A study conducted by the Institute of Public Health (IPH) on Dhaka's water quality found that 94% of water in sidewalk tea shops contained faecal bacteria.
Additionally, 44% had other bacteria, and 29.4% exceeded acceptable levels of heavy metals, the study revealed.
Experts warn that these harmful bacteria and metals can lead to life-threatening diseases when people are exposed to them.
Dr Nasir Uddin Mithu, director of the institute, said: "While this study was carried out before my tenure here, and due to the critical Covid-19 situation, it wasn't initially published or publicized. Nonetheless, this research is crucial as it provides valuable insights into Dhaka's water quality. By ensuring safe water, we can significantly reduce health issues among Dhaka residents."
Institute of Epidemiology, Disease Control and Research (IEDCR) former chief scientific officer Dr Mushtaq Hossain said: "Urbanization has surged in the country, but safe water availability has not kept pace. Consequently, city dwellers have resorted to tapping into water supply lines. When water pressure is low, sewage can mix in, carrying dangerous bacteria like E-coli."
"Using contaminated water introduces harmful germs that cause severe diseases like stomachaches, hepatitis, jaundice, and typhoid into the body. Drinking unsafe water not only affects health but also leads to financial hardship. Many who consume this water may not show immediate symptoms, but it damages the digestive system and can lead to serious illness," he added.
According to the study, the water collected by shopkeepers in the capital comes from various sources: 31.4% from rickshaw-vans, 28.8% from motor vans, 19.9% from deep tube wells, 14.7% from Wasa and 5.1% from other sources.
Pathologist Dr Mushtaq Hossain pointed out that those supplying water in jars under the guise of filtered water are essentially deceiving consumers.
He stressed the need for legal action against such practices.