A new study has found strong links between air pollution and poor birth outcomes in India. According to data from the National Family Health Survey (NFHS) 2019-21, about 13% of children were born prematurely, while 17% had a low birth weight. Researchers say air pollution may be playing a major role.

The study was carried out by experts from IIT Delhi, the International Institute for Population Sciences, Mumbai, and research institutes from the UK and Ireland. They used national health data along with satellite-based pollution data to understand how exposure to dirty air affects babies in the womb.

The team focused on PM2.5—tiny particles in the air that are smaller than 2.5 microns and are known to be dangerous for health. These particles mainly come from burning fossil fuels and biomass.

They found that increased exposure to PM2.5 during pregnancy raised the risk of low birth weight by 40% and premature delivery by 70%.

“Utilising data from the national family health survey and raster images, the study employs various statistical analyses and spatial models to elucidate the connection between in-utero exposure to air pollution and birth outcomes,” the authors wrote.

Northern India shows worse outcomes

The study noted that children living in northern parts of India are more at risk. Areas like Uttar Pradesh, Bihar, Delhi, Punjab, and Haryana had some of the highest levels of PM2.5, while states in the south and northeast had relatively lower levels.

In terms of premature births, Himachal Pradesh had the highest rate at 39%, followed by Uttarakhand (27%), Rajasthan (18%), and Delhi (17%). On the other hand, states like Mizoram, Manipur, and Tripura showed much lower numbers.

When it comes to babies born underweight, Punjab topped the list at 22%, followed by Delhi, Dadra and Nagar Haveli, Madhya Pradesh, Haryana, and Uttar Pradesh. Again, northeastern states performed better on this front.

The researchers pointed out that even a 10 microgram increase per cubic metre of PM2.5 could lead to 5% more low birth weight cases and 12% more premature births.

They added that nearly 1 in 5 children born in the five years before the NFHS-5 survey had a low birth weight.

The researchers have urged the government to take targeted actions, especially in pollution-heavy northern districts. They called for a stronger push under the National Clean Air Program, which was launched in 2019 to bring down pollution levels.

They also suggested including climate adaptation plans in public health efforts. These may include heat action plans, better water management, and more awareness campaigns for pregnant women.

“Awareness of risks due to air pollution and climate change should be raised as part of public health initiatives, especially among pregnant women,” the team said.