Press Trust of India: The global food crisis, climate change and pandemic influenza are the main threats to human health, the UN health agency says. “These three critical events, these clear threats to international security, have the potential to undo much hard-won progress in public health,” WHO Director-General Margaret Chan said on Monday. Speaking at the opening of the 61st session of the World Health Assembly, which is WHO’s supreme decision-making body, Chan said the organisation …