Toxic chemicals used in textile, ship-breaking, oil refinery, cosmetics, cleaning agent, and other industries have been found in Dhaka's tap water that may expose the human body to health hazards, including cancer.
The chemicals include perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), two widely-used chemicals in the industrial sector worldwide and have been detected in both surface and tap water in Dhaka, says a report.
Experts have called for immediate action to eliminate these chemicals from the city's water supply to protect people from life-threatening diseases.
Tap water samples were collected from Lalmatia and Banani areas of Dhaka and Panpara Bazar in Savar in 2019 and tested in the laboratory of Brown University, USA as part of the Environment and Social Development's (ESDO) "PFAS Bangladesh Situation Report 2020".
The report found 8 parts per trillion (ppt) of PFOA in samples taken from Lalmatia, 6.8 ppt in Panpara and 5.18 ppt in Banani.
As for PFOS, 2.3 ppt was found in Lalmatia's sample, 2.6 ppt in Panpara and less than 1ppt in Banani.
PFOA and PFOS are two chemicals of the per- and polyfluoroalkyl substances (PFAS) chemicals group. More than 4,500 manmade chemicals belong to the PFAS group.
The ESDO tried to identify the most harmful 13 chemicals of the PFAS group in tap and surface water in Dhaka and its surroundings.
Dr Gholam Mostafa, chairman of the Dhaka Wasa Board, told The Business Standard that Wasa will fix the next course of action after scrutinising the report.
"We have not received the report yet. We will send the report after collecting it to our relevant departments to fix the next course of action," he said.
In 2017, the Stockholm Convention Persistent Organic Pollutants (POPs) Review Committee noted the link between PFOA and serious illnesses in humans, including high cholesterol, ulcerative colitis, thyroid disease, testicular cancer, kidney cancer, and pregnancy-induced hypertension.
PFOS is extremely persistent and has shown no degradation under any environmental condition that has been tested. These two chemicals along with other PFAS together cause more dangerous effects in human health.
Humans can be exposed to PFOA and PFOS from air, water and food and from their surrounding occupational environment.
Findings of the report are a warning
Experts said that the detection of PFAS – including PFOS and PFOA – in Dhaka's tap water is a warning as these chemicals are highly persistent and can cause serious threats to human health. They said the amount of these chemicals will increase in soil, water and air unless proper action is taken.
They called for eliminating the use of these chemicals from different kinds of products and their related industries.
PFOS and its related substances are used in a variety of products and processes including firefighting foams, carpets, leather goods, upholstery, packaging, industrial and household cleaning products, pesticides, photographic applications, semiconductor manufacturing, hydraulic fluids, catheters, and metal planting.
PFOA is used to make non-stick pans, and is found in different products including textiles, fire-fighting foams and medical devices. PFOA-related compounds, including side-chain fluorinated polymers, are used as surfactants and surface treatment agents in textiles, paper and paints, and firefighting foams.
Dr Abu Zafar Mahmood, former chairman of the Department of Chemistry, Dhaka University, said, "PFAS chemicals are highly dangerous. They affect the human body from blood to brain. They can create cancer. We know almost all the bad consequences of heavy metals like mercury and lead. But the total diversity of danger of PFAS exposure is not fully identified. These chemicals attack infants before their birth."
Siddika Sultana, executive director of ESDO, said, "We do not clearly know in which products these chemicals are being used in Bangladesh as we do not have any source detection research in this regard. Generally, oil refineries, power-generating sites, ship-breaking sites, cosmetics industries, timber, dying and painting, paper and pulp production, cleaning agents, waxes and floor polish, firefighting foams, PVC and rubber industries, and photographic industries, use these chemicals."
"We detected these chemicals in the tap water of Dhaka Wasa. High concentrations of them have been found downstream from the Dhaka EPZ, which suggests these chemicals are coming to the environment from the industrial units of DEPZ," she said.
The United States Environmental Protection Agency has established the health advisory levels for the chemicals at 70 ppt.
In this regard, Siddika Sultana said, "Western countries damaged their environment due to reckless industrialisation. Now they are shifting hazardous industries like textile and ship-breaking to Third World countries to keep themselves safe from these toxic chemicals. We may stand in a far better position compared to them in case of PFAS, if we start eliminating these chemicals from now."
"At first, we have to identify the sources properly and then we have to take steps to eliminate these chemicals before it is too late," she added.
"We were the first country in the world to ban polythene shopping bags. We can create another example by banning PFAS and the products that contain it," she further added.
The European Union regulated the use of PFOA and PFOS, and different states of the USA have fixed different limits of PFAS level in drinking water. Six major US companies have also voluntarily stopped producing PFOA and PFOS in the US, so far.
PFAS in surface water
Surface water also contains a high amount of these chemicals as 515.2 ppt of PFOA and 381.9 ppt of PFOS have been found in the water of the River Karnatoli in Savar, just downstream from the textile manufacturing zone of Ashulia. However, 70.63 ppt of PFOA and 91.92 ppt of PFOS have been found in the river near the Bank Town area of Savar.
In the samples of the River Turag, 85.96 ppt of PFOA have been found in the middle of the River Turag.
Along with these two widely used PFAS chemicals, 10 other most dangerous chemicals were also found in all the samples collected from both tap water and surface water of these areas.
The Stockholm Convention on Persistent Organic Pollutants decided that countries must take measures to eliminate the production and use of PFOA and must take measures to restrict the production and use of PFOS.
Before deciding on any chemical, the Persistent Organic Pollutants Review Committee (POPRC), an expert committee of the convention, conducts three technical assessments. If the chemical passes the first three stages, the POPRC may recommend it to the fourth stage for considering the listing by the Conference of the Parties to eliminate or restrict the chemical's production and use.
Bangladesh is a signatory of the Stockholm Convention but the country has yet to ratify the decision of including PFOS and PFOA as persistent organic pollutants. However, the Department of Environment is hopeful to ratify it along with some other chemicals within six months.
Mirza Shawkat Ali, director (Climate Change and International Convention) of the Department of Environment, said, "The Stockholm Convention has recently included these chemicals as persistent organic pollutants. We hope to ratify these newly-included chemicals within six months. Then we will formulate legal provisions to regulate and eliminate the production and use of these chemicals."
"These chemicals are really harmful to human health," he admitted.