The Supreme Court has closed the four-decade-old MC Mehta v. Union of India case on air pollution in Delhi-NCR. Filed in 1985 by environmentalist MC Mehta, it became a landmark Public Interest Litigation in Indian environmental law and led to measures such as the shift to CNG in Delhi's public transport and tighter pollution norms. In its place, the court has started a suo motu case titled 'Re: Issues of air pollution in NCR' and directed that pending applications be converted into separate writ petitions, so that air pollution issues in the National Capital Region are handled faster and more effectively.