You mean the people who were actively recuited and invited to come to live here to fill the 'employment opportunities' in our hospitals and factories?
At that time employers were unable to meet orders and hospitals were unable to take in patients - schools had trouble retaining pupils because factories sent recruiters to their gates to offer money to the senior year to come and work for them.
Bonuses were paid to anyone who could bring in a good worker or a family member to a factory.
On the subject of RAF ground crew - the grease, oil and aviation spirit were dangerous - my father gashed his hand and got blood poisoning when a spanner slipped. He was so ill that the MO shouted at the men who came to take him up on a charge - deliberatly making yourself unfit for duty was a crime. He was lying in bed with his hand swollen and throbbing and wondering who the poor fellow was who was so ill, and it came as quite a shock when he realised it was him!!