6. (1) If the Mines Board of Health approve any measures reported by a Sanitary Officer under clause (a) of sub-section (3) of section 5, or if they consider that any other measures should be taken to provide for any of the purpose referred to in that clause, the Board shall serve,- (a) on the owners of all mines in which are employed persons residing in the mining settlement, or in the part of the mining settlement to which such measures relate, or (b) on the holders of the land occupied by such mining settlement or part, if they are not the owners of the said mine, a notice specifying such measures and requiring such owners or landholders- (i) to execute, within a period to be fixed by the notice, all works that the Board may consider necessary for carrying such measures into effect, and to maintain in good repair all works so executed, or (ii) to carry on continuously such periodical operations as the Board may direct, for carrying such measures into effect, or (iii) both to execute and maintain works and to carry on operations as aforesaid. (2) Nothing in this section shall apply to landholders other than proprietors, permanent tenure-holders, rent-free holders or holders of a maintenance grant.