Mother’s exposure to pollution may lead to shorter babies: Study

The study, of at least 200,000 children born between February 2010 and December 2015, noted the highest decline in height in children born between November and January, when the pollution levels in the country are at the peak.

Newborn babies and foetuses of women in their third trimester, who are exposed to high levels of air pollution, are at a higher risk of being shorter for their age or stunted in later life, a study conducted by researchers at the Indian Institute of Technology, Delhi, has revealed.

Newborn babies and foetuses of women in their third trimester, who are exposed to high levels of air pollution, are at a higher risk of being shorter for their age or stunted in later life.(REUTERS Photo)

The study, of at least 200,000 children born between February 2010 and December 2015, noted the highest decline in height in children born between November and January, when the pollution levels in the country are at the peak.

The study was published in the journal, Environmental Health, on last Tuesday.

An increase of 100 μ g/m3 in the ambient PM2.5 levels during the birth month was associated with a decrease of 0.05 in the height-for-age, the study found. The study used population data from the Demographic and Health Survey 2015-16 and compared it to satellite-based district level PM 2.5 concentrations during the birth month of the children.

A five-year-old girl would be 0.24 cm shorter than average, said study authors. “It may seem like a small change, especially when compared to the effects of other factors such as nutrition and sanitation, but the effect of ambient air pollution is experienced everywhere in the country and affects 30 million births every year,” said Sagnik Dey, one of the authors of the study and associate professor at the Centre for Atmospheric Science at IIT-D, which collaborated with University of Texas and Indian Statistical Institute for the study.

“This study adds to the evidence that air pollution also affects the health and development of the next generation. The study accounted for compounding factors like the height of the mother and whether the child is born in a rural or urban setting, but the decrease in the height of children with increase pollution levels was noted across board,” said Dey.

While taller mothers had taller children, a decline in height was noted with an increase in the pollution levels during the birth month. A loss in height was noted in both rural and urban children, although rural children were on average shorter than their urban counterparts.

“Other factors like malnutrition and open defecation also play a role in rural areas, but programmes to address air pollution are largely urban centric; even the National Clean Air Programme focuses on the non-attainment cities. The effects of high air pollution are felt in the rural areas, where household pollution is higher due to the use of solid fuels,” said Dey.

Stunting delays cognitive development, lowers school performance and raises morbidity and mortality from non-communicable diseases like diabetes and hypertension in later life.

In 2017, 12.5% of all the deaths and 8.1% of all the life years lost due to premature death or disability could be attributed to air pollution, according to the state-level disease burden study published in The Lancet in 2018.