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 Subject: Animal respiration. Category: Science > Biology Asked by: federico-ga List Price: \$10.00 Posted: 21 Oct 2002 12:50 PDT Expires: 20 Nov 2002 11:50 PST Question ID: 86080
 ```What quantity of carbon dioxide per day is contained in the exhaled respiration of an average adult human being?```
 ```Hello Federico, Thank you for your question. According to the solutions to “Take a Breath Worksheet” from the College of Chemistry – University of California - Berkeley, 432 L. of carbon dioxide is exhaled by an average adult per day. This is how the results were obtained: The volume of a breath and number of breaths per minute will vary with the size of the person and the level of activity. A reasonable range for the average volume of a breath is 0.1-1.0 liters. 0.5 liters is the volume of an average breath, so we will use that number for the calculation. “The average volume of air moved during normal quiet breathing is 0.5 L. “ College of Science and Mathematics, James Madison University http://csm.jmu.edu/biology/danie2jc/respiration.htm The average person breathes approximately 15 times per minute during normal activity. For one person, the approximate volume of air exhaled per day is: 0.5 L of air 15 breaths 60 minutes 24 hr 10,800 L of air ------------ X ---------- X ---------- X ----- = --------------------- breath min. hr. day day “The next assumption to consider is what portion of the volume of air exhaled is carbon dioxide. The maximum it could be is ~20%, which is the amount of oxygen in the atmosphere. However, it is unlikely that the conversion of oxygen to carbon dioxide is 100% efficient. A reasonable estimate is that one quarter to one half of the oxygen inhaled is converted to carbon dioxide. We'll pick one quarter for the calculation, which is 4% of the air exhaled. Thus, the approximate volume of CO2 exhaled by one person is: 10,800 L of air 432L of CO2 --------------- x 0.04 = ----------- day day Source: College of Chemistry – University of California, Berkeley http://www.cchem.berkeley.edu/~chem1a/fall95/discussion/week1/takeabreathsoln.html According to the book “PULMONARY PHYSIOLOGY IN CLINICAL PRACTICE” - chapter 4, on the average 288 L of carbon dioxide are produced per day A short excerpt from this text: “At rest, the average sized adult produces approximately 200 ml of carbon dioxide per minute. Carbon dioxide production (VCO2) is of course a continuous process, as is oxygen consumption. VCO2 increases during exercise and declines slightly during sleep. On the average, 288 L of carbon dioxide are produced per day (1440 min x 200 ml CO2/min). (..) Carbon dioxide elimination is accomplished by bringing fresh air into the lungs; there is no other way to excrete the body's CO2 production. A minuscule amount of carbon dioxide, less than 1%, is excreted by the kidneys as bicarbonate.” Source: Mt. Sinai Hospital Website http://www.mtsinai.org/pulmonary/books/physiology/chap4_1.htm 360 L a day of carbon dioxide is given off by a human being lying down flat on his back. This is a calculation made based on 250 ml. carbon dioxide exhaled per minute. http://sunsite.berkeley.edu:2020/dynaweb/teiproj/oh/science/reeves/@Generic__BookTextView/4964 Averaging out the three above figures, (432+288+360), we can assume that 360 L. of carbon dioxide per day is exhaled by an average adult human being. Additional information that may interest you: Normal Respiratory Rates: Adults: 12-20/minute Children: 18-24/minute Infants: 40-60/minute The average volume of gas inhaled/exhaled in one breath for an adult male is 500 mL. Source: Rogers State university http://www.rsu.edu/faculty/cohman/images/aryanat.ppt During normal breathing about 6-7 mL of air moves in and then out of the lungs with each breath for every kg a person weighs. Thus, if you weigh about 70kg (155lb), the amount that you breath in and out with each breath is about 500 mL and is referred to as the tidal volume. http://dropoflife.org/Fly/html/body_fly_f_p_4.html “The concentration of carbon dioxide in an exhaled breath varies with time; the first portion contains no carbon dioxide and comes from the upper respiratory tract where no gas exchange takes place (the anatomical dead space - 2mls/kg). The concentration of carbon dioxide then rises rapidly to a plateau of about 5% as alveolar gas is breathed out.” http://www.nda.ox.ac.uk/wfsa/html/u07/u07_012.htm “In the life-supporting process of aerobic respiration, oxygen from incoming air enters the blood; and carbon dioxide, a waste gas from the metabolism of food, is exhaled into the atmosphere. Air entering the lungs contains about 21 percent oxygen and 0.04 percent carbon dioxide. Air leaving the lungs contains about 14 percent oxygen and about 4.4 percent carbon dioxide. The composition of the air changes between inspiration and expiration, when the air is deep in the lung tissue.” Western Skies Dialysis Website http://westernskiesdialysis.com/education/lungs.html Search Criteria: amount of carbon dioxide exhaled carbon dioxide eliminated expiration carbon dioxide exhaled respiration average adult average end tidal volume carbon dioxide in adults I hope you find this helpful. Best Regards, Bobbie7-ga```
 federico-ga rated this answer: ```The answer was well researched, well documented, and well explained. The researcher is quite evidently very intelligent and very systematic.I'm delighted!```