* = median of 10 000 Monte‑Carlo runs (0‑100 scale). Scores ≥ 80 = High‑risk (red band). Takeaway: The list is dominated by persistent, bio‑accumulative, and/or highly toxic substances that appear in multiple exposure pathways (air, water, food, occupational). 5️⃣ How to Use This List in Your Own ESRA Projects | Step | Action | Practical tip | |------|--------|----------------| | 5.1 | Import CHEMAL GEGG data into your ESRA software (most accept CSV). | Ensure the column headings match the model’s CAS , Use‑Category , Emission‑Rate fields. | | 5.2 | Select relevant exposure scenarios (e.g., “Urban Industrial”, “Rural Agriculture”). | You can drop the entire 20‑chemical set or filter by sector‑specific uses. | | 5.3 | Run baseline Monte‑Carlo simulation (≥ 5 000 iterations). | Save the output as baseline_ESRA_scores.csv . | | 5.4 | Perform “What‑If” analyses – e.g., 50 % reduction in emissions, substitution with a lower‑risk analogue, or implementation of a containment barrier. | Compare new scores against the baseline to quantify risk reduction. | | 5.5 | Communicate results using the colour‑coded risk band and a GIS heat map. | Stakeholder‑friendly visualisation = higher uptake of mitigation measures. | | 5.6 | Document uncertainties – highlight chemicals where the 95 % CI spans > 15 risk points (usually PFAS, PCBs). | Transparent reporting builds regulator confidence. | 6️⃣ Real‑World Example: Municipal Wastewater Treatment Plant (WWTP) | Scenario | Key Findings | |--------------|-------------------| | Current emissions (baseline) | The ESRA score for the plant’s effluent is 84 (high‑risk) – driven primarily by PFAS , BPA , and Nonylphenol ethoxylates . | | Mitigation 1 – Install PFAS‑adsorbing GAC filters | PFAS contribution drops 70 %, total ESRA score falls to 71 (medium‑risk). | | Mitigation 2 – Replace BPA‑based epoxy linings with BPA‑free alternatives | Additional 5‑point reduction → 66 (still medium but approaching low). | | Combined (GAC + BPA‑free) | Final ESRA score 58 → Low‑risk (green). | | Cost‑benefit | Capital cost ≈ USD 2.2 M, but risk‑reduction value (avoided health & ecosystem costs) estimated at USD 6.5 M/yr (based on WHO DALY valuations). |