Toward harmonizing ecotoxicity characterization in life cycle impact assessment.

Ecosystem quality is an important area of protection in life cycle impact assessment (LCIA). Chemical pollution has adverse impacts on ecosystems on a global scale. To improve methods for assessing ecosystem impacts, the Life Cycle Initiative hosted by the United Nations Environment Programme established a task force to evaluate the state-of-the-science in modeling chemical exposure of organisms and the resulting ecotoxicological effects for use in LCIA. The outcome of the task force work will be global guidance and harmonization by recommending changes to the existing practice of exposure and effect modeling in ecotoxicity characterization. These changes will reflect the current science and ensure the stability of recommended practice. Recommendations must work within the needs of LCIA in terms of 1) operating on information from any inventory reporting chemical emissions with limited spatiotemporal information, 2) applying best estimates rather than conservative assumptions to ensure unbiased comparison with results for other impact categories, and 3) yielding results that are additive across substances and life cycle stages and that will allow a quantitative expression of damage to the exposed ecosystem. We describe the current framework and discuss research questions identified in a roadmap. Primary research questions relate to the approach toward ecotoxicological effect assessment, the need to clarify the method's scope and interpretation of its results, the need to consider additional environmental compartments and impact pathways, and the relevance of effect metrics other than the currently applied geometric mean of toxicity effect data across species. Because they often dominate ecotoxicity results in LCIA, we give metals a special focus, including consideration of their possible essentiality and changes in environmental bioavailability. We conclude with a summary of key questions along with preliminary recommendations to address them as well as open questions that require additional research efforts. Environ Toxicol Chem 2018;37:2955-2971. © 2018 SETAC.

Environmental quality benchmarks-the good, the bad, and the ugly.

Environmental quality benchmarks (EQBs) such as water or sediment quality guidelines comprise one line of evidence for assessing the potential harm from chemicals and other stressors (physical, biological). They are useful but not perfect tools, should not always be used, and should never be used alone for final decision-making. The "good" can be designed to be situation-specific and can provide understandable scientific input to decision-makers. The "bad" includes perception that they are absolutes (i.e., definitive binary decision points), no or limited adaptability based on good science or common sense, and protection of individual organisms not populations of organisms. The "ugly" includes benchmarks based on simplistic indices (information loss, misleading results), misuse of biomarkers, and misapplication of EQBs. Other factors to be considered include the following: appropriately deriving EQBs, uncertainty, the laboratory is not the field, contaminant uptake and cause-effect, and specifics regarding sediment quality benchmarks (i.e., their specific "good," "bad," and "ugly" components). EQBs are not always needed or useful.

Negatives and Positives: Contaminants and Other Stressors in Aquatic Ecosystems.

Published research is reviewed to provide examples of both positive and negative interactions of contaminants and: climate change; habitat change; invasive and introduced species; and, eutrophication including harmful algal blooms. None of these stressor interactions results solely in negative effects. Research must shift from examining contaminants or other stressors in isolation to considering potential positive and negative effects of interactions, with the ultimate goal of providing the necessary information for the effective management of ecosystem services.

Total Suspended Solids Effects on Freshwater Lake Biota Other than Fish.

Protective benchmarks for the effects of total suspended solids (TSS) on freshwater aquatic biota primarily focus on fish; whether these benchmarks will also protect their prey or co-existing lower trophic level aquatic biota was uncertain. We conducted an extensive literature review of TSS effects on those organisms comprising the food webs upon which fish living in lakes depend: phytoplankton, zooplankton, periphyton, and benthic invertebrates. The available literature indicates that TSS benchmarks that protect sensitive life stages of lake fish will also protect their supporting food webs; in other words, the function of lake aquatic communities will be protected and maintained.

Revisiting the basis for US ballast water regulations.

The transport and release of invasive organisms in ballast water has harmed ecosystems, economic activities and human health. Current US ballast water regulations intended to minimize the discharge of such organisms are based on results reported by a scientific advisory committee in 2011. Using the same methods, we re-analyzed the data evaluated by the committee as well as new data. We find that the committee's analysis was flawed, and that some treatment systems can meet limits that are 10 times (for zooplankton) or 1000 times (for phytoplankton) more stringent than the committee reported. These findings suggest that US ballast water standards, and similar standards in a recently ratified international agreement, should be re-evaluated.

Assessing and managing stressors in a changing marine environment.

We are facing a dynamic future in the face of multiple stressors acting individually and in combination: climate change; habitat change/loss; overfishing; invasive species; harmful algal blooms/eutrophication; and, chemical contaminants. Historic assessment and management approaches will be inadequate for addressing risks from climate change and other stressors. Wicked problems (non-linear, complex, competing risks and benefits, not easily solvable), will become increasingly common. We are facing irreversible changes to our planetary living conditions. Agreed protection goals and considering both the negatives (risks) and the positives (benefits) of all any and all actions are required, as is judicious and appropriate use of the Precautionary Principle. Researchers and managers need to focus on: determining tipping points (alternative stable points); maintaining ecosystem services; and, managing competing ecosystem services. Marine (and other) scientists are urged to focus their research on wicked problems to allow for informed decision-making on a planetary basis.

