Air Pollution Soucres Natural Particulates Pollen, smoke, dust/ash from volcanoes,fungus spores, salt pray Gases Carbon monoxide, terpenes from pine trees, hydrogen sulfide and methane decomposition

Air Pollution Sources Man-made Stationary combustion Transportation Industrial processes Solid waste disposal

Human Health and Air Pollution Threshold There are several possible relationships between pollutant dose (the amount to which you are exposed) and human response (an effect caused by the pollutant). Some pollutants have no effect at low doses, but very severe effects at high doses. In other words, there is a threshold below which the pollutant has no adverse effect.. Other pollutants seem to produce an effect at any level. Scientists have not been able to quantify the relationship between most pollutants and the effect they cause.

Total Body Burden Not all of the pollutant a person is exposed to comes from the air. For example a person may breathe in about 50 micrograms of lead per day while their intake from food and water could be 300 micrograms per day.

Most pollutants require time to react and cause an effect. The time of exposure is as important as the amount of the pollutant. Time vs Dosage Example CO combines with hemogloben to form carboxyhemoglobin. When your blood has 60% carboxyhemoglobin you die from lack of oxygen.

Synergism The effect is greater than the sum of the parts. For example, black lung in coal miners occurs mostly when the miner also smokes. Coal mining alone, or smoking alone will usually not cause black lung.

Respiratory System When pollutants are taken into the body they may be adsorbed into the bloodstream or moved out of the lungs by small hair cells called cilia that are constantly sweeping mucus up into the throat. Particles larger than 0.1 microns are usually caught in the upper respiratory system and swept out by the cilia. Particles smaller than 0.1 microns can move into the alveoli where there are no cilia and they are trapped, causing damage to the lung tissue.

Acid Rain SO 2 + O  SO 3 SO 3 + H 2 O  H 2 SO 4 NO + O 3  NO 2 + O 2 NO 2 + O 3 + H 2 O  2 HNO 3 + O 2

Photochemical Smog