Hello,
Thanks for the query to H.C.M. Forum.
Since your husband exposed to asbestos , coal etc almost 43 years ago.
You have not mentioned the duration of present symptoms your husband is having.
There is
cough, congestion, whistling sound (
wheezing) , expectoration & breathlessness, relieved with
prednisolone may be due to ,
1 Interstitial lung disease, diagnosis can be confirmed by M R I and physical examination by a pulmonologist .
2 asthmatic allergic
bronchitis , diagnosis can be confirmed by physical as well clinical examination by a physician .
3 May be smokers cough , if your husband is a chain smokers from last 30-40 years , so consult a physician and get his opinion because dark colored sputum is usually associated with smokers disease.
In my opinion consultation with a pulmonologist will help.
Good luck.
Dr. HET