HAVSPRESENTATION

7/31/2019 HAVSPRESENTATION

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HAVS

Chris Pugh


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HAND ARM VIBRATION SYNDROME

Common condition

Serious

Preventable

Partly understood

Potentially disabling

Primarily affects men during their economically activeyears


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HAVS is a general term embracing various kinds ofdamage including

Vascular

Characteristically episodic blanching of fingers due to

arterial/arteriolar spasm, with subsequent reactive

hyperaemia (painful)

usually precipitated by cold

occurs more frequently in winter

lasts 1 minute 1 hour (approx)

normal finger colour between attacks

normal blood flow returns spontaneously or on

deliberate re-warming

symptoms such as finger pain, numbness, coldness,

loss of dexterity and co-ordination may occur during

attacks


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Sensorineural

Not precipitated by temperature changes and tend to be

constant. May include:

tingling (persistently and not just on exposure)

numbness

loss of manual dexterity

reduced sensitivity to touch/temperature


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Musculoskeletal

muscle fatigue and reduction in grip strength

Possible periarticular ossification and osteoarthritis


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Whats the Size of the Problem?

In the UK 5 million exposed to HAV

2 million at risk of developing HAVS


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What is the prognosis?

Vascular symptoms:

become more severe with continuing exposure

may improve with a reduction or cessation of exposure

any improvement may take several years

age of subject, severity of disease at cessation of exposure and

duration of exposure after onset of symptoms influence prospects ofimprovement

Neurological symptoms:

Limited evidence of improvement after cessation of exposure;appears to occur at even slower rate than improvement in vascular

symptoms


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Is there any treatment?

No generally recognised effective treatment, but some

evidence that treatment with Ca+-channel antagonists

may result in both symptomatic and objective improve-ment, even with continuing exposure


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Who is at risk?

At risk individuals are those who regularly and frequently use:

hand held power tools

hand guided powered machinery

hand fed machinery

e.g. chainsaws, rock drills, scabblers, grinders, sanders, concretebreakers, riveting hammers, needle guns, rock drills, chippinghammers, road breakers, ballast tampers, linishers, pedestalgrinders, strimmers etc., etc.


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Does exposure vary?

Yes it can vary enormously between workers

in a single worker from day to day

even where the same tool is in use for the same task

Variables include: tool type, how its being used and its condition

the strength of grip used

Impulsive tools tend to give higher exposures than rotary

action tools. Environmental conditions

Note: manufacturers exposure data may notreflect field exposure.


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Vibration at Work Regulations

To implement Physical Agents (Vibration)Directive

To control exposure to HAV and wholebody vibration

Due to become law in July 2005


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Transitional Period

Relates to limit values

Allows them to be exceeded until 2010 forequipment in use by 2007 BUT ONLY WHERE

LATEST TECHNICAL/ORGANISATIONALDEVELOPMENTS DO NOT ALLOW LIMITS TOBE COMPLIED WITH

Limits do apply to new equipment after 2007


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Requirements

Eliminate risk or if not reasonablypracticable reduce to a minimum

Carry out risk assessment and review itregularly

Assess exposure levels


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Exposure Values

These are triaxial sums and assume an 8hour working day

Exposure action value (EAV) 2.5 m/s2

A(8)

Exposure limit value (ELV) 5.0 m/s2 A(8)


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If EAV exceeded

Carry out program of organisational andtechnical measures to reduce exposure toa minimum

Appropriate to activity

Consistent with risk assessment


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What measures?

Alternative ways of working whicheliminate need to hold vibrating equipment

Appropriate tool for task, least possiblevibration

Ensuring tool accessories suitable and ingood condition

Minimise time on tool e.g. by job rotation


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What if ELV exceeded

It shouldnt be!!

If it is immediate measures need to betaken to reduce it below the ELV


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Other duties

Provide information and training

Carry out health surveillance onindividuals exposed at or above EAV


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HSE Enforcement?

Possible areas

Enforcement of ELV

Emphasis on control of risk to much

measurement to little control

Health Surveillance

?lower below EAV


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How is it caused?

Vascular

Either disorder of sympathetic nervous system leading to

vasospasm, orLocal damage to blood vessels, resulting in tendency

to episodic vasospasm

Sensorineural

HAVS is known to be associated with a loss of dermal nerve fibres.In very severe cases gross damage to peripheral trunks may be

found

Musculoskeletal

Unclear whether reported reductions in muscle strength result from

muscular or neurological damage. Osteoarthritis and periarticular

ossification at the elbow are said to occur in users of tools which

generate percussive vibration


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Stockholm grading (vascular)

Vascular component

0 No attacks

1V Mild Occasional attacks affecting onlythe tips of one or more fingers

2V Moderate Occasional attacks affectingdistal and middle (rarely alsoproximal phalanges of one ormore fingers

3V Severe Frequent attacks affecting all

phalanges of most fingers

4V Verysevere

As in stage 3, with trophicchanges in the fingertips


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Sensorineural component

Stage Description

OSN Vibration-exposed but no symptoms

ISN Intermittent numbness with or without

tingling

2SN Intermittent or persistent numbness,reduced sensory

3SN Intermittent or persistent numbness,

Reduced tactile discrimination

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HAVSPRESENTATION