οὐκ ἔστι γῆρας τοῦδε τοῦ μιάσματος → that pollution never wears out, that pollution can never grow old
P. and V. διάπυρος (Plato, timae. 58C; Eur., Cyclops 631), V. καυστός (Eur., Cyclops 633), ἐγκεκαυμένος (Eur., Cyclops 393), κεκαυμένος (Eur., Cyclops 457).