The alarming rise in carbon dioxide (CO2) levels is not just an environmental concern; it's a health issue that's affecting us on a personal level. A recent study has revealed a disturbing trend: the CO2 in our atmosphere is impacting our blood chemistry, and it's a change that's measurable and potentially concerning for our future health.
Over the past two decades, scientists have analyzed health data from a US population database, and the results are eye-opening. They've found shifts in blood chemistry that align with increased exposure to CO2. While it's not an immediate danger, the study's modeling predicts that if this trend continues, certain blood chemistry values could reach the limits of what's considered healthy by 2076.
Respiratory physiologist Alexander Larcombe from Curtin University in Australia explains, "What we're witnessing is a gradual alteration in blood chemistry that mirrors the rise in atmospheric carbon dioxide, which is a key driver of climate change."
The study's findings suggest that average bicarbonate levels, which are crucial for maintaining healthy pH levels in the body, could approach the upper limit of their healthy range within the next 50 years. Additionally, calcium and phosphorus levels could drop to the lower end of their healthy ranges later this century.
This is a significant departure from the stable CO2 levels that Earth's atmosphere has maintained for at least the last 150,000 years, with levels hovering around 280 to 300 parts per million (ppm). In recent decades, however, CO2 levels have skyrocketed, rising from around 369 ppm in 2000 to approximately 420 ppm today.
When CO2 enters the bloodstream, it's converted into bicarbonate. Larcombe and his colleague, retired geoscientist Phil Bierwirth from the Australian National University, theorized that bicarbonate could serve as a tracer, indicating atmospheric CO2 levels in the blood.
Their analysis of blood chemistry data from the US National Health and Nutrition Examination Survey (NHANES) revealed a clear trend. Over the study period, the average blood concentration of bicarbonate increased from 23.8 to 25.3 milliequivalents per liter, a rise of about 7 percent or 0.34 percent annually. This increase mirrored the rise in CO2 levels during the same time frame.
Conversely, calcium and phosphorus levels in the cohort showed a downward trend, with calcium decreasing by 2 percent and phosphorus by 7 percent.
This shift is likely due to the body's attempt to maintain its acid-base balance when carbon dioxide dissolves in the bloodstream. To keep blood pH within a healthy range, the kidneys conserve bicarbonate, a buffering molecule that helps neutralize excess acidity. Bones also contribute by exchanging minerals like calcium and phosphorus to buffer acid.
At present, these changes are minor and within the body's tolerance range. However, the parallel rise is a cause for concern. If the researchers' theory holds true, we may witness physiological changes at a population level over time.
Bierwirth adds, "I believe what we're seeing is a result of our bodies' inability to adapt. It seems we're adapted to a range of CO2 levels in the air that may have been surpassed. The normal range is a delicate balance between CO2 in the air, our blood pH, our breathing rate, and bicarbonate levels. With higher CO2 levels in the air, it appears to be accumulating in our bodies, and it may be vital to limit atmospheric CO2 levels."
The research, published in Air Quality, Atmosphere & Health, highlights the urgent need to address rising CO2 levels and their potential impact on human health.
