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¦.
1 Neither type of typhoid vaccine is 100 percent effective; both protect 50 to 80 percent of recipients. 2  If you get the shot, the health care provider will administer the vaccine. 3  It is recommended that you have the shot two weeks before any possible exposure. Side effects of the typhoid vaccine shot can include fever, headache or redness or swelling at the injection site; side effects of the oral vaccine can include fever, headache, abdominal discomfort, nausea, vomiting or, in rare cases, a rash.