A Peptide Identification-free Shotgun Proteomics Workflow to Differentiate Escherichia coli Isolates by Faecal Sources

Shao W. G.¹, Zhang M.², Lam H.^1,3 and Lau S. C. K.^2,4
1Division of Biomedical Engineering, the Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China
²Division of Environment, the Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China
³Department of Chemical and Biomolecular Engineering, the Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China
⁴Division of Life Science, the Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China

Presenting author’s email: scklau@ust.hk

Understanding the Influence of Multiple Stressors on Chemical Effect Thresholds is a Prerequisite of the Quest for the “Holy Grail”

Leung K. M. Y.
The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
Presenting author’s email: kmyleung@hku.hk

Challenges in Derivation of Water Quality Guidelines for Dissolved Oxygen, the Alien

Chiu J.¹ and Wu R.^2
1Biology Department, Hong Kong Baptist University, Hong Kong SAR, China;
²Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong SAR, China
Presenting author’s email: rudolfwu@hku.hk

Eutrophication and hypoxia are now a wide spreading problem worldwide.   Setting up water quality guidelines (WQG) for dissolved oxygen is inarguably important, and yet very difficult.
First, dissolved oxygen (DO) is very different from other water quality parameters in many aspects.  Both temporal and spatial variations of DO in a single water body are typically large, and this is further augmented by marked diurnal oscillations.  This makes it extremely difficult to have a representative estimate of DO without extensive measurements (i.e., different days including both sunny and dull days, day and night, and different depths), which is often impractical.  Jurisdictions adopting average DO in their WQG is obviously wrong and misleading.
Second, DO levels may not necessarily be low enough to cause mortality.  More often, low to moderate DO levels may lead to growth reduction, reproductive impairment and abnormal development, thereby posing a threat to sustainability of the aquatic species.  While numerous studies have been carried out to determine the short term acute effects caused by extreme hypoxic conditions, there is an acute shortage of scientific data on chronic exposure and sublethal effects of hypoxia.  The required scientific studies, albeit important, are understandably difficult, since: (a) the effective window for sublethal hypoxic effects to occur is typically narrow, and (b) the physiological response and adaptive strategy of most species is largely dependent upon the period of hypoxic exposure.
Third, tolerance of aquatic organisms varies considerably among different species (particularly between warm-water and cold-water species), and different life stages (eggs, larvae, adults).  Reproductive and developmental stages appear to be more sensitive.  Very few information is available on the hypoxic tolerance of marine and estuarine species, especially for warm water species.  Since most existing WQG for DO are derived from cold water and/or freshwater species, their applicability to warm water marine environments is questionable.
The use of a field-based biological assessment approach for deriving WQG of DO will be discussed.

Study of Environmental Criteria of Heavy Metal Cr(VI), Pb and Cd in China

Liu Z. T.
State Environmental Protection Key Laboratory of Ecological Effects and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
Presenting author’s email: liuzt@craes.org.cn

Purpose: This study aims to develop aquatic life criteria and soil environmental criteria for Cr(VI), Pb and Cd in China using the toxicity data of native species.
Experimental description: First of all, toxicity data of native species for Cr(VI), Pb and Cd were selected. The quality and quantity of selected toxicity data were checked.  Secondly, acute/chronic toxicity tests were carried out when toxicity data of native species were lacking.  Thirdly, aquatic life criteria and soil environmental criteria based on toxicity data of native species were derived using the species sensitivity distribution method recommended by US EPA (i.e., US-SSD method).
Results: The acute/chronic toxicity data of aquatic life for Cr(VI), Pb and Cd were selected.  The chronic toxicity of terrestrial species for Cr(VI), Pb were tested.  The aquatic life criteria based on toxicity data of native species for Cr(VI), Pb and Cd were derived using the US-SSD method.  The soil environmental criteria based on tested toxicity data for Cr(VI) and Pb were derived using the log-logistic SSD method.
Conclusions: The criteria maximum concentrations of protecting aquatic life for Cr(VI), Pb and Cd were 17.73, 131 and 1.15 μg/L, respectively.  The criteria continuous concentrations of protecting aquatic life for Cr(VI), Pb and Cd were 12.15, 5.1 and 0.12 μg/L, respectively.  The soil environmental criteria for Cr(VI) and Pb were 1.5~7.7 and 31.7~158.3 mg/kg, respectively.

