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4.4.4 Occupational safety and health risk associated with the technology

The term ‘occupational safety and health’ in this section is intended to cover the potential hazards and risks to workers involved in implementing the remediation technology [IAEA-2006b]. Safety risks may result from accidents during deployment. Health risks may result from workers being exposed to radionuclides and other contaminants. Because the occupational risks of different technologies can vary substantially, these risks may be an important consideration in selecting a technology.

Worker and public health and safety is a critical component of any remediation project and is an essential consideration in developing characterization strategies and choosing a particular remediation option(s). The remediation of a mixed contaminant site is typically complex and requires a significant amount of evaluation. The costs of a remediation project can rise significantly as a result of establishing the necessary health and safety practices.

During a remediation programme at a mixed contaminant site, the health and safety programme will cover all phases where workers and the public are at risk, including site characterization. For example, during the characterization phase, workers may be exposed to toxic chemicals while taking samples and undertaking other field work. As another example, during extraction and treatment of organic contaminants, site workers could become exposed to vapours if working in confined spaces (e.g., in an excavation pit) or through leaks in a soil vapour extraction (SVE) system. Another possibility is that the remediation technique may be subject to an accident that results in a fire, with release of toxic emissions. The types of hazard that might be addressed in a mixed contaminant remediation project include, but are not limited to, radiological, chemical, biological, explosive, industrial, electrical and transportation hazards.

The following steps may be considered in ensuring a proper health and safety programme:

  1. Establish an effective multidisciplinary project team and conduct comprehensive work planning to avoid unsafe operations and work stoppages.
  2. Conduct a hazard characterization and exposure assessment to determine the breadth of the health and safety programme, and the associated cost and impact.
  3. Develop a site specific health and safety plan.
  4. Establish access and hazard controls during the characterization and remediation activities through the application of a hierarchy of access and hazard control methods; this may include, for example, using remote handling equipment, establishing special, enclosed, working areas, or using appropriate levels of personal protective clothing.
  5. Establish place and procedures for decontamination of personnel and equipment.

These elements are commonly accompanied by rigorous training and medical surveillance programmes for the site workers, as well as an emergency preparedness and response plan.

Remediation of a contaminated site involving the removal of large numbers of drums or other packaged wastes may give rise to specific safety concerns. Drums may be corroded and containment not assured. Special attention may need to be given to the risks associated with, for example, mechanical or manual handling, inhalation of contaminated vapour or dust, and fire and explosion hazards. In this respect, the risks associated with chemical, flammable and explosive materials may be greater than those associated with radiological hazards. The remediation of some chemically contaminated sites has already given rise to severe accidents and deaths.

Many remediation projects will involve a wide range of conventional civil engineering activities including:

  • Decommissioning and decontamination of buildings;
  • Stabilization of excavations;
  • Transport and storage of excavated soils;
  • Contouring and similar civil engineering activities;
  • Excavations;
  • Drainage of excavations;
  • Sorting of contaminated soils.

These lead to typical building site exposures and hazards such as weather, draughts, dust, fumes, gases, noise and vibration, suspended loads and moving machinery. Some of these may be associated in addition with toxic or radioactive exposures. The toxicity or radioactivity of hazards may be known or unknown in quantity and intensity, and may vary over the project duration.

A variety of precautions can be taken, such as the establishment of safe procedures, technical measures and personal protective measures. Technical measures include, for instance, use of remote handling equipment and enclosed cabins on earth moving equipment, while personal protection measures largely consist of protective clothing and use of respirators. Monitoring of the concentrations of hazardous materials in the various workplace media is an integral part of health and safety measures.

Safe procedures are designed to minimize the handling of hazardous material and to handle it in such a way that a minimum of dispersion occurs. Such procedures also ensure that the organizations and people involved in the remediation project are adequately qualified for the project in hand.