Effect of Inhaling Various Concentrations of CO2 on Electrical Activity of the Heart
The human body functions best in a relatively stable environment. Deviations out of the acceptable ranges of tolerance have unpleasant consequences. In such a way, drastic changes in the air humans breathe have calamitous effects of body. Respiration is the basis for gas exchange, as oxygen is inhaled and carbon dioxide is exhaled. In some settings such as in small, enclosed rooms, when oxygen consumption exceeds production, or with diseases such COPD, humans breathe in dangerously high concentrations of CO2. For this reason, it is important to analyze the properties of carbon dioxide, its role in the body, and the effects on cardiac activity under stress.
A carbon dioxide molecule is comprised of two oxygen atoms covalently bonded to a carbon atom, forming a linear bond. It is in a gaseous form in the atmosphere at standard temperature and pressure, but can be a solid if cooled to -78° in dry ice (Rick, 2008). Forests and rocks act as sinks for carbon dioxide, but it can also be dissolved in the bodies of water, such as oceans. Plants and other photosynthetic organisms use atmospheric carbon dioxide for photosynthesis: 6 CO2 + 6 H2O + Energy for Sun→ C6H12O6 + 6 O2, where carbon molecules are used to make sugar molecules in the Calvin cycle within the cells' chloroplasts (Kling, 2009). Respiration by cells breaks down sugar molecules to obtain energy, and in turn, releases carbon dioxide as a byproduct: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP. When organisms die and decay, carbon dioxide returns to the air. The atmosphere consists of about 0.04 percent CO2. In the past years, the concentrations have been much lower, but due to human activities such as burning fossil fuel and deforestation, concentrations have risen at a rate of 2.07 ppm/year and exceeded 400 ppm (CO2Now, 2014). As a green house gas, the rising concentrations of carbon dioxide have contributed significantly to climate change. The Keeling curve has shown that while the levels increased through the years, they we affected by seasonality, with concentration growing in spring-early summer and falling in the fall-early winter (Scripps Institution of Oceanography, 2014). Carbon dioxide can accumulate in spaces without much air circulation. Humans are comfortable up until 1000 ppm. Occupied areas generally contain 350-1000 ppm of CO2 (Wisconsin Department of Health Services, 2013). Concentrations of 1000-2000 ppm carbon dioxide cause drowsiness. Upwards of 2000-5000 ppm cause sleepiness and headaches. The stuffy air has been observed to cause nausea and increase heart rate. The air starts becoming toxic if it exceeds 5000 ppm CO2. The threshold of normal breathing is at 40,000 ppm. Studies have found that at concentrations of 100,000 ppm and more result in sudden unconsciousness (Dakota Gasification, n.d.).
During inhalation, oxygen diffuses from the alveoli into the capillaries of the lungs, and...