The document discusses four types of environmental hazards: biological, chemical, nuclear, and radiological. Biological hazards involve viruses or infectious diseases that can spread. Chemical hazards refer to toxic molecules that could harm all life. Nuclear hazards include nuclear fallout from widespread detonation of nuclear weapons. Radiological hazards involve deadly radiation that could mutate DNA. Specific examples discussed include anthrax as a biological hazard and the "Tsar Bomba", the most powerful nuclear weapon ever tested, which caused third-degree burns over 60 miles away. The effects of radiation exposure and potential DNA mutations from environmental hazards are also outlined.