Radon Springs: What's in a name?

Supervising Scientist staff monitoring at Radon Springs, Kakadu National Park.

Part One of a two-part feature on radon, a chemical element associated with radiation.

RADON gas occurs naturally in the ground. When groundwater comes to the surface as a spring, it sometimes brings radon with it, which then dissipates into the air.

This is also true for water coming out of a tap in any home. In 2000, the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) determined ingestion of radon in water does not pose a sufficient risk to health to warrant setting a guideline value.

Simply put, UNSCEAR does not consider drinking water affected by radon to be a sufficient threat to human health to even set a standard for safe and unsafe levels. However, guideline values have been set for radon build up through degassing of radon from tap water in dwellings.

Conjecture surrounds the name assigned to the permanently flowing headwaters of Gulungul Creek, i.e. “Radon Springs”, with some people suggesting the spring must be radioactive to have been so named.

Radon Springs is an attractive, rainforest-lined gorge within Kakadu National Park, about 11km south of Jabiru, which combines challenging walking tracks with spectacular views and provides a through walk to either Baroalba Creek or Nourlangie rock art site.

Due to the site’s significance to Aboriginal people, camping is only allowed with a permit, obtainable from Kakadu National Park Permits Office.

Camping and water use does not put you at risk from radon

Supervising Scientist staff took water samples from the spring and had them analysed in the laboratory. The samples revealed naturally elevated radon levels in the spring.

This suggests early researchers in the Alligator Rivers Region collecting baseline information for future mining of the Ranger uranium deposits (in the 1970s) had analysed the waters of the spring for radon, and finding similarly high levels, named the spring accordingly.

Consistent with the UNSCEAR 2000 finding, these levels represent no health threat to people drinking from the springs.

There are a number of other springs around the world named Radon or Radium, in places such as Colorado, Georgia, Albany and New Mexico. It is likely that the natural phenomenon we observed in our local Radon Springs is present there too

The naturally-elevated levels of radon at Radon Springs are not a risk to people’s health. Camping and water use does not put you at risk from the levels of radon observed at Radon springs.

RADON THROUGH HISTORY

Radon is a radioactive noble gas and was discovered in 1900 by Friedrich Ernst Dorn.

In the past radon was thought to be a miracle cure and so radium, the pre-cursor of radon, was added to jewellery, toothpaste, hair creams, medicines, food items and even used to clean dentures.

Many people around the world still expose themselves to low doses of radon found in natural springs as they believe it will result in positive health benefits. This view is not shared by the scientific community or modern medical practitioners.

While it is potentially unsafe to be exposed to any levels of radiation over time, radiation is found naturally throughout the world and can come from various sources. By far the most common way humans are exposed to radiation is through natural radon build-up in poorly sealed or badly ventilated homes. In these homes, the most common radiation exposure comes from inhaled alpha radiation, a byproduct of radon decay. Improving ventilation in and under the home greatly reduces the chance of radon accumulation.

Supervising Scientist measures radon level in the open atmosphere around the Ranger mine. To date we have not detected levels that are of concern to human health. There are many cities in the world have higher average concentrations of radon in air than Jabiru or Jabiru East.

From the pages of The Monitor, the Supervising Scientist’s ARR monitoring update.

In Part Two of this feature we look at how Supervising Scientist monitors radiation levels in the Alligator Rivers region.