Independent studies have detected antibiotics and hormone-disrupting substances in Ho Chi Minh City's tap water due to the lacks of a system to monitor or decontaminate it, Saigon Tiep Thi Online reported.

A study conducted by Associate Professor Nguyen Tan Phong of the HCMC University of Technology and partners in July detected nonylphenol ethoxylates at the Tan Hiep Water Plant and in tap water samples collected throughout the city.

The chemical group is commonly used in detergents and is considered very toxic to fish and other water-dwelling organisms due to its hormone-disrupting properties.

The survey found concentrations of 28-54 ng/l of the substances in tap water collected from several locations.

In a toxicity test, researchers used untreated water collected near the water plant’s source to test on zebra fish and micro crustaceans.

Half of the fish and crustaceans died to toxins in the water.

The nonylphenol ethoxylates-contaminated water was found near factories and in upstream tributaries and reservoirs along the Dong Nai River, which feeds the plants that supply tap water to millions of people in HCMC and the nearby areas.

Another study by Nguyen Dinh Tuan, former director of the HCMC University of Natural Resources and Environment, found high concentrations of antibiotics and nonylphenol ethoxylates in the Dong Nai River.

Since the city's water treatment plants have no systems to remove antibiotics, it's highly possible they will end up in tap water, researchers said.

Earlier, the Health Ministry also announced that three water plants in HCMC supply water that contains high levels of manganese and iron in addition to microorganisms.

No criteria for new pollutants

According to Tuan, the former director of the HCMC University of Natural Resources and Environment, the antibiotics and hormone-disrupting substances the scientists found are new pollutants that are not well-monitored or screened due to the prohibitive cost of doing so.

Hoang Thi Thanh Thuy, a member of Tuan’s research team, said the long-term presence of antibiotics could lead to the development of resistant bacteria.

Meanwhile, Do Hong Lan Chi of the Environment and Natural Resources Institute said nonylphenol ethoxylates could cause genetic problems in human, especially among children and teenagers.

“They can cause deformities among newborns, hormonal imbalances and increase one's risk of cancer,” she said.

According to associate professor Nguyen Huu Duc of HCMC University of Medicine and Pharmacy, the city's existing water plants can't screen for or eliminate antibiotics, which can affect the human liver and kidneys.

“Only chemical treatments can render them harmless,” he said.

Dang Ngoc Chanh of the HCMC Institute of Hygiene and Public Health, said Vietnam should issue criteria for antibiotic concentrations in waste water.

“The government needs to follow up and make sure people follow these guidelines,” he said.

“Meanwhile, water treatment plants should be upgraded with new technology because they are drawing water from polluted sources."