The Hidden Threat in Confined Indoor Spaces: High Concentration CO₂ and Respiratory Acidosis

When we remain for extended periods in crowded meeting rooms, enclosed classrooms, or poorly ventilated buildings, we often experience dizziness, difficulty concentrating, and even chest tightness and shortness of breath. Most people attribute these symptoms to "hypoxia" (oxygen deficiency). However, modern medicine indicates that the true culprit is often the quietly rising concentration of carbon dioxide CO₂ in the indoor air.

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An issue that cannot be ignored is whether this gas, which we exhale every moment, can, when present at excessively high concentrations, induce dangerous respiratory acidosis?

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Respiratory acidosis specifically refers to a condition resulting from impaired pulmonary ventilation, leading to significant retention of CO₂ in the body. This retained CO₂ subsequently combines with water to form carbonic acid, causing hypercapnia, which is characterized by a primary increase in the partial pressure of carbon dioxide (PCO₂) in the blood and a decrease in pH.

Acute phase symptoms include dyspnea (difficulty breathing), headache, and confusion; severe cases may progress to coma or ventricular fibrillation. Chronic phase symptoms are often masked by those of the underlying primary disease. Prolonged exposure to hypercapnia can lead to the development of hypertension.

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When the CO₂ concentration exceeds 1000 ppm, individuals begin to experience respiratory discomfort, along with decreased attention, reduced work efficiency, and drowsiness.

A research report from the Harvard T.H. Chan School of Public Health indicates that when the CO₂ concentration exceeds 900 ppm, human cognitive performance declines by 15%; when the CO₂ concentration exceeds 1400 ppm, cognitive performance declines by 50%.

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In extreme environments— such as submarines, air-raid shelters, or cellars, where spaces are small and densely populated—CO₂ concentrations can surge to tens of thousands of ppm. Under such conditions, even healthy individuals face a risk of developing respiratory acidosis.

For individuals with pre-existing respiratory diseases, pulmonary dysfunction, or a history of chest trauma, even a mild elevation in indoor CO₂ concentration imposes an additional expiratory burden on the respiratory system, thereby posing a potentially fatal threat to their health.

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A clear causal relationship exists between elevated indoor CO₂ concentration and respiratory acidosis. The detrimental effect of high-concentration CO₂ on cognitive function is a scientific consensus. Furthermore, its potential fatal threat to patients with respiratory diseases, as well as its indiscriminate impact on any individual under certain extreme environmental conditions, serves as an urgent warning.

Actively improving indoor ventilation and installing  CO₂ concentration monitors in public spaces are not only measures to enhance comfort and efficiency but also important steps to safeguard basic health. In confined, windowless indoor spaces, or in environments where air conditioning is used without opening windows, SINGRASS® can provide a green, ecological, and efficient solution, imperceptibly mitigating the health threats posed by  CO₂.