Not to be confused with volume overload. Hypervolemia, or fluid overload, is the medical condition where there is too much fluid in the blood. The opposite condition is hypovolemia, which is too little fluid volume in the blood. Fluid volume excess in the intravascular compartment occurs due to an increase in total body sodium content and a consequent increase in extracellular body water.
The smell was put into natural Gas in the aftermath of a school explosion in New London Texas 1937. 300 students and faculty members lost their lives after the school exploded and was leveled when the trapped natural gas was ignited. The School was being fueled by gas directly from the near by oil wells.
Pure natural gas is colourless and odourless. This means if there is a leak people will not be able to detect it until it builds up enough to become explosive. For this reason a chemical called Mercaptan is added to the gas to make is smell. Mercaptan is harmless, non-toxic and has a strong rotten egg smell.