Bhopal : Madhya Pradesh Chief Minister Shivraj Singh Chouhan has urged the Centre to constitute a special committee for assessing the quantum of soil and water pollution around the Union Carbide premises here. In a letter to Prime Minister Manmohan Singh, Chouhan urged the Centre to assess the quantum of soil and water polluted around the defunct Union Carbide plant and added that the state government will extend full cooperation in achieving this task, official sources said on Thursday.