Tarah Hagen

Technical Director, Toxicologist & Risk Assessor – Asia Pacific



Tarah is a certified toxicologist based in our Melbourne office, with over 15 years’ experience in conducting screening and detailed human health and ecological risk assessments for a variety of industries and government. This includes industrial and vehicle emissions, contaminated land and water, consumer goods and food. She has written and co-written numerous major reports, which have been influential in shaping Australian health risk assessment methodology and policy decisions in relation to environmental issues. She also has considerable experience in sourcing, collating and interpreting toxicological hazard information. Tarah creates chemical toxicology profiles in which hazards and toxicity reference values are carefully described thereby ensuring the information is fit for the purpose of the risk assessment. She is also adept in building exposure scenarios for human and environmental risk assessment.

Tarah has been involved with numerous projects requiring health impact assessment of criteria pollutants from vehicular and industrial emission exposures to the general public including for large new urban developments.

Tarah has considerable expertise in classifying mineral ores and concentrates as to their health and environmental hazard for transport purposes. This includes sourcing toxicity and ecotoxicity information for numerous metals and metalloids, evaluating data quality and collating the information into databases, deriving toxicity reference value to be used for dangerous goods classification, and interpreting test reports.

She has been involved in several complicated risk assessments dealing with lead contamination and is adept at using and applying the results of the US EPA Integrated Exposure Uptake and Biokinetic (IEUBK) Model for lead. She has also applied this knowledge in helping derive recommendations for ambient air license limits for industries handling concentrates of lead ores (as well as other metal ores), as well providing advice for recommended changes to the occupational exposure limit for lead. She has also provided advice regarding the interpretation of biological monitoring results for arsenic exposure by mine process workers, as well as providing the associated communication to workers.

Tarah has also been involved with various publications reviewing the toxicity of engineered nanomaterials in relation to work and public health and safety, the latter particularly concerning their use as food additives and migration from food packaging into foods. She has also been involved in several complex human health risk assessment for occupational and public exposure to per and poly fluorinated alkylated substances (PFAS). This work has included reviewing and interpreting toxicology information for consideration of appropriate toxicity reference values, delineating potential exposure pathways, as well as estimating and interpreting internal exposure metrics with respect to human health. This work also has involved desktop assessments of livestock health and productivity.

She has also been one of the lead researchers on long running projects investigating the clearance and tissue distribution of PFAS in cattle and sheep. The results of this research have been presented at numerous conferences, written up as reports for government, and written up for publication in the scientific community.The research provides integral data for PFAS risk assessment and has facilitated derivation of suggested stock water guideline for PFAS protective of stock and human health, the latter due to produce consumption.

Tarah has a good understanding and experience in ecotoxicity testing which has been used to derive trigger values for contaminants in water using probabilistic species sensitivity distribution methodology.

She has acted as an independent expert in the fields of toxicology and human health risk assessment in several court cases.

She regularly teaches University master’s students in the fields of toxicology and epidemiology.

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  • Fellow of the Australasian College of Toxicology & Risk Assessment (FACTRA) (2022)

  • Certified as a Diplomate of the American Board of Toxicology (DABT) (2017)