seven astronauts on board. The debris field extended from New Mexico to Mississippi. Sea travel Ships can sink, capsize or crash in disasters. Perhaps the most infamous sinking was that of the Titanic which hit an iceberg and sank, resulting in one of the worst maritime disasters in history. Other notable incidents include the capsizing of the Costa Concordia, which killed at least 32 people; and is the largest passenger ship to sink, and the sinking of the MV Doña Paz, which claimed the lives of up to 4,375 people in the worst peacetime maritime disaster in history. Environmental hazards Environmental hazards are those hazards where the effects are seen in biomes or ecosystems rather than directly on living organisms. Well known examples include oil spills, water pollution, slash and burn de-forestation, air pollution, and ground fissures. Waste disposal In managing waste many hazardous materials are put in the domestic and commercial waste stream. In part this is because modern technological living uses certain toxic or poisonous materials in the electronics and chemical industries. Which, when they are in use or transported, are usually safely contained or encapsulated and packaged to avoid any exposure. In the waste stream, the waste products exterior or encapsulation breaks or degrades and there is a release and exposure to hazardous materials into the environment, for people working in the waste disposal industry, those living around sites used for waste disposal or landfill and the general environment surrounding such sites. Hazardous materials Organohalogens Organohalogens are a family of synthetic organic molecules which all contain atoms of one of the halogens. Such materials include PCBs, Dioxins, DDT, Freon and many others. Although considered harmless when first produced, many of these compounds are now known to have profound physiological effects on many organisms including man. Many are also fat soluble and become concentrated through the food chain. Toxic metals Many metals and their salts can exhibit toxicity to humans and many other organisms. Such metals include, Lead, Cadmium, Copper, Silver, Mercury and many of the transuranic metals. Radioactive materials Radioactive materials produce ionizing radiation which may be very harmful to living organisms. Damage from even a short exposure to radioactivity may have long term adverse health consequences. Exposure may occur from nuclear fallout when nuclear weapons are detonated or nuclear containment systems are compromised. During World War II, the United States Army Air Forces dropped atomic bombs