Pollution raises risk of childhood stunting, leading to lifelong impact: Study

New Delhi: Children in parts of India with high air pollution are more likely to be stunted or severely stunted, according to a study that for the first time looks at how dirty air affects the development of children

New Delhi: Children in parts of India with high air pollution are more likely to be stunted or severely stunted, according to a study that for the first time looks at how dirty air affects the development of children.

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According to the researchers, when children were exposed to significantly higher levels of PM2.5 particles than the average exposure across the country, they were almost 5 and 2.4 percentage points more likely to suffer from stunting or severe stunting.

“Back-of-the-envelope estimates suggest that, if average pollution levels in India were brought down to WHO recommended standards, i.e., an eightfold reduction from current levels, the shares of stunted and severe stunted children would decrease by 10.4 and 5.17 percentage points, respectively,” said the study, published in the Journal of Environmental Economics and Management over the summer and only recently made freely available via the HAL open archive.

“This would correspond to approximately 14.3 million less stunted children in India,” the paper added. The researchers are affiliated to Heidelberg University in Germany, the Center for Economic Research ETH, Zurich and the University of Rennes, France.

A US-based environment research organisation, the Health Effects Institute (HEI), found that in 2019, Indians overall had an average PM2.5 exposure of roughly 82 microgams per cubic metre of air (ug/m3). But this figure varies widely depending on where in India someone lives. In Delhi, instance, according to the same HEI study, people in Delhi were exposed to an average of 118ug/m3 of PM2.5 levels.

PM2.5 particles are easily inhaled and absorbed by the lungs into the bloodstream, leading to a host of ill effects that manifest in cardiovascular illnesses, leading to a higher mortality and disease burden.

The authors of the new study looking at child development now flag a previously unrecognised socio-economic burden caused by growth stunting.

In the short term, they note citing the past studies, stunting is linked to weakened immune system lower cognitive development, poorer educational performance and higher mortality rate.

In the longer term, stunted children are more likely to experience short stature as adults, reduced cognitive skills and work capacity, higher risk of obesity and chronic illness, lower income and wealth and worse reproductive outcomes.

“The consequences of air pollution exposure, similarly to other health shocks during childhood, are expected to be long-lasting,” said the study, while also finding that women are harder hit than men.

“Based on estimates from the literature, we compute the additional contribution of air pollution exposure to the well-known height premium in earnings and find that an increase in PM2.5 by one standard deviation during childhood translates into lost yearly earnings in adulthood in the range of 1.4 – 1.8% for men and 1.6 – 2% for women, pointing to a potential new dimension of the gender gap in India,” it added.

In concluding, the authors say the “results indicate that the negative impacts of pollution on child development are substantial, underlying once again the urgency to reduce air pollution in India.”

They cite recent insights from other studies that suggest the willingness to pay for clean air was extremely low in India and therefore, the solutions “will not be led, at least in the short term, by citizen-led initiatives, but needs to be mediated by policy makers”.