The stakeholders’ understanding of the fundamentals of risk assessment should be determined and, if possible, stakeholders should be given opportunities to increase their knowledge through public meetings and access to available information. In this document, Using Bioavailability in Risk Assessment describes the calculation process for incorporating RBA values in the risk assessment. ITRC has recently published guidance on human health risk assessment (ITRC 2015), Decision Making at Contaminated Sites: Issues and Options in Human Health Risk Assessment. This ITRC guidance includes information about using risk assessment in site cleanup. The guidance also includes links to USEPA and state agency guidance on risk assessment.

Will changing environmental conditions make contaminants more bioavailable in the future? Stakeholders worry that compounds for which the site-specific cleanup goals include low bioavailability may become more bioavailable in the future as environmental conditions change, either through human activities or natural changes. The effect of future land use should be considered in determining whether a bioavailability assessment should be conducted and what the scope of that assessment should be. The decision process chapter discusses these issues. The lead, arsenic, and PAHs chapters include some discussion of the chemical reactions and properties that would affect reversibility.

Inhalation and dermal exposure (except for PAHs) are not addressed in this guidance, but these exposure pathways can be concerns. One community group in New York has sued a developer because of concerns about inhaling lead-contaminated dust from a proposed construction site. Proponents of site-specific cleanup goals must explain to stakeholders why the site-specific cleanup goals are health protective and why these pathways are or are not relevant, regardless of the difficulty and complexity of assessing exposure through these routes.

Stakeholders are concerned about all environmental pathways and may not accept excluding pathways such as ingesting homegrown vegetables from risk assessments. For example, if contaminants could be absorbed through the roots of plants, then this pathway should be addressed in the risk assessment. Any risk-based, site-specific cleanup goals should explain the rationale for including or excluding exposure pathways, including dermal exposure and inhalation.

Do soil samples represent the worst-case scenario? Stakeholders require assurance that the sampling efforts have characterized the worst exposure threats. Composite sampling methods, such as incremental sampling methodology (ISM), may raise heightened concerns about the adequacy of the samples.

Although this guidance does not specifically address ecological receptor risks, stakeholders may be concerned that site-specific cleanup goals based on a bioavailability assessment for human health will transfer risk assumptions to ecological receptors. For example, species of lead that are left in the soil because they are not a risk to humans may present a risk to ecological receptors. Proponents of site-specific cleanup goals based on a bioavailability assessment for human health should clarify that the bioavailability assessment only addresses human oral ingestion exposure, or PAH dermal exposure, as applicable. Requirements for any separate ecological risk assessment should be met, but are not discussed in this guidance. Animal studies, however, are often used as surrogates to estimate human health effects, so it is reasonable to assume that the same studies might be used for assessing eco-risk. The methodology chapter discusses the specific animal tests (in vivo methods) used for bioavailability assessment of the human exposure pathway for ingestion of contaminated soil. Although ecological studies take more variables into consideration, the two risk assessments (human health and ecological) are difficult to differentiate once the animal study is completed. Stakeholders may see this as a backdoor means to develop new eco-risk calculations. Tribes are particularly concerned about including ecological receptors in risk assessments because many tribal members eat wild game.

If contaminants are in the news as a national threat to human health (such as lead in drinking water and household paint), the science behind a bioavailability assessment may be outweighed by public perception of the hazards. On the other hand, if communities can see tangible benefits from a bioavailability assessment (as is the case in a California community that saw parks and schoolyards deemed safe with an RBA value developed using a bioavailability assessment), they may welcome bioavailability assessments. In either case, when a bioavailability assessment is considered for a specific contaminant and site, the stakeholder perception of the contaminant should be considered early in the decision-making process.

Some tribes view any level of contamination of their land and natural and cultural resources as unacceptable. Many tribes have culturally significant or sacred areas, which may include springs, mountains, hunting areas, plant-gathering areas, or burial sites. When culturally significant or sacred areas are at stake, traditional methodologies that nontribal environmental professionals rely on (such as the applicable exposure scenarios, pathways, or factors for a risk assessment) may be superseded. Some plants and animals can also have tremendous cultural or religious importance to a tribe, including birds and feathers, game animals, herbs, grasses, and trees. These areas, items, and living things may be used in ways that are not addressed in standard risk assessment scenarios. In addition, the exposure scenarios, pathways, and factors used in the risk calculations for tribal activities may differ from the USEPA or state default values. These values should be considered in the risk assessment scoping and may counter the decrease in risk gained by a site-specific RBA value.

Tribes are sovereign entities that have established government-to-government relationships with federal, state, and local governments—relationships that must be recognized in the decision-making process. When a site affects a tribe, the project timeline must include tribal approvals in addition to other typical agency approvals. Sampling, research, and services on tribal lands generally require Institutional Review Board (IRB) or Tribal Council approval. Each sovereign nation operates differently, ranging from tribes that have no research capacity to tribes that have a full review board with a formal application process. The initial steps in the approval process may include drafting a proposal, preparing a poster or podium presentation, and presenting to the tribal government.

Once tribal approval is granted and the project commences, the practitioner must obey tribal protocol with respect to cultural practices. The tribe may reserve the right to retain the findings in the case of exploratory research and restrict publication. Regulatory findings for water and soil concentration, level of treatment, and monitoring are first reported to the tribe’s Department of Environmental Quality or Natural Resources and then forwarded to USEPA.

Effective stakeholder engagement not only reduces impediments to completing projects on schedule, but also helps responsible parties and regulators to make better decisions. The best way for regulators and responsible parties to engage the public is to seek out members of the community who are willing to devote time to project oversight, share information with these individuals as early in the process as practical, and give them the tools they need to participate constructively.

The following steps outline an approach for effective stakeholder engagement. The success of engagement programs depends on effective planning and outreach to build a working relationship between stakeholders and those conducting and overseeing cleanup. By reaching out and responding to stakeholders not only when required by law, but throughout the process, regulators and responsible parties can build trust with stakeholders. Finally, including stakeholders in site decisions makes them partners in a process that protects them, their families, their property, and their communities.

1. Plan for stakeholder engagement. Read More

2. Engage the stakeholder community through outreach. Read More

3. Build trust through communication. Read More

4. Build trust by clearly explaining technical concepts. Read More

5. Include stakeholders in decision making. Read More