Toward Sustainable Environmental Quality: Priority Research Questions for Asia.

Environmental and human health challenges are pronounced in Asia, an exceptionally diverse and complex region where influences of global megatrends are extensive and numerous stresses to environmental quality exist. Identifying priorities necessary to engage grand challenges can be facilitated through horizon scanning exercises, and to this end we identified and examined 23 priority research questions needed to advance toward more sustainable environmental quality in Asia, as part of the Global Horizon Scanning Project. Advances in environmental toxicology, environmental chemistry, biological monitoring, and risk-assessment methodologies are necessary to address the adverse impacts of environmental stressors on ecosystem services and biodiversity, with Asia being home to numerous biodiversity hotspots. Intersections of the food-energy-water nexus are profound in Asia; innovative and aggressive technologies are necessary to provide clean water, ensure food safety, and stimulate energy efficiency, while improving ecological integrity and addressing legacy and emerging threats to public health and the environment, particularly with increased aquaculture production. Asia is the largest chemical-producing continent globally. Accordingly, sustainable and green chemistry and engineering present decided opportunities to stimulate innovation and realize a number of the United Nations Sustainable Development Goals. Engaging the priority research questions identified herein will require transdisciplinary coordination through existing and nontraditional partnerships within and among countries and sectors. Answering these questions will not be easy but is necessary to achieve more sustainable environmental quality in Asia. Environ Toxicol Chem 2020;39:1485-1505. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Assessment of organophosphorus flame retardants and plasticizers in aquatic environments of China (Pearl River Delta, South China Sea, Yellow River Estuary) and Japan (Tokyo Bay).

The concentrations and spatial distribution of 14 organophosphorus flame retardants (OPFRs) and plasticizers were studied in aquatic environments of China, namely, the Pearl River Delta (PRD), South China Sea (SCS) and Yellow River Estuary (YRE), as well as Tokyo Bay (TB) in Japan. These locations were characterized by different levels of socioeconomic development and human activities. The spatial pattern of OPFRs revealed their ubiquity along the coasts of China and Japan; the concentrations ranged from 15 to 1790, 1 to 147, 253 to 1720, and 107 to 284 ng L-1 in the PRD, SCS, YRE and TB, respectively. The most frequently detected OPFR was triethyl phosphate (TEP), followed by triphenylphosphine oxide (TPPO) and tris(2-chloroethyl) phosphate (TCEP). A positive relationship (R2 = 0.668, p = 0.004) was observed between OPFR contamination and socioeconomic activity, measured by gross domestic product (GDP) per capita, for the studied cities in China and Japan. The results suggest that an increase in manufacturing and construction activities in the studied areas may aggravate coastal contamination with OPFRs. The potential threat to aquatic organisms from exposure to TCEP, a suspected carcinogen, was revealed by the hazard quotient (HQ) and probabilistic assessments. Further investigation of OPFR exposure in the aquatic environment of China is urgently required.

Harvesting the promise of AOPs: An assessment and recommendations.

The Adverse Outcome Pathway (AOP) concept is a knowledge assembly and communication tool to facilitate the transparent translation of mechanistic information into outcomes meaningful to the regulatory assessment of chemicals. The AOP framework and associated knowledgebases (KBs) have received significant attention and use in the regulatory toxicology community. However, it is increasingly apparent that the potential stakeholder community for the AOP concept and AOP KBs is broader than scientists and regulators directly involved in chemical safety assessment. In this paper we identify and describe those stakeholders who currently-or in the future-could benefit from the application of the AOP framework and knowledge to specific problems. We also summarize the challenges faced in implementing pathway-based approaches such as the AOP framework in biological sciences, and provide a series of recommendations to meet critical needs to ensure further progression of the framework as a useful, sustainable and dependable tool supporting assessments of both human health and the environment. Although the AOP concept has the potential to significantly impact the organization and interpretation of biological information in a variety of disciplines/applications, this promise can only be fully realized through the active engagement of, and input from multiple stakeholders, requiring multi-pronged substantive long-term planning and strategies.

Use of prospective and retrospective risk assessment methods that simplify chemical mixtures associated with treated domestic wastewater discharges.

