UAE’s increasingly crucial groundwater monitored for radiation

2017-04-10

For thousands of years in the Middle East, groundwater has been used for agriculture, an essential support system for communities where shortages of rainfall are common.


In many areas, the practice was to create a system of qanats or falajs, tunnels that use gravity to extract and distribute water that lies beneath, typically, a hill.


Among the most impressive that survive is Al Ain’s network of channels used to irrigate palm trees and gardens. This has been described as one of the oldest in the world, dating back 3,000 years.


Communities in Oman, Iran, Afghanistan and many other countries have employed the same ingenious methods, working in harmony with nature to support agriculture.


In modern times, the need for groundwater in the region is increasing as a result of a large agricultural sector, growing populations and the demands of industry.


Now, mechanically pumped wells and other more high-tech methods are used to extract groundwater.


"The climate in [the Middle East] is not particularly conducive for long-term conservation of surface water resources," says Steve Thornton, a professor of environmental engineering science and member of the groundwater protection and restoration group at the University of Sheffield in the United Kingdom.


"In many areas, groundwater forms the primary supply source of potable [drinking] water. The population is growing in these areas of the world. You have a finite resource and, if you’re to sustain that growth, you must balance this demand with the availability to support industrial and economic development."


Given the continued importance of groundwater to all aspects of life in the region, it is vital that it remains free of hazardous substances.


Scientists at the United Arab Emirates University (UAEU) in Al Ain are in the middle of a major survey measuring radioactivity levels in groundwater.


The work, started in 2012, is looking at a variety of radioactive isotopes (an isotope is a form of a chemical element with a particular number of neutrons in the nucleus), along with alpha radiation (clumps of protons and neutrons that are not usually harmful) and beta radiation (high-energy particles that can damage living material).


So far, alpha radiation and beta radiation, along with isotopes such as radon-222 and radium-226, appear to be present at safe levels.


The focus of the research has been on the north and east of the UAE, but it is will be extended nationwide before the end of next year.


"It’s something new for us and we need to go in-depth with the results," said Professor Ala Aldahan, one of the four UAEU researchers involved in the project.


The analysis so far has not, said Prof Aldahan, looked for a number of radioactive isotopes that could be there as a result of human activity, but the researchers are planning to focus on these later.


Among them is caesium-137, which is found only as a result of human activity, being produced by nuclear reactors and nuclear explosions.


It can easily spread in water because the salts that it forms are very soluble. So easily, in fact, that several years after the Fukushima nuclear disaster in Japan in 2011, which led to significant leaks of radioactive material, it was found in waters off the coast of Canada.


Another indicator of radioactive pollution caused by humans – and another isotope the scientists are likely to be looking for in the UAE research – is iodine-129, which is produced by nuclear fission in nuclear reactors.


Less than a week after Fukushima, levels of this isotope in rainwater at Vancouver in Canada had increased significantly, although scientists said they quickly returned to normal.


Even so, it means that the contaminants the scientists in the UAE will be looking for could well have come from outside.


Human activity is responsible for other forms of groundwater contamination. In urban areas, said Prof Thornton, it is often the result of industrial processes, organic chemicals, metals or other substances released over time because of poor working practices or because they have not been disposed of properly.


In the Middle East, hazards caused by nature have also been a major concern.


In the research carried out so far by the UAEU team, the levels of radioactivity in groundwater in the Jebel Hafeet area were found to be higher, due to natural effects, than those considered safe by the World Health Organisation. Fortunately, in other parts of the country tested so far, radioactivity was found to be at safe levels.


It has been highlighted as a larger concern elsewhere in the Middle East, where overuse of groundwater is also a major problem.


The Disi aquifer in Jordan has radioactivity levels many times those recommended by the WHO. As in some of the region’s other aquifers, this is the result of uranium and thorium in sedimentary rock. Reports in international media have highlighted the possible health effects, such as increases in cancer rates, this radioactivity could have on those who drink water sourced from the aquifer.


Most of the Disi aquifer is actually present inside Saudi Arabia, where it is known as the Saq aquifer. Saudi Arabia, which gets about half of its water from underground sources, is said to treat supplies from the Disi aquifer to remove hazardous material, allaying health concerns.


There are potential natural radioactive dangers associated with underground water supplies in other countries in the Middle East and North Africa, among them Libya.


The many examples certainly highlights the importance of the UAEU research.

 

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