaces to produce molten glass that they then blow into shapes to make glasses and vases. During their work they are exposed to different types of non-ionizing optical radiation.

(a) Identify the possible ill-health effects to the glass blowers from exposure to the non-ionizing optical radiation. (3)
(b) Describe the specific requirements of the personal protective equipment that would be required to protect the glass blowers from the non-ionising optical radiation. (3)
(c) Other than ill-health effects and control measures, outline what should be considered in a radiation risk assessment.

Answer 12

a. skin cancers and eye damage in the form of cataracts and photo conjunctivitis
skin reddening and burns
b. Since the risks are to the skin and eyes, the PPE will be overalls, gloves and/ eye protection.
Skin Protection – The overalls must be flame resistant or fire retardant and long-sleeved to protect against ultraviolet radiation and leather gloves or gauntlets to protect the skin from infrared radiation would be required.
Eye Protection: Certified laser glasses to protect against infrared radiation or a full welder’s face shield.
c. Level of radiation exposure to the workers
comparison with any applicable exposure limits or values

Question 13

The UK Health and Safety Executive (HSE) identifies six stress Management Standards, one of which is Change. The requirement of this standard is that ‘Employees indicate that the organisation engages them frequently when undergoing an organisational change’.
(a) An organisation is about to undergo a significant change.
Outline steps the organisation could take to help reduce the risk of workers suffering from work-related stress as a result of this change. (6)
(b) Identify TWO other HSE stress Management Standards AND give the requirement for EACH.

Answer 13

This question was based on the HSE’s stress Management Standards, which is clearly identified as requiring tuition time in the syllabus guide. Candidates generally understand the concept of stress and how to reduce its impact within the workplace when this topic is asked in a general/holistic expression. However, in this question, candidates had to understand the individual standards, which presented a problem to the majority in this sitting.
The responses to part (a) were limited, as despite being given the definition of the standard in the question, candidates provided general answers regarding stress management. Better answers identified the need to consult with staff and inform them of the need for change, the need to ensure that staff were aware of the impact upon their jobs along with the need to have a system whereby staff could raise questions, concerns, etc.
Some candidates did not attempt part (b) providing further indication of a lack of knowledge regarding the standards. The other standards that could have been identified were Demands, Control, Support, Relationships or Role.

Question 14

Outline what is meant by the term ‘biological monitoring’. (2)

(b) Outline circumstances in which biological monitoring may be appropriate. (4)
(c) Outline difficulties an employer must overcome when introducing a program of biological monitoring.

Answer 14

Biological monitoring is the measurement of hazardous substances or their metabolites in various media.

Question 15

Workers in a busy restaurant frequently use hand-held trays to carry plates of food and drinks from the kitchen to the customers’ tables. These hand-held trays can be heavy and unstable.
There are regular incidents where workers drop the trays.
To help reduce these incidents, the employer has decided to introduce non-powered trollies, on wheels, that will be used by the restaurant workers to transport their customers’ food and drink orders.
(a) Outline what the employer should consider when selecting suitable non-powered trollies for this task. (14)
(b) Comment on how this change could affect the manual handling risks to the workers.
(c) Comment on how this change could affect other risks to the workers and to customers’ safety and health

Answer 15

• Need for consultation with staff
• The use of trials of equipment.
• The height requirements of the trolleys
• The suitability of the handles
• The requirement for brakes
• The type of wheels and floor or surfaces for stable and smooth running.
  b. The trollies reduce the risk of carrying trays
• Introduction of the trollies present a new manual handling risk.
  (c) This change could be positive, such as the reduction in carrying heavy trays; and negative, such as introducing a new risk from pulling/pushing the trollies.
• Reduced risks of food being spilled on the floors and on staff/clients with a resultant reduction in risks of slips, trips and falls.
• Increased risks associated with fire exits being blocked
• Trollies moving on their own if not properly secured.

