I certainly didn't live on another planet, Q, but in a suburb of West London, and well remember 'pea souper' fogs. All fires were coal and in winter the smoke was very smelly in the air outside. But I can truthfully say I never heard of or saw any asthma during my schooldays, including at grammar school, or even at Uni in Edinburgh. I just hadn't come across it, and had never heard the word mentioned.