Ecological & Environmental Risk Assessment

Exponent is nationally and internationally recognized as a leader in the development and implementation of approaches for assessing and managing ecological and environmental risks. Ecological risk assessments are performed to evaluate whether particular environmental conditions (e.g., chemical contamination in air, soil, surface water, sediment, or biota; changes in climate; or the introduction of invasive species) pose a risk to ecological resources and their associated ecosystem services. Ecological risk assessments are a required part of environmental projects in many countries to evaluate the ecological risks associated with environmental contamination associated with spills, legacy contamination, or to address the potential risk of new projects, or products, or expansion of existing projects or new uses of existing products.

Exponent’s scientists and risk assessors combine practical approaches with state-of-the-art science to address our clients’ diverse needs. The Exponent team not only addresses the risks of chemicals but also addresses new technologies, facilities, biological stressors (introduced species), physical alterations of ecosystems, and aspects of climate change. Projects have been implemented in most environments of the world, including suburban environments, watersheds, deserts, rain forests, and oceans. In the absence of specific regulatory guidance at the National or state level, we have developed approaches that satisfy the needs of our clients (e.g., major corporations, government agencies) and that are where necessary defensible in the applicable court system including international courts.

Exponent has a diverse group of professionals that make up our ecological and environmental risk assessment practice. Expertise within this group encompasses a variety of disciplines, including aquatic biology, terrestrial biology, environmental chemistry, forensic chemistry, aquatic ecology, terrestrial ecology, environmental toxicology including but both aquatic toxicology, and terrestrial toxicology, pharmacology, fisheries biology and management, wetland biology, oceanography, resource management, restoration ecology, limnology, veterinary science, nuclear physics, statistics, and spatial analysis. Our ecologists, environmental scientists, and wildlife veterinarians can draw on the knowledge and expertise of scientists, engineers, physicians, veterinarians, communication specialist, and business consultants in more than 90 additional technical disciplines, including the closely-related health sciences practices.

Our ecological and environmental risk practitioners work closely with our health sciences practices on many projects, because most projects are multifaceted and need to address not only the ecological risks, but the human health risk associated with a project. A number of our professionals have expertise in both ecological and human health risk assessment. It is important to have the big picture in mind and to balance the ecological and human health aspects of a project, and we have a reputation for doing that well. In addition, we have a reputation for clear and concise risk communication of the results of our evaluations. As needed, our environmental scientists can work with communication specialists within our visual communications practice to effectively communicate the results of our ecological and environmental risk assessments.


Our primary services include:

  • Designing, conducting, and interpreting aquatic and wildlife exposure and toxicology studies to evaluate specific environmental conditions 
  • Conducting ecological assessments to evaluate risk associated with releases to the environment of chemicals, petrochemicals, and consumer and industrial products in a wide variety of terrestrial and aquatic environments 
  • Provide ecological assessments to support registration of consumer products, pesticides and pharmaceuticals (including both human and veterinary drug formulations) 
  • Conducting specialized sediment-related ecological and environmental assessments to address the bioavailability and associated risk of chemicals (including direct measure of sediment pore water or use of innovative passive sampling devices)
  • Providing technical review and support related to product stewardship to evaluate the ecological and environmental implications of current products or new products and existing technologies (e.g., pipeline conveyance systems) or new technologies (e.g., unconventional drilling technologies) 
  • Offering technical support related to ecology and the environment during negotiations and litigation associated with difficult environmental or ecological issues including for example, Natural Resource Damage Assessment (NRDA) claims or developing risk-based sediment toxicity thresholds. 
  • Providing technical review and support during the development of regulatory policies and guidelines 
  • Evaluating ecological implications of remedial action decisions at hazardous waste sites, such as Superfund or Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) sites and Resource Conservation and Recovery Act (RCRA) facilities 
  • Developing cost-effective compliance strategies and monitoring programs for National Pollutant Discharge Elimination System (NPDES), Total Maximum Daily Load (TMDL), and other regulatory requirements under the Clean Water Act 
  • Applying unique spatially explicit exposure models and food-web evaluations in support of ecological and environmental risk assessments.

The primary environments in which we have worked include:

  • Coastal and open water marine environments 
  • Estuaries 
  • Inland lakes and streams 
  • Wetlands 
  • Deserts 
  • Shortgrass prairie 
  • Tallgrass prairie 
  • Tundra 
  • Deciduous and coniferous forests.


Exponent’s experience includes the following primary chemical and biological stressors:

  • Heavy metals, including arsenic, barium, lead, cadmium, chromium, arsenic, mercury, and methyl mercury 
  • Nanomaterials, including nonmetallic materials such as nano-silver
  • Petroleum hydrocarbons related to crude oil and its derivatives 
  • Polycyclic aromatic hydrocarbons (PAHs) 
  • Polychlorinated biphenyls (PCBs) 
  • Polybrominated diphenyl ethers (PBDEs)
  • Endocrine disrupting chemicals (EDCs)
  • Human and veterinary products
  • Pharmaceuticals
  • Pesticides 
  • Dioxins and dibenzofurans 
  • Explosives and explosives-related compounds such as trinitrotoluene 
  • Radionuclides
  • Bacterial agents 
  • Viral agents 
  • Invasive species.



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