Question 16

Building maintenance workers use hot and cold methods to strip old paint containing lead from doors and windows. This produces dust, fume and vapour containing lead.
(a) Identify the specific health effects to the workers relating to working with lead. (4)
(b) Outline the requirements for health surveillance for workers who work with lead. (4)
(c) Workers have a general duty to comply with the health and safety measures put in place by their employers.
Outline what the workers should do to protect their health. (12)

Answer 16

This question about stripping of old lead paint was not well answered; however, it was a popular question.
This question provided candidates with a scenario involving lead fumes, dust and vapours and therefore required general knowledge of the hazards of working with lead, how to monitor for exposure levels through health surveillance and how to control exposure.
Responses to part (a) of this question were limited. Many candidates did not have an adequate knowledge of the specific health effects of lead poisoning and answered in very general terms, such as nausea and headaches. Some of the better answers identified some of the well-known health effects encountered with exposure to lead, such as anaemia, weight loss and nerve damage.
(b The purpose of health surveillance is to measure the amount of lead in the workers body and for lead, biological sampling is the only effective method. At regular intervals (every 3, 6 or 12 months) during the work, blood or urine samples are provided for analysis. This method of health surveillance is well documented in examples of studies into diseases of occupations who work with lead.
(c) The question also used the general duties on workers to comply with the health and safety measures put in place by their employers to provide a framework to help candidates answer the question. Some candidates discussed a hierarchy of controls that did not answer the question, while others displayed very basic awareness of the control of hazardous substances. Better answers outlined
* workers use their training, knowing what to do if potentially exposed
* inspecting engineering controls prior to working with lead
* reporting damaged or defective equipment.

Question 17

(a) (i) Explain what is meant by the term ‘carcinogen’. (2)
(ii) Outline the advantages and disadvantages of human epidemiology. (5)
(iii) Outline the advantages and disadvantages of animal studies. (5)
(b) Outline the control measures that should be in place in a workplace where a carcinogenic substance is used.

Answer 17

This question examined the candidate’s knowledge of two topic areas, carcinogens and epidemiology. Epidemiology studies are often carried out when exploring the health effects associated with exposure to carcinogens, with animal studies being particularly useful due to the unpredictable way in which carcinogens can affect human beings.
Part (a) was answered reasonably well, although some candidates attempting this question, while having good knowledge of animal studies, proceeded to imply human epidemiology was the testing of a substance directly on humans to investigate the effect in the same way in which animal studies are carried out. In (a) (i) most candidates explained that carcinogens cause cancer, but many did not achieve a second mark for inducing a tumour, promoting genetic mutations or increasing the rate of cell division. Human epidemiology appears not to be generally well understood; however, those who had a good knowledge discussed the disadvantages with sensitivity and specificity, lifestyle factors affecting the study, and the time consuming nature associated with human studies. Advantages included the retrospective nature and use of real experiences in populations.
In (a) (iii) candidates seemed to have a better understanding of animal studies in that it is a study set up in a laboratory where animals in the test group are exposed to carcinogens intentionally and the effects observed and recorded. There was a good general understanding that an advantage is that laboratory animals have very similar or identical biochemistry to humans; however, the ethical considerations are a disadvantage.
Responses provided for part (b) were to a better standard with outlines of a managed hierarchical approach being discussed and the candidates having sufficient understanding and experience to draw conclusions from similar circumstances with hazardous substances. Many candidates were able to discuss procedures for time limitation, reduction in numbers of people exposed, prohibition of eating drinking and smoking in working areas and the need for segregation of contaminated clothing. A lesser number of candidates discussed engineering/process controls, such as total enclosure, segregation or local exhaust ventilation (LEV). Although a considerable number of candidates outlined the use of PPE, it was often in the context of routine use rather than as a temporary expedient until risk was removed or eliminated.

Question 18

during each 8-hour working day.
(i) Describe how static measurements of sound pressure level can be made while the operator is operating the machines. (4)
(ii) Explain how to determine the daily personal noise exposure (LEP,d) for the operator from the static measurements of these sound pressure levels. (3)
(b) The result of a personal dosimetry measurement of noise exposure for this operator on a similar working day provides an LEP,d that is 4 dB(A) greater than that determined in part (a).
Other than equipment errors, outline possible reasons for the difference. (3)
(c) Outline the possible technical control measures that could be introduced to help reduce the workers’ exposure to the noise.

