Federal Contaminated Site Risk Assessment in Canada, Part V: Guidance on Human Health Detailed Quantitative Risk Assessment for Chemicals (DQRACHEM)[Health Canada, 2010]

2010
ISBN: 978-1-100-17926-1
Cat.: H128-1/11-639E-PDF

This guidance document (Federal Contaminated Site Risk Assessment in Canada, Part V: Guidance on Human Health Detailed Quantitative Risk Assessment for Chemicals (DQRA_Chem)) was prepared to provide guidance for federal departments. It addresses complex contaminated sites and those sites for which a preliminary quantitative risk assessment (PQRA) is considered too conservative or not adequate to support a risk management plan.

The purpose of a site-specific or DQRA is to produce a more accurate (realistic), defensible, and representative estimate of risks than that generated by a PQRA. Although the level of detail of such an HHRA can vary considerably, depending on the objectives of the assessment, a DQRA typically uses more comprehensive site characterization data, more representative or site-specific exposure information and, in many cases, a higher level of sophistication in the fate, transport, and exposure modelling. The need for a greater level of detail is usually assessed in the context of the benefits of reduced uncertainty in the risk estimate as compared to the costs and resources to collect the additional data and conduct a more detailed assessment, or as compared to the costs and resources required to conduct remediation/risk management.