The Supreme Court today accorded its nod to the Centre's graded response action plan to tackle different levels of pollution and asked the Central Pollution Control Board (CPCB) to upgrade its existing infrastructure and set up additional monitoring stations in Delhi-NCR within six months. <br/><br/>A bench headed by Chief Justice T S Thakur said enforcement of graded response action plan shall be under the orders of Environment Pollution (Control and Prevention) Authority (EPCA) and all other authorities should act in aid of such direction. <br/><br/>It also directed the Centre to examine within four weeks about harmful effects of petroleum coke and furnace oil used in industries and power generation plants in NCR and issue appropriate directions in this regard.<br/><br/>The Centre earlier told the court that when air pollution reaches alarming proportion, immediate steps are needed to be taken including ban on construction activities and implementation of odd-even scheme.