‘Arsenic level in water not above permissible value’

LAHORE: The myth that the arsenic level in groundwater of the provincial capital is increasing has finally been disproved as arsenic level in the city’s drinking water is not above permissible value, but in fact falling considerably under that value.

Recently, Punjab Food Authority (PFA) along with teams of Water and Sanitation Agency (Wasa) took samples from more than 600 tube-wells and these samples were sent to Punjab University’s Chemistry Department for independent testing. The PU’s Chemistry Department released a detail report a few days back, which revealed that the levels of arsenic were contrary to the propagated belief. “Our tests are based on standard methods for testing of chemical samples with greatest possible accuracy using modern equipment available.

The instrument used for this research was ICP-OES Optima 2100 spectrometer. It is an advanced system with flexibility of conventional system and is considered an ideal solution for research and quality assurance laboratories”, said Prof Dr Muhammad Makshoof Akhtar, Director Institute of Chemistry of Punjab University. However, there may be a slight variation in the values of very low or undetectable parameters, he added.

The issue of arsenic’s presence in Lahore’s drinking water has been highlighted several times in past by various forums including media. Various surveys conducted in past claimed that the arsenic level in Lahore’s groundwater had increased about 40-80 ppb.

However, according to Pakistan Standards and Quality Control Authority (PSQCA) guidelines for drinking water, arsenic is carcinogenic contaminant and its permissible limit is 50 parts per billion (ppb).

About 640 samples of water from nine towns of the city were tested and their results were compared with the standard set by PSQCA which is 50 ppb. According to the report available with the scribe, no sample tested by the Chemistry Department overshot the permissible criterion, which disproved the myth that the level of arsenic contamination in Lahore has shot up.

While the arsenic values from an overwhelming majority of areas of the city came out to be in the range of 8-20, there were a very few that appeared approaching the bar set by the PSQCA. Parts of Aziz Bhatti Town registered values in mid twenties while only two samples from Nishtar town were tested for 45 ppb, the report revealed.

Assistant Professor Industrial Biotechnology National University of Sciences and Technology (NUST) Dr Najam-us-Sahar, when asked about the values approaching the permissible limit, said if there was a pattern of high values in the locality identifiable through a range of values proven through lab results, it is considered an alarming sign and is indicative of an industrial intrusion. However, if there are just a couple of such values in a data set of over 640, it could be a result of a very acutely localised factor which can be ignored as an outlier, he claimed.

Dr Richard Culas and Dr Michael Mitchell from Charles Sturt University (CSU)’s Institute for Land, Water and Society (ILWS) visiting Pakistan in relevance with drinking water issues, while commenting on the issue had said that the need for Pakistan to develop better techniques to ensure provision of clean water for drinking and irrigation should be a national concern and an emergent need of the hour.

When contacted to comment on the results, Wasa’s Managing Director Zahid Aziz said: “The authority had always contested previous reports claiming that Lahore’s water was a virtual arsenic dump yard, and the report vindicated us.”

“Around 1,000 arsenic removal filtration plants have been installed in Lahore, generally, two effective techniques are in practice to eliminate this hazardous substance, we are still working to establish better mechanism while increasing the plant numbers,” the MD said.

Reverse Osmosis is not feasible everywhere due to high energy consumption and water wastage, said an environmental expert, adding the second option is installation of arsenic removal filters and chlorination, which is more efficient and feasible.