Edema has many possible causes: 1  Prolonged standing or sitting, especially in hot weather, can cause excess fluid to accumulate in the feet, ankles and lower legs. 2  Tiny valves inside the veins of the legs can become weakened, causing a common problem called venous insufficiency.
Cars with nitrous-equipped engines can be identified by the purge of the delivery system that most drivers perform prior to reaching the starting line. A separate electrically operated valve is used to release air and gaseous nitrous oxide trapped in the delivery system.
Nitrous oxide is a colourless gas which is commonly used for sedation and pain relief, but is also used by people to feel intoxicated or âhighâ 1.