WQC Derivation and Ecological Risk Assessment for Bisphenol A Considering its Endocrine Disrupting Features

Li Z. Y.^1,2, Guo L.¹, Zhang J. J.¹ and Hu H.^1
1College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China;
²Key Laboratory of Marine Environmental Science and Ecology, Ministry of Education, Qingdao 266100, China
Presenting author’s email: zhengyan@ouc.edu.cn

The ecological risk assessment for contaminated sediments is technically challenging due to heterogeneity and complexity of sediment’s physicochemical characteristics.  Several decision-making tools for addressing the magnitude of the chemical threat in sediments have been developed (Wenning et al., 2005; Mount et al, 2003).  Among the approaches, the derivation of sediment quality guidelines (SQGs) development is relatively simple and inexpensive when comparing to the other approaches depending on toxicity tests, bioaccumulation studies, benthic community studies, or other data-intensive tools (Burgess et al., 2013).
The currently developed SQGs can be categorized into two general forms: empirical and mechanistic ones.  The empirical approach was employed in this study.  The target contaminants included copper, lead, zinc, cadmium, mercury, arsenic, chromium, total petroleum hydrocarbon, DDTs and HCHs.  The paired data of sediment’s chemistry and infaunal diversity were concurrently collected in Tangshan, Yinkou, Jinzhou, Dalian, Xiamen coasts and Changjiang estuary.  The amphipods Grandidierella japonica and bivalves Ruditapes philippinarum were exposed to field-collected bulk sediments, and spiked sediments for acute toxicity test and bioaccumulation test.  Both the ecological risk of contaminants elutriated from the sediment to overlaying water and the health risk of contaminants transferred from food chain to human were taken into consideration.  A biological effect database which matched with sediment’s chemistry and indaunal diversity, sediment acute and/or chronic toxicity data, and bioaccumulation data was constructed.  The threshold effect level (TEL) and probable effect level (PEL) were derived with varying likelihoods of causing adverse effects to benthic organisms.  The probability of adverse effects for each of the target contaminants with chemical concentrations in the sediment sample < TEL was found to be no more than 15%, and the probability with chemical concentrations in the sediment sample > PEL was more than 75% except 66.6% for HCHs due to limited data.

High-throughput Screening and Prioritization for Chemicals with Hazard or Risk Potencies

Wang D. H. and Wang Z. J.
State Key Laboratory of Environmental Aquatic Chemistry, RCEES/CAS, China
Presenting author’s email: wangzj@rcees.ac.cn

Thousands of industrial chemicals have been produced and released into the environment.  Nevertheless some of the chemicals have been classified to have risks on both human and ecosystem by the targeted risk assessment, they represent only a small portion of potential hazardous contaminants.  Prioritization procedures are generally required before any action could be taken as the countermeasures, such as setting up the environmental quality criteria or benchmarks for regulatory supervision.  Among varieties of prioritization algorithms, ranking methods based on field monitoring data or on the fugacity models are generally adapted in practical uses.  In the presentation, a prioritization approach based on high-throughput screening analysis and tier-1 risk assessment was proposed for targeting the potential aquatic contaminants for further actions.   
A screening tool includes a high efficiency analytical method and a tier-1 hazard and risk assessment procedure.  Hazard assessment was performed on both health and ecotoxicological data with focus on EMR categories or environmental endocrine disruptors when there is no sufficient information, such as HC5 or NOEC.  Risk assessment was performed by the risk quotient (RQ) approach when PNEC was the deliverable.  For risk assessment, a HQ larger than unity was regarded as “chemical at risk”, and a RQ larger than 0.3 and below unity was regarded as “chemical at potential risk”.  In the approach, a universe data bank, a process for ranking and a candidates list would be the outputs.  In general, a larger data bank implies more potential targets being inclusive.  However, in chemical analysis, more targets indicate the increasing difficult for separation and resolution. 
Two approaches have been verified for field application, i.e., the targeted analysis for chemicals known as toxicants and the non-targeted analysis for chemicals reported to present in the environment.  In the targeted analysis, traditional methods include Standard Protocols issued by different authority organizations (USEPA methods for example), multi-residues analysis applied in pesticides analysis, qualitative mass spectrum allocation using NIS data bank, as well as group analysis developed in recent years.  In the targeted screening, the group analysis shows to be a powerful tool when combined with retention time lock (RTL) and chromatogram deconvolution (CD).  As an example, more than 50 phenol compounds with HPV property were selected to build up a mass data bank, and priority phenolic contaminants with potential risk in Taihu Lake were listed as a candidates list for further tire-2 risk assessment. 
The non-target screening was performed by a two-dimensional chromatography (2xGC-TOFMS).  While there are many advantages using 2xGC/MS, the disadvantages of the method are lacking tools for extracting useful information from mass data and for verification/confirmation of the targets found from chromatogram.  Index of retention time during temperature programming proposed by Van den dool and Kratz etc was adapted to increase the accuracy of target identification in the complex matrix.
In our recent survey for Chinese waters, 137 chemicals were identified from more than 400 chemicals known as toxicants by applying the targeted screening.  About 3000~3500 chemicals could be found from waters of Chinese major river basins by the non-targeted screening, and 93 emerging chemicals were categorized into the candidate list because of their hazardous level or at risk level.
In the presentation, we would like to share our recent knowledge and research progress so as to stimulate the discussion and future collaboration.

