Cancer-causing 'forever chemicals' in Dhaka water sources: Study

Potentially toxic PFAS chemicals, commonly referred to as "forever chemicals," have been detected in rivers, lakes and tap water in Dhaka, as well as in clothing, posing significant health risks, a recent study says.

Findings of the study titled "Persistent Threat: PFAS in textiles and water in Bangladesh," jointly conducted by the NGOs Environment and Social Development Organisation (ESDO) and International Pollutants Elimination Network (IPEN), were revealed at ESDO's Dhaka office today (29 May).

PFAS, or per- and poly-fluoroalkyl substances, are a group of chemicals often called "forever chemicals" because of their persistence in the environment. These chemicals are used in industries to make products nonstick and oil- and water-repellent.

Researchers said exposure to these chemicals above a certain level can cause cancer, birth defects in the unborn, weakened immunity and liver damage. They can also affect thyroid hormone function. 

In the study, 31 samples collected from a total of 8 areas of Dhaka in 2019 and 2022 were tested. The presence of PFAS was found in 27 of 31 surface water samples (87%). Of these, 18 samples (58%) contained one or more of the globally banned PFAS chemicals PFOA, PFOS, and/or PFHxS, and 19 samples (61%) had PFAS levels exceeding the proposed EU regulatory limit.

Some of the substances have been banned globally, while some others are under review to be banned.

Siddika Sultana, executive director of ESDO in Bangladesh, said, "Bangladesh is an international textiles manufacturing hub, and the prevalence of toxic chemical emissions from the sector puts residents at higher risk."

In 2019, PFAS chemicals were detected in the Karnatali River in Savar with levels more than 300 times the proposed EU limit. The sample also had the highest level of two banned PFAS substances, more than 1,700 and 54,000 times above current Dutch advisory limits.

Another sample collected from Hatirjheel Lake in 2022 also contained both PFOA and PFOS, the latter testing at 185 times above the current Dutch advisory level for PFOS. Three of the four tap water samples from 2019 contained PFAS and tested above the US PFOA threshold for drinking water.

In the study, PFAS was detected in all five clothing items sampled, with one men's jacket containing the globally banned chemical PFOA.

Dr Shahriar Hossain, senior policy and technical adviser for ESDO and lead author of the study, said, "PFAS in our waterways, tap water, and clothing pose serious health and environmental threats, yet industry and policymakers have been slow to respond." 

Public health expert Dr Lenin Chowdhury called for raising awareness among people regarding the harmful effects of PFAS substances.

"PFAS chemicals are harmful to human health. Since these are more common in industrial areas, measures should be taken to stop their use," he told The Business Standard.