Understanding Health Surveillance: Applications and Appropriate Usage

An integral aspect of occupational health involves assessing how the work environment can potentially impact the well-being of workers. Employers have a responsibility to ensure that the work does not have adverse effects on the health of their employees. Health surveillance is a systematic program that involves regular health assessments aimed at identifying any work-related illnesses.

According to health and safety laws, health surveillance is mandated when workers continue to be exposed to health and safety risks, even after implementing control measures. This requirement exists because control measures may not always be fool proof, despite thorough checks, training, and maintenance. Health risks that necessitate health surveillance include noise, vibration, and exposure to hazardous substances.

Furthermore, specific hazards such as asbestos, lead, and ionizing radiation also require health surveillance and medical monitoring in accordance with legal requirements.

Exploring the Spectrum of Health Surveillance Methods

Hearing surveillance/Hearing checks

Surveillance for hearing will require a hearing test performed at regular intervals in a controlled manner. Ideally starting before workers are exposed to noise, however it can be used for individuals starting new jobs or changing roles, this will give baseline information. It can be started at anytime if employees are exposed to noise. Followed by annual checks for the foreseeable future if risk to damage is high or damage to hearing is evident.

The Control of Noise at Work Regulations 2005 (Noise Regulations 2005) require employers to prevent or reduce risks to health from exposure to noise at work. There are lower and upper exposure action values that require specific action to be carried out.
The values are:

• lower exposure action values:
  • daily or weekly exposure of 80 dB(A)
  • peak sound pressure of 135 dB(C)
• upper exposure action values:
  • daily or weekly exposure of 85 dB(A)
  • peak sound pressure of 137 dB(C)

 
Regarding health surveillance and noise, it is a requirement when workers are exposed to the upper exposure action value, which is 85 dB(A) over a daily or weekly basis and peak exposure of 137dB(C).

The difference between dB(A) and dB(C) is that the A weighting like the human ear, effectively cuts off the lower and higher frequencies that the average person cannot hear and C-weighting is less severe on low frequencies than A-weighting and represents the response of the human ear to loud sounds (over 100 dB).

This is not taking hearing protection into account, as with PPE being the last line of defence it is difficult for employers to categorically say that the employee’s being exposed wore their hearing protection devices correctly for the entirety of them being exposed at or above 85 dB(A).

Lung function checks or skin checks

The law requires you to adequately control exposure to materials in the workplace that cause ill health. This is the Control of Substances Hazardous to Health Regulations (COSHH).
Health surveillance is a process; it may be a regular planned assessment of one or more aspects of a worker's health, for example: lung function, usually a spirometry test or peak flow test or skin condition check which would usually be a questionnaire/examination.

However, it is not enough to simply carry out suitable tests, questionnaires or examinations. Employers must then have the results interpreted and take action to eliminate or further control exposure. It may be necessary to redeploy affected workers if necessary.
It is necessary to develop a health surveillance programme if workers are regularly exposed to substances that;

• a disease is associated with the substance in use (eg COPD, Asthma, Dermatitis, Cancers);
• it is possible to detect the disease or adverse change and reduce the risk of further harm;
• the conditions in the workplace make it likely that the disease will appear.

 
This would cover many substances and many workplaces, eg coal-mine dust, silica, flour dust, grain, wood dust, metal fumes, and irritating gases such as nitrogen oxides and sulphur dioxide can all cause a disease such as chronic obstructive pulmonary disease (COPD). Some of these can cause other diseases too. However, if monitored and risk of exposure is low, employers may decide that health monitoring is unsuitable.
 

Substance	Notation	Recommend Health surveillance
Respirable Crystalline Silica	Carc	Yes
Flour	Sen	Yes
Grain	Sen	Yes
Sulphur dioxide	No notation on WH40 but associated with disease/exacerbation with asthma	Yes
Nitrogen oxides	No notation on WH40 but associated with disease	Yes
Nickel (sulphate)	Sen	Yes
Glutaraldehyde	Sen	Yes
Softwood dust	Sen	Yes
Hardwood dust	Carc, sen	Yes
Benzene	Carc, Sk	Yes
Cobalt	Sen	Yes
Isocyanates	Sen	Yes

 
Health surveillance is applicable when any substance with a notation has been detected, even if below the WEL.

If it has been deemed necessary, the employer would need to appoint a qualified health professional. To assess workers' respiratory health before they start a relevant job to provide a baseline, this would usually be a lung function test and questionnaire. Introduce regular testing as advised by the health professional. This could involve further questionnaires and lung function assessments on either annual basis or sooner if abnormalities arise. The health professional must explain the test results to the individual and report to you on the worker's fitness to work. Health professionals should be suitably qualified, eg with an Association for Respiratory Technology and Physiology (ARTP) diploma. This means that their tests will be ‘right’. Health professionals should interpret the result trends for groups and individuals and identify any need to revise the risk assessment.

Hand arm vibration checks tier 2 & 3

 
The purpose of the Control of Vibration at Work Regulations 2005 is to make sure that people do not suffer damage to their health from hand-arm vibration (HAV) – so controlling the risks from exposure to hand-arm vibration should be where you concentrate your efforts. Every year approximately 3000 cases of industrial injury disablement benefit are made in relation from exposure to HAV.

The regulations introduced exposure action valves below;

• Exposure action value (EAV) of 2.5 m/s² A(8) at which level employers should introduce technical and organisational measures to reduce exposure.
• Exposure limit value (ELV) of 5.0 m/s² A(8) which should not be exceeded.
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It also requires employers to provide suitable health surveillance at or above the EAV. Also in other cases such as a previous diagnosis of hand arm vibration syndrome (HAVS) or carpel tunnel syndrome (CTS) and continuing use of vibrating tools. A health surveillance scheme for HAVS can involve a set of short simple questions such as reporting signs or symptoms. Regular annual intervals would be required to keep in line with regulations.

A tier 3 HAV assessment would usually follow a tier 2 assessment when symptoms are reported. A presumptive diagnosis can be recorded in tier 3 but a formal diagnosis is made by a doctor in tier 4 which would then make it RIDDOR reportable.