Human Health Risk Assessment (HHRA) Services

Evaluation of Potential Human Health Concerns Associated with a Spectrum of Exposure Scenarios

Roux's team of toxicologists, industrial hygienists, and human health risk assessors have evaluated complex exposure, toxicity, and risk assessment in the context of product safety evaluations, occupational exposure, contaminated site investigation and cleanup, and in toxic tort litigation. Our human health risk assessors guide efficient cleanup of contaminated sites via creative technical approaches to exposure unit/land use assumptions, background contributions, historic fill, and statistical approaches under various regulatory regimes across the United States.

Roux also provides qualitative and quantitative industrial hygiene assessments for commercial and industrial clients in various industries to assist them with both complex and regulatory challenges. Our services include guiding clients through product regulatory testing and compliance and identifying additional potential product exposure hazards. Roux also has a team of experienced expert witnesses who have offered expert opinions on general causation (mechanistic toxicity data, animal bioassays, and epidemiological data), dose reconstruction, and association of exposure-specific health outcomes. Roux has been retained and testified in some of the country’s highest profile cases, as outlined below.


National Director of Human Health Risk Services
Vice President/Principal Scientist
Technical Director
Ariel Newman
Senior Scientist
Stella Keck, MPH
Senior Scientist
Areas Of Expertise:
  • Site-specific Human Health Risk Assessments from Environmental Media
    • Contaminated site risk assessment
    • Dose reconstruction/exposure modeling
    • Monte Carlo evaluations (probabilistic risk assessments)
    • Evaluation and modeling of air emissions and concentrations
    • Health-based risk allocation of liability
    • Groundwater flow modeling
    • Environmental Justice concerns and assessments
  • Occupational Exposure Assessments
    • Area and personal exposure monitoring and measurement
    • Development and/or guidance for sampling strategies
    • Indoor air quality
    • Exposure mapping
    • Evaluation of biomonitoring data
    • Development of workplace controls to mitigate identified or potential employee exposures
  • Consumer Product Safety and Regulatory Compliance
    • CPSC, Cal/EPA, CA Prop 65
  • Regulatory Basis for Health-based Standard
    • Critical review of State and Federal regulations and advisory levels (e.g., PFAS, ethylene oxide), derivation of site-specific levels
  • Risk Communication to Non-technical Audiences
  • Assessment of Potential Health Risk from Emerging Contaminants
  • Toxic Tort Evaluations
    • General Causation
      • Integrated analysis of mechanistic, toxicology, and epidemiology literature
    • Specific Causation
      • Evaluation of associations between specific exposures and health outcomes
    • Alternative Causation
      • Assessment of other relevant factors associated with claimed health outcomes

High-Profile Projects

Roundup Product Liability Litigation

MDL No. 2741

Roux testified in this Multi District Litigation (MDL) case. This MDL concerns plaintiffs' claim that the prolonged use of Roundup herbicide causes various cancers, such as Non-Hodgkin’s Lymphoma (NHL).

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Johnson & Johnson Talcum Powder Litigation

MDL No. 2738

Roux was retained as an expert for this case. This MDL concerns plaintiffs' claim that the prolonged use of J&J's talcum powder causes various cancers, such as mesothelioma and ovarian cancer.

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Aqueous Film-Forming Foams (AFFF) Products Liability Litigation

MDL No. 2873

Roux testified in this MDL case. This MDL concerns plaintiffs' claim that the prolonged exposure to PFAS chemicals released during AFFF training and use causes various adverse health effects.

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