The Environment Department (DOE) has stepped up enforcement and surveillance at open burning hotspots to tackle the haze, said its director-general Datuk Wan Abdul Latiff Wan Jaffar in a media briefing on July 31.br br He said as of July 30, a total of 4,247 patrols and 859 aerial surveillance using drones had been carried out. He also said the department is studying the development of a haze forecast system by Universiti Kebangsaan Malaysia.