OSHA defines an excavation as any man-made cut, cavity, trench, or depression in the earths surface formed by earth removal. A trench is defined as a narrow underground excavation that is deeper than it is wide, and is no wider than 15 feet (4.5 meters). Dangers of Trenching and Excavation. Cave-ins pose the greatest risk and are much more likely than other excavationrelated accidents to result in worker fatalities.
How long does a typhoid shot last?   According to the CDC website, a booster dose is needed every 2 years for people who remain at risk.. The oral (live) vaccine lasts 5 years before another dose is neededâ¦.
Typhoid vaccines. Typhoid vaccine can prevent typhoid. There are two vaccines to prevent typhoid. One is an inactivated (killed) vaccine gotten as a shot. The other is a live, attenuated (weakened) vaccine which is taken orally (by mouth). Top of Page. Who should get typhoid vaccine and when? Routine typhoid vaccination is not recommended in the United States, but typhoid vaccine is recommended for: Travelers to parts of the world where typhoid is common. (NOTE: typhoid vaccine is not 100% effective and is not a substitute for being careful about what you eat or drink). People in close contact with a typhoid carrier.