cyanide

Hydrogen cyanide, under the name Zyklon B, was used as a genocidal agent by the Germans in World War II. this deadly gas was also used to execute prisoners in San Quentin prison up until 1994. cyanide pellets would be placed under the chairs of the prisoners then released into an acid causing the gas to rise and be inhaled. once inhaled the sensation of not being able to breath and the feeling of a heart attack would be the fate of the people strapped into the chairs. After the execution was over and the person pronounced dead 10-12 minutes later, the gas inside the chamber would be released threw a chimney into the atmosphere...to again affect human life. Why are people still releasing this chemical into the environment if it was deliberately used to kill people?