Rising CO2 Could Be Altering Our Blood Chemistry, Study Suggests : ScienceAlert

The Impact of Rising CO₂ Levels on Human Blood Chemistry

A recent study suggests that the increase in carbon dioxide (CO₂) levels in Earth’s atmosphere is not only detectable but also measurable in the blood of human beings. Researchers have analyzed two decades of health data from a US population database and identified shifts in blood chemistry that are consistent with higher exposure to CO₂.

While the current levels of CO₂ in the atmosphere are not yet dangerous, the study predicts that if the trend continues, certain blood chemistry values could approach the upper limit of today’s accepted healthy range by around 2076. This gradual shift in blood chemistry mirrors the rise in atmospheric CO₂, which is a major driver of climate change according to respiratory physiologist Alexander Larcombe from Curtin University in Australia.

The study indicates that average bicarbonate levels in the blood could approach the upper limit of the healthy range within the next 50 years if current trends persist. Similarly, calcium and phosphorus levels may reach the lower end of their healthy ranges later in this century.

Historically, Earth’s atmospheric CO₂ levels have been relatively stable, but in recent decades, they have risen significantly. This increase has led to the conversion of CO₂ into bicarbonate in human blood. Bicarbonate plays a crucial role in maintaining healthy pH levels in the body, but it can also serve as a blood tracer for atmospheric CO₂ levels.

The researchers analyzed data from the US National Health and Nutrition Examination Survey (NHANES) spanning from 1999 to 2020. They observed a 7% increase in blood bicarbonate levels during this period, paralleling the rise in CO₂ levels. Additionally, calcium and phosphorus levels in the blood showed a decreasing trend, likely due to the body’s efforts to maintain acid-base balance in response to higher CO₂ levels.

While the current shifts in blood chemistry are within the body’s tolerable range, the researchers suggest that continued exposure to elevated CO₂ levels may lead to physiological changes at the population level over time. It appears that human bodies may not be adapting to the unprecedented levels of CO₂ in the atmosphere, emphasizing the importance of limiting atmospheric CO₂ levels to safeguard human health.

The study has been published in Air Quality, Atmosphere & Health.