The Organisation for Economic Co-operation and Development (OECD) has published a report on endocrine disrupting chemicals (EDCs) in freshwater, wastewater, and drinking water, describing ways to monitor and regulate such chemicals. The report presents new monitoring methods, such as bioassays (cells, fish or frog embryos, or animals used to test whether a chemical, or water, is toxic) and non-targeted analysis, to capture the impacts of EDCs in water, supplementing traditional substance-by-substance chemical analysis of water quality.

EDCs interfere with the endocrine system in humans and wildlife, and can have negative developmental, reproductive, neurological, and immune effects. While such chemicals are present in water, addressing EDCs in water is complex due to their ability to trigger adverse effects at very low concentrations, their potency in mixtures with other chemicals, and the range of sources and entryways into the environment.

Titled, ‘Endocrine Disrupting Chemicals in Freshwater: Monitoring and Regulating Water Quality,’ the report notes that with only 5% of all known chemicals monitored through targeted chemical analyses, EDCs are not extensively regulated in OECD countries, and endocrine disruption is characterized by uncertainty. It outlines policy instruments to manage the chemicals’ lifecycle from source to end-of-pipe, proposes tools and regulations that respond to the negative effects of endocrine disruption, even if the culprit chemical is still unknown, and draws on case studies from OECD countries to provide practical examples and concrete policy actions.

Elaborating on ways to monitor endocrine disruption in water, the report discusses:

• targeted chemical analysis, or substance-by-substance monitoring, which determines the concentration of individual chemical of interest in a selected water sample;
• non-targeted analysis, which identifies all chemicals present in an environmental sample without quantifying their concentration; and bioassays, which identify the adverse impacts of chemicals, are a promising supplement to targeted chemical analysis, and can detect chemical activity without the need for substance-by-substance analysis; and
• in situ wildlife monitoring, which surveys species in the wild for significant physical, molecular, or behavioral changes that could indicate changes in the endocrine system.

On how to manage EDCs in freshwater, the report outlines several life cycle approaches, noting that a combination of approaches can be used. Relevant instruments include: source-directed measures, such as chemical assessment; end-of-pipe and end-of-life measures, such as wastewater treatment and discharge permits; and use-oriented measures, including waste disposal campaigns, consumer awareness campaigns, labeling schemes, and private sector initiatives.

The report elaborates on several effect-centered approaches to manage endocrine disruptors in freshwater, including:

• response plans, which can include: methods for collecting evidence; temporary no-regret or low‑cost mitigation options; a description of the roles and responsibilities of those behind the source of emission; and a communication plan on how to explain potential risks and actions being taken;
• national strategies and action plans on endocrine disruptors, which send a policy signal on government priorities related to endocrine disruptors;
• environmental quality norms or water quality criteria, which could be developed, as many existing environmental quality standards for chemicals do not consider endocrine disrupting properties of substances; and
• policies that consider the impacts on vulnerable populations, including Indigenous Peoples, which could include: chemical risk assessments targeting vulnerable groups and populations; information campaigns targeting specific groups, such as dietary advice campaigns during pregnancy; and assessing, modeling, and reporting biodiversity changes.

The report highlights international coordination of actions as desirable as endocrine disruptors cross administrative boundaries through international water basins and trade, as this can make responses more cost-effective. Such actions could include: standardiaztion and validation of test methods; stimulating the demand for bioassays; international research partnerships; and international science-policy agendas. [Publication: Endocrine Disrupting Chemicals in Freshwater: Monitoring and Regulating Water Quality] [Publication Landing Page] [Policy Highlights]