Application of QSAR in Deriving Water Quality Criteria for Metals

Wu F. C.¹, Mu Y. S.¹, Chen C.¹, Wang Y.¹, Qie Y.¹, Zhao X. L.¹ and Giesy J. P.
¹State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China;
²Toxicology Centre, University of Saskatchewan, Saskatoon, Canada
Presenting author’s email: wufengchang@vip.skleg.cn

Metals are widely-distributed pollutants in water, and can have detrimental effects on some aquatic life and humans.  Over the past few decades, the United States Environmental Protection Agency (USEPA) has published a series of criteria guidelines, which contain specific criteria maximum concentrations (CMCs) for 10 metals.  However, CMCs for other metals are still lacking due to financial, practical or ethical restrictions on toxicity testing.  Herein, a quantitative structure activity relationship (QSAR) method was used to develop a set of predictive relationships, based on physical and chemical characteristics of metals, and predict acute toxicities of each species for five phyla and eight families of aquatic organisms for 25 metals or metalloids.  In addition, species sensitivity distributions (SSDs) were developed as independent methods for determining predictive CMCs.  The quantitative ion character-activity relationships (QICAR) analysis showed that the softness index (σp), maximum complex stability constants (log-βn), electrochemical potential (∆E0) and covalent index (Xm2r) were the minimum set of structure parameters required to predict toxicity of metals to eight families of representative organisms.  Predicted CMCs for 10 metals are in reasonable agreement with those recommended previously by the US EPA within a difference of 1.5 orders of magnitude.  CMCs were significantly related to σp (r2 = 0.76, p = 7.02×10-9) and log-βn (r2 = 0.73, p = 3.88×10-8).  The novel QICAR-SSD model reported here is a rapid, cost-effective, and reasonably accurate method, which can provide a beneficial supplement to existing methodologies for developing preliminarily screen level toxicities or criteria for metals, for which little or no relevant information on the toxicity to particular classes of aquatic organisms exists.

Screening of Priority Pollutants and Resident Test Organisms for Development of Water Quality Criteria in China

Yan Z. G.
State Environmental Protection Key Laboratory of Ecological Effects and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
Presenting author’s email: zgyan@craes.org.cn

Metagenomic Profiling of Zooplankton Community Reveal Environmental Threshold of Ammonia in Eutrophic Aquatic Ecosystem: A Case Study on Tai Lake, China

Yang J. H., Xie Y. W., Zhang Y., Yu H. X. and Zhang X. W.
State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023 China
Presenting author’s email: zhangxw@nju.edu.cn

CRED – Criteria for Reporting and Evaluating Ecotoxicity Data

Ågerstrand, M.
Department of Environmental Science and Analytical Chemistry (ACES), Stockholm University, Sweden
Presenting author’s email: marlene.agerstrand@aces.su.se

