Evaluating Human and Ecological Risk Assessments and Remediation Decisions: Is the Cure Worse than the Disease?
John Toll, Windward Environmental LLC
The Human Health Risk Assessment and Ecological Risk Assessment Advisory Groups (AGs) held a session at the Boston meeting on whether current risk assessment and risk management practices are doing more harm than good. Both of these AGs are concerned about the harm caused by too much active remediation of hazardous substances. This was a natural topic for them to collaborate on because an active remediation decision based on an assessment of ecological risk might produce side effects that harm people, or vice versa. The best way to give a flavor for what the session was about is to list the discussion topics that the AGs compiled for the session:
1. Are we properly accounting for risk of remediation?
- Are we doing more harm than good by mobilizing contaminants?
- Are we overlooking risk of remediation in pursuit of mass removal?
- Is there a need for policy/guidance on making tradeoffs between short- and long-term effectiveness of remedial alternatives?
- How do we accelerate progress toward a sustainable remedy paradigm?
2. Why aren’t we making greater use of compensatory mitigation as a risk management tool?
- Compensatory mitigation can be a cost-effective way to restore ecological services while natural recovery occurs.
3. When are we going to get over HQs and start actually characterizing how remedial alternatives will benefit affected populations?
- Are ecological populations measurably affected by hazards to susceptible individuals?
- Are there alternatives other than active remediation that would more cost-effectively benefit ecological populations?
- Will impacts of short-term habitat loss during remediation be overcome by greater long-term productivity after recovery?
- What’s the public health benefit of the remedy? Is the remedy efficient from a public health perspective?
- Is it worth destroying productive habitat to reduce theoretical human cancer risk that is too small to measure?
4. Should we be using residential human health clean-up objectives for redevelopment of properties for recreational use?
- The end result is to favor commercial redevelopment over conservation/ recreational reuse. Is that what we want to do?
5. Can we use ecosystem services to better merge HHRA and ERA paradigms?
- If we take an approach that benefits to humans from ecological processes are the real endpoint in ecological risk assessment then this would put most of our assessments of the risk of chemical releases to the environmental in terms of impacts (either directly or indirectly) to humans. Such a reframing of ecological risk could allow for an overall development of an "environmental risk assessment" framework.
6. Risk is a chance of an undesirable outcome, but risk assessment, by in large, ignores the chance element. Whatever happened to the chance element of risk assessment?
- Remediation goals should not be treated as bright lines. Changing "the number" doesn’t move us from protective to non-protective. It just incrementally changes probability of protectiveness. Huge increases in costs may only yield nominal differences in the probability of protectiveness. We need to characterize risk in terms of the how much remedial action alternatives are expected to increase the probability of protectiveness, relative to one another.
7. Is environmental risk assessment and management doomed to fail until we start framing our analyses and decisions holistically? Why or why not? What would a holistic problem formulation look like?
- Holism leads to different questions, different investigative designs, different communications methods, and ultimately different decisions about tradeoffs.
These discussion topics clearly struck a chord with the session’s speakers and audience. The audience was actively engaged in the session from start to finish.
The speakers’ opinions about whether current risk assessment and risk management practices are doing more harm than good varied, but each of the speakers provided good empirical evidence of shortcomings in the current state of the practice. This idea was expressed in various ways, ranging from the need to be both more farsighted and more detail-oriented in designing and executing data gathering efforts, to focusing on relative risk reduction instead of absolute risk, to being more open to actions that offset risk rather than remediate it, to thinking about risk in its broader societal context.
One thing that all the presenters seemed to agree on is that far too little attention is paid to problem formulation, i.e., to thinking through exactly what we’re doing and why at the front end of risk assessments. Another point of consensus seemed to be that risk assessments focus too much on baseline conditions and too little on what risk management alternatives can do to reduce risk or improve the flow of ecosystem services. A third area of common ground seemed to be that cost ineffective management options should be screened out early so that resources aren’t unnecessarily spent assessing risk for those options.
Further conversations are needed to tease this out, but there also seemed to be a consensus emerging that the way we’re interpreting separation of risk assessment and management is flawed. This is not to say that the speakers, or audience, generally thought that risk assessors should be making risk-management decisions, or that risk managers should be directing risk assessors. The notion of separate and distinct roles for risk assessors and managers probably is safe for now. There do seem to be growing doubts, though, about how those roles are playing out. There seems to be a sense that risk managers should be doing much more to flesh out management alternatives during the risk assessment problem formulation. A firm and inclusive set of risk management alternatives should be laid out early to inform the risk assessment. Risk assessors, in turn, should stop looking for lost keys under the lamppost and tackle the hard questions that risk managers need answered, even though those answers won’t be found in hazard quotients.
In the lead up to the meeting, the ecological and human health risk assessment AGs framed the session almost as a debate about the merits of two competing principles:
- No regrets – In the face of uncertainty, err on the side of a more stringent remedy
- First do no harm – Only resort to active remediation if other less invasive remedies won’t work
Neither of these holds up as a guiding principle for environmental risk assessment and management but they made for a useful point-counterpoint. First do no harm conflicts with the adaptive management principle, which calls for experimentation as a way to learn about what sorts of environmental and resource management solutions do and don’t work for particular problems. Adaptive management accepts harm as a byproduct of experimentation because experimentation promotes the greater good of discovering cost-effective ways to solve problems. No regrets, interestingly, conflicts with the precautionary principle (Rio Declaration Principle 15). The precautionary principle says not to let uncertainty stand in the way of making decisions, but it explicitly calls for measures to be cost-effective and aligned with capabilities of the performing parties. It comes closer to being a useful guiding principle than either no-regrets or first-do-no-harm. It stops short, though, of saying how to do environmental risk assessment and management.
The Boston session was an important stepping stone. It helped members of the ecological and human health risk assessment AGs answer the question of whether current risk assessment and risk management practices are doing more harm than good. The answer is probably no, they’re not doing more harm than good. They’re better than nothing, but could be better. We’re lacking positive guidance that will consistently lead to cost-effective risk management solutions that align with the capabilities of the performing parties.
In the discussion of principles, we gave the last word to Hippocrates, who said:
"LIFE is short, and Art long; the crisis fleeting; experience perilous, and decision difficult.
"The physician must not only be prepared to do what is right himself, but also to make the patient, the attendants, and externals cooperate."
Aphorisms. Sect. 1, No. 1. Translated by Francis Adams.
We risk assessors are, by analogy, Hippocrates’ "physicians." The burden is on us to "do what is right," as well as to persuade others to meet the challenge with us.
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