Over 60m Pakistanis at risk of arsenic poisoning from contaminated groundwater: Study

The high-risk area mapped out in the study broadly covers the middle and lower reaches (Central Punjab, South Punjab, upper Sindh) of the Indus River and its tributaries, before they empty into the Arabian Sea.

Irshad Salim — Some 60 million are at risk of arsenic poisoning from contaminated groundwater in Pakistan’s Indus Valley — far more than previously thought, according to a new study.

The potential high risk figure, according to the findings, is more than a third of the 150 million already estimated by the World Health Organisation (WHO) to be drinking, cooking and farming with arsenic-laced water worldwide.

The findings were published on Wednesday in the journal Science Advances.

“Pakistan is aware of the growing problem, with arsenic levels rising in some areas,” said Lubna Bukhari to AP, who heads the government’s Council for Research in Water Resources.

“It’s a real concern,” she said. “Because of lack of rules and regulations, people have exploited the groundwater brutally, and it is driving up arsenic levels.”

Some local independent observers said the number of people at risk could be as high as 80m –even 90m, with majority in the heartland — Pakistan’s largest province of Punjab.

Arsenic concentrations measured in Pakistan groundwater — Arsenic exceeds the WHO guideline of 10 μg/liter in large parts of the Indus plain. The green to brown coloring illustrates the topography. The Indus River and its major tributaries as well as the major cities are indicated. The samples were collected for this study (n = 1184) between 2013 and 2015.

The authors of the study developed a map highlighting areas of likely contamination based on water quality data from nearly 1,200 groundwater pumps tested from 2013 to 2015, and accounting for geological factors including surface slope and soil contents. They determined some 88 million people were living in high-risk areas.

Given that about 60-70 per cent of the population relies on groundwater, they calculated that roughly 50 million — maybe even 60 million — were potentially affected. That’s equal to at least a third of the 150 million already estimated by the World Health Organisation (WHO) to be drinking, cooking and farming with arsenic-laced water worldwide.

“This is an alarmingly high number, which demonstrates the urgent need to test all drinking water wells in the Indus Plain,” with hotspots around the densely populated cities of Lahore and Hyderabad, said the study’s lead author, Joel Podgorski, of the Swiss Federal Institute of Aquatic Science and Technology, known as Eawag.

The high-risk area mapped out in the study broadly covers the middle and lower reaches (Central Punjab, South Punjab, upper Sindh) of the Indus River and its tributaries, before they empty into the Arabian Sea.

Scientists had expected this area might be affected.

Normally, that arsenic would stay in the ground. But in the last few decades, South Asian countries concerned with pathogen-infused surface water have been pumping enormous volumes of groundwater, causing the water tables to drop drastically and tapping into new water pockets tainted by the colorless, odorless toxin. The WHO considers arsenic concentrations above 10 micrograms per liter to be dangerous. Pakistan’s guideline is five times that, and many of its wells test much higher.

Arsenic is naturally occurring and kills human cells — causing skin lesions, organ damage, heart disease and cancer. There is no cure for arsenic poisoning.

“This study is important because it draws attention to an overlooked — yet solvable — problem of vast magnitude affecting the health of millions of villagers,” said geochemist Alexander van Geen of Columbia University’s Lamont-Doherty Earth Observatory, who was not involved in the study. He said the patterns it identifies are broadly consistent with data he and other researchers have collected from some 10,000 well tests in the region.

One of those researchers, Abida Farooqui, assistant professor of environmental sciences at Islamabad’s Quaid-e-Azam University, said the new study’s sample size may be too small to draw clear conclusions.

One Comment

  • Ch Naseer Ahmad Ex-MD WASA Lahore says:

    Though arsenic is an issue in moet of the areas identified in the report yet in most of the cases th e concentration of arsenic is less than 50ppb as per relaxed standered for south asia fixed by WHO.Even Pakistans water quality standards also limit it to 50 ppb.In my opinion biological cotamination is a serious issue for pakistan as most of ground water contain feacal coliform.Major reason beinig that all the raw sewage both domestic as well as industerial is disposed in to rivers/revines untreated.Unfortunately not a single functional waste water plant exist in Pakistan.Since WASH sector is not a priority area of any of Federal or provincial governments not neing a cosmetic project therefore this area is totally neglected.An other reason is overmining of ground water much more than the recharge.Lahore will be in big trouble in comming year as ground watet is dratically depeleting due to over extraction.Water table in Gulberg,Anarkali,Ichara,Shadman and adjoining areas is in red zone where water level is155 meter as compared to 210 meter near Ravi Syphon.Lot of studies have conducted for construction of WWT and shifting of water source at upper reaches where water table is high but Govt is only interested in cosmetic projects having visual effect.No planned investmet has been made in this sector till todate.In contrast almost all the world made huge investment in WASh Sector from1985 to 2015.

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