Review Article

Cumulative Risk Assessment Toolbox: Methods and Approaches for the Practitioner

Table 2

Selected resources for planning, scoping, and problem formulation.

Resource and accessPurpose and scopeCumulative risk remarks

Resources for planning, scoping, and problem formulation

(2.1) Guidance on Cumulative Risk Assessment—Part 1, Planning and Scoping (EPA);
http://www.epa.gov/OSA/spc/pdfs/cumrisk2.pdf
Published in 1997, this guidance outlines EPA policy for planning and scoping for CRAs. The guidance directs each office of the EPA to take into account cumulative risk issues in scoping and planning major risk assessments and to consider a broader scope that integrates multiple sources, effects, pathways, stressors, and populations for cumulative risk analyses in all cases for which relevant data are available. This guidance also includes discussion pertaining to community-based decision making, flexibility in achieving goals, case-specific responses, a focus on all environmental media, and holistic reduction of risk. Identifies four key steps for planning and scoping: determine overall purpose and risk management objectives for assessment; determine scope, problem statement, participants and resources; determine risk dimensions and technical elements that may be evaluated; formulate a technical approach including a conceptual model and analysis plan for the assessment.

(2.2) Lessons Learned on Planning and Scoping for Environmental Risk Assessments (EPA);
http://www.epa.gov/osa/spc/pdfs/handbook.pdf
Published in 2002, this report provides feedback to EPA scientists and managers regarding EPA's experiences with planning and scoping as the first step in conducting environmental assessments. It is intended to reinforce the importance of formal planning and dialogue prior to conducting complex cumulative assessments and to provide case studies and “lessons learned” for planning.Provides information and feedback from the Part 1 planning guidance that offer insights for designing and conducting CRAs.

(2.3) Framework for Cumulative Risk Assessment (EPA);
http://www.epa.gov/raf/publications/framework-cra.htm
Published in 2003, the document provides a flexible framework for CRAs. It identifies the basic elements of the process, describes a number of technical and coordination issues, and defines terms. This framework has served as a foundation for the CRAs developed since its publication. Defines general structure and components of CRAs; provides the groundwork for scoping context considered in this paper.

(2.4) EJView (EPA);
http://epamap14.epa.gov/ejmap/entry.html
Jointly developed by the EPA Office of Environmental Information and Office of Environmental Justice, EJView is a GIS-based module that can be used to guide front-end scoping of CRAs. It combines environmental, socioeconomic, and demographic data and health indicators in statistical tables, as well as providing facility-level data. This tool can help identify problems to be assessed in a CRA. Although presented here within the planning/problem formulation phase, this tool is also useful for other phases, including risk characterization.

Resources for stakeholder involvement

(2.5) Superfund Community Involvement Handbook, Appendix A: Superfund Community Involvement Requirements (EPA);
http://www.epa.gov/superfund/community/involvement.htm;    
http://www.epa.gov/superfund/community/cag/pdfs/ci_handbook.pdf
Superfund guidance on suggested community involvement structure, communications, and approach. For contaminated sites, the lead agency informs the public of the availability of technical assistance grants (TAGs). The TAG is a grant program that provides funds for citizen groups to hire independent technical advisors to help them understand and comment on technical decisions regarding Superfund cleanup actions. (This is now part of a broader community involvement toolkit.)Developed for the Superfund program; with cross-cutting information about community involvement, including forming community advisory groups (CAGs), this resource is also useful for CRAs at contaminated sites.

(2.6) Community Air Screening How-To Manual (EPA);
http://www.epa.gov/oppt/cahp/pubs/howto.htm
Explains how to form a partnership, clarify goals, develop a detailed local source inventory, and use a risk-based process to identify priorities and develop options for risk reduction. Developed by the EPA’s Office of Pollution Prevention and Toxics based on the Baltimore (Maryland) approach. Presents a step-by-step process a community can follow to form a partnership to access technical expertise, identify and inventory local sources of air pollutants, review these sources to identify known hazards that might pose a health risk to the community, and set priorities and develop a plan for making improvements. Covers only the air pathway.

(2.7) Hanford Site (DOE), Hanford Advisory Board (HAB), Public Involvement Resources and Calendar; http://www.hanford.gov/page.cfm/hab,    
http://www.hanford.gov/public/calendar/
HAB was established to provide recommendations and advice to DOE, EPA, and the State of Washington’s Department of Ecology on a number of issues related to cleanup of the Hanford site. Among its activities, the HAB created a calendar for public involvement to list upcoming meetings and other events at which input from affected parties and stakeholders was encouraged. A comment response tracking system was also developed to coordinate issues identified by stakeholders during iterative planning and scoping, throughout the assessment process, and to track followups. The HAB mission language, online tools, and other information can serve as examples for other CRA projects.

