The Supreme Court on Thursday re-imposed the ban on construction activities in Delhi and National Capital Region (NCR) and directed the States to provide subsistence to workers from the funds collected as labour cess for the period during which such activities are prohibited. The special bench headed by Chief Justice NV Ramana, in an interim order uploaded Wednesday night, also directed the commission for air quality management in the NCR and adjoining areas to “commission a scientific study of air quality based on available data of previous years bearing upon recorded levels of air pollution”.