Final answer:
Small particulate emissions controls (PM 2.5) have successfully reduced lung disease by reducing the amount of small particles that can penetrate deeply into the lungs. This can lead to respiratory illnesses such as pneumonia, bronchitis, and asthma.
Step-by-step explanation:
Small particulate emissions controls, specifically PM 2.5, have been a major success in reducing lung disease. These small particles, such as soot, can penetrate deeply into the lungs and cause respiratory illnesses like pneumonia, bronchitis, and asthma. For example, a small firm that emits 50 pounds per year of small particles into the air can contribute to respiratory illnesses and impose costs on individuals and firms.