Predicted No Effect Concentrations (PNECs) or Environmental Quality Standards (EQSs), are derived in a large number of legal frameworks worldwide.  When deriving these safe concentrations, it is necessary to evaluate the reliability and relevance of ecotoxicity studies.  This evaluation is often subject to expert judgment, which may introduce bias and decrease consistency when risk assessors evaluate the same study. 
The CRED-project, short for Criteria for Reporting and Evaluating ecotoxicity Data, is a collaboration between the Dutch RIVM, the Swiss Centre for Applied Ecotoxicology, EAWAG, and Stockholm University.  It aims at improving the reproducibility, consistency and transparency of reliability and relevance evaluations of ecotoxicity studies, both within and between regulatory frameworks, countries, institutes and individual assessors.  To this end, the CRED evaluation method was developed.  The method contain 20 reliability and 13 relevance criteria.  Each criterion is accompanied by extensive guidance that helps evaluators navigate throughout the assessment. 
Reliability concerns the intrinsic quality of a study, regardless of the purpose for which it is assessed.  It is determined by an assessment of the design, performance and analysis of the experiment.  For example, a study may be considered less reliable because of an inadequate experimental design (e.g. too few replicates), poor performance (e.g.  too high mortality in the controls) or insufficient data analysis (e.g.  inadequate statistics). 
In addition, to improve the reporting of ecotoxicity studies, a set of recommendations for reporting methodological details and results was established.  Researchers performing aquatic ecotoxicity studies are advised to use these recommendations when designing their experiments to make sure that all aspects connected to reliability are considered.

Current Status of Water Quality Standards for the Protection of Human Health and Aquatic Ecosystems in Korea

An Y.-J.¹, Kwak J.  I.¹, Lee J.-H.² and Park C.-H.^3
1Department of Environmental Health Science, Konkuk University, Korea;
²Institute of Environmental Safety and Protection, NeoEnBiz Co. Korea;
3Water Environmental Engineering Research Division, National Institute of Environmental Research (NIER), Korean Ministry of Environment (MOE), Korea
Presenting author’s email: anyjoo@konkuk.ac.kr

U.S. EPA’s Current Approach to Developing Aquatic Life Ambient Water Quality Criteria, Recent Successes, and Efforts to EPA’s Methodology for Deriving Criteria

Gallagher K. and Elias M.
United States Environmental Protection Agency (U.S. EPA), Office of Water, Office of Science and Technology, Washington, DC, USA
Presenting author’s email: Gallagher.Kathryn@epa.gov

The U.S.  EPA’s Office of Water develops U.S.  national Aquatic Life Ambient Water Quality Criteria by gathering all available, high quality toxicity data on a range of taxa.  Criteria include recommended limits on the magnitude, frequency and duration of exposure to a given chemical that are intended to be protective of 95% of aquatic organisms an ecosystem.  EPA uses all available data in a weight-of-the-evidence analysis that includes consideration of information on chemical mode of action, potential exposure pathways, bioaccumulation potential, persistence, as well as field data, in developing criteria.  In the past several years, EPA has been focusing on developing criteria that follow EPA’s Ecological Risk Assessment Paradigm, including problem formulation and development of conceptual models, and on accelerating its efforts to develop more high quality criteria more rapidly.  Recent key criteria issued in the past few years include: the updated final freshwater ammonia criteria, which include consideration of site pH and temperature, and are protective of sensitive mussel and snail species; and an updated draft freshwater selenium criterion, which accounts for the bioaccumulation and persistence of selenium and is EPA’s first aquatic life fish tissue criterion.  EPA is also moving forward with updated freshwater and saltwater copper aquatic life criteria.  The updates to the freshwater and Saltwater copper criteria will be based on use of a Biotic Ligand Model which incorporates consideration of water chemistry effects on the bioavailability of copper to aquatic organisms. 
Recognizing that EPA’s methods need to be updated to reflect more current approaches to effects analysis development, EPA has begun a focused effort to update its Guidelines for Deriving Numerical National Water Quality Criteria for the Protection of Aquatic Organisms and Their Uses (USEPA 1985).  EPA held an “Invited Expert Meeting on Revising Guidelines for Deriving Numerical National Water Quality Criteria” in September of 2015, which represented a first major step in the Guidelines revision process.  Based on the 2015 meeting, EPA has decided to take a two-pronged approach to updating its Aquatic Life Criteria methods: 1) a “Fast-track” criteria approach focused on developing a larger number of criteria more rapidly, for the broader protection of aquatic life, and 2) a “Comprehensive Criteria” approach which will be focused on refining methods for deriving state-of-the-science criteria through comprehensive analyses.  The first objective reflects the recognition that tens of thousands of chemicals enter the environment from anthropogenic activities.  Because rigorous testing of all chemicals is infeasible, EPA is in interested applying existing approaches to efficiently derive criteria by estimating safe environmental concentrations with limited empirical data, and as necessary, developing new approaches to accomplish this task.  The second objective reflects the issue that for a smaller group of chemicals, criteria development may be scientifically complex, and deriving robust criteria may require extensive study. 

