340821-001 FINAL United Keno HHERA 4 May 2011

Human Health and Ecological Risk Assessment for the Historic Keno Hill Mine Site
1.0 INTRODUCTION
A Human Health and Ecological Risk Assessment (HHERA) for exposure to constituents in the
aquatic and terrestrial environments at the historic Keno Hill Mine site, Yukon was carried out
by SENES Consultants Limited on behalf of Access Consulting Group. This work will support
the “Reclamation Plan for the Existing State of the Mine” being developed by Elsa Reclamation
and Development Company Ltd. (ERDC).
This report details the methodology and assumptions and presents the results of the Detailed
Quantitative Risk Assessment (DQRA) for the site. The risk assessment was based on reasonable
maximum likely exposures to Constituents of Potential Concern (COPC) at the site. It was
assumed that people (represented by a variety of age groups) would be on the site for some
portion of the year. The assessment was carried out for the site using data and information
documented in various environmental assessment reports (Access 2009; EDI 2008, 2009, 2010;
Laberge 2005, 2008; Minnow 2008, 2009, 2010a; WMEC 2006).
1.1 RISK ASSESSMENT APPROACH
The use of risk assessment to establish whether a site can be safely used by the most sensitive
receptors likely to occupy it involves the application of a staged, formal and reproducible process
that incorporates procedures accepted by the regulatory authorities in the jurisdiction within
which the study is being undertaken.
The human health risk assessment was conducted according to Health Canada guidance on
DQRA (Health Canada 2009a). The DQRA evaluated the probability of adverse health
consequences to humans caused by the presence of constituents of concern in the environment.
Receptor characteristics (e.g., proportion of time spent in the study area, source of drinking
water) and exposure pathways (e.g. inhalation and ingestion) were taken into consideration.
The ecological risk assessment was carried out using the framework as provided by the Canadian
Council of the Ministers of the Environment (CCME 1996).
The assumptions made for the risk assessment are intended to err on the side of caution and
therefore likely result in over-estimated intakes. The level of caution in these assumptions is
consistent with the approach typically adopted in risk assessments (Health Canada 2009a).
1.2 REPORT STRUCTURE
The report has been structured into several sections, each of which describes specific aspects of
the DQRA. These aspects include:
340821-001 – FINAL – May 2011 1-1 SENES Consultants Limited