High level  rivers’ contamination badly impacting fish populations, can spread cancer among humans

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By Adeel Saeed

PESHAWAR, Dec 20 (APP):Researchers working on a project to analyze endocrine disrupting chemicals and types in Kabul and Swat rivers have warned that high level contamination in both the rivers is badly impacting fish populations.

“Our research studies during the project found high concentration of phthalates, dissolved form of plastic, which is badly affecting fish health and diversity in both the major rivers of Khyber Pakhtunkhwa,” informed Dr. Bushra Khan, Associate Professor, Environmental Science Department University of Peshawar.

Dr. Bushra has recently completed a three- year project titled as `Endocrine Disrupting Chemicals (EDCs) in Kabul and Swat Rivers and their impact on Fish Population and Rural Community Livelihood’. 

The project is jointly carried out by the Environmental Science Department University of Peshawar in collaboration with Purdue University Indiana (USA). The project helped four students in Pakistan to do research for PhD studies and four MS. While three students in the USA are doing PhD and three MS on the basis of research and analysis in this project. 

Talking to APP, Dr. Bushra informed that project research found high concentration of phthalates in both the rivers, mostly in Kabul, which is affecting fish population by damaging the reproduction capability of fish due to hormonal changes. 

Phthalates, she continued, are known carcinogen which are not only causing decline in fish population but also can spread cancer among humans because this water is used for irrigation and can enter into the food chain. Water sampling from eight locations in Kabul river, from Warsak to Attock and 12 locations from Madyan, Panjigram to Landakay at Swat river in two seasons, summer and winter, found more than two dozen types of chemicals including pesticides, pharmaceuticals, contaminated sediments etc. 

The phthalates which are also known as plasticizers were of different types including Benzyl Butyl, Di nonyl, Diethyl, Diisobutyl, Bis and others. Bisphenol A, another plasticizer known to disrupt the endocrine system, was also found in most of the samples but at lower concentration than phthalates. 

These chemicals are getting accumulated in river water due to discharge of untreated effluent of more than 100 small and large scale industries besides municipal waste of different big cities including Swat, Mardan, Charsadda, Peshawar and Nowshera, Bushra opined. 

Due to bad impact on fish health, the number of fish species in Kabul river has been reduced from existing 59 to less than half, she disclosed. The decline in fish population is also affecting the livelihood of hundreds of thousands of people living near embankments and engaged in the business of fish catching and selling,
she added. 

Sharing the data about concentration of different chemicals in river Kabul and Swat, Dr. Bushra apprised that phthalate ranged from 200-900 ppt during high flow and 400-1000 ppt during low flow. The total pharmaceutical concentrations ranged to 10 ppt during high flow and 800 ppt during low flow. 

Heavy rains during the monsoon season bring additional chemicals such as herbicides and pesticides used in agriculture. “Between 2018 and 2019, a total of 121 fish belonging to six species were sampled and processed,” informed Sabah Shaukat, a student of the Environment Department doing PhD by holding research in the project. Scarcity of fish population in these rivers could be gauged from the fact that “we did not collect the same fish species from all sites within each river system, “Sabah informed APP.

 Due to phthalates presence as dominant endocrine disrupting chemicals in the water, the fish examined
were mostly found to have defective reproduction systems due to hormonal changes, she added. In some fish we could not be able to differentiate their gender, she hastened to add. During the project, 445 household surveys were also conducted to evaluate how water quality and quantity has impacted the livelihood of water users. 

The data shows that livelihood in this area is significantly shaped by changes in water quality and quantity as all interviewers reported a substantial decrease in the fish number and size. While households reported diversifying their livelihoods, changing water sources and increasing their agriculture input in response to increasing social-ecological change and water stress. Dr. Bushra, who is Principal Investigator from the Pakistan side, also warned that if water from the River Kabul is used for human consumption without proper treatment, it will prove to be much detrimental for human health. 

She said the KP government was  planning to launch a scheme for supply of drinking water from Kabul river to the population of its provincial metropolis, Peshawar. Before execution of the project, proper steps needed to be taken for evaluating quality of the water and treatment of waste water before dumping into river water, she stressed.

In Khyber Pakhtunkhwa there was no facility for treatment of waste water which was entering into rivers without getting any treatment as a result of which water was getting much contaminated, badly impacting aquatic biodiversity as well as human health besides environment.

About the project suggestions, she said, it mainly focused on proper treatment of wastewater before entering into rivers. There is also a need to design a National River cleaning strategy as rivers in other provinces are also serving as waste dump thus affecting aquatic flora and fauna besides endangering human health and environment as well. The project also suggested holding more studies in these river systems to determine the ultimate cause of fish population decline.