The Curious Case of Radioactivity in Disi Aquifer

High controversey has been generated in Jordan in the last couple of days after the biggest global news agency "Reuters" published a news item about a scientific study claiming high levels of radioactive isotopes found in Jordan major strategic water reservoir; the Disi Basin.

The scientific study was conducted by a team of researchers composed of 9 researchers from the USA, Jordan, Israel and Palestine. One of the Jordanian researchers is Dr Omar Rimawi the president of the Balqa Applied University and an authority on groundwater hydrology in Jordan.

The lead author is Avner Vengosh from Duke University, who is an Israeli and considered as a leading scientist in hydrology. The findings of the study were really worrisome as they indicated high levels of radioactive isotopes in Disi aquifer. The full study is accessible only by subscription to online research portals but the abstract goes as follows

"High naturally occuring radioactivity in fossil groundwater from the Middle East"

"High levels of naturally occurring and carcinogenic radium isotopes have been measured in low-saline and oxic groundwater from the Rum Group of the Disi sandstone aquifer in Jordan. The combined ²²⁸Ra and ²²⁶Ra activities are up to 2000% higher than international drinking water standards. Analyses of the host sandstone aquifer rocks show ²²⁸Ra and ²²⁶Ra activities and ratios that are consistent with previous reports of sandstone rocks from different parts of the world. A compilation of previous data in groundwater from worldwide sandstone aquifers shows large variations in Ra activities regardless of the groundwater salinity. On the basis of the distribution of the four Ra isotopes and the ratios of the short- to long-lived Ra isotopes, we postulate that Ra activity in groundwater is controlled by the balance of radioactive decay of parent Th isotopes on aquifer solids, decay of the dissolved radium isotopes, and adsorption of dissolved Ra on solid surfaces. The availability of surface adsorption sites, which depends on the clay content in the aquifer rocks, is therefore an important constraint for Ra activity in sandstone aquifers. These findings raise concerns about the safety of this and similar nonrenewable groundwater reservoirs, exacerbating the already severe water crisis in the Middle East."

The Disi aquifer is the strategic water resource for Jordan. A mega project to channel water from Disi to Amman for drinking purposes at the cost of 600 Million USD. Such results are a direct blow for Jordan's plans in terms of financial mobilization and consumers' trust. The Ministry of Water and Irrigation refuted the results in statements to newspapers. Furthermore, some "researchers" and officials labelled the study as a "political conspiracy" to halt Jordan's future use of Disi water.

The problem is that the Article has not been accessed and even read by many of the commentators. I have sent an e-mail to Dr Vengosh to provide me with the study but there was no response. It has been very disappointing that up until now no scientific response has been published in Jordanian media apart from the nonsense conspiracy theories. This shows the lack of scientific discipline in media and in the characters of a lot of so-called experts and offocials. One of them told the Jordan Times, on condition of anonymity, questioned the timing of the study which comes weeks before the financial closure of the multimillion-dollar Disi Water Conveyance Project. This official thinks that publishing a scientific article is like publishing a newspaper article. The first draft was received by the magazine on October 21, 2008 and at that time I wonder if the authors were informed about the timing of the financial closure to select a day of publishing that is one week earlier of the all important financial disclosure.

The damage has already been done, with countless media reports published in the region and globally about the results of the study. The ultimate impact on the Disi project and Jordan water strategy will only remain to be seen. The Ministry of Water and Irrigation has declared that water is safe based on its own testing. This declration of course assumes that the citizens and consumers have the adequate trust for public statements. Time has proved again and again that this assumption is both dangerous and unrealistic.

Dr Saqer Salem, a Jordanian expert on environmental health assisted me with some online research and got a few more information.

Prof. Jiwchar Ganor of the Department of Geological and Environmental Science, Ben-Gurion University of the Negev is part of an international team of researchers and on the university website the following was mentioned: " The team investigated water from 37 pumping wells in the Disi aquifer's Rum Group, where low-saline groundwater is extracted from Cambro-Ordovician sandstone, and from wells in the Khreim Group, where saltier water is extracted from an aquifer containing larger amounts of clay minerals and oxides. All samples were analyzed for major and trace elements and for four radium isotopes. For comparative purposes, sandstone rocks from the Disi aquifer, along with Nubian sandstone rocks from the nearby Negev Desert in Israel, were also measured for radium.

"We found a lack of correlation between salinity and radioactivity," Vengosh said. "Instead, our findings suggest that an aquifer's geological properties may be a much more significant factor."

Vengosh and his group hypothesize that an aquifer with a higher content of clay minerals and oxides provides more adsorption sites for radium, and this results in lower radionuclide levels in the water itself. Sandstone aquifers, on the other hand, offer fewer adsorption sites, and, as a result, generate radium-rich groundwater.

"Given that most of the aquifers in the region that contain fossil water are composed of Nubian sandstone and are characterized by low-saline groundwater, similar to that in the Disi aquifer, we suggest that high-radioactive groundwater may also exist in these basins. This could pose health risks for a large population," Vengosh said. Groundwater from the Disi aquifer is already used for drinking water in parts of Jordan and, more extensively, in Saudi Arabia, where it is known as the Saq aquifer. "Making groundwater from the Disi aquifer and similar sandstone basins in the region safe for long-term human use will require a significant reduction of radionuclide levels," Vengosh added.

Health officials could reduce radioactivity to safe levels by diluting radium-rich water with low-radium water from other sources, he said, or by treating it with ion exchange, reverse osmosis desalination or lime softening. Each of these three treatment technologies does a good job of removing radium, Vengosh noted, but each produces solid and liquid residues that would have to be handled and disposed of as low-level radioactive waste.

In an email to New Security Beat, Dr. Vengosh wrote:"Most of the Jordanian population is not using the fossil water for drinking—for now. Only few thousand people in Aqaba and Karak might be currently exposed to this water. However, Jordan has launched a huge water project to transfer the water from the aquifer in the south to the capital Amman, which would expose a large population to this water.”

This is a cynical "analysis" of the article

http://www.dailykos.com/storyonly/2009/2/19/122354/700/355/699335

At the end, I cannot have a judgement without accessing the article and reviewing the source of samples and the duration of the sampling. Even then, I am not an authority on the issue and the only credible response should be based on sound science and not politicization of a very damgerous outcome.