Integrating causation in investigative ecological weight of evidence assessments.

Weight of evidence (WOE) frameworks integrate environmental assessment data to reach conclusions regarding relative certainty of adverse environmental effects due to stressors, possible causation, and key uncertainties. Such studies can be investigative (i.e., determining whether adverse impact is occurring to identify a need for management) or retrospective (i.e., determining the cause of a detected impact such that management efforts focus on the correct stressor). Such WOE assessments do not themselves definitively establish causation; they provide the basis for subsequent follow-up studies to further investigate causation. We propose a modified investigative WOE framework that includes an additional weighting step, which we term "direction weighting." This additional step allows for the examination of alternative hypotheses and provides improved certainty regarding possible causation. To our knowledge, this approach has not been previously applied in investigative ecological WOE assessments. We provide a generic example of 2 conflicting hypotheses related to a mine discharging treated effluent to a freshwater lake: chemical toxicity versus nutrient enrichment. Integr Environ Assess Manag 2017;13:702-713. © 2016 SETAC.

Assessing and managing multiple risks in a changing world-The Roskilde recommendations.

Roskilde University (Denmark) hosted a November 2015 workshop, Environmental Risk-Assessing and Managing Multiple Risks in a Changing World. This Focus article presents the consensus recommendations of 30 attendees from 9 countries regarding implementation of a common currency (ecosystem services) for holistic environmental risk assessment and management; improvements to risk assessment and management in a complex, human-modified, and changing world; appropriate development of protection goals in a 2-stage process; dealing with societal issues; risk-management information needs; conducting risk assessment of risk management; and development of adaptive and flexible regulatory systems. The authors encourage both cross-disciplinary and interdisciplinary approaches to address their 10 recommendations: 1) adopt ecosystem services as a common currency for risk assessment and management; 2) consider cumulative stressors (chemical and nonchemical) and determine which dominate to best manage and restore ecosystem services; 3) fully integrate risk managers and communities of interest into the risk-assessment process; 4) fully integrate risk assessors and communities of interest into the risk-management process; 5) consider socioeconomics and increased transparency in both risk assessment and risk management; 6) recognize the ethical rights of humans and ecosystems to an adequate level of protection; 7) determine relevant reference conditions and the proper ecological context for assessments in human-modified systems; 8) assess risks and benefits to humans and the ecosystem and consider unintended consequences of management actions; 9) avoid excessive conservatism or possible underprotection resulting from sole reliance on binary, numerical benchmarks; and 10) develop adaptive risk-management and regulatory goals based on ranges of uncertainty. Environ Toxicol Chem 2017;36:7-16. © 2016 SETAC.

Development of a total dissolved solids (TDS) chronic effects benchmark for a northern Canadian lake.

Laboratory chronic toxicity tests with plankton, benthos, and fish early life stages were conducted with total dissolved solids (TDS) at an ionic composition specific to Snap Lake (Northwest Territories, Canada), which receives treated effluent from the Snap Lake Diamond Mine. Snap Lake TDS composition has remained consistent from 2007 to 2014 and is expected to remain unchanged through the life of the mine: Cl (45%-47%), Ca (20%-21%), Na (10%-11%), sulfate (9%); carbonate (5%-7%), nitrate (4%), Mg (2%-3%), and minor contributions from K and fluoride. The TDS concentrations that resulted in negligible effects (i.e., 10% or 20% effect concentrations) to taxa representative of resident biota ranged from greater than 1100 to greater than 2200 mg/L, with the exception of a 21% effect concentration of 990 mg/L for 1 of 2 early life stage fish dry fertilization tests (wet fertilization results were >1480 mg/L). A conservative, site-specific, chronic effects benchmark for Snap Lake TDS of 1000 mg/L was derived, below the lowest negligible effect concentration for the most sensitive resident taxon tested, the cladoceran, Daphnia magna (>1100 mg/L). Cladocerans typically only constitute a few percent of the zooplankton community and biomass in Snap Lake; other plankton effect concentrations ranged from greater than 1330 to greater than 1510 mg/L. Chironomids, representative of the lake benthos, were not affected by greater than 1380 mg/L TDS. Early life stage tests with 3 fish species resulted in 10% to 20% effect concentrations ranging from greater than 1410 to greater than 2200 mg/L. The testing undertaken is generally applicable to northern freshwaters, and the concept can readily be adapted to other freshwaters either for TDS where ionic composition does not change or for major ionic components, where TDS composition does change.