Occupational Health : Hand-Arm Vibration Medical (HAVS)

Control of Vibration at Work Regulations July 2005
The purpose of these regulations is to protect workers against risks to both health and safety from hand arm vibration syndrome (HAVS). HAVS at work can arise from using hand-held power tools (such as grinders, hammer drills and sanders), hand-guided machinery (such as lawnmowers and plate compactors) and hand-fed machinery (such as pedestal grinders).

The majority of the regulations relate to the responsibilities of the employer to protect their employees and reduce the potential for them to develop HAVS

Part of this involves surveillance of the employees so it is therefore the employers’ responsibility to ensure each employee has suitable and sufficient health surveillance carried out by a suitably qualified professional.

Regulation 7:   Health Surveillance
Health surveillance is a programme of systematic health checks to identify early signs and symptoms of disease and to allow action to be taken to prevent its progression. This allows employers to monitor the effectiveness of their control measures.

Employers are, therefore, required to introduce suitable health surveillance for employees who are at risk of exposure from hand arm vibration

As a result of the introduction of these regulations, Newcastle Occupational Health & Hygiene (NOHH) decided to offer health surveillance to both new and existing non-NHS clients, but in order to do this additional knowledge and skills were required by the same medical and nursing personnel.

Clinical Effects

Employees whose hands are regularly exposed to vibration may suffer from symptoms due to the pathological effects on:

• Peripheral nervous system
• Peripheral vascular system
• Muscles and other tissues of the hand and arm

These symptoms are collectively known as Hand Arm Vibration Syndrome (HAVS):

Neurological component includes:

• Numbness and tingling of hands
• Reduced sense of touch & temperature

Vascular component includes:

• Episodic finger blanching

Muscular & soft tissue component includes:

• Joint pain
• Stiffness in hand-arm
• Reduced grip strength

An individual with HAVS may not experience a complete range of symptoms, e.g. neurological symptoms may be present in the absence of vascular symptoms, or vice versa. Neurological symptoms generally appear earlier than finger blanching.

Carpel Tunnel Syndrome, which gives rise to tingling, numbness, weakness, pain and night wakening, can be caused by exposure to vibration.

Employees suffering HAVS can experience difficulty in carrying out work involving fine or manipulative tasks and have reduced ability to work in cold conditions. It may impact on social and family life.

• Periodic attacks of ‘white finger’ will occur on watching outdoor sports
• Everyday tasks, e.g. fastening small buttons, may become difficult

Prognosis

• Symptoms of HAVs are usually progressive with continuing exposure to vibration.
• There is individual variation in timing and rate of deterioration
• The degree to which symptoms regress on removal from exposure is not known and the condition may be irreversible
• Limited evidence to indicate that neurological symptoms do not improve
• Vascular symptoms may show improvement after reducing or ceasing exposure in individuals <45yrs and when disease has not yet reached the advanced stages associated with disability
• Any improvement is slow and may take several years
• Smoking can undermine recovery
• Vascular symptoms generally do not get worse after cessation of exposure. Where it does occur, it may be associated with other conditions
• The condition can appear up to 1 year after exposure

Competency and Training

It is necessary that the clinicians involved in HAVS screening can demonstrate the necessary expertise. It is, therefore, required that they attend a recognised training course organised by an ‘approved body’ to become a ‘qualified person’. Consequently, several of the medical staff and the Clinical Nurse Leader attended relevant courses. A tiered approach to the surveillance as recommended by the Health & Safety Executive within the regulations is applied in the following way:

Tier 1:  Initial or Baseline Assessment
This applies to new individuals or those changing jobs who are required to complete a self administered questionnaire. This is assessed by a competent person, in this case a nurse working in NOHH.

Those with no symptoms suggestive of HAVS, or relevant medical history, are considered fit for work with exposure to vibration.

Those with symptoms suggestive of HAVS (positive answers) will be further assessed by a ‘qualified person’.

Tier 2:  Annual Screening  
A self administered questionnaire is issued annually and screened by a nurse working in NOHH. Tier 3 surveillance is then recommended for those who have disclosed symptoms suggestive of HAVS. At this stage, this does not necessarily mean that the individual has HAVS but it does indicate that further clinical assessment needs to be carried out by a ‘qualified person’.

Tier 3: Assessment by a Qualified Person
A ‘qualified person’ administers a questionnaire that enquires about relevant symptoms and carries out a range of clinical tests.

Examination is aimed at vascular and neurological function in the hand and arm. A limited musculoskeletal examination is also carried out. Grip strength and manual dexterity is tested using a Purdue pegboard. If relevant symptoms are reported or clinical effects found, a formal diagnosis will be required. A presumptive diagnosis may be made depending on the skills/experience of the person, but a formal diagnosis is made by a doctor in Tier 4.

Tier 4:  Formal Diagnosis
Formal diagnosis is made by a doctor. It is required by the employer to report cases under RIDDOR 1995 and fitness for work recommendations. The reported history of symptoms is the most useful diagnostic information. Additional standardised tests (Tier 5) are an option, the results of which can be considered by the doctor when arriving at a diagnosis of HAVS.

Tier 5: Use of Standardised Tests (Optional)
In addition to clinical findings from Tiers 3 & 4, standardised tests can be conducted at some sites or referral centres for employees who have signs or symptoms of HAVS. This testing is aimed at providing a quantitative assessment which is compared against ‘normal data’. Even if such testing is carried out, the final diagnosis still depends on the judgement of the doctor and will need to take account of the reported symptoms.

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