Kolkata: A recent study has revealed that air pollution is increasingly threatening the mangrove ecosystem of Sunderbans in West Bengal which has the ability to shield Kolkata against extreme weather conditions.
The study revealed how considerable amounts of pollutants, mainly black carbon or soot particles, arriving from Kolkata and the entire Indo-Gangetic Plain (IGP) region, are significantly deteriorating Sunderbans air quality, thus affecting its ecosystem.
As per the researchers, pollutants transported from the IGP, as well as localised pollutants like biomass burning and emissions from local boat services, is making the particulate matter (PM) suspended over Sunderbans highly acidic and rich in trace metals. Old motors in local boats were identified as a major source of heavy toxic metals in the air.
Sunderbans mangrove ecosystem plays a vital role in climate change mitigation by acting as a net sink (absorber) of such climate warming greenhouse gases. Its potential to absorb atmospheric carbons and other climate warming greenhouse gases is higher than the Amazon rainforest.
The study titled “Acidity and oxidative potential of atmospheric aerosols over a remote mangrove ecosystem during the advection of anthropogenic plumes” was conducted by Professor Abhijit Chatterjee, department of Chemical Science, Bose Institute, Kolkata, along with the lead author Abhinandan Ghosh from IIT Kanpur. The team included Monami Dutta, Sanat Kumar Das from Bose Institute and Professor Mukesh Sharma from IIT Kanpur. The study was published in March 2024 in the noted Elsevier journal “Chemosphere.”
The study revealed the acidic components of PM 2.5 pollutants favoured the formation of Reactive Oxygenated Species (ROS) in the presence of heavy metals. Such production of ROS above the capacity of any living organism could damage the living cells. Surprisingly, the study revealed that oxidative stress due to PM 2.5 pollutants in the Sunderbans – despite being sparsely populated – is as severe as in many urban areas. “Our research clearly indicates that the transported and regionally emitted air pollutants have a significant effect on the ecology and biogeochemistry of the pristine environments of the Sunderbans mangrove ecosystem that needs to be solved with utmost priority. The marginalised and under-privileged community living in the Sunderbans do not deserve such pollution-induced and climate-change-induced catastrophe. They contribute almost nothing to global warming, yet suffer the most,” Prof Abhijeet Chatterjee said. A unique geographical location, weather conditions, social economic conditions, transport of air pollutants from other metropolises and local emissions from nearby villages sends Sunderbans air quality plummeting, especially during the winter. These aspects also make it more challenging to frame policies to combat pollution in the region with 4.5 million inhabitants.
To stop the ecosystem degradation, the researchers recommended promotion of solar energy, leveraging the extensive coastline to set up windmills for electricity generation, strict control of tourism activities such as banning plastics and prohibiting tourists from bringing non-degradable items. Use of electric boats and other e-transport solutions were suggested, besides offering subsidies for LPG to stop burning of wood or cow-dung for cooking in rural areas. Discontinuing transportation of toxic waste and ash to and from the Sundarbans, shutting down or restricting factories that emit carbon near and regulation of brick kilns are also recommended.