HAVS Risk Management

 

Medical Health Surveillance

Health Surveillance is necessary to help detect any early signs of HAVS symptoms and to monitor the effectiveness of control measures put in place to prevent those identified with symptoms progressing to a worsening condition.

The generic heading of HAVS is complex as it describes a multitude of disorders requiring different types of medical assessment for their detection.

Initial questioning will help identify those employees who are susceptible to developing the injury but further examination by a qualified medical practitioner is necessary.

Assessment will include a clinical inspection of the hands/arms and requires completion of number of medical tests designed to test vascular pulse, manual dexterity, grip strength, touch and sensory nerves, cold provocation etc.

 

Once medical assessments are complete individuals are staged according to the Stockholm Workshop System 86 (1987).

A scale of the neurological component of the HAV syndrome proposed at the Stockholm Workshop 86 (1987), consisted of 3 stages according to symptoms and results of clinical examination and objective tests;

  • 1. Sensorineural stages of the Stockholm Workshop scale for hand-arm vibration syndrome

Stage

Signs and symptoms

0SN

Exposed to vibration but no symptoms

1SN

Intermittent numbness, with or without tingling

2SN

Intermittent or persistent numbness, reduced sensory perception

3SN

Intermittent or persistent numbness, reduced tactile discrimination and/or manipulative dexterity

Source: Stockholm Workshop 86 1987.

  • 2. Numerical system for VWF symptoms was developed by Griffin and based on scores for the blanching of different phalanges; The Stockholm Workshop scale for staging cold-induced Raynaud's phenomenon in the hand-arm vibration syndrome. Stage Grade Symptoms

Stage

Grade

Symptoms

0
-

No Attacks

1

Mild

Occasional attacks affecting only the tips of one or more fingers

2

Moderate

Occasional attacks affecting distal and middle (rarely also proximal) phalanges of one or more fingers

3

Severe

Frequent attacks affecting all phalanges of most fingers

4

Very severe

As in stage 3, with trophic skin changes in the finger tips

Source: Stockholm Workshop 86 1987.

  • 3. The Health & Safety Executive have also produced a table showing the functional affect outlining work and social interference

Stage

Condition

Work & Social Interference

0

No blanching of digits

No complaints

0T

Intermittent tingling

No interference with activities

0N

Intermittent numbness

No interference with activities

1

Blanching of one or more fingers without tingling & numbness

No interference with activities

2

Blanching of one or more fingers with numbness – usually confined to winter

Slight interference with home & social activities

3

Extensive blanching, frequent attacks in the summer as well as winter

Definite interference at work, at home, with social activities, restriction of hobbies

4

Extensive blanching most fingers, frequent episodes summer and winter

Occupation change to avoid further exposure because of severity of signs and symptoms

  • 4. The Physical Agents (Vibration) Directive (220/44/EC) introduces control measures for vibration exposure

Levels (ms-1) 

A(8)*

Definitions

Threshold

1

The exposure value below which continuous and/or repetitive exposure has no adverse effect on health and safety of workers

Action

2.5

The value above which one or more of the measures** specified in the below must be undertaken

Exposure limit value

5

The exposure value above which an unprotected person is exposed to unacceptable risks. Exceeding this level is prohibited and must be prevented through the implementation of the provisions of the Directive***

* A(8) = 8 h energy-equivalent frequency-weighted acceleration.
** Information, training, technical measures, health surveillance.
*** Appropriate measures for the protection of health and safety.