Karachi: The water being supplied to the Malir town is heavily contaminated with faecal material and is unfit for human consumption, says a research study conducted at Karachi University’s Institute of Environmental Studies.
The study has found that none of the tap water samples collected from 42 different sites in Malir contained residual chlorine, which is an effective safeguard against microbial contamination that also prevents infection from Naegleria fowleri (better known as ‘brain-eating’ amoeba) that has already claimed a dozen of lives this year so far.
At least one of the victims of the deadly amoeba was a Malir resident.
Titled Physico-chemical and bacteriological characteristics of drinking water of Malir town, Karachi, the study was recently published in an international journal. The research was conducted by Aamir Alamgir, Moazzam Ali Khan, Syed Shahid Shaukat, Omm-i-Hany, Mr Furqanullah, Mohammad Raheel Khan Abbasi, Sarang Memon and Arshad Hussain.
Under the study, water samples were collected from 42 different sites from August to October 2014. When tested, the samples were found to have relative good physic-chemical properties from the public health point of view but they failed to meet the World Health Organisation guidelines on the bacteriological quality of drinking water.
“Most of the samples were contaminated with the faecal material, therefore, potentially dangerous for human health. All the water samples failed to meet the WHO guidelines [on the bacteriological quality of drinking water]. No residual chlorine was detected from any sample,” the study says.
The presence of residual chlorine in drinking water indicates that (i) a sufficient amount of chlorine was added initially to the water to inactivate the bacteria and some viruses that cause diarrhoeal disease and (ii) the water is protected from recontamination during storage.
The findings indicate that the Gharo treatment plant located close to the Malir town is not treating the water properly. “This could be predicted by the common gastrointestinal tract problems prevalent in the town. The poor hygienic and sanitation conditions in the area are alarming,” it says.
According to the study, the reason for the faecal contamination can be the faulty and obsolete water distribution network. Water supply lines and sewage lines are overlapping one another in the area and there is permanent risk of sewage and drinking water getting mixed due to defective and old lines.
“Also intermittent water supply creates a vacuum during which impurities as well as sewage can seep in and mix with the water supply,” the study adds.
According to the study, Pakistan has one of the highest infant mortality rates in the region and one of the major factors contributing to infant mortality in the country is the consumption of contaminated water.
About 11pc child mortality is directly linked to unsafe water and poor sanitation, the study says, citing the Unicef data.
About 44pc population in the country do not have access to safe drinking water resources, it says, while referring to the Pakistan Council of Research in Water Resources data according to which more than 80pc water supplies in the country have water quality below the recommended standards for human consumption.
According to another recent report, a health department committee has found that water being supplied to most parts of the city contains less than the required amount of chlorine.
An adequate level of chlorine in tap water is believed to be an effective protection against Naegleria fowleri, a free-living amoeba found in warm freshwater environments such as lakes and rivers. It causes primary amoebic meningoencephalitis (PAM) — a disease of the central nervous system — that has been proved to be 100 pc fatal in Pakistan.
Humans become infected with the disease when water containing Naegleria fowleri enters the nose while bathing, swimming or making ablution.