Perspectives on Alternative Endpoints in Aquatic Toxicology and Environmental Quality Criteria Derivation

Brooks B. W.
Department of Environmental Science, Baylor University, Waco, Texas, USA
Presenting author’s email: bryan_brooks@baylor.edu

Breaking from Tradition: Establishing More Realistic Sediment Quality Guidelines

Burton Jr. G. A.
University of Michigan, Ann Arbor MI, 48109, USA
Presenting author’s email: burtonal@umich.edu

Environmental Quality Benchmarks – The Good, the Bad, the Ugly

Chapman P. M.
Chapema Environmental Strategies Ltd, North Vancouver, BC, Canada
Presenting author’s email: Peter@chapmanenviro.com

Water Quality Criteria in the 21st Century

Giesy J. P.^1,2,3,4, Zhang X. Q.⁴, Jin X. W.⁵,Li Y. B.⁴, Xu E. G. B.⁶, Liu W.³, Chen Y.⁷, Liu H. L.⁴, Xing L. Q.⁸, Liu Z. T.⁹, Jin X. W.⁹, and Yu H. X.^4
1Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
²Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada
³School of Biological Sciences, University of Hong Kong, SAR, China
⁴State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
⁵China National Environmental Monitoring Center, Beijing, 100012, China
⁶Department of Environmental Sciences, University of California, Riverside, CA92521, USA
⁷Jiangsu Provincial Academy of Environmental Sciences, Nanjing, Jiangsu 210036, China
⁸Nanjing University & Yancheng Academy of Environmental Protection Technology and Engineering, Yancheng, Jiangsu 224000, China
⁹State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
Presenting author’s email: JGiesy@aol.com

There have been a number of advances in derivation of water quality criteria, to make them more ecologically relevant.  Over the last 20 years, probabilistic analyses have been applied to describe a greater proportions of sensitivities among species likely to occur in ecosystems.  Water quality criteria, determined based on controlled laboratory studies with individual surrogate species, do not incorporate the complexity of ecosystems.  Probabilistic approaches, such as Species Sensitivity Distributions (SSDs) have been incorporated into derivation of WQC.  Historically, ecosystems have been characterized by use of taxonomic descriptions based on visual characteristics, which was labour intensive, for collection and identification and enumeration and required extensive experience to assign each individual to a species or genus.  Here an apparent effects threshold (AET) approach based on meta-barcoding was used to characterize genetic diversity in the mitochondrial cytochrome, c oxidase I (COI) region of DNA of freshwater zooplankton as a novel environmental monitoring tool, with which to identify adverse effects on ecosystems. A novel, rapid SSD approach based on operational taxonomic units (OTUs) observed under field conditions for development of water quality criteria (WQC) to protect the aquatic environment from exposure to toxic ammonia. The WQC developed was then compared to values developed, using more traditional, laboratory based approaches. DNA meta barcoding significantly increased the number of zooplankton observed.
Oversupply of ammonia and other nutrients can lead to eutrophication and subsequent toxicity in Tai Lake, the third largest lake in China. Nutrients, especially total ammonia and nitrite, which can be toxicity to zooplankton, had a significant effect on the structure of the zooplankton community than did other environmental factors in the catchment of Tai Lake, freshwater ecosystem in China that has been culturally eutrophicated.  This has affected both the lotic and benthic communities.  Over decades, the significant decline in diversity of the benthic invertebrate community of Tai Lake (from 68 species in 5 phyla in 1980s to 40 species in 3 phyla in 2008) could be attributed to continuous exposure to unionized ammonia (NH3).

