Atmospheric pressure decreases with increasing altitude, while the percentages of the different components remain the same. Atmospheric pressure is measured with a barometer. The troposphere is our immediately surrounding atmosphere. Above that is the ozone layer, stratosphere and, at the top, the mesosphere. Maximum levels are established and measured based on the toxicity of each individual component.
Carbon monoxide interupts the delivery of oxygen in the blood stream.
Can lead to death, is dangerous to cardiovascular patients, affects visual perception, manual dexterity and learning ability. Ozone affects respiration, reduces lung function, causes chest pain, coughing, sneezing, and pulmonary conjestion. A triatomic molecule of oxygen, it has a sharp odor. Sulfur dioxide and nitrogen oxides are irritants, increase the risk of infection, especially in the elderly, young children, asthmatics and persons with emphysema. Principle cause of acid rain.