Radiation testing services

Our NATA accredited radiation testing and analysis services include testing for Gross Alpha, Beta, Radon 222 (Rn-222), Radium 226 and 228, Lead 210, Polonium 210 and Total Uranium and Thorium for a range of water matrices, including drinking water, and source waters such as groundwater and wastewater.

Features of our radiation testing services include:

• high sensitivity with lower limits of detection
• fast turnaround times
• rapid response services for health-related incidents
• local expertise to help with technical enquiries.

Sources of radiation are all around us. Some occur naturally in the environment and some are human-made. Radiological contamination of drinking water can result from:

• Naturally occurring concentrations of radioactive materials, such as the radionuclides of the Radium, Uranium and Thorium, being absorbed by groundwater as it moves through the earth.
• Technological processes involving high concentrations of naturally radioactive materials, such as mining.

The largest proportion of human exposure to radiation comes from natural external sources including ingestion or inhalation of radioactive materials and solar radiation.

While a very low proportion of the total human exposure comes from drinking water, there is evidence from both human and animal studies that low to moderate radiation dose exposure can increase the long-term incidence of genetic disorders and cancer.

Depending on the exposure situation, there are different limits and guidance levels that may result in an action to reduce health risk and so the World Health Organisation and Australian Drinking Water Guidelines (ADWG) recommend drinking water and source water supplies be routinely monitored for radioactivity.

Radiological monitoring

The ADWG recommend an annual dose of 1 mSv per year should be applied for radioactivity in drinking water. If the dose is above 1 mSv per year, the source water should be analysed on a more regular basis. However, if the dose from the use of a water supply exceeds 10 mSv per year, immediate action must be taken to reduce the existing or potential exposure.

The process of identifying individual radioactive species and determining their concentrations in water requires sophisticated and expensive analysis, which is normally not justified due to concentrations in most circumstances being low. For this reason, a more practical approach involves using a screening procedure, where the total radioactivity present in the form of Alpha and Beta radiation is determined without regard to the identity of the specific radionuclides.

The Australian Drinking Water Quality guidance level in drinking water is 0.5 Bq/l for Gross Alpha and 0.5 Bq/l for Gross Beta (excluding K40 activity). Modelling has demonstrated that at these levels of Alpha and Beta activity, the annual dose is unlikely to exceed the 1 mSv limit.

The ADWG state that samples with measured activity above the 0.5 Bq/l guideline should be further investigated. For example, the impact of Uranium, Radium and Lead isotopes on dose should be considered.

Where source water is groundwater or water that has contacted minerals (such as soil) the water should also be tested for Radon (Rn222) because this nuclide will not be detected by the Gross Alpha Beta method. The ADWG has a limit of 100 Bq/l for Rn222.

Australian water utilities perform screening tests on their water sources every two or five years, depending on historical results. If the screening levels are not exceeded there is no need for further assessment. If any screening levels are exceeded, further investigation is necessary to identify the nature of the radioactivity.