Extended exposure to PM 2.5 air pollution can lead to anaemia among children under the age of 5 years, according to a study by the Indian Institute of Technology (IIT), Delhi, and Harvard University. This is the first Indian study to establish a clear association between exposure to PM 2.5 and anaemia in young children.

Meeting air pollution control goals under the National Clean Air Programme (NCAP) could go a long way in improving child health in India, concluded the study titled “The Association Between Ambient PM 2.5 Exposure and Anaemia Outcomes Among Children Under Five Years of Age in India”. 

Anaemia is a condition in which the blood doesn’t have enough healthy red blood cells, or haemoglobin. This leads to reduced oxygen flow to the body’s organs, which makes bodies tire easily. Globally, India carries the largest burden of anaemia, especially among women and children. The study, published in the journal Environmental Epidemiology, has found that for every 10 micrograms per meter cube increase in PM2.5 levels exposure, there is a decrease of 0.07 grams per dL in average haemoglobin levels.

“This is a huge increase if you see the difference between PM 2.5 levels in Himachal Pradesh as opposed to Delhi,” Dr. Sagnik Ray, the lead author of the study, told the Indian Express. “The exposure of children under 5 years to PM 2.5 living in the capital will obviously be more. The study is important because so far anemia has been looked at through the prism of nutrition deficiency, specifically that of iron. But even if government programs like Poshan Abhiyan were strengthened, till air pollution is curtailed or exposure of children to PM 2.5 is brought down, anemia is likely to continue to persist.”

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The IIT study included over 98,000 children in the individual analysis across 636 districts in the country, based on data from the national family and health survey 2015-16. About 63% of the included children were found to be anemic. Children with anemia were, on average, slightly younger compared with children without anemia, came from lower-income backgrounds, and had higher percentages of maternal anemia.

Even though health programs were introduced to decrease anemia, it has remained a major issue despite an increase in available food fortified with iron. “Other potential risk factors for childhood anemia must be identified and understood,” the study observes.

In the past, high air pollution levels have been associated with adverse cardiovascular, respiratory, mental health, and mortality outcomes. For children, it has been associated with a shorter lifespan, worsening psychiatric disorders, and cognitive delays.