Application of Effect-Based Methods to Water Quality Monitoring: Answering Frequently Asked Questions by Water Quality Managers, Regulators, and Policy Makers

Abstract

Effect-based methods (EBM) have great potential for water quality monitoring as they can detect the mixture effects of all active known and unknown chemicals in a sample, which cannot be addressed by chemical analysis alone. To date, EBM have primarily been applied in a research context, with a lower level of uptake by the water sector and regulators. This is partly due to concerns regarding the reliability and interpretation of EBM. Using evidence from the peer-reviewed literature, this work aims to answer frequently asked questions about EBM. The questions were identified through consultation with the water industry and regulators and cover topics related to the basis for using EBM, practical considerations regarding reliability, sampling for EBM and quality control, and what to do with the information provided by EBM. The information provided in this work aims to give confidence to regulators and the water sector to stimulate the application of EBM for water quality monitoring.

Sentinels for future coral reef conditions: assessment of environmental variability and water quality in semi-enclosed inland bays in the southern Caribbean

“…Even the modest set of two in vivo and two in vitro bioassays, representing two relevant reef organism groups and two relevant modes of action, elucidated the effects of a wide range of bioavailable contaminant mixtures in the environment. In future effect-based water quality assessments of coral reef environments, the set of applied bioassays can be expanded to include the oxidative stress response as well as bioassays targeting integral life stages or functions of coral reef biota such as scleractinian coral and sea urchin larvae (Neale et al, 2023; Shaw et al, 2009). The highest cumulative effect-based risk quotient was found for Spaanse Water Bay, followed by Santa Martha Bay, Santa Martha Reef and Spaanse Water Reef.…”

“…Effect-based trigger values (EBTs) were used to identify potential ecotoxicological risks based on the bioassay responses (Neale et al, 2023). The EBTs available in the scientific literature are commonly derived for risk assessments in freshwater systems.…”

Effect-Directed Analysis Combined with Nontarget Screening to Identify Unmonitored Toxic Substances in the Environment

“…However, in the case of highly toxic substances, like N -(1,3-dimethylbutyl)- N ′-phenyl- p -phenylenediamine (6PPD)-quinone found in tire leachate, toxic fractions could be clearly isolated even in in vivo bioassays . Occasionally, the toxic potency is greater following fractionation than in the parent fraction, possibly due to the complex interactions, such as mixture effects and/or removal of compounds causing masking effects. ,,, Stringent quality control is necessary during bioassays; fractions should be recombined, and their toxicity is compared to that of the parent fraction. In addition, certain chemicals may simultaneously activate multiple pathways in test organisms in a nonspecific manner.…”

“…In recent years, the identification of novel toxic substances has been enabled due to the development of high-resolution mass spectrometry (HRMS) . Nontarget screening (NTS) aims to detect and identify all substances present in a sample and can be usefully applied in EDA to identify causative toxic substances in highly potent fractions. − The combined use of EDA and NTS addresses the limitations of performing only NTS, which lacks information on the potential toxicity of compounds in environmental samples. − ,− EDA combined with NTS has been applied successfully for the identification of unmonitored toxicants in sediment, wastewater, biota, etc. ,, This approach will help to expand the scope of analysis to include unknown substances, moving away from existing methods that rely solely on target chemical monitoring. , Furthermore, it is expected to facilitate the efficient incorporation of effect-based monitoring (EBM) into environmental monitoring programs. , The purpose of this paper is to describe the current status and limitations of EDA combined with NTS, with case studies of its successful application. In addition, we provide suggestions for the integration of EDA into future environmental monitoring programs and management policies.…”

“…However, there are thousands of toxic substances in the environment, including metabolites and TPs, while target chemical monitoring evaluates only a small portion of them (about hundreds). , Furthermore, chemical analysis cannot account for the mixture effects of chemicals in the environment. Even if individual compounds are present below the EQGs and detection limits, they can cause significant toxicity due to mixture effects . To compensate for this limitation, EBM has recently been proposed, and related elements are actively being developed. , …”