Whereas workplace assessment and monitoring focus on the physical conditions in the place of work, the aim of health surveillance is to assess the initial and ongoing health of workers, to provide detection of any health effects on them due to their work. The scope for further work as a result of such detection varies between the stipulations of professional bodies, or national legal or good practice requirements.
The ILO set out basic requirements for health surveillance as follows:
Surveillance of the workers’ health should include, in the cases and under the conditions specified by the competent authority, all assessments necessary to protect the health of the workers, which may include:
- health assessment of workers before their assignment to specific tasks which may involve a danger to their health or that of others
- health assessment at periodic intervals during employment which involves exposure to a particular hazard to health
- health assessment on resumption of work after a prolonged absence for health reasons for the purpose of determining its possible occupational causes, of recommending appropriate action to protect the workers
- and of determining the worker’s suitability for the job and needs for reassignment and rehabilitation
- health assessment on and after the termination of assignments involving hazards which
- might cause or contribute to future health impairment.
Following the above, further detail on these four categories can be provided below.
Pre-placement health checks, which are carried out before starting a job. Caution is needed here, as in some jurisdictions it is illegal to ask health questions of job candidates or unfairly discriminate against them as a result. Some general questions can be asked, but the pre-placement check needs to be carried out once a candidate has been offered a job but before starting it. This is to protect the worker, rather than discriminate against them in offering them the job, and should health problems be found, the issue of reasonable adjustments will then need to be considered. Such checks can also provide a baseline against which future health surveillance can be assessed.
Health or medical assessment at intervals is carried out to check for any signs of health effects on workers caused by their jobs. This should be done periodically as determined by the initial health risk assessment, or following changes in the job or workplace. While health monitoring is not an alternative to suitable control measures, it can give information on the effectiveness of controls or on the need to review them. The range of checks will depend on the types of health risk to which workers are exposed.
Some of these checks will involve intrusions into the body, eg, taking blood samples, and so consent will be needed from workers.
The range of checks could include:
- audiometry, to check for any deterioration in a worker’s hearing that could be caused by their working conditions, and whether hearing protection used by them is adequate
- lung function tests, which are used to check for any effects on a worker’s respiratory system, such as asthma, that could be caused by exposure to dust or gases, and whether RPE is effective
- blood and biological testing (urine, blood and saliva), which are used to detect whether a worker’s body has absorbed any harmful substances (eg, lead, cadmium, mercury) and/or whether any absorption has had an effect on body systems
- skin checks, which are used to detect problems such as dermatitis caused by substances in the workplace, oils being one example
- checks for damage caused by exposure to high levels of vibration (eg, vibration white finger)
- medical examinations for night shift work.
Fit-for-role surveillance is carried out periodically, often in compliance with legal requirements (eg, heavy goods vehicle drivers, divers) to determine the ongoing suitability of the worker on health grounds.
It can also be used when workers have a health issue that could affect their safe performance at work, or where an incident is suspected to have been caused or contributed to by health issues such as fatigue, co-ordination problems or drug or alcohol misuse. If a worker is to change to a different job, such a check may be needed to determine their suitability for the new role.
Health assessment on resumption of work is carried out after a period of absence by the worker, and may include the consideration of return-to-work arrangements and adjustments to the worker’s job or workplace. Absence management and rehabilitation are closely linked, as the aim of any system should be to get the worker back to work as soon as possible, since statistically the longer time someone is absent due to illness, the lower the chances of them returning to work. Rehabilitation is concerned with how a worker is returned to work, including such issues as phased returns and reasonable adjustments in the workplace.
Post-assignment health surveillance, when a worker is to leave a job, can also be carried out to determine if their employment to that point has caused any ill-health effects. Eyesight tests are required in some jurisdictions for workers who use display screen equipment, to detect the onset of the relevant aspect of vision deterioration (and corrective spectacles for DSE work are often provided by the organisation, where required).