Exponent uses a multidisciplinary approach in developing and evaluating site-specific risk assessments. Site-specific risk assessments are an appropriate scientific tool for evaluation of the health risk posed by sites and circumstances that involve possible exposures to known or potentially toxic agents. The elements of a site-specific risk assessment include site characterization and data evaluation, exposure assessment, dose-response evaluations (toxicology), and risk characterization. Using well-established scientific principles along with innovative approaches, our uniquely qualified team of professionals can investigate and provide a detailed assessment of risks to both onsite and offsite receptors.
Regulatory agencies routinely use the results of site-specific risk assessments as the primary bases for decision-making at contaminated sites. The results of a site-specific risk assessment can help determine the need for and nature of remedial actions at hazardous waste sites, support the derivation of cleanup levels, and assist in permitting new facilities and developing closure plans for solid waste management units and facilities that are going out of service. At Exponent, our scientists and engineers perform and critique site-specific risk assessments and derive risk-based remediation goals for hazardous waste sites and facilities under a variety of federal and state regulatory frameworks.
We also perform these services for clients acting voluntarily to address sites not governed by any regulatory mandate. These risk analyses can be a powerful tool in assessing potential environmental liabilities and managing an inventory of sites. Our risk assessors have applied their expertise to perform site-specific analyses and assist our clients in developing effective strategies for managing hundreds of sites.
Our services include: 
- Data evaluation
- Bioavailability studies
- Fish consumption surveys and studies
- Toxicity assessments
- Chemical Fate and Transport modeling
- Emissions characterization
- Air dispersion modeling
- Characterization of exposed populations
- Screening-level risk evaluations
- Comprehensive baseline risk assessments
- Sensitivity analysis
- Derivation of risk-based cleanup levels
- Deterministic and probabilistic exposure assessments
- Research and development to address sources of uncertainty
- Risk communication in public forums, seminars, and presentations
- Expert/consulting-level support for toxic tort, class action, and general litigation
The assessment of exposure in site-specific risk assessments has taken an increasingly important role, and sophisticated methods are being applied to improve exposure estimates, thus reducing uncertainty in risk estimates. Our professionals are leaders in the exposure assessment field. The Center for Exposure and Dose Reconstruction specializes in exposure assessment, a stage in the risk assessment process that often represents a key source of uncertainty in the risk outcome. We can perform exposure assessments involving any contaminant and all media to which an individual can be exposed, including soil, indoor dust, drinking water, surface water, outdoor and indoor air (including vapor intrusion), contact with residues on surfaces, locally-grown fruits, vegetables, meat, dairy or egg products, and breast milk. We are involved in the leading exposure assessment scientific societies and have made numerous contributions to the scientific literature in the field of exposure assessment.
Several software packages have been developed that can greatly aid in the computational aspects of risk assessment. Exponent scientists are familiar with EPA and commerically-available software packages and, when necessary, have developed our own site-specific analysis systems. This experience gives us an unparalled knowledge of the underlying theory, limitations, and sensitivity of risk assessment methodologies.
As necessary, this work is done in concert with evaluations performed by other Exponent scientists and engineers. Our analyses support assessment of appropriate and cost-effective remedial strategies for specific sites and provide critical documentation for site administrative records.
We effectively communicate our approaches and results to industry, regulatory personnel, and the public. Our presentations at national and international meetings, and our published research papers and articles in the peer-reviewed literature, cover many of these issues. These efforts have earned us a well-established scientific reputation and lend greater credibility to our assessments.