Pure water is associated with life. Given that a moment without water is unfathomable and that 70 percent of an adult's body is formed of water, it is acceptable to argue that water pollution is an emergency. Bangladesh is at the forefront of the possibility that the globe may soon experience a fresh water crisis. According to a report by Asian Water Development Outlook, among 48 countries in Asia and the Pacific Ocean, river water is being polluted the most in Bangladesh. The annual International Day of Action for Rivers was held on 14th March and was devoted to preserving, honouring and raising public awareness of the value of rivers worldwide. International Rivers, a global environmental organization, established the International Day of Action for Rivers. In 1998, the first International Day of Action for Rivers was held in response to the rising threats to rivers around the world. Like Bangladesh, in other developing nations, more than 80% of sewage is discharged into rivers and other water sources without being treated, which pollutes them. We must consider water for our own survival, and we must take action at every level to prevent water contamination. As a result of pollution and encroachment, many of our rivers have become unusable.
According to a survey conducted by the Department of the Environment, the contamination level of 29 of the nation's major rivers has been exceeded. Their water pollution reaches hazardous levels, particularly from November to April, during the dry season. Another study undertaken by the Department of Fisheries and the international organisation World Fish revealed that they have become severely polluted. These rivers contain hazardous heavy metals that are damaging to human health. These two studies have uncovered some of the reasons for the persistent contamination of the country's river water. Essentially, the majority of industries located on riverbanks throw their trash into the river without treatment. Even though waste treatment machines are present in the factories, they are not utilised appropriately. Agricultural excess fertilisers and pesticides are frequently washed into rivers by irrigation runoff. This river is the largest damping ground of domestic garbage in the city, and the slums. The Department of Environment maintains 132 monitoring stations for analyzing the water quality of the major rivers. In the past two years, the survey has revealed where pollution has spread, including these locations. In addition, new polluted regions have been detected by satellite imagery and field assessments. It has been determined that unsafe amounts of water pollution exist in 29 major rivers. Recently, Investigating the Buriganga River's physiochemical status, the Center for Atmospheric Pollution Studies (CAPS) discovered that the river has a very high biological oxygen demand (BOD) but very low dissolve oxygen (DO) level which means that the aquatic environment of the body of water is very unfriendly to its living habitat.
In 2010, at the direction of the High Court, the Department of Environment prepared an assessment on the water quality of the country's major rivers. According to the analysis of the study, the oxygen content of the Buriganga, Shitalakshya, Turag and Balu rivers is nearly nonexistent. During the dry season, there is almost minimal oxygen. There must be at least five milligrammes of oxygen per litre of water for fish and other aquatic life to survive. The government has however punished polluting industries. The government utilised funds to protect the river and relocated the leather industry from Hazaribagh to Savar. According to an analysis by the Asian Development Bank (ADB), Bangladesh is in a precarious position. Bangladesh, along with India and Pakistan, is in the most vulnerable position on the national water security index. Dumping sewage without treatment has resulted in widespread chemical contamination of waterways.
Bangladesh ranks sixth among the nations utilising extra underground water for agriculture, whereas India ranks top. This excessive usage or reliance on groundwater threatens the environment. As a result of excessive electric irrigation systems and deep tube wells, the water table is approaching a perilous level in many regions of the country, including North Bengal. From household to economic and environmental perspectives, the global population faces a massive water shortage. Bangladesh's Buriganga is the most polluted river in the country. Along with the Buriganga, the water of the Turag, Balu, Dhaleswari, and Shitalakshya has become so filthy that fish cannot survive in the majority of locations. If the water in the Sadarghat neighbourhood of Dhaka is tainted by its colour and odour throughout the winter, then these rivers can be converted into large-scale sewers or drains. Daily, 4,500 tons of rubbish and 5.7 million gallons of filthy water flow into the waterways surrounding the capital, according to a Department of Environment report. Outside of the capital, manufacturers are expanding in Ashulia, Savar, New Leather Industrial Zone, and Tongi. Rapid industrialization exists on the banks of the Karnaphuli in Chittagong, near to the Mawa Ghat on the Padma, and on the banks of the Meghna. The majority of these industries do not use waste treatment technology, according to the research. In excess of the standard, heavy metals such as chromium, iron, and zinc were detected in several rivers. The standard set by the World Health Organization is 5,5 micrograms per litre. In some rivers, however, 8.8 to 8.2 micrograms per litre were detected.
Agriculture-related chemicals and pesticides cause river water contamination. Using this contaminated water causes damage to the brain and reproductive organs. Polluted river water enters the food supply through the food manufacturing process. The result is physical disabilities and malnutrition among children. Consuming contaminated water causes damage to the brain and reproductive system. The kidney and liver are most severely impacted. Asthma, heart illness, physical disability, and other water-borne disorders affect children.
The major significant water sources are becoming increasingly polluted and harming the living world. Moreover, incidents involving oil tankers in locations with abundant natural resources, such as the Sundarbans, pose a grave threat to the biodiversity of these regions. These rivers contain hazardous heavy metals that are damaging to human health. Essentially, the majority of industries located on riverbanks throw their garbage into the river without treatment. Agricultural excess fertilisers and pesticides are frequently washed into rivers by irrigation runoff. In addition to raising public awareness to avoid river pollution, the government should develop and implement stringent policies.
The writer is the Dean, Faculty of Science, Stamford University Bangladesh. E-mail: [email protected]
