Prof Dr Ahmad Kamruzzaman Majumder :
Plastic pollution in aquatic habitats is a significant environmental problem. It has severe influence on ecology putting aquatic species in danger. Riverine ecosystems are directly impacted by plastic pollution despite the fact that rivers are recognized a significant part in the transportation of land-based plastic garbage to the world’s oceans.
Bangladesh uses 87 thousand tonnes of single-use polyethylene plastic annually. Plastic straws, cotton swabs, food packaging, food containers, bottles, plates, plastic spoons, plastic bags, pastes, shampoo packets, etc. are examples of single-use plastics used in the country. Massive amounts of plastic garbage are produced in China, India, and Nepal. Through the Padma, Yamuna, and Brahmaputra rivers, these wastes reach Bangladesh. A significant amount of the garbage generated within Bangladesh is also mingled with them in waterways. These plastics end up in agricultural fields, water drainage systems, rivers, canals, and seas. As a result of excessive use and poor waste management, they are seriously harming the ecosystems.
Every day, polythene and plastic waste is accumulating in the river through various drains and canals of the city. Again, various types of waste are being thrown on the river banks, these wastes are mixing with water and polluting the river. One-time plastic or single-use small plastics are accelerating the pollution of rivers. The use of one-time plastic products is increasing day by day. These plastics and polythene are thrown away after being used once. The polythene-plastic is falling into the river through canals, and finally gets its way into the sea through the rivers. Many river and sea species are dying by consuming tiny plastic and polythene waste as food. These tiny particles of plastic get mixed with sea water, which subsequently causes harm to aquatic species.
Deposition of polythene in the bottom of the river has a negative impact on the fisheries along with detrimental effects on the biodiversity and ecosystem of the river. Due to polythene pollution, fish are not available in the river as before and the oxygen content has drastically reduced in many rivers making the environment unworthy for fishes to survive. The layer of polythene in the riverbed has become so thick that even dredging of the river has become difficult. In rural areas, 22 percent of the plastic that ends up in rivers is used, whereas in urban areas, it is 78 percent, according to a research by the Environment and Social Development Organization (ESDO). The industry that uses plastics the most is food packaging. Every year, almost 54,000 food packages end up in the trash. Then come shampoo, paste tubes, cotton buds, and straws. Restaurants, hotels, airlines, superstores, and companies that manufacture common goods are the main users of these products.
The silting up of the Surma River because of plastic is one of the causes of the recent catastrophic floods in Sylhet. All trans-boundary rivers have experienced collapses due to the North-East India’s heavy rains. With this flood thousands of tonnes of silt and sand came through the rivers. About 26 tiny and large mountain ridges (natural canals) and water channels run through Sylhet city carrying 100 tonnes of polythene and plastic trash into the Surma River daily. The Surma River has overflowed as its bottom fills up causing water to reach the city. Thirteen Sylhet upazilas as well as a number of Sunamganj upazilas have been affected by the flooding, in addition to Sylhet city. The only explanation for this is the recent filling of all the rivers including Surma and Kushiara. Rivers throughout the country, not only those in Sylhet, exhibit the same pattern. Country’s rivers and streams in the metropolitan areas, notably the capital city of Dhaka, are the ones mostly impacted by polythene pollution. They included the Kirtankhola River in Barisal, the Turag, Buriganga, Banshi, Balu, Shitalakshya, and Dhaleshari rivers in Dhaka. In Chittagong, the Karnaphuli and Halda rivers are now covered by a thick layer of plastic.
In addition, many rivers including the Narsunda, Surma, Karatoya, Navganga, and Ichamati have plastic pollution. The Buriganga, Turag, Balu, Shitalakshya, Halda, and Karnaphuli rivers are also destroying biodiversity due to pollution. Plastic pollution threatens the life cycle of fish. Environmentalists assert that if plastic and polythene are not removed from the riverbank, flooding will occur in several places almost every year including the capital Dhaka like Sylhet.
A major dredging project was started to deepen Karnaphuli in order to save the port, but polythene has become a problem. A thick layer of polythene traps the dredger. At least 30 canals in Karnaphuli are experiencing severe polythene fallout. The work of capital dredging project has to be done slowly as a result of excess polythene in the riverbed.
Production and marketing of polyethylene was banned in 2002 under the Environmental Protection Act. The Act states, ‘Manufacture, import and marketing of polythene articles prescribed by the government shall be punishable with imprisonment for a term not exceeding 2 (two) years or with fine not exceeding 2 lakhs or with both and for each subsequent offense with a term not exceeding 2 years, the offenders shall be punished with imprisonment not exceeding 10 years or not less than 2 (two) lakh taka, monetary penalty (fine) not exceeding 10 lakh taka or both. “Selling, displaying for sale, storing, distributing, transporting for commercial purposes or using for commercial purposes is punishable with imprisonment not exceeding 1 year or a fine not exceeding 50 thousand taka or both”.
Although polythene is banned by law, its production, marketing and use still go on. Billions of polythene bags are thrown away after use every day across the country.
The main cause of river and river water contamination is polythene. The collapse of the river will soon have an effect on the economy and development of a developing nation like Bangladesh. Both the general public and the country’s policy leaders need to be aware of the need to prevent river pollution. For river contamination, the government should take appropriate action.
(Dr Kamruzzaman is Dean, Faculty of Science and Chairman, Department of Environmental Science, Stamford University Bangladesh).
