In Odisha, coal dust is clogging leaves and blocking carbon uptake Premium

Bengal Nagpur Railway's coal mining impact on vegetation in Jharsuguda studied using satellite data, highlighting environmental concerns.

The Bengal Nagpur Railway had been tasked by the British Indian government with developing rail networks in eastern and central India. In 1900, when its workers were digging in Jharsuguda, now a district in Odisha, they stumbled upon large coal deposits. Nine years later, Jharsuguda’s first coal mine was established and a century later the region was producing more than 15 million tonnes of coal in a year.

Coal is a fossil fuel produced by the decomposition of dead plants trapped in layers of soil. Around three-fourths of India’s electricity is produced by coal-fired power plants. It’s also critical in the iron, steel, cement, and fertiliser industries. India is one of the largest producers and consumers of coal worldwide, second only to China.

In Jharsuguda, most coal mines are open-cast. Miners here start at the surface of the soil, removing soil and rocks to expose the coal deposits. This is more cost-effective than underground mining, which requires digging tunnels to access the deposits.

But open-cast mining pollutes the air more. The dust from blasting rocks, drilling holes in the ground, and transporting the coal and rock waste disperses through the air and can choke lungs when inhaled. The dust also settles on the leaves of plants nearby. When this happens, stomata — the small pores on leaves through which plants exchange carbon dioxide, water vapour, and oxygen — are clogged, affecting photosynthesis and temperature regulation in the plants.

Estimating the impact of mining dust on nearby vegetation requires researchers to collect a large number of dust-laden leaves from plants spread in the area surrounding a mine. With the dust spreading as far as 30 km away from the mining site, this is a Herculean task.

In a October 2024 study published in the Journal of Geophysical Research: Biogeosciences, researchers from the University of Southampton in the UK and the National Institute of Technology (NIT), Rourkela, reported using freely available data from several satellites to investigate how plants are affected by mining dust.

“Use of satellite data provides a great opportunity to efficiently monitor larger areas,” study co-lead and University of Southampton professor of remote sensing Jadu Dash said.