Daily Times

Pakistan is a home to 207.8 million people. It is the 6th largest populated country in the world. The majority of Pakistanis are living in rural areas (62.5 percent households) and providing food for domestic consumption and export. Agriculture contributes to about 25 percent to the national GDP(Gross Domestic Product) and employs around 46 percent of the labor force. Therefore the fertile land and freshwater attracted 70 percent of the population to live in the Indus river basin (IRB). 60 percent of them are living in densely populated rural areas (415 person km-2). These rural areas are swiftly merging into expanding cities. This merging is also due to concentrated land ownership of the areas in the IRB. Just two percent households own nearly half of the area. 43 percent of the area rural population is unable to do independent agriculture either due to landlessness or lack of other agricultural inputs.

The IRB stretches in the north from the mountains of Himalaya, to the South, in the plains of Sindh. The IRB covers 1.12 million km2 of Southeast Asia (54 percent of total area). Its largest part, 47 percent, is in Pakistan. The rest is distributed in India 39 percent, China,8 percent and Afghanistan 6 percent (See Table1).

The IRB is an agricultural basin and the 12th largest amongst the world’s drainage basins. It has the largest irrigation system in the world irrigating 190,000 km2 of cropland. The basin is relatively flat and consists of homogeneous and deep, fine grained, fertile and very permeable soils deposits. The 5th largest delta and 7th largest mangrove is in the IRB. In the past year, lack of sustainable river flow has disintegrated the delta ecosystem. The area has limited crop production, and fish and mangrove depletion due to salinity. Water pollution has reached high levels due to a disposal of untreated domestic, agricultural and industrial waste in the river and tributaries. The Indus basin irrigation system brought water and irritated the land but over-irrigation has disturbed the water balance and caused water logging.

Underlying the IRB, groundwater has been a major source of fresh water used for agriculture, industry, and drinking. High concentrations of arsenic were found near industrial areas, indicating the presence of untreated industrial water.Skin lesions disease was reported in District Khairpur, due to high arsenic contamination in the ground water (See Table 3).

In 2010 the number of population affected by arsenic reached 2,000,000 (See Table 2).

In the recent published study by Podgroski (2017), groundwater quality was tested along the Indus River and its tributaries, including Multan, Lahore, Kasur, Sheikhupura, Gujranwala and around Hyderabad. The shocking results revealed extremely high concentrations, above 200 ng.ml-1.Thisalarmed 50 to 60 million people who reside in the identified hotspots(Figure1). The authorrecommended further research to determine the exact reason of this contamination.

Arsenic is a major heavy metal naturally present in the soil. It is the most common inorganic water contaminant globally. It is a tasteless and odorless, and it can be detected in a laboratory only. It is highly toxic, hence in the US its safe limit was reduced from 50 to 10 ppb. Long-term ingestion of arsenic even in low concentrations can be lethal.

The major source of arsenic poisoning can be contaminated drinking water. However, some crops can uptake arsenic and on regular consumption can create toxicity.

The presence of arsenic in high concentration can be due to the release of arsenic from the soil. This is often caused by the microbial activity due to availability of organic matter. The other reason can be pumping depth, as some experts suggest a combination of shallow and deep pumping can help to reduce arsenic contamination. Direct disposal of industrial and agricultural waste is a common practice in Pakistan. It can be another major reason since arsenic is largely used in agriculture and industry e.g. used in insecticides and poisons.

It is also used for wood preservation, coloring agents, electronics industry, glass manufacture, lead alloying, bronzing and pyrotechnics. Organic compounds of arsenic are less toxic and intentionally added in chicken feed to promote the growth. Under some conditions, the arsenic in chicken feed is converted to the toxic inorganic form.

The massive ground water contamination needs an emergency response from the government and the public. Clean water should be provided and water filtration should be subsidized. Reverse osmosis filters should be installed to remove any contamination from drinking water. Such filters can be purchased for Rs 16000.

Thinking about the environment is essential for living a healthy life. The current situation is an opportunity to think about environmental issues and pollution. The attention can be used to educate and inculcate personal and collective responsibility towards the environment. It is also a chance for the government to make strict laws to reduce pollution and improve the environment.

Table.1: Distribution of Indus river basin in Southeast Asian countries

Table 2. Arsenic (As) polluted countries in South Asia with affected population and the reason/mechanism of pollution

Table 3. Diseases reported in Pakistan due to high Arsenic contamination

The writer has a PhD from Germany in Crop Sciences and is currently employed as a scientist there. He can be reached at phyto_pak@yahoo.co.uk and his twitter handle is @Joshua_Lahro

Published in Daily Times, September 12^th 2017.