Recent Developments in the Derivation and Implementation of Environmental Quality Standards for Chemicals in the UK

Merrington G.¹, Peters A.¹, Whitehouse P.² and Clarke R.^4
1wca, Faringdon, Oxfordshire, UK;
²Environment Agency, Wallingford, Oxfordshire, UK;
³Scottish Environment Protection Agency, Holytown, North Lanarkshire, UK
Presenting author’s email: graham.merrington@wca-environment.com

Field-Based Approaches to Derive Environmental Quality Standards

Peters A., Whitehouse P., Johns T., Adams B., Schlekat C., and van Assche F.
WCA Environment Limited, Faringdon, Oxfordshire, UK
Presenting author’s email: Adam.Peters@wca-consulting.com

Environmental quality standards (EQS) and objectives for chemical toxicants are typically derived from the results of laboratory toxicity tests.  A potential alternative approach involves the use of observations of ecological quality in the field in relation to the levels of the toxicant(s) of interest.  In situations where there is a comparable assessment of ecological quality, for example under the Water Framework Directive (WFD) in Europe, the use of field evidence to derive guidelines and standards may allow a closer link between the assessment of environmental quality for both the chemistry and ecology.
A limiting function approach, based on quantile regression analysis, has proved to be a valuable tool in assessing datasets which may be affected by a wide range of potential pressures.  This approach derives a threshold concentration for a substance above which a high state of ecological quality is unlikely to be achieved, regardless of the concentrations of other toxicants which may also be present.  This approach has been used to derive thresholds for individual families and whole communities directly from field data, and may also be used in the validation of standards derived from laboratory data only.  The approaches require extensive datasets of matched chemical and ecological monitoring information, and data availability is likely to be a significant limitation to the inclusion of direct field evidence in EQS setting. 
Assessments may also be based on the identification of sensitive taxa from field monitoring information, or comparisons between standards derived from laboratory data and evidence of adverse effects in the field.  There may be differences between the principles behind chemical and ecological quality standards which mean that they are not directly comparable with one another.  Possible solutions to some of the problems which may be encountered are considered and examples of the derivation or validation of environmental quality standards for chemicals using field data will be presented which make use of a variety of different approaches.

Development of Water Quality Guidelines for Metals in Tropical Ecosystems

Stauber J. L.¹, Gissi F.^1,2, Adams M. S.¹, Binet M. T.¹, Golding L. A.¹, Smith R. E. W.³, Schlekat C. E.⁴, Garman E. R.⁴, Merrington G.⁵, Peters A. J.⁵, Leung K. M. Y.⁶, Wang Z.⁶ and Jolley D. F.
¹CSIRO Land and Water, Sydney, NSW, Australia;
²Department of Chemistry, University of Wollongong, Wollongong, NSW, Australia;
³Hydrobiology Pty Ltd, Brisbane, Queensland, Australia;
⁴Nickel Producers Environmental Research Association, Durham, North Carolina, USA;
⁵WCA, Faringdon, Oxfordshire, UK;
⁶School of Biological Sciences, The University of Hong Kong, Hong Kong SAR, China
Presenting author’s email: jenny.stauber@csiro.au

Tropical regions have unique ecosystems comprising sensitive habitats, unusual taxa and a unique biodiversity compared to temperate regions. Direct application of environmental quality standards developed for North America, Europe and Australasia to tropical regions may not be appropriate due to differences in geochemistry, organic matter, climatic conditions and differences in the physiology of the evolutionarily distinctive biota. These differences may be particularly important for metals, for which bioavailability models have been developed in temperate regions to support refined risk assessment. Bioavailability-based water quality guidelines for metals rely on accurate knowledge of metal speciation and the ability to predict effects to wide ranges of taxa, both of which are poorly studied in the tropical Asia-Pacific region. Both typical exposure data, such as temperature, pH and dissolved organic carbon, as well as effects data for metals, particularly to key species such as corals, are lacking in tropical regions. Consequently guidelines for the protection of tropical species are usually generated from species sensitivity distributions of temperate data, which may be over- or under-protective depending on species, water quality parameters and the metal of interest.
In order to develop environmental quality guidelines for tropical ecosystem protection, we need:
1. Read across methods to determine if temperate data can be used to predict effects in tropical systems
2. Additional chronic tropical toxicity tests with key taxa, especially for marine waters and sediments
3. Generation of effects data using these tests
4. Better understanding of how water quality parameters in tropical systems affect metal bioavailability
Using nickel as an example, this paper will discuss recent work to fill these gaps to enable the development of water quality guidelines in tropical regions, with particular reference to SE Asia, Melanesia and Northern Australia.

