HK rivers among world’s most drug polluted

Hong Kong’s Kai Tak and Lam Tsuen rivers have been ranked the 29th and 70th most polluted rivers in the world, according to a global study on pharmaceutical pollution.

Scientists measured the concentration of 61 active pharmaceutical ingredients along 258 rivers across the globe, and found that more than a quarter of them contain “potentially toxic levels” of over-the-counter and prescription drugs.

Hotspots with very high levels of contaminants include Lahore in Pakistan, La Paz in Bolivia, Addis Ababa in Ethiopia and India’s Delhi.

Only two places were unpolluted – Iceland and a Venezuelan village where the indigenous people do not use modern medicines.

Kenneth Leung, the director of the State Key Laboratory of Marine Pollution at City University of Hong Kong, was one of the more than 100 researchers who contributed to the study.

He said the SAR needs to do more to clean up its waterways, with the Kai Tak and Lam Tsuen rivers being named the 29th and 70th most polluted.

Water samples from Kai Tak also contained 34 pharmaceutical ingredients – the most of any waterways studied.

Leung explained that these drug pollutants end up in rivers after being consumed by people and excreted into the sewage system.

“Most importantly, the sewage treatment plant cannot remove all the chemicals in the sewage, so in our study many chemicals are actually very persistent in the sewage,” he said

“This is telling us that we have to do something, we have to control the use of the pharmaceuticals and also enhance the treatment ability, capacity, in our sewage treatment plants.”

Leung said these compounds do not just hurt the ecosystem, they also substantially drive up the risk of drug resistance and can lead to the creation of “superbugs”.

The professor urged people not to flush their expired medication down the toilet, saying they should send drugs back to clinics so they can be disposed of properly.

Leung added that he hopes the government’s plan to upgrade the territory’s sewage treatment plants will alleviate the pollution problem.