Answer:
smoking
Step-by-step explanation:
because it goes straight to respiratory system
lungs can be very badly affected by smoking. Coughs, colds, wheezing and asthma are just the start. Smoking can cause fatal diseases such as pneumonia, emphysema and lung cancer. Smoking causes 84% of deaths from lung cancer and 83% of deaths from chronic obstructive pulmonary disease (COPD).