My geat uncle served in WW1,  As long as I can remember him he had shocking lungs...as a kid I thought it was smokers cough until Dad explained he had been gassed during the war.

He lived to a ripe old 83 but was never a well man.  He was the quintessential Aussie larrikin as I found out recently when I read his war records....he went AWL in London for 5 days at one stage and was fined 10 days pay for his trouble.  But he seems to have spent as much time in hospital with lung complaints as fighting a war....Trench Fever, Pneumonia, Bronchitis and gassing.