Because of pollution along the Estoril Coast, you should not swim any closer to Lisbon than at Estoril itself, which has been granted an EU blue flag (for safe conditions).
All of Lisbon is safe for swimming.
mnli hypothesis: All of Lisbon is safe for swimming. premise: Because of pollution along the Estoril Coast, you should not swim any closer to Lisbon than at Estoril itself, which has been granted an EU blue flag (for safe conditions).