Hazardous Gas Helps Climate Scientists

IAEA and WMO Collaborate to Improve Atmospheric Research Using Radon

This 5000 litre detector (on side of building) operates as part of the Cape Grim Baseline Air Pollution Station in Tasmania, Australia. It´s the largest running radon detector in the world, with a lower limit of detection better than 10 mBq m-3. (Photo: W. Zahorowski)

The IAEA and the World Meteorological Organisation (WMO) have taken another step in their global initiative to improve atmospheric investigations that use radon.

Radon is a heavy radioactive gas formed by the decay of radium. It is emitted from the land and disperses into the atmosphere. It´s considered dangerous to human health when allowed to accumulate in confined places like cellars and basements. However, the gas has significant research applications.

Radon in the air is useful for studying how pollutants move through the atmosphere. A particularly important application is its use in estimating greenhouse gas emissions. It is also measured at stations of the WMO´s Global Atmosphere Watch network.

"Its value is in tracing atmospheric movements and contributing to the validation and ultimate improvement of global climate models. These models are used to predict climate change and global warming," says Wlodek Zahorowski, Environmental Researcher at the Australian Nuclear Science and Technology Organisation.

But there are some impediments to radon´s use.

Environmental scientists in different countries use different methods to measure radon being emitted from the land, so many results end up being incomparable and therefore unusable for global projections. Also, rates of radon emission vary based on the amount of rainfall or the uranium content of the local soil.

The IAEA and WMO are helping scientists overcome these hurdles by working on an initiative aimed at standardising radon measurement tools and practices.

The latest joint IAEA/WMO meeting was held in June in Vienna, Austria. Scientists and engineers involved in measuring radon emission from land, those involved in measuring atmospheric radon, and modellers met at the IAEA´s headquarters.

"The Agency´s Environment programme includes a new project on the use of nuclear techniques for monitoring air pollution and investigating atmospheric processes. As part of this project we´ll help scientists worldwide to standardise their radon emission measurements and improve the quality of their data," says Gabi Voigt, Director of the IAEA´s Laboratories at Seibersdorf in Austria.

Background

Radon is a naturally occurring gas that is measured when testing the accuracy of atmospheric dispersion models.

Atmospheric dispersion modelling is the mathematical simulation of how air pollutants (including greenhouse gases) move around in the air we breathe. Such models help scientists predict the effects of pollutants on air quality and the climate.

However, the models´ reliability can only be established by comparing their predictions with measurements of gases like radon.

Although other gases can be, and are used for checking atmospheric models, radon has a number of advantages that make it easy to measure and track. It has a radioactive half-life of 4 days, it doesn´t participate in chemical reactions with other gases in the air, and it comes from only one place - the land.

Last update: 14 November 2014