What other factors besides overcrowding might have contributed to the race riots of 1919? consider the impact of world war i ending and thousands of american soldiers returning home from europe

The fact that many people came to the US from Europe and the various countries of Africa, as well as the Middle east and Asia. This happened because Europe was destroyed more or less at the time and it didn't present many opportunities for people. Therefore, they moved to the US. And all of this mixing of different ethnicities of people who have seen war and its attrocities lead to a lot of tensions. 

Smoking damages the respiratory system by inhalation of a foreign substance, that is absorbed and residue is left behind on our lungs sponge like substance. the gas that is inhaled also increase your blood pressure and dilates your blood vessels. also the process of inhaling and exhaling the smoke it causes irritation to the throat and mouth. smoking can cause lung cancer and other respiratory and circulatory diseases. 

Few days to several months depending on the severity of the stroke ;