A sealed pick-up head for a mobile sweeper comprises a housing defining a substantially hollow interior and a suctioning bottom opening, A suctioning from opening is for receiving debris into the substantially hollow interior of the housing. A door frame surrounds the suctioning front opening. A rotatable door has at least a first door portion and a second door portion joined together at a central pivot axis, and is operatively mounted at the central pivot axis in rotatable relation on the pick-up head at the suctioning front opening. A seal is operatively disposed between the rotatable door and the door frame for sealing the rotatable door with respect to the door frame, to thereby substantially preclude air from ingressing into the substantially hollow interior of the housing through the suctioning front opening, as the rotatable door rotates to permit debris to enter the substantially hollow interior of the housing. A dust and debris outlet in the housing permits dust and debris to be suctioned from the substantially hollow interior of the housing into a hopper.