Almost through out the winter season, Lahore was named one of the most polluted city across the world due to heavy smog. Now, another report has found the river flowing through Punjab's capital is among the world's most polluted rivers, with active pharmaceutical ingredients posing a ‘threat to environment and human health’, according to a BBC report.

The study was conducted at the University of York on pharmaceutical pollution of the world’s rivers and published by Proceedings of the National Academy of Sciences of the US, read the report.

The study detected pharmaceutical particles including paracetamol, nicotine, caffeine and epilepsy and diabetes drugs in the rivers and stated the impact of many of the most common pharmaceutical compounds in rivers is still largely unknown.

According to the study, waterways in Lahore, Bolivia and Ethiopia are among the most polluted, while rivers in Iceland, Norway and the Amazon rainforest fared the best.

Samples for study were collected from more than 1,000 test sites in more than 100 countries.

Overall, more than a quarter of the 258 rivers sampled had what are known as "active pharmaceutical ingredients" present at a level deemed unsafe for aquatic organisms, read the report.

After the report surfaced, social media users expressed concerns over the toxic water flowing in the river, with one user saying the main source of contamination of the Ravi River is wastewater drains that flow into it.

Another mentioned scarcity of clean drinking water and asked authorities to resolve issue of water pollution in the river which was causing "many diseases".

Talking about reasons of the water pollution, another used said: "The overall status of water quality is very polluted, primarily due to residential and industrial wastewater directly discharged into the Ravi River through a network of drains."

Another user said "discharging municipal sewage" in the river was "constantly polluting the ground water".