Contaminated sites are areas of land including the surface, subsurface soil and ground water that have become polluted with materials or chemicals which may present a risk to human health and the environment.

This contamination may have arisen from a range of industrial activities including manufacturing by-products and waste burning and dumping. To prevent further environmental damage or to re-use the land, remediation is required through various processes to remove the contamination. These processes will disturb the material and this may result in exposure of humans to substances potentially hazardous to their health either by working on the remediation project itself or in the immediate vicinity of the project.

Remediation work is generally subject to an array of regulatory requirements, including environmental and health and safety legislation. Legislation requires employers to ensure that any potential exposures are not going to result in significant harm to their employees and others in the vicinity of the site. There are a number of potential hazardous substances that can be found in such sites and to reduce the risk of ill health to employees and others, a process of risk assessment is required, identifying what the substances are, how workers may be exposed and to how much.

Experienced Occupational and Environmental Physicians are able to assist organisations keep their workforce healthy while conducting these activities. This may involve health monitoring and we are often asked simply to undertake such monitoring for all the substances that have been identified on the site in question, including biological testing. This can be a costly exercise and often lacks any scientific basis for the request. Health monitoring is a statutory requirement for certain substances and employees who are exposed to these or other substances that represent a significant risk to their health.

Some employers also confuse health monitoring with medical screening designed to assess if a candidate is suitable for a particular position based on the inherent requirements of that position. Health monitoring is actually used to detect ill health due to the effects of exposure to a hazardous substance at an early stage, so employers can introduce better controls to prevent the issue from getting worse. It can also provide data to employers to evaluate workplace health risks.

Before conducting any medical assessment of employees or others Occupational and Environmental Physicians engage with the organisation in a dialogue about the exposures and specific hazardous substances that have been identified by risk assessment as having the potential to cause adverse health outcomes. Following this, we can develop a protocol for hazardous substance health monitoring. This protocol can be used to determine what type of health monitoring is required, the frequency of the screening and the type of hazardous substance health assessment that will be undertaken.

Health monitoring is designed to detect the effects of chronic low level exposure and not short term acute exposure in individuals who visit the site on an infrequent basis. Occupational and Environmental Physicians are able to advise about when exposure might be sufficient to determine that health monitoring is required or whether someone whose exposure is no more than an hour or two on an occasional basis might be classified as a visitor and therefore exempt from such monitoring.

This approach may be varied at any time, with the agreement of the organisation concerned based on the recommendation of the Occupational and Environmental Physicians. This may result from obtaining and reviewing updated site monitoring information. We encourage the organisations to provide us with this critical information so that it can be considered as part of the process of supervising the health monitoring programme. This information may also indicate the requirement for more frequent health assessment or additional health monitoring measures (e.g. biological exposure monitoring) based on the specific exposure information for the relevant hazardous substances, such as heavy metals (arsenic, cadmium, chromium, lead and mercury), volatile organic compounds, polycyclic aromatic hydrocarbons or various pesticides.

For more information on how Sonic HealthPlus' Occupational and Environmental Physicians can assist you contact us on

Dr David Jones
MSc, MB ChB, MFOM (RCP)(UK), Fellow AFOEM (RACP)Regional Medical Officer

Dr David Jones is an experienced occupational physician who has been in specialist practice for over 25 years. He is currently an Occupational and Environmental Physician with Sonic HealthPlus, providing a range of consulting services for corporate and government clients.

Read full bio
More from this category