(HealthDay News) -- Your lungs are delicate organs, and whatever is in the air you breathe can directly affect their health.

The American Lung Association says warning signs of lung disease include:

• A cough that lasts at least a month.
• Shortness of breath after little or no activity, or that doesn't improve after you've finished exercising.
• Wheezing or other signs of difficulty breathing.
• Chronic chest pain that lasts at least a month.
• Producing blood when you cough.