A framework is presented that is intended to facilitate the evaluation of potential aquatic ecological risks resulting from discharges of down-the-drain chemicals. A scenario is presented using representatives of many of the types of chemicals that are treated domestically. Predicted environmental chemical concentrations are based on reported loading rates and routine removal rates for 3 types of treatment: trickling filter, activated sludge secondary treatment, and activated sludge plus advanced oxidation process as well as instream effluent dilution. In tier I, predicted effluent concentrations were compared with the lowest predicted-no-effect concentration (PNEC) obtained from the literature using safety factors as needed. A cumulative risk characterization ratio (cumRCR) < 1.0 indicates that risk is unlikely and no further action is needed. Otherwise, a tier 2 assessment is used, in which PNECs are based on trophic level. If tier 2 indicates a possible risk, then a retrospective assessment is recommended. In tier 1, the cumRCR was > 1.0 for all 3 treatment types in our scenario, even though no chemical exceeded a hazard quotient of 1.0 in activated sludge or advanced oxidation process. In tier 2, activated sludge yielded a lower cumRCR than trickling filter because of higher removal rates, and the cumRCR in the advanced oxidation process was << 1.0. Based on the maximum cumulative risk ratio (MCR), more than one-third of the predicted risk was accounted for by one chemical, and at least 90% was accounted for by 3 chemicals, indicating that few chemicals influenced the mixture risk in our scenario. We show how a retrospective assessment can test whether certain chemicals hypothesized as potential drivers in the prospective assessment could have, or are having, deleterious effects on aquatic life. Environ Toxicol Chem 2018;37:690-702. © 2017 The Authors. Environmental Toxicology and Chemistry Published by Wiley Periodicals, Inc. on behalf of SETAC.

Binary mixture toxicities of triphenyltin with tributyltin or copper to five marine organisms: Implications on environmental risk assessment.

Triphenyltin (TPT) often coexists with tributyltin (TBT) and Cu in coastal waters worldwide. The combined toxic effect of TPT and TBT has always been assumed to be additive without any scientific proof, and the combined effect of Cu and TPT on marine organisms has not been vigorously studied. This study, therefore, investigated the acute toxicity of binary mixture of TPT/Cu and TPT/TBT to five selected marine species including Thalassiosira pseudonana, Skeletonema costatum, Tigriopus japonicus, Brachionus koreanus and Oryzias melastigma. The interaction between TPT and TBT or Cu was modeled antagonistic based on concentration addition (CA) model, while it was synergistic according to response addition (RA) model. Both model well predicted the toxicity of binary mixtures to the five organisms. As for the environmental risk assessment, CA overestimated the toxicity in most cases and thus is a more conservative model than RA model for assessing the toxicity of these chemical mixtures.

An integrated environmental risk assessment and management framework for enhancing the sustainability of marine protected areas: the Cape d'Aguilar Marine Reserve case study in Hong Kong.

Marine protected areas (MPAs), such as marine parks and reserves, contain natural resources of immense value to the environment and mankind. Since MPAs may be situated in close proximity to urbanized areas and influenced by anthropogenic activities (e.g. continuous discharges of contaminated waters), the marine organisms contained in such waters are probably at risk. This study aimed at developing an integrated environmental risk assessment and management (IERAM) framework for enhancing the sustainability of such MPAs. The IERAM framework integrates conventional environmental risk assessment methods with a multi-layer-DPSIR (Driver-Pressure-State-Impact-Response) conceptual approach, which can simplify the complex issues embraced by environmental management strategies and provide logical and concise management information. The IERAM process can generate a useful database, offer timely update on the status of MPAs, and assist in the prioritization of management options. We use the Cape d'Aguilar Marine Reserve in Hong Kong as an example to illustrate the IERAM framework. A comprehensive set of indicators were selected, aggregated and analyzed using this framework. Effects of management practices and programs were also assessed by comparing the temporal distributions of these indicators over a certain timeframe. Based on the obtained results, we have identified the most significant components for safeguarding the integrity of the marine reserve, and indicated the existing information gaps concerned with the management of the reserve. Apart from assessing the MPA's present condition, a successful implementation of the IERAM framework as evocated here would also facilitate better-informed decision-making and, hence, indirectly enhance the protection and conservation of the MPA's marine biodiversity.

Seemingly unrelated intervention time series models for effectiveness evaluation of large scale environmental remediation.