Incorporating Bioavailability within Environmental Quality Standards: Use of in situ Fluxes of Contaminants from Sediments

Simpson S.
CSIRO Land and Water, Lucas Heights, NSW, Autralia
Presenting author’s email: stuart.simpson@csiro.au

The quantification of the risk posed by contaminated sediments is critical for regulators.  This process considers the concentrations and forms of sediment contaminants, and the likelihood that the contaminants may cause adverse effects to selected receptors in the environment.  Chemical and biological (ecotoxicological and ecological) methods provide useful lines of evidence for the assessment process, however, inadequacies in the misapplication of guidelines, assessment tools and frameworks frequently impede decision-making processes, increasing the costs to both industries and regulators.
Sediment properties (e.g. particle size, organic carbon, sulfide content) strongly influence the bioavailability of contaminants. Consequently, environmental quality standards (“guidelines”) based on total concentrations of contaminants are often not effective for predicting effects on benthic organisms. Although these properties are now well embedded in risk-based assessment frameworks, contaminant bioavailability is often overlooked in the management of risks due to an inadequate knowledge or unavailability of suitable tools.  In this presentation, I will describe our recent experiences, and several advances, in the use of both existing and new methods for assessing contaminant bioavailability and toxicity.
Toxicity occurs when the contaminant exposure results in the rate of uptake exceeding a tolerance threshold of the organism (influenced by the combined rates of detoxification and excretion).  Thus, the measurements of the flux of bioavailable contaminants from the sediment to an organism may enable guideline development. Metal fluxes measured using diffusive-gradients-in-thin-films (DGT) may be used to predict metal exposure or effects to a range of benthic organisms in field, and laboratory exposures to metal-contaminated freshwater and marine sediments.  The method is compared with traditional approaches to estimate the bioavailable metal fraction, e.g. pore waters, acid-volatile sulfide-simultaneously extractable metal (AVS-SEM) relationships, and other non-exhaustive metal extraction procedures.   For metal and organic contaminants, guidelines based on in situ measurements of fluxes or non-exhaustive extractions that target the more labile concentrations are increasingly becoming effective for assessing risks and potentially setting guidelines.

How Specific is Site-Specific? Proposed Guidance for Deriving Location-Specific Water Quality Guideline Values

van Dam R. A.¹, Harford A. J.¹, Humphrey C. L.¹, Hogan A. C.^2
1Environmental Research Institute of the Supervising Scientist, Australian Government Department of the Environment, Darwin, Australia;
²NRA Environmental Consultants, Cairns, Australia
Presenting author’s email: Rick.vanDam@environment.gov.au

Whilst generic water quality guidelines values (GVs) provide an important starting point for managing water quality, they cannot account for the large spatial and/or temporal variation in natural water quality, including variation in environmental variables that influence the bioavailability and toxicity of contaminants.  Consequently, the past decade has seen increasing awareness of the need for site-specific GVs, with several jurisdictions (e.g. Australia, New Zealand, Canada, Europe) recommending them over generic GVs where ever possible, and with some providing formal guidance on their derivation.  In reality, there exists a continuum of ‘types’ of water quality GVs, based on both temporal (e.g. annual, seasonal, daily) and spatial (e.g. national, regional, local) factors, which is far more complex than the binary comparison of generic versus site-specific GVs suggests.  Adding to this complexity, GVs can be derived or modified in various ways with varying robustness.  When the above issues are considered in the context of the increasing use of site-specific GVs for regulatory purposes, it becomes apparent that there is a need for clear guidance on the different types that can exist, including their strengths and weaknesses and appropriate applications.  This presentation addresses some key questions about site-specific GVs and, in doing so, aims to move towards clear guidance for their appropriate classification and, consequently, use.
Relevant questions that will be discussed include:
What factors need to be considered when determining the requirements for a site-specific GV (e.g. spatial scale, spatial and temporal variability of water quality)?
What constitutes a location (e.g. a site, a reach, a catchment, a region) and why is this important?
Can we classify site-specific GVs that have been derived using different approaches and/or modified to different degrees?
Examples, drawing on our experience in northern Australia, will be used to illustrate the key issues and support recommendations.

