Client: Department for Environment, Food, and Rural Affairs (Defra)
Year: 2024
eftec Team: Ece Ozdemiroglu, Thea Sletten, Zachary Leather, Rob Tinch, Natalya Kharadi, Su Gulmus, and Victoria Reeser
Service area(s): Chemicals Policy
Location: UK
Full report: Accessible here
Thousands of chemical substances are in use across the economy, yet their impacts on nature remain poorly understood, measured and valued.
A key challenge is the limited understanding of how chemical exposure affects different taxonomic groups of flora and fauna, how those effects translate into changes in ecosystem functions, and ecosystem services. As a result, policy decisions often rely on qualitative assessments or the precautionary principle. While these approaches remain valuable, there is a clear need to develop more systematic, and quantitative approaches to compare environmental risks from different chemicals and benefits of their uses.
Funded by Defra, eftec, UKCEH, and wca collaborated to create a conceptual framework for analysing the environmental impacts more coherently. The framework moves beyond individual substances that are identified as being of particular concern and offers a consistent comparison of relative impacts on ecosystems of all substances.
The five-step framework is called ENRICH (Environmental Risks and Impacts of Chemicals), where each step produces standalone outputs that can support decision-making. It integrates knowledge from toxicology, ecology, and economics that can be applied to a wide range of substances and produce outputs at different levels – from identifying hazardous substances to highlighting affected ecosystem services – even where full data are not available:
Step 1 – Hazard and Potency Assessment: Evaluates the chemical’s hazards (e.g. genotoxicity, endocrine disruption or bioaccumulation), and ranks its potency relative to other chemicals. It also identifies taxonomic groups that may be impacted by exposure to the chemical.
Step 2 – Exposure and Species Sensitivity: Assesses environmental exposure levels using monitoring data and compares this against exposure levels of other chemicals. It combines hazard, exposure and species sensitivity data to determine the proportion of species within affected taxonomic groups could be impacted.
Step 3 – Identification of Ecosystem Endpoints: Uses species-level impact estimates to infer reductions in species richness following exposure to a chemical, then uses logic chains to link these ecological impacts to broader ecosystem functions and ecosystem services (or endpoints)
Step 4 – Quantifying Ecosystem Endpoint Impacts: Combines information from previous steps to investigate how each ecosystem endpoint is affected due to the chemical's presence in the environment, expressed as % of ecosystem endpoint remaining, given the exposure level.
Step 5 – Connecting to Ecosystem Services and Economic Value: Maps changes in ecosystem endpoints to the most pragmatic source of data at this stage, i.e. the values of ecosystem services used in the UK natural capital accounts. So far, this step stops at this mapping. Monetary valuation of impacts on endpoints
The report presents further information on ENRICH and the look-up tools developed for each step (Excel spreadsheets), containing all underlying data and calculations. These can be updated when better data is available.
Uncertainty is unavoidable in any comprehensive and multidisciplinary framework liked this. Care has been taken to ensure the uncertainties are transparently reported, and that useful outputs are generated across all the steps.
Key recommendations for future improvement include:
Expand monitoring and data coverage – especially for terrestrial environments and species
Strengthen links between biological impacts and ecosystem functions – by improving the ecological understanding of how species loss affects wider processes.
Enhance use of economic evidence – existing valuation data can be better matched to ecosystem endpoints and new research commissioned to capture public preferences, particularly for more strategic risks like bioaccumulation or persistence.