Human Health Risk Assessment & Toxicology

Phoenix's toxicologists have a range of experience extending from fundamental bench science, the evaluation of scientific data on a wide range of chemicals, through site-specific risk assessments, to development of policy at governmental/international levels.

Definition: Human health risk assessment (HHRA) is a process intended to calculate or estimate the risk to a human (sub) population, including the identification of attendant uncertainties, in the presence of a particular agent or mixture, taking into account the inherent characteristics of the agent/mixture of concern as well as the characteristics of the specific target system. HHRAs may be carried out on the basis of literature toxicity and exposure data or may utilize site-specific exposure data. In each case the steps in the process are hazard identification, hazard characterization (sometimes termed dose-response assessment), exposure assessment and risk characterization. The overall goal of any HHRA is to estimate the level of risk associated with agents (chemicals) in the human environment to provide guidance on whether the attendant risks are acceptable for the intended use.  [definition adapted from IPCS / OECD]


Phoenix toxicologists are eminently qualified to provide the following services:

  • Assess human health risks for acute and chronic human exposures to chemicals in all environmental media and the workplace
  • Develop HHRA reports per regulatory expectations
  • Perform environmental and occupational exposure limits
  • Multimedia exposure assessments
  • Carry out site-specific HHRA
  • Develop remediation goals
  • Prepare toxicology profiles
  • Develop numerical exposure limits
  • Carry out peer reviews
  • Provide expert witness testimony

Recent Projects Undertaken

  • Human Health Risks from PCBs at the former Mid Canada Line Radar Site
  • Review of HHRA, Former Radar Base
  • Review of Site Specific HHRA Screening Level HHRA prepared as part of an IAQ investigation of five buildings conducted by other Phoenix OHC personnel
  • Critical reviews of Environmental Health Criteria Documents prepared by National and International Governments and Organizations.
  • Scientific critic of the toxicology of lead and copper in drinking water, which involved presenting expert testimony to the United States District Court in the Northern District of California.
  • Critical review of a report on a large site-specific HHRA related to metal contaminants in soil; testimony was prepared for possible presentation at an Ontario Environmental Review Tribunal Hearing.


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