Biological Monitoring

Biological Monitoring

Lead Hazards

Exposure to lead at work, where lead dusts, fumes or vapours are created, can cause health problems. Biological monitoring can assess one’s exposure to lead dusts, fumes and vapours.

The body absorbs lead through:

Exposure to lead should be strictly controlled and monitored in accordance with the Control of Lead at Work Regulations 2002.


Lead which is absorbed into the body will circulate in the blood. Whilst the body will excrete a small amount of lead in the urine, however some will stay in the body, stored mainly in the bones.

Lead can be stored in the body for many years without the individual feeling ill. However, if the level of lead in the body gets too high it can cause:

Continued uncontrolled exposure could cause:

Exposure to lead during pregnancy, especially during the early weeks, can serious affect the unborn child.

Is Medical Surveillance required?

Medical surveillance is required where the risk assessment considers an employee’s exposure to lead to be ‘significant’.

Significant exposure is defined in the Control of Lead at Work Regulations 2002 ACOP and guidance where one of the following three conditions are satisfied:

If, as part of the assessment process, blood lead or urinary lead is measured and it is identified at a level equivalent to or greater than the levels below, the employee should be placed under medical surveillance:

Is it a legal requirement?

Exposure to lead and its compounds is subject to the Control of Lead at Work Regulations 2002. Medical surveillance is a legal requirement where exposure is ‘significant’.

What does the surveillance entail?

Annual Medical Surveillance with an Occupational Physician consists of:

Biological Monitoring consists of:

How long does it take?

Medical surveillance with the Occupational Physician takes around 30 minutes.
Biological Monitoring takes around 10 minutes.

How often should surveillance be done?

Biological monitoring is clinically indicated by exposure and previous results. The frequency of medical surveillance is determined by the blood lead levels, but it should be undertaken at least annually with an Occupational Physician. With women of reproductive capacity and young persons, the biological monitoring should be undertaken at least 3 monthly.
With all other categories the frequency is given below:

Category Blood0lead Maximum interval between blood-lead measurements
A Under 30 12 months
B >20 and <40 6 months
C >40 and <50 3 months
D >50 and <60 3 months
E 60 and over

Want to Find Out More?

For more information about our work-related health services, contact us.

Published date: 19th February 2018

Last revision: 10th May 2021

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