Farakka PM2.5 Study Links Pollution Exposure to Gender Differences in Biological Ageing

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Women living downwind of the Farakka coal-fired power plant in West Bengal show greater signs of biological ageing than men, according to a study conducted jointly by researchers from Karolinska Institutet, Linköping University and the Indian Institute of Technology (IIT) Mandi. The study, accepted for publication in Communications Earth and Environment, examined the environmental and biological effects of exposure to fine particulate matter (PM2.5) around the plant during the winter of 2021–22. Researchers collected ambient air samples from locations upwind and downwind of the plant, analysed them for metals and organic pollutants, and collected blood samples from residents alongside household surveys on cooking practices.

The overall concentration of fine particulate matter was broadly similar on both sides of the plant, but the chemical composition differed. Air samples collected downwind contained higher levels of several metals associated with fuel combustion, including vanadium, iron, thallium and selenium. Blood samples from people living downwind showed that genes associated with inflammation were more active, while those involved in cellular energy production showed reduced activity. Using blood tests that estimate biological age based on patterns of gene activity, researchers found that women’s biological age was ahead of men’s, with the difference most evident among those living downwind. Researchers said household air pollution from cooking with wood, dung and other solid fuels could be an additional exposure for women, who often spend more time cooking. More than 800 million people live on the Indo-Gangetic Plain, one of the world’s most polluted regions. The researchers cautioned that the study involved a relatively small group of people examined at a single point in time, and while it shows a link between pollution and changes in biological markers, it cannot establish that pollution caused accelerated biological ageing.

What is the Farakka Barrage Project and when did it begin?

The Farakka Barrage Project was commissioned in 1975 to divert water from the Ganga into the Bhagirathi-Hooghly river system to flush silt and improve navigability at the Kolkata port. The barrage is located in Murshidabad district, West Bengal, about 18 kilometres from the Bangladesh border. Its construction and operation have been a long-standing source of dispute between India and Bangladesh over water sharing, leading to the signing of the Ganga Water Treaty in 1996. The NTPC Farakka Super Thermal Power Station, situated near the barrage, was commissioned in stages starting in 1986. The region falls within the Indo-Gangetic Plain, which is known to suffer from high baseline levels of air pollution due to geographical and meteorological factors that trap pollutants.

What did the study find in air and blood samples?

The research was conducted during the winter of 2021–22. Ambient air samples collected downwind of the Farakka plant had higher levels of vanadium, iron, thallium and selenium compared to upwind samples, even though overall PM2.5 concentrations were similar. Blood samples from downwind residents showed increased activity of genes associated with inflammation and reduced activity of genes involved in cellular energy production, a pattern that Dr Ujjwal Neogi, one of the study’s senior authors, said is often seen when the body is under long-term stress.

Why may women be more vulnerable?

Researchers believe household air pollution from cooking with solid fuels such as wood and dung could be an important factor. In rural India, a substantial proportion of households continue to rely on such fuels, and women, who often spend more time cooking, may face prolonged exposure to indoor smoke in addition to outdoor pollution. The study’s findings underline how overlapping sources of pollution could create a disproportionate health burden for women, though the researchers emphasised that the small, single-point study can only show an association, not causation.