Recent Development of Water Quality Guidelines in Australia and New Zealand

Warne M. St. J.^1,2,3,4, Batley G. E.⁵, Van Dam R.^6,7, King O.² and Smith R. A.^2,3,8
1Centre for Agroecology, Water and Resilience (CAWR), Coventry University, UK;
²Department of Science, Information Technology and Innovation, Brisbane, Australia;
³Australian Rivers Institute (ARI), Griffith University, Brisbane, Australia;
⁴National Research Centre for Environmental Toxicology (EnTox), University of Queensland, Brisbane, Australia;
⁵CSIRO Land and Water, Sydney, Australia;
⁶Environmental Research Institute of the Supervising Scientist, Darwin, Australia;
⁷Royal Melbourne Institute of Technology University (RMIT), Melbourne, Australia;
⁸Charles Darwin Research Station, Puerto Ayora, Galapagos Islands, Ecuador
Presenting author’s email:michael.warne@coventry.ac.uk

Water quality in Australia is managed through the National Water Quality Management Strategy (NWQMS), a key document of which is the Australian and New Zealand Guidelines for Fresh and Marine Water Quality.   This document is revised periodically to maintain its relevance, scientific accuracy, to address new knowledge gaps and to derive guideline values (GVs) for new chemicals and improved GVs for existing chemicals.   The current revision began in July 2009 and has had three distinct phases: (1) the development of the scope of work; (2) the development of a new BurrliOZ software program to calculate toxicant GVs and revision of the GV derivation method; and (3) derivation of new guideline values for over thirty priority chemicals using the products from Phase 2.   Phases 1 and 2 have been completed and Phase 3 will be completed by December 2016.   
Some of the major improvements that will be discussed are:

Critical Review of Mercury Sediment Quality Values

¹Fuchsman P., ²Wenning R., ³Magar V.  and ²Henning M.
¹Ramboll Environment, Cleveland, OH, USA
²Ramboll Environment, Portland, Maine, USA
³Ramboll Environment, Chicago, Illinois, USA
Presenting author’s email: rjwenning@ramboll.com

Sediment quality values (SQV) are commonly used to characterize the need for environmental investigation and to derive strategies for commercial effluents and sediment management. At present, approximately 40 SQVs have been set for mercury, nearly all of which are co-occurrence SQVs derived from databases of paired chemistry and benthic invertebrate effects data obtained from field-collected sediment. Co-occurrence SQVs are rarely derived in a manner that reflects cause–effect, concentration–response relationships for individual chemicals, because multiple potential stressors often co-occur in the data sets used to derive SQVs. This work highlights the current limitations in mercury SQVs. Current available sediment chemistry and toxicity data were compiled to characterize mercury-specific effect thresholds. The median (interquartile range) co-occurrence SQVs associated with a lack of effects (0.16 mg/kg [0.13–0.20 mg/kg]) or a potential for effects (0.88 mg/kg [0.50–1.4 mg/kg]) were orders of magnitude lower than no-observed-effect concentrations (NOEC) reported in mercury-spiked toxicity studies (3.3 mg/kg [1.1–9.4 mg/kg]) and at mercury-contaminated sites (22 mg/kg [3.8–66 mg/kg]). Additionally, there was a high degree of overlap between co-occurrence SQVs and background mercury levels. Consequently, spiked sediment and site data may provide more appropriate and useful information for characterization and management purposes. Further research is recommended to refine mercury effect thresholds for sediment that address the bioavailability and causal effects of mercury exposure.