Answer 18

This question explores the concept of measuring noise in the workplace, understanding how to determine daily personal noise exposure and the potential reasons for differences between personal and static measurements. It also asks candidates to think about the technical control measures that can be used to reduce noise exposure in a workplace.
In part (a) candidates appeared to be confused about how to measure personal noise exposure. While the question clearly states the requirement for static measurement, some candidates provided responses indicating they had dosimeters in mind. The command words are ‘describe’ and ‘explain’; however, candidates did not demonstrate they had the breadth and depth of knowledge relating to how to take static measurements and how to determine daily personal noise exposure. Some candidates were able to specify that the static measurements are taken at the operating positions with the microphone as close to the operator’s head as possible, but no discussion of the choice of sound level meter or the measurements that are taken. As some candidates did not understand how to take static measurements of sound pressure they were unable to demonstrate how those measurements are used to determine daily personal noise exposure. Those who clearly understood noise measurement were able to discuss the use of a formula or ready reckoner to convert exposure to points, add the points together and convert back into a value in dB(A).
Candidates answering part (b) were generally unable to discuss reasonable suggestions to account for the discrepancy between static and personal dosimetry results.
Better answers commented on the operator’s actual position relative to the sound measurement, different machines and materials giving variable sound outputs and the impact of other sound outputs in the workplace. There was little or no mention of wrong estimation of times spent by the operator at different machines.
Answers to part (c) included a number of generic responses, lacking in specific detail with many candidates who answered this question discussing administrative and procedural controls, rather than technical controls stated in the question. Answers were limited in scope, with a narrow range of suggestions, however suggestions to replace older and noisier equipment with newer, quieter machines, isolation and segregation of noisy equipment, the use of acoustic screens or enclosures and use of rubber or sprung mounts for the equipment were awarded marks. Any reference to hearing protection did not include reference that it was a last resort, or that it should be chosen based on octave band analysis measurements.

Question 19

An employer has an occupational health department that carries out vocational rehabilitation.
(a) Outline the meaning of the term ‘vocational rehabilitation’. (2)
(b) Outline the benefits of vocational rehabilitation to:
(i) the employer; (4)
(ii) a worker. (4)
(c) A worker is required to take 12 months away from their work to receive treatment for a long-term medical condition.
Outline what the employer can do to assist the worker BOTH during the absence and at the time of their return to work. (10)

Answer 19

This question required candidates to have knowledge and understanding of what vocational rehabilitation is, how recognising it could be of benefit to both employer and worker, and to know what an employer could do to practically implement it into their organisation.
Part (a) required candidates to know what the term ‘vocational rehabilitation’ means. Candidates were able to provide a response answer that included whatever helps someone return to work or remain in work following an absence or injury. A few were able to go on to state that it includes provision of support or access to treatment and some responses included that this might involve psychological support and overcoming physical barriers such as a new disability. Some common pitfalls were to drift off into answering part (b) and candidates are reminded to read and re-read the whole question prior to providing a response and to pay attention to the marks available.
There was some confusion between the benefits to the employer versus the benefits to the worker and candidates were generally better able to provide responses to the latter. Candidates were able to more easily discuss the direct benefits such as in part (b) (i) benefits to the employer, reduction of costs due to sickness absence with improved productivity. A few candidates were able to discuss benefits such as improved morale of the workforce. Answers to part (b) (ii) benefits to the worker, were better, with candidates able to envisage the scenario relating to a rehabilitated worker. Responses provided included that the worker would receive support during their return to work and as they remained in work. They were also able to outline that they would receive a full salary. Aside from the financial benefits, there was little awareness of the psychological benefits to the worker of the rehabilitation process such as interaction with other workers increasing their sense of belonging, self-worth and work satisfaction. Some candidates were able to see the benefits of the care expressed by an employer.
13
Answers to part (c) of the question were limited. Candidates did not demonstrate a depth of understanding of the topic, therefore not providing a breadth of responses and instead focused on the financial issues and return to work interview process. Candidates discussed the need for a phased return to work with adjusted duties and hours in the early stages of the rehabilitation process. This encompassed adjustment to working hours and work patterns.
Better answers explored the different elements that make up the return to work process and took into account the need for additional equipment, medical appointments and in some cases, homeworking/flexible working arrangements. Most candidates were not able to appreciate the strategic management approach adopted by the employer, such as the need for a single point of contact and to work with others in the organization in planning the return to work. There were also few responses that represented the administrative arrangements and principals such as gaining consent and the relevance of keeping records and reviewing risk assessments.