Global iron deficiency—already a significant problem—may increase along with rising levels of human-generated carbon dioxide (CO2) emissions, according to a new study from Harvard T.H. Chan School of Public Health. There are 1.4 billion children under age 5 and women of childbearing age in parts of Asia and Africa who face the greatest risk.
The study was published May 11, 2017 in the journal GeoHealth.
Researchers based their findings on recent studies that showed that certain highly consumed crops—including wheat, rice, barley, legumes, and maize—have lower iron concentrations when grown under increased atmospheric CO2 concentrations.
The study estimated the percentage of dietary iron that would be lost due to human-generated CO2 emissions between now and 2050. Researchers took into account the diets of people in 152 countries around the world, as well as the current prevalence of anemia, roughly half of which is thought to be caused by a lack of adequate iron in the diet.
Those most at risk include 354 million, or 58%, of all children under 5, and 1.06 billion, or 60%, of all women of childbearing age. Regions with the highest risk are located in South and East Asia and in North and East Africa, where people have mostly plant-based diets. Across all countries, the estimated percentages of lost dietary iron under rising CO2 levels range from modest to more severe—1.5% to 5.5%.
Harvard Chan School authors of the study included Matthew Smith, Christopher Golden, and Samuel Myers.
Learn more
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Rising CO2 poses significant threat to human nutrition (Harvard Chan School release)