Large scale environmental remediation projects applied to sea water always involve large amount of capital investments. Rigorous effectiveness evaluations of such projects are, therefore, necessary and essential for policy review and future planning. This study aims at investigating effectiveness of environmental remediation using three different Seemingly Unrelated Regression (SUR) time series models with intervention effects, including Model (1) assuming no correlation within and across variables, Model (2) assuming no correlation across variable but allowing correlations within variable across different sites, and Model (3) allowing all possible correlations among variables (i.e., an unrestricted model). The results suggested that the unrestricted SUR model is the most reliable one, consistently having smallest variations of the estimated model parameters. We discussed our results with reference to marine water quality management in Hong Kong while bringing managerial issues into consideration.

Progress of environmental management and risk assessment of industrial chemicals in China.

With China's rapid economic growth, chemical-related environmental issues have become increasingly prominent, and the environmental management of chemicals has garnered increased attention from the government. This review focuses on the current situation and the application of risk assessment in China's environmental management of industrial chemicals. The related challenges and research needs of the country are also discussed. The Chinese government promulgated regulations for the import and export of toxic chemicals in 1994. Regulations for new chemical substances came into force in 2003, and were revised in 2010 based on the concept of risk management. In order to support the implementation of new regulations, Guidance for Risk Assessment of Chemicals is under development in an attempt to provide the concepts and techniques of risk assessment. With increasing concern and financial support from Chinese government, China is embarking on the fast track of research and development in environmental management of industrial chemicals.

Integrated stochastic environmental risk assessment of the harbour area treatment scheme (HATS) in Hong Kong.

Submarine ocean outfalls are commonly used for the disposal of partially treated effluents in coastal cities. Typically, the greatest environmental risk caused by toxic substances occurs in the near field of the outfall discharge. The ecological impact of the effluent varies greatly under different discharge and environmental conditions that are characterized by both regular and stochastic variations. For a comprehensive environmental risk assessment of a coastal discharge, it is necessary to determine both the likelihood and severity of the adverse effects on the biological community. We present the first integrated stochastic (Monte Carlo) environmental risk assessment of a major coastal sewage outfall discharge--the Stonecutters Island outfall of the Harbour Area Treatment Scheme (HATS) in Hong Kong. Unionized ammonia (NH3) is used as the target pollutant. To accurately envisage the ambient concentrations of NH3, a Lagrangian jet model (JETLAG/VISJET) is used to analyze pollutant concentrations in the nearfield of the outfall. The environmental conditions are simulated from 3D hydrodynamic model simulations over a 4 month period for typical wet and dry seasons. Statistical characteristics of the effluent discharge and receiving water temperature are derived from field data. The probability distribution of predicted exposure concentrations (EC) is generated from this integrated simulation. A species sensitivity distribution, which represents a statistical distribution of threshold sublethal effects levels or benchmark concentrations (BC) for various marine organisms is constructed using available chronic toxicity data. The environmental risk of NH3 on the marine community is characterized by computing statistical distributions of Hazard Quotient (HO = EC/BC) using Monte Carlo simulation. It is found that the probability of HO > for HATS Stage 1 (1.6 million m3/day sewage treated with chemically enhanced primary treatment) is around 0.11 for wet season but just about 0.06 for the dry season. The risk increases by about 10% to 0.08-0.13 with additional sewage loads of 0.8 million m3/day at the same level of treatment (HATS Stage 2A). With an upgrade to secondary treatment (HATS Stage 2B), the probability will be reduced to 0.03-0.05. Compared to the use of "worst case" scenarios or point pollution threshold estimates, the present method offers a more holistic ecological assessment, and is much less sensitive to arbitrary choice of model parameters. The present risk assessment approach can be readily extended to the accurate determination of mixing zones based on statistical evaluation of ecological risks.

Acclimation effect and fitness cost of copper resistance in the marine copepod Tigriopus japonicus.

Copper (Cu) contamination is common and widespread in coastal marine environments. This study used the marine copepod Tigriopus japonicus to test whether Cu resistance can be developed through multigeneration acclimation to elevated Cu levels and whether the resistance has a fitness cost. T. japonicus (F0) were acclimated to three Cu concentrations (0, 10, and 100 microg l(-1)) and offspring (F1 and F2) of each treatment were subsequently acclimated at these three concentrations, respectively. Our results evidently indicated that Cu resistance of the copepod was increased even after one generation of acclimation to 100 microg Cu l(-1). The acquired Cu resistance had a fitness cost, as the intrinsic population growth rate of this Cu resistant lineage was significantly lower than the control. The Cu resistance of the offspring from Cu resistant copepods, when raised under control conditions, returned to a level comparable to the control implying a plastic physiological adaptation.