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A Continuous Need To Determine What We Should Protect In Ecological Risk Assessments Yuichi Iwasaki*,† and William H. Clements‡ †
Research Center for Life and Environmental Sciences, Toyo University, 1-1-1 Izumino, Itakura, Oura, Gunma 374-0193, Japan Department of Fish, Wildlife and Conservation Biology, Colorado State University, Fort Collins, Colorado 80523, United States are asked “Let us assume contamination from an industrial plant is occurring in the pond. Which level do you want to protect? Note that in this case the industrial plant pays for the cost of protection.” Students are asked to pick a single protection level from four choices (suborganismal, individual, and population levels, and no protection; Figure 1). The second similar question
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Figure 1. Hypothetical protection levels and corresponding examples. In this example, it is assumed that end points at lower levels of biological organization are more sensitive to pollution and their protection is more costly.
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is “Assume that domestic wastewater from your house was discharged into your pond. What do you want to protect? Note that in this case the homeowner (i.e., you) should pay for the cost of protection.” Interestingly, in this situation the choice often changes to an assessment of higher-level end points (say, a student who chose “suborganismal level” in case of industrial payment picked “population level” in case of her/his payment). A likely reason for the switch is that if an individual is not required to pay then they pursue an ideal. In contrast, if an individual is required to pay they select a practically feasible answer. The circumstances supposed in ecological risk assessment and management are usually closer to the latter situation because we usually have limited resources that can be allocated. Thus, in order to better address the fundamental questions raised above, one of our suggestions here is that stakeholders and risk assessors/managers explicitly recognize the gap between what we personally (ideally) want to protect and what we can/should practically protect. At one extreme, do you pay for protecting each individual within a population of mayflies or Daphnia? Furthermore, by explicitly recognizing the gap between our personal preferences and what we can practically achieve, we can identify the critical studies necessary to answer our two fundamental questions: (1) What aspects of ecosystems should we protect?; and (2) How much of an effect on this ecosystem would be acceptable?
WHAT TO PROTECT What aspects of ecosystems should we protect from the adverse impacts of chemicals? How much of an effect on these end points would be acceptable? While a commonly advocated protection goal is viability of species,1 which is developed typically at the population (e.g., density) or community level (e.g., species richness), these are long-standing and fundamental questions that have been rather ambiguously dealt with in general ecological risk assessments and in the establishment of water quality criteria. Use of no observed effect concentration (NOEC) is a typical example. Using laboratory toxicity testing on individual- (or organismal-) level end points such as survival and reproduction, NOEC is determined solely by statistical significance which depends on experimental design, sample size, effect size, and data variability. Who knows what real ecological consequences have resulted from this reliance on statistical significance.
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BE AWARE OF IDEALS AND REALITY WHEN DETERMINING WHAT TO PROTECT Pursuing ideals is important. However, we should also recognize that we cannot protect all aspects of all ecosystems exposed to chemicals, particularly as the number of registered chemicals continues to increase. Here, we introduce two hypothetical questions that one of the authors often asks undergraduate students in the classroom. Suppose each of us has a small pond with a fish population of value in her/his home. Then, students © 2015 American Chemical Society
Received: April 9, 2015 Published: June 17, 2015 7520
DOI: 10.1021/acs.est.5b01804 Environ. Sci. Technol. 2015, 49, 7520−7521
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Environmental Science & Technology It should be stressed that we are not claiming that what we should (or can) protect is more important than what we personally (or ideally) want to protect, or that providing practical answers is more valuable than, say, seeking any effect of chemicals. However, given an environmental standard for a chemical, it is rather easy to find an effect below the standard, and is difficult to find a more convincing (and feasible) way to establish a more defensible standard. Therefore, balancing these efforts would be a key for improving ecological risk assessments, especially given that the number of potential assessment end points developed at suborganismal- (e.g., genes2) and ecosystem-levels (e.g., ecosystem services3) has been increasing owing to recent technological and scientific developments.
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CALL FOR DISCUSSION AND STUDIES ADDRESSING WHAT TO PROTECT Although the fundamental questions will likely remain unsolved, we believe these suggestions would aid in conducting more convincing ecological risk assessment and management. There will never be a single answer (or end point) that can be applied to all management decisions. In addition, following accumulation of scientific knowledge and development of technologies as well as changes in societal values, what we should protect would likely change. Therefore, we hope discussion and research directly addressing the fundamental questions will be intensively performed.
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AUTHOR INFORMATION
Corresponding Author
*Phone: +81-276-82-9337; fax: +81-276-82-9337; e-mail:
[email protected]. Notes
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS This study is partly supported by a Grant-in-Aid for Strategic Research Base Project for Private Universities, which is funded by the Ministry of Education, Culture, Sport, Science, and Technology, Japan, 2014−2018 (S14111016).
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REFERENCES
(1) Hommen, U.; Baveco, J. M.; Galic, N.; van den Brink, P. J. Potential application of ecological models in the European environmental risk assessment of chemicals I: Review of protection goals in EU directives and regulations. Integr. Environ. Assess. Manage. 2010, 6 (3), 325−337. (2) Bencic, D. C. The challenge: Real-world application of ‘omics endpoints. Environ. Toxicol. Chem. 2015, 34 (4), 700. (3) Millennium Ecosystem Assessment. Ecosystems and Human Wellbeing: Biodiversity Synthesis; Island Press: Washington, DC, 2005.
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DOI: 10.1021/acs.est.5b01804 Environ. Sci. Technol. 2015, 49, 7520−7521
