Human Blood Indicators May Change With CO2, Study Warns of Approaching Health Limits Within 50 Years

An Australian study has found that human blood indicators linked to carbon dioxide, particularly serum bicarbonate, are undergoing gradual changes. Researchers warn that if this trend persists, these levels could approach the upper boundary of the healthy range within the next 50 years. The findings were published in the journal 'Air Quality, Atmosphere & Health'.

A research team from the Australian Institute for Children's Health and Welfare, Australian National University, and Curtin University analyzed blood test results from over 7,000 Americans using data from the National Health and Nutrition Examination Survey (NHANES) between 1999 and 2020. Their analysis revealed an approximate 7% increase in average serum bicarbonate concentration among Americans after 1999. Serum bicarbonate plays a key role in the body's ability to transport carbon dioxide and maintain acid-base balance.

Concurrently, the study observed a decrease in average calcium and phosphorus concentrations in American blood during the same period. These physiological shifts occurred while atmospheric carbon dioxide levels rose from approximately 369 parts per million (ppm) in 2000 to over 420 ppm currently. This correlation suggests that the human body might be beginning to react to changes in atmospheric composition.

Researchers explained that the body may retain more bicarbonate to stabilize blood pH when carbon dioxide levels increase. However, maintaining this regulatory state for extended periods could have physiological consequences. The study emphasizes that while a direct causal link between the changing blood chemistry and rising CO2 has not been definitively proven, the trend is concerning. Projections indicate that average serum bicarbonate levels could reach the upper limit of the recognized healthy range within 50 years, with calcium and phosphorus potentially nearing their lower limits later this century.