Utilização de um regossolo português para derivar valores de referência para arsénio
Soil reference values (SRV) are preliminary screening benchmark values used to evaluate the potential toxicity of specific contaminants in soils. The Portuguese Environmental Agency has proposed SRV for metals and metalloids based on soil uses but without consideration for the soil type. This project aims to derive SRV for arsenic (As) using a natural Portuguese soil since it is known that soil properties can influence the mobility and bioavailability of contaminants. To achieve this aim, a non-contaminated regosol was collected and spiked with a range of concentrations of As. After, a battery of ecotoxicological tests was performed using the spiked soil, including microbial parameters, reproduction with invertebrates, plant growth assays, and aquatic organisms ( to evaluate elutriates from the spiked soil) following standard protocols (ISO and OECD) and aimed at deriving concentrations that cause a x% effect (ECx) to the tested organism and/or the test endpoints assessed. The endpoints will be used to estimate a SRV (e.g., PNEC- predicted no effect concentration to the ecosystem or HC5 – hazard concentration for 5% of the species of the ecosystem) using Species Sensitivity Distribution (SSD) models. The results showed that As was very toxic to all the tested organisms, and based on the data we collected, an HC5 based on 10% effect concentrations HC5 (EC10) of 2.80 mg kg-1 of soildw was proposed as SRV for regosol.