(2.8) Los Alamos National Laboratory (LANL) (DOE), Risk Assessment Corporation (RAC), Risk Analysis, Communication, Evaluation, and Reduction (RACER) project;
http://www.racteam.com/racer.html
The Risk Assessment Corporation (RAC) team developed an open process for assessing cumulative risks at LANL and for creating a decision analysis framework for risk reduction, with guidance for participation and an integrated database (with data from multiple collecting organizations) to support risk analyses. Stakeholder participation was actively sought in both open progress meetings and one-on-one meetings held in various settings; the Internet was also used, to announce activities and availability of draft documents for stakeholder review and to solicit inputs. Objectives were to develop (1) a process for extensive stakeholder involvement in risk assessment and decision-making processes for LANL; (2) a method for estimating current human health risks and ecological impacts using available data on chemicals and radionuclides measured in environmental media; (3) a method for implementing a comprehensive risk-informed decision analysis framework, including a prospective risk and ecological impact assessment to guide long-term management of risks and ecological impacts; (4) a consistent approach for compiling, using, and updating data to support the risk assessment and decision-making processes. The RACER project has also involved local schools in science projects, inviting the public to provide input to exposure scenarios. Insights for cumulative assessments can be found in the RAC guidelines for stakeholder involvement, open survey questions, plans for soliciting (in various venues) and summarizing inputs to guide the assessment, and suggestions for pursuing grants for ongoing stakeholder involvement (aimed to be administered through an independent group), as well as other plans and products that can be found on the project website.

(2.9) Savannah River Site (DOE), Citizens Advisory Board (CAB);
http://www.srs.gov/general/outreach/srs-cab
A CAB was created to facilitate public outreach for the DOE Savannah River Site, consisting of 25 individuals who reflect the cultural diversity of the local population. The CAB provides advice and recommendations to DOE, EPA, and the South Carolina Department of Health and Environmental Control on environmental remediation, waste management, and related issues. Regular meetings and public comment sessions were kept open to the public.Recommendations and information on workshops published on this website can offer insights for similar projects.

(2.10) Weldon Spring Site (DOE), Partners in Education;
http://www.lm.doe.gov/Weldon/CPAR_WSSRAP_Update_Jun92.pdf;    
http://www.lm.doe.gov/Weldon/10_23_2002summary.pdf
A scientific educational partnership established more than 20 years ago at the Weldon Spring Site in Missouri promoted community involvement in evolving evaluations for this DOE legacy waste site, toward ultimately supporting site cleanup plans. An open door policy with the community translated to weekly meetings during certain periods.This early project illustrated the essential role of the community in developing and implementing a CRA for a legacy waste site.

Resources for guiding data quality

(2.11) Guidance on Systematic Planning Using the Data Quality Objectives Process (EPA, QA/G-4);
http://www.epa.gov/quality/qs-docs/g4-final.pdf
Published in 2006, this guidance outlines a systematic planning process for collecting environmental data. Designed to help analysts ensure that data are collected for a specific purpose, it includes the approach for determining which chemicals to evaluate or test for, in which media, and at what locations, as well as detection limits.Recommended planning process when environmental data are used to select between two opposing conditions, useful for CRAs. The focus is on the (cumulative risk) questions to be answered, while maintaining awareness of the appropriate statistical techniques that should be considered to produce scientifically defensible results.

(2.12) Software (EPA, QA/G-4D);
http://www.epa.gov/quality/qs-docs/g4d-final.pdf
Computer-based software for determining the feasibility of DQOs using a systematic process. Calculates the appropriate number of environmental samples required to statistically answer whether soil or water concentrations are above or below a risk-based level; can be used to estimate sampling costs.General analytical guidance can be applied to multiple media and multiple contaminants. Could be adapted to support chemical grouping.

(2.13) Guidance on Choosing a Sampling Design for Environmental Data Collection (EPA, QA/G5S);
http://www.epa.gov/quality/qs-docs/g5s-final.pdf
Guidance on applying standard statistical sampling designs (such as simple random sampling) and more advanced sampling designs (such as ranked set sampling and adaptive cluster sampling) to environmental applications. Can be useful to identify colocated contaminants to support grouping for a CRA at a contaminated site or situation.

(2.14) Guidance for Quality Assurance Project Plans for Modeling (EPA, QA/G-5M);
http://www.epa.gov/quality/qs-docs/g5m-final.pdf
General guidance for developing quality assurance project plans (QAPPs) for modeling projects.Can be useful for CRAs, particularly where air or groundwater models are needed to extrapolate small data sets to the site or community level.

(2.15) Guidance on Environmental Data Verification and Data Validation (EPA, QA/G-8);
http://www.epa.gov/quality/qs-docs/g8-final.pdf
Guidance to help organizations verify and validate data. Applying this to laboratory analytical data allows analysts to understand uncertainties associated with concentration measurements (which impacts assessment results).Useful for determining appropriate data for chemicals to be evaluated in a CRA; important with regard to results, especially when using conservative screening approaches.

(2.16) Data Quality Assessment: A Reviewer’s Guide (EPA, QA/G-9R);
http://www.epa.gov/quality/qs-docs/g9r-final.pdf
Describes procedures and methods for ensuring sound data are used in the risk assessment. Identifies tools for reviewing DQOs and sampling design, reviewing preliminary data, selecting statistical tests to summarize and analyze data, verifying the assumptions of the statistical test, and performing calculations. Can indicate differences in statistical robustness that might affect data combinations for chemical grouping and selection of representative concentrations.

(2.17) Data Quality Assessment: Statistical Methods for Practitioners (EPA, QA/G-9S);
http://www.epa.gov/quality/qs-docs/g9s-final.pdf
Same as (2.16).
Same as (2.16); for example, if some data were collected according to DQOs established with decision error feasibility trials while other data were collected under another program that required fewer samples, care would be warranted when combining these data.