Attached and unattached radon progeny, humidity and air temperature data in Jabiru East and Jabiru town: QUT – eriss Project data

Department of the Environment, 1998

Internal Report 295
Quintarelli F, Akber RA & Pfitzner J
Supervising Scientist Division

About the report

This report describes the data obtained over a period of 2 years starting in mid 1992 and ending in mid 1994 at Jabiru Town and Jabiru East, two sites in tropical Australia. The data consisted of the attached and unattached radon progeny. The study is relevant since the sites are located in Kakadu National Park, a popular tourist destination and in close proximity to ERA Ranger uranium mine.

The importance of the study stems from the fact that the radiotoxicity to humans depends on the size of the aerosol to which the radon progeny are attached. The unattached progeny are those decay products which are attached to very small aerosols. Because of their small size, these particles behave in much the same way as gas particles and are capable of penetrating deeply into the human respiratory tract. The attached progeny consist of progeny which are attached to aerosols which, because of their large size, behave more as dust particles, consequently, these do not penetrate as far into the respiratory tract. There is no clear distinction (in terms of their sizes) between attached and unattached progeny. For this study, the division is set at about 2.8 nm, the aim being to mimic the deposition processes in the human respiratory tract.