translate English to French: This method has allowed to decrease the Pb concentration by approximately 57%, thus reducing the Pb content below the C criteria (1000 mg/kg) for commercial or industrial use in the province of Quebec.
L'ajout d'un procédé de lixiviation chimique a enlevé environ 57 % du Pb et a permis le respect du critère C (1000 mg Pb/kg) appliqué au Québec.