Why Do We Fear Radiation? 4
Based on health considerations, the concentration of uranium in drinking water should not exceed the health-based guideline value of 0.02 mg/L. This health-based guideline value is based on chemical toxicity. The chemical toxicity of uranium is more restrictive than its radiological toxicity. – Australian Drinking Water Guidelines (ADWG).
Uranium in the Environment
Uranium is naturally present in the environment as a result of leaching from soils, rocks and natural deposits. It can also be released from mining and mill tailings, from the combustion of coal and other fuels, and from the production or use of phosphate fertilizers (which can contain as much as 150 mg/kg uranium).
Food is the major source of uranium intake and the highest concentrations are typically found in shellfish (UNSCEAR 2000). Dietary intake of uranium through food is estimated between 0.001 and 0.004 mg/day (WHO 2004). Intake through drinking water is normally low; however, drinking water can contribute the majority of daily intake in circumstances where uranium is present at higher concentrations in drinking water (WHO 2004).
In most Australian drinking water supplies uranium concentrations are well below 0.02 mg /L. However, concentrations up to 0.12 mg/L have been measured in some groundwater supplies in remote areas. In humans and experimental animals, the main toxic effect of short-term exposure to high concentrations of uranium is inflammation of the kidney. Little information is available on the effects of long-term exposure to low concentrations. (AWQG).
Comparison of the Chemical and Radiological Standards for Uranium
The Radiological drinking water standard for uranium in Australia is incredibly conservative. It is calculated using a maximum addition of radiation of 0.1mSv/year. This is one tenth of the already very conservative allowable extra exposure limit of 1mSv/year.
The radiological standard is incredibly low at 3 Bq/L based on consuming 2 litres of water every day for a year. https://www.waterquality.gov.au/guidelines
The health-based guideline value of 0.02 mg/L is equivalent to an activity concentration of 0.2Bq/L. This indicates that the health-based guideline value based on chemical toxicity is considerably more restrictive than one based on radiological data. -(AWGL)
The chemical toxicity of uranium at least 15 times more hazardous than the radiation from uranium.
The Pine Creek Geosycline
Australia is rich in uranium deposits in a number of geological formations. The Pine Creek Geosyncline covers a large part of the Northern Territory and has many major uranium deposits. In the early part of this millenium, I managed a travelling monitoring team as a regulator for mining in the NT. Consequently, I saw data from rivers and streams all over the Pine Creek Geosyncline. Often the lowest levels of uranium measured were downstream of Ranger and Jabiluka uranium mines.
It is too easy to blame radiation from substances that do emit radiation for any “sickness”. I remember one instance when Aboriginals that lived not far downstream of Ranger mine were all becoming ill. Investigation showed the illness to result from faecal bacteria in the billabong. Work undertaken to prevent raw sewage entering the billabong led to a rapid cure.
Remote Community Sues NT Government for Compensation
In 2018, the government-owned utility company Power and Water Corporation (PWC) found that the drinking water in Laramba contained 0.046 milligrams of uranium per litre (mg/L), which was more than twice the recommended level. The community had known about problems with the water supply since at least 2008, but the scale of the issue was not revealed until 2018. A new water treatment plant using ion-exchange technology was opened in 2023, making the uranium almost undetectable. https://www.abc.net.au/news/2023-04-30/water-treatment-plant-opens-in-remote-laramba
The Laramba community celebrates their new water supply which ensures uranium levels are extremely low. (ABC Alice Springs: Charmayne Allison)
The Northern Territory’s Court of Appeal on Friday 29 November heard arguments from lawyers representing the Territory government and the residents of Laramba, a town of just more than 200 people 205km northwest of Alice Springs. It was the latest instalment in a five-year legal battle, which could continue beyond this court’s eventual decision.
The court case centres on whether the NT government, as landlord to the Laramba residents, should be responsible for the quality of the drinking water.
The NT Supreme Court last year found the Territory government was responsible, with judge Peter Barr ruling the quality of the water went to the habitability of the housing. The NT government subsequently appealed the decision. https://www.theaustralian.com.au/nation/indigenous/call-for-feds-to-sort-out-remote-community-drinking-water-issues/news-story/75bc23a800352ee822123a5b170c30ac
“The case continues, because we say our clients were forced to drink that water for over 10 years so they should be entitled to some compensation,”
“But more importantly, we want to establish the point that the government in remote communities has an obligation to provide people with safe water.”
Nowhere in the press reports I read, was it clarified that the uranium level was a chemical toxicity issue and not a radiological one. This builds unnecessary fear of radiation in both Aboriginal communities and the general public.
Pamela Jones
My Blog has become My Nuclear Journey 