Bangladesh stands at a critical juncture as rapid urban population growth places unprecedented stress on our sanitation infrastructure. Urbanization has hampered the coverage of our sewage systems and has caused surface water to be grossly polluted. This development is dangerously unhealthy, as a large number of populations survive on dirty water for their everyday activities.
In Dhaka, the urgency of the crisis is particularly stark. Despite some progress, 61% of households now have access to improved sanitation, untreated wastewater is still frequently discharged into the city's drains and rivers. About a third of the city's inhabitants have pour-flush toilets connected to the drains. A further 30% use septic tanks that are prone to fail and discharge effluent directly into the city's surface waters. The gross environmental mismanagement has brought about astronomically high levels of fecal coliform bacteria in the open drains in Dhaka, aggravating the health situation by introducing higher levels of pollution in the water sources.
The regular floods and waterlogging that Dhaka experiences is a result of its low-lying topography, dense population, and quick urban growth, all of which exacerbate the issue. Proximity to multiple rivers, insufficient drainage infrastructure, and heavy rainfall all contribute to stagnant water that frequently mixes with sewage. The risk of contracting watery illnesses including cholera, dysentery, and typhoid is greatly increased by this contamination. Due to Dhaka's dense population, disease-causing bacteria spread more quickly, placing a great deal of strain on the healthcare system and resulting in large financial losses, decreased productivity, and a decline in overall quality of life.
In urban settings, direct contact with infected drain or flood waters, as well as exposure to contaminated surface water while bathing or using household items, are the main ways that waterborne infections spread. Communities are more susceptible to waterborne illnesses as a result of these exposure pathways, underscoring the necessity of thorough evaluations of the health concerns connected to contaminated surface waters. This is especially important in cities since there are many different ways for humans to become infected by viruses. We have used Quantitative Microbial Risk Assessment (QMRA) in our latest work to show how serious this problem is. In Dhaka's impoverished and slum regions, the study discovered startlingly high incidence of gastrointestinal ailments connected to tainted water. Children are more vulnerable since they inadvertently consume more water. Three-quarters of all illness cases occur each year in surface water, with open drains accounting for 34% and floodwater for 29%. Improved sewage treatment is desperately needed, as evidenced by the projected 16,276 illness occurrences each year that result in 2,441.4 Disability-Adjusted Life Years (DALYs).
The Dhaka Water Supply and Sewerage Authority (DWASA) faces a significant challenge. According to a study in 2014, E. coli bacteria were found in 63% of the city's water supply, which exposed a malfunctioning distribution network and badly run sewage facilities. Multidisciplinary evaluations of DWASA's water production are lacking, which heightens worries regarding microbiological safety. With groundwater levels depleting rapidly, DWASA plans to shift from groundwater to surface water sources for drinking water. However, rivers near Dhaka are heavily polluted with chemicals, microbes and industrial waste. DWASA's plan is to source water from more distant, less polluted rivers up to 60 km away-reflects the severity of the problem. Our study indicates that water from these distant rivers is also unsuitable for drinking water production and bathing, especially after extreme rainfall events. Substantial improvements in microbial water quality through adequate sewage treatment are essential to continue drinking water production using raw water from any of the rivers.
These issues are further made worse by climate change. Elevated temperatures and precipitation are anticipated to worsen fecal pollution and increase the likelihood of disease outbreaks. Even if the hazards are relatively manageable today, projections for the future indicate that the situation will probably get worse due to continuous population pressure and climate change.
Make large investments in wastewater treatment to meet these difficulties. The three most important actions are to upgrade drainage infrastructure, upgrade sewage management systems, and enhance surveillance and monitoring. In addition to investing in new treatment facilities, the interim government must impose stronger restrictions for the treatment of domestic wastewater. There is hope that the government's recent commitment to fight corruption will lower prices for infrastructure projects like wastewater treatment, which have been driven up over the last 16 years by corruption.
Our study outcomes emphasize the need for targeted public health interventions to reduce the burden of waterborne diseases. Improving water quality and sanitation infrastructure, especially in areas with high exposure to contaminated surface water, should be a priority. To achieve the SDG 6 targets (ensuring safe water and sanitation) by 2030, where we are lagging behind, sewage treatment capacity improvement projects must be undertaken and implemented urgently. Some of the dangers can also be reduced by educational efforts that encourage safe water habits, lessen unintentional water ingestion, and prevent direct contact with flood and drain water. Furthermore, as children are more vulnerable as a result of larger exposure volumes, therapies should be specifically designed to address this susceptibility.
Above all, reversing the deterioration of surface water quality is an urgent public health issue as well as an infrastructure problem. To control the dangers related to wastewater exposure, public health authorities, urban planners, and community stakeholders must work together in a concerted effort. In our fast urbanizing cities, we can enhance public health outcomes and drastically lower the burden of waterborne diseases by putting comprehensive water and sanitation measures into place.
The writer is a member of BCS (Administration) and Director, Anti-corruption Commission
