My husban is a smoker and has been coughing up phlegm with black spots. what could this be?

Abnormal sputum: This could be traces of blood or other substances. Your husband needs a thorough medical evaluation to rule out cancer and other serious disease of the lungs.

He should see doctor: Black spots could just be from the tars in the cigarette smoke, but old blood also looks very dark and can seem black. I would strongly urge his seeing his doctor asap and being evaluated. If he came to me, i would be at least getting a chest xray, and if there were other suspicions, perhaps a chest ct scan as well. He needs to stop smoking, and you need to stop too if you are a smoker.