Answer:
What happened in 1970 Major News Stories include Concorde first supersonic flight, Jumbo Jet goes into service, Isle of Wight Festival, Chicago Seven found guilty, Aswan High Dam completed, US and the UK lowers the voting age to 18, 100,000 demonstrate in Washington DC against the Vietnam War, First Earth Day, Beatles disband.
I found that from April to mid-June there's an increase in the ground level ozone which creates smog (smog is created by the emissions from vehicles and smokestacks when they come in direct with sunlight.)
Nitrogen Dioxide (NO2) It comes factories, old cars from the 1900s, etc. it is a poisonous gas that comes from old engines can when breathed into the human body it can cause loss of fatigue, restlessness, anxiety, etc.. When it is released it gets stuck into the atmosphere but still gets stuck into the air but a small amount so little it can't harm large number of humans or animals.
Generally speaking, it was the "slum dwellers" and the "immigrants" who did not share in the prosperity of the late 1800s in the United States, since they were the lower class workers.
Disease .................
