Using records from the U.S. National Health and Nutrition Examination Survey (NHANES), Alexander Larcombe of The Kids Research Institute Australia and Phil Bierwirth of the Australian National University tracked the levels of bicarbonate (HCO3), calcium (Ca) and phosphorus (P) in the blood of adults in the U.S. between 1999 and 2020, and found a seven percent rise in HCO3 over the two decades of survey data that corresponded to the rise in atmospheric CO2 over the same period, along with a steady decrease in Ca and P levels.
After our cells have metabolized the oxygen they absorb from our blood, they expel CO2 as a waste product; this CO2 is picked up by our red blood cells, where the gas is converted to bicarbonate for transport to the lungs, at which point the chemical process is reversed and we exhale the resulting CO2.
For the purposes of this study, titled “Carbon dioxide overload, detected in human blood, suggests a potentially toxic atmosphere within 50 years”, bicarbonate was used as a proxy to gauge the subjects’ blood-CO2 levels: as it is with carbonated water, CO2 dissolved in the blood causes the blood’s pH to drop, meaning the blood becomes more acidic.
The body has a number of mechanisms that it can use to deal with such a situation, including drawing calcium and phosphorus from the bones to use as chemical buffers to neutralize the body’s pH levels.
These measures are typically employed for short periods, for instance if one is caught in a poorly-ventilated area and breathes in too much carbon dioxide. However, if persistently-high levels of CO2 are present everywhere, this condition becomes chronic, resulting in the body continually leaching calcium and phosphorus out of our bones to offset the blood’s increased acidity, and in turn causing a chronic weakening of our skeletons.
“If these trends continue, blood bicarbonate values could be at the limit of the accepted healthy range in half a century, and Ca and P will be at the limit of their healthy ranges by the end of this century,” the study stated.
“Studies indicate that, after this time, elevated atmospheric carbon dioxide, leading to CO2 accumulation in the body, has the potential to cause a range of adverse health effects,” the text continued. “These findings highlight the urgent need for significant reductions in anthropogenic CO2 emissions to safeguard public health.”