Carbon Monoxide isn't a direct pollutant, but it enhances the effects of other chemicals. For example - Methane, Troposphoric Ozone, and Carbon Dioxide. CO reacts with OH's, forming carbon dioxide, which is more harmful than the other pollutants.
Carbon monoxide has its effects on humans. Health wise, it can cause headaches, nausea, vomiting and dizziness. If inhaled in mass quantities, it can lead to unconsciousness and also death.
Carbon dioxide causes heating of the earth. Plants and trees help keep the earth cool, but because of an increase in the level of carbon dioxide, they fail to do so. Carbon dioxide thickens the atmospheric layer and traps in more heat.
Effects of carbon dioxide on humans -
Carbon dioxide reduces the amount of oxygen available for animals and when exposed to an excess amount, can cause death and unconsciousness.
Sulfur dioxide is one the most harmful pollutants. Sulfur dioxide and nitrogen oxides are one of the main pollutants that cause acid rain. Sulfur is formed from combustion of coal and oil.
When sulfur dioxide is inhaled, it irritates the nose and throat, causing coughing, irritation in the lungs, etc.
Nitrogen dioxide is an irritant gas that assists sulfur dioxide in the formation of acid rain. Nitrogen dioxide affects the vegetation. It can cause leaf damage.
When exposed to humans, it can cause inflammation of the throat. Long term exposure can cause decreased lung function.
Nitric acid is a corrosive compound used in the industry. It is used in synthetic fibers, explosives, etc. It is a combination between nitrogen oxide and water. It's reaction rate is high and in some cases can cause a chemical reaction leading to explosions.
When nitric acid is inhaled or consumed, it can produce injury. Nitric acid is harmful for all body parts.