The ratio of the activity of the SLRDs to the activity of the radon gas is called the Equilibration Ratio (ER). Equilibrium usually occurs in about three to four hours. When an individual receives a dose of one WL in 170 hours (a miner's month), the exposure then becomes called a working level month or WLM.
I imagine it was probably my first Prehospital Trauma Life Support class back in 1990 that I first heard of the three collision rule. Since then, it has remained a useful tool in examining the mechanism of injury after auto accidents. If you havenât heard of it, please allow me to elaborate. The three collision rule states that, in any auto accident, there are three collisions that occur and the keen EMT needs to be aware of all three.
In 2010, there were an estimated 5,419,000 crashes, 30,296 of with fatalities, killing 32,999, and injuring 2,239,000. About 2,000 children under 16 die every year in traffic collisions. Records indicate that there has been a total of 3,613,732 motor vehicle fatalities in the United States from 1899 to 2013. Although the number of deaths, and deaths relative to the total US population, declined over most of the previous two decades, the trend reversed in 2015 and continued to move upward in 2016.