The hidden threat in confined indoor spaces: High CO₂ Concentration and hypertension
- SINGRASS
- 2 days ago
- 2 min read
In winter, outdoor temperatures are low, and people tend to keep doors and windows tightly closed to maintain indoor warmth, resulting in poor air circulation between indoors and outdoors. Occupants continuously exhale CO₂ without corresponding ventilation measures, causing indoor CO₂ concentrations to accumulate continuously and greatly exceed standard levels.
Research indicates that in ordinary living rooms with doors and windows closed, the activity of just two or three people for a few hours can easily push the CO₂ concentration beyond the alert level of 1,000 ppm, and it can even reach 2,000 - 3,000 ppm, far exceeding the normal outdoor level of approximately 400 ppm.
Especially during nighttime sleep, indoor CO₂ concentrations often remain above 2,500 ppm for extended periods. Excessive CO₂ in the sleep environment can disrupt sleep architecture, leading to reduced deep sleep and increased nocturnal awakenings, leaving individuals feeling groggy the next day and creating a vicious cycle of "the more you sleep, the more tired you feel."
The effect of CO₂ on blood pressure is primarily achieved through the regulation of vascular tone and the autonomic nervous system. Short-term elevation of CO₂ concentration can dilate certain blood vessels ( e.g., cerebral blood vessels) but may also elevate blood pressure by activating the sympathetic nervous system. Long-term hypercapnia may further complicate blood pressure changes due to acid-base imbalance or compensatory mechanisms.
Chronic CO₂ retention leads to a decrease in blood pH (respiratory acidosis), triggering compensatory renal acid excretion and base retention. However, if compensation is insufficient, acidosis can directly depress myocardial contractility and impair vascular reactivity, potentially resulting in blood pressure fluctuations or decreases.
In winter, outdoor activities are sharply reduced, and the body's metabolism and blood circulation tend to be relatively sluggish. However, for certain high-risk groups— such as individuals with hypertension, the elderly, and those at high risk for cardiovascular disease— the time spent indoors is relatively longer. The physiological stress induced by high indoor CO₂ levels may become the final straw that triggers abnormal blood pressure fluctuations and even increases the risk of cardiovascular and cerebrovascular events.
In winter, particularly in cold northern regions, actively improving indoor air quality becomes an important strategy for the prevention and management of hypertension. The Singrass® Indoor Smart Eco System (ISES™) — utilizing leafy vegetables to establish plant communities — brings the Singapore Botanic Gardens into every high-rise building. While absorbing CO₂, it produces traceability-free, pollution-free fresh vegetables, offering a more efficient and sustainable choice for safeguarding your health.
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