Other states lack this authority, but they can adopt California's standards to regulate pollutants in exhaust fumes outside of carbon dioxide. This includes nitrogen oxides and volatile organic compounds, which react in the presence of sunlight to form ozone, or smog. Ozone inhalation can cause airway inflammation and reduced lung function, as well as worsen respiratory ailments like bronchitis emphysema and asthma. About two hundred counties in 22 states and the District of Columbia do not meet the most recent ozone standards, according to the EPA. This includes major cities like New York City, Washington D.C., Chicago, and Phoenix, as well as most of California.