Frequent or long-term exposure to high levels of nitrogen oxides can increase the incidence of acute respiratory illness in children. Carbon monoxide is a colorless, odorless gas that is produced by burning organic matter such as oil, natural gas, fuel, wood, and charcoal. Carbon monoxide displaces oxygen in red blood cells, which reduces the amount of oxygen that human cells need for respiration. Exposure to CO can result in fatigue, angina, reduced visual perception, reduced dexterity, and death. The elderly, young children, and people with pre-existing respiratory conditions are particularly sensitive to carbon monoxide pollution.
Carbon monoxide is extremely deadly in an enclosed space, such as a garage or bedroom.
Sulfur dioxide is a colorless gas produced by motor vehicles, refineries, and power plants that burn fossil fuels. Fossil fuels like coal and oil vary in sulfur concentrations and as a result the amount of sulfur dioxide they produce when burned. A high level of sulfur dioxide in exhaust gas can interfere with emission control mechanisms for other pollutants. Sulfur dioxide reduces respiratory volume, and increases breathing resistance in those exposed, especially asthmatics. Studies have also shown that sulfur dioxide increases nasal airway resistance.