The human body relies on the exchange of gases to sustain life. Oxygen fuels bodily functions, while carbon dioxide is a byproduct that must be removed. An excess of carbon dioxide can be detrimental to health.
The Body’s Essential Gas Exchange
Respiration involves taking in oxygen and expelling carbon dioxide. Air enters the lungs, where oxygen moves from alveoli into the bloodstream through capillaries. This oxygen-rich blood then circulates, delivering oxygen to cells.
Within cells, oxygen participates in cellular respiration, converting nutrients into energy (ATP). This generates carbon dioxide as a waste product, which then diffuses into the bloodstream.
The bloodstream transports carbon dioxide back to the lungs for exhalation. Carbon dioxide is carried in various forms, including bicarbonate ions, bound to hemoglobin, or dissolved in plasma. Once in the lungs, carbon dioxide moves from the capillaries into the alveoli and is exhaled.
Why Carbon Dioxide is Harmful
When carbon dioxide accumulates, it leads to hypercapnia. This significantly impacts blood pH. Carbon dioxide combines with water to form carbonic acid, which dissociates into hydrogen ions. An excess of carbon dioxide increases hydrogen ions, making the blood more acidic, a condition known as respiratory acidosis.
Increased acidity disrupts bodily functions, as the body maintains a narrow pH range for optimal operation. The body attempts to compensate by increasing the breathing rate. However, in chronic hypercapnia, this drive can become blunted, reducing responsiveness to high carbon dioxide.
High concentrations of carbon dioxide in the inhaled air can displace oxygen, reducing its availability for absorption. This can lead to hypoxia, a state of insufficient oxygen supply to tissues. The combined effects of acidosis and reduced oxygen severely impair cellular and organ function.
Symptoms of Carbon Dioxide Exposure
Symptoms of carbon dioxide exposure vary by concentration and duration. Mild to moderate levels can cause headache, dizziness, drowsiness, and fatigue. Individuals might also experience rapid breathing and an increased heart rate.
As carbon dioxide levels increase, symptoms become more pronounced, including nausea, vomiting, confusion, and impaired consciousness. Higher concentrations lead to severe manifestations like convulsions, blurred vision, sweating, and tremors. In extreme cases, very high levels can result in coma and be fatal. These effects underscore the importance of proper ventilation and monitoring where carbon dioxide concentrations might rise.