ToxStrategies’ multidisciplinary scientists provide a comprehensive range of consulting services, including both ecological and human health risk assessment. Our expert ecotoxicologists and human health toxicologists routinely conduct screening level and comprehensive environmental risk assessments. Our extensive experience with global safety requirements across industries and governments enables us to successfully address technical and regulatory challenges tailored to clients’ individual needs.
Ecological risk assessment often requires tiered, weight-of-evidence (WoE)-based methods. Thus, to ensure compliance and efficiency, the evaluation must be performed by risk assessors with expertise in three key areas: environmental fate and exposure, ecological hazard, and risk assessment strategy. ToxStrategies scientists and engineers are subject matter experts in these areas and advise clients on state-of the-art approaches to assembling and distilling the necessary evidence for each unique ecological risk assessment.
Skills and Qualifications:
Ecological Risk Assessments
- Development and implementation of screening-level and site-specific ecological risk assessments under various regulatory paradigms
- Use of existing evidence and/or models to develop predicted no-effect concentrations (PNECs), assessment factors (AFs), predicted environmental concentrations (PECs), risk quotients (RQs), etc.
- Design of conceptual site models (CSMs) integrating contaminant pathways, exposure media, and receptor characterization
- Evaluation of ecological receptors, exposure pathways, and toxicological endpoints for terrestrial, aquatic, and sediment environments
- Preparation of scientifically robust ecological risk assessment reports and technical memoranda supporting risk management decisions
Environmental Data Analysis and Decision Support
- Primary literature search strategies and demonstrated leadership advancing robust study quality evaluation approaches to support a multitude of safety assessment needs
- Application of ArcGIS, R, and Python tools for environmental data visualization and probabilistic modeling
- Development of transparent, defensible documentation and expert support for regulatory and legal proceedings
Ecotoxicology and Bioassessments
- Interpretation of ecotoxicology study data across multiple trophic levels and modeling of potential exposure estimates
- Ecotoxicology study design, monitoring, and utilization of standard (e.g., OECD, OCSPP/OPPTS, ASTM) and non-standard toxicity test reports across relevant trophic levels to inform fit-for-purpose hazard and risk assessments
- Assessment of potential for endocrine disruption (human health and non-target/ecotoxicological), consisting of WoE evaluations for endocrine-mediated activity, adversity, and plausible relevance to estrogen, androgen, thyroid, and steroidogenesis pathways
- Hazard assessment of data-poor chemicals, including utilization of existing in silico tools and methods (e.g., quantitative structure-activity relationship (QSAR) models) and support for read-across and chemical grouping strategies
New Approach Methodologies (NAMs) in Ecological Risk Assessment
- Analysis and application of in vitro, in silico, and omics-based (e.g., transcriptomics, metabolomics, lipidomics) tools and/or data to evaluate chemical toxicity, mode(s) of action, and ecological relevance
- Selection and laboratory placement (monitoring) of NAMs assays (e.g., OECD 236—Fish Embryo Acute Toxicity; OECD 249—Fish Cell Line Acute Toxicity, etc.)
- Derivation of molecular points of departure (PoD) (e.g., transcriptomic PoDs) for ecological species using benchmark dose (BMD) modelling to inform chemical risk assessment
- Translation of NAM results into risk-based decision frameworks through a WoE evaluation
Databases, Tools, & Software
- ECOTOX Knowledgebase
- ECOSAR
- VEGA
- EPISuite
- OPERA
- T.E.S.T.
- OECD Toolbox
- BMDExpress
- ArcGIS
- Python
- R
- RShiny applications
Case Study #1:
To support the state of knowledge regarding a contaminant of emerging concern (CEC) for ecological receptors, ToxStrategies was asked to develop a literature database on hazard and exposure data on the CEC and to communicate findings regarding potential ecological risk to a client. A dynamic state of knowledge program was developed whereby the scientific literature was searched weekly, screened for relevance, and reviewed to provide a client with up-to-date information related to potential for ecological risk. The state of knowledge was displayed in a web-based dashboard for easy accessibility and tiering of information from high-level summaries to detailed data extraction and analyses. This work generated several presentations at scientific conferences.
Case Study #2:
ToxStrategies researched and developed proposed water quality values protective of aquatic life for over 250 CECs. This project was conducted to support the client’s exploration into expanding state water resources. ToxStrategies reviewed existing water quality criteria and benchmarks from federal (e.g., EPA) and state agencies, and their underlying basis. In addition, existing data from EPA’s ECOTOX Knowledgebase and the peer-reviewed literature was reviewed and used to develop proposed aquatic life threshold values in compliance with existing guidance from a state regulatory agency. These >250 proposed aquatic life thresholds will be considered across multiple programs within a state regulatory agency.
Case Study #3:
To understand how NAMs, specifically toxicogenomics, can be used to support ecological risk assessment, ToxStrategies was asked to develop a case study employing toxicogenomic technologies relevant to ecological receptors. ToxStrategies first reviewed and evaluated existing regulatory frameworks that consider toxicogenomics in ecological risk assessment, as well as the applications those frameworks currently utilized. ToxStrategies then designed and conducted a case study using transcriptomics data to fill identified data gaps and further define the applicability of transcriptomics technologies in ecological risk assessment.