CO2 Part II - Carbon Dioxide- Part II Ambient Levels &...

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Carbon Dioxide- Part II Ambient Levels & Breathing: Is CO 2 a Pollutant? Some of the earliest experiments regarding the composition of air included the famous “mouse in a bell jar” demonstration. It was readily observed that a mouse in tightly closed jar soon became lethargic and if no relief was granted, eventually it died, or in modern terms, suffocated. Conversely, when methods became available to create 100% oxygen in a closed jar, the mouse was observed to be very active and highly stimulated. Nevertheless, these experiments did not originally discern that it is the increased presence of carbon dioxide that respiratory animals respond to, in order to control their breathing, not the paucity of oxygen. Thus, there are examples of humans falling unconscious, without prior warning, in rooms where liquid nitrogen boil-off filled the room, and the scarcity of oxygen was undetected. Clearly, at some level carbon dioxide is a lethal gas, and well below that lethal limit, respiratory animals experience discomfort. Human exhalation from the lungs typically contains 35,000 to 50,000 ppmv (parts per million by volume) depending somewhat on the state of physical activity and the other factors affecting metabolic rates. The exhaled gas is not depleted in oxygen
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This note was uploaded on 01/16/2012 for the course ENVIRON 404 taught by Professor Rasmussen during the Fall '11 term at University of Michigan.

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CO2 Part II - Carbon Dioxide- Part II Ambient Levels &...

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