Our approach to risk assessment and toxicological assessments is based on three goals that we strive to achieve for each and every one of our projects:
- Consistency with standard (i.e., USEPA, CalEPA, ASTM) methodology and guidance
- Scientific and legal defensibility
- Innovative and cost-effective strategy developed together with our client
These are further described below in regard to our project approach.
The United States Environmental Protection Agency (USEPA) methodology framework represents the most widely applied guidance for risk assessment. The USEPA risk assessment methodology, initially established by the National Academy of Sciences (NAS, 1983), was formally adopted by the USEPA in 1989 and by CalEPA in 1992. The framework provides the appropriate scientific basis upon which to identify and evaluate potential health risks associated with a specific chemical release and/or for a specific property. The American Society for Testing and Materials (ASTM) also provides risk assessment guidance (ASTM, 1995, 2000) that is consistent with USEPA guidance and is used by most professionals as a supplemental guidance (for example, chemical properties data and chemical transport models are provided in the ASTM guidance). The risk assessment process (1) identifies the quality and quantity of environmental sampling data necessary to make definitive conclusions, (2) identifies the specific chemicals of interest that are carried through the risk evaluation, (3) identifies the possible chemical migration and exposure pathways that determine how and where a person might receive a dose of chemicals originating from an adjacent source, (5) conservatively estimates the chemical doses and health risks at locations of interest and (6) places the estimated doses and risks into perspective in terms of background exposure and acceptable risk. An example of our typical project approach is given below.