High levels of lead, arsenic found in Indus River bodies: study
KARACHI: The Indus River bodies from the northernmost territory of Gilgit-Baltistan to the lower parts of Sindh are getting contaminated with high levels of lead and arsenic, according to a study.
The yet-to-be published study has been conducted by Dr Fahim Siddiqui and Dr Mohammad Uzair Khan, currently associated with Karachi University, Dr Kanwal Nazim of the Sindh forest department and Adam Khan, a PhD student of the Federal Urdu University for Arts, Science and Technology (Fuuast).
Prof Moinuddin Ahmed, a former foreign faculty member of Fuuast and presently associated with the department of Earth and Environmental System of the Indiana State University, the US, was their research supervisor.
Under the study, 70 water samples from 70 different locations of the upper Indus basin, glaciated valleys, and nullahs from the Gilgit-Biltistan area including the Indus River from Skardu to Hyderabad, Sindh, were collected. The highest sampling elevation was 4,683 metres near Khunjrab Pass and the lowest about 76 metres near the Hyderabad city.
According to the study, amounts of arsenic and lead are increasing in the water of the Indus at an alarming rate.
At 24 places, water coming from glaciated valleys or nullahs showed zero amount of arsenic while some nullahs contained arsenic with levels between 36.36µg/l and 163µg/l. At other places, the arsenic level was: rivers from Gilgit to Khunjrab 394.6µg/l to 399µg/l, Gilgit to Dosai plains 259µg/l to 300µg/l, Skardu to Gilgit 394µg/l to 400.9µg/l and Gilgit to Chitral 385.5µg/l to 396µg/l. They all contributed water to the Indus River that contained arsenic ranging from 385.4µg/l to 400.4µg/l.
Also similar levels of lead were recorded in the Indus. In 37 samples, it was less than 1,000µg/l, while the rest had levels between 2,060µg/l and 2,500µg/l.
The physical parameters of the water samples were analysed by Dr Kanwal Nazim with the help of Hanna multi-parameter at the Sindh forest department while heavy metals were analysed by the KU staff at the university’s centralised laboratory.
Dr Uzair Khan, who works at the KU marine reference collection and resource centre, said: “The permissible limit of arsenic and lead in drinking water according to WHO standard is 0.01mg/l (10µg/l) for arsenic and 0.01mg/l (10µg/l) for lead.”
Prof Moinuddin Ahmed said: “The levels of contamination shown in this report are very alarming. The arsenic levels in the Indus River are twice the levels reported in Bangladesh in the late 1990s, eight times higher than the national limit and 40 times greater than the internationally accepted level.”
He said the situation warranted urgent attention of policymakers and scientists. About the sources of contamination, Prof Ahmed said it was a small-scale study and, to explore the origin of these two toxic metals, more extensive sampling and analysis was required.
“Eighty per cent of Pakistan’s agricultural and domestic needs are dependent upon the Indus water. Hence, any contamination in this water would have far-reaching environmental and health implications,” he noted.
The study would be published in a scientific journal with detailed maps, sampling sites and results, he said.
The project conceptualized by US-based Empower the Future, an non-governmental organization working towards environmental awareness and sustainable economic development, was funded by Geolink (Pvt) Ltd.
Prof Ahmed, who earlier worked at Fuaast laboratory of plant ecology and dendrochronology, also has to his credit a research titled Five Centuries of Upper Indus River Flow from Tree Rings. Published in the Nature Geoscience in 2012, the study showed that Karakorum glaciers, in contrast to the widely held opinion that glaciers are fast melting on account of climate change, have grown over the last decade. It was the first paper that traced the Indus River flow over the past five centuries with the help of tree-ring chronologies.
“Long-term exposure to arsenic from drinking-water and food can cause cancer and skin lesions. It has also been associated with developmental effects, cardiovascular disease, neurotoxicity and diabetes,” says the WHO website.
Lead, according to experts, is a cumulative toxicant that affects multiple body systems and is particularly harmful for young children. “Its widespread use has resulted in extensive environmental contamination, human exposure and significant public health problems in many parts of the world,” adds the WHO website.