RADON AND EARTHQUAKES

Radon is causing intellectual earthquakes within the health physics community as a result of Cohen's work showing decreasing lung cancer incidence with increasing radon exposure. There is also increasing evidence that radon is useful in the prediction of actual earthquakes.

"Anomaly in Atmospheric Radon Concentration: Possible Precursor to the 1995 Kobe, Japan, Earthquake'' by Y. Yasuoka and M. Shi-nogi, Health Physics 72, No. 5, pp 759-761 (1997), reports that the concentration of radon 222 (which has a half-life of 4 days) in air sampled 16 feet above the ground became markedly higher two months before the 7.2 magnitude earthquake that devastated Kobe Japan on 17 January 1995. These air samples were continuously measured between 1984 and 1996 at a site near a major fault and 12 miles from the earthquake center. Figures 1 and 2 are from the Yasuoka and Shinogi paper.

During the 10 years preceding the earthquake, a careful record was made of diurnal and seasonal variations in atmospheric radon 222 levels. These measurements were used to calculate the smoothed mean radon concentration and the standard deviations of that mean. These deviations were those caused by all variables that occurred during that ten year period. Figure 2 summarizes these calculations and actual measurements during a two-year period that included the earthquake.

The difference between the smoothed radon concentration and the smoothed mean radon concentration is plotted as the "residual value'' in Figure 2. The UCL and LCL lines represent the 95% and 99% confidence levels for expected fluctuation from line FIT which is the predicted line.

Based upon the ten-year historical record, there is only one chance in one hundred that the residual radon concentration will drift outside of the UCL 99 or the LCL 99 range during the time interval of this graph. Yet, the figure shows that this value drifted above UCL99 at the end of November 1994 and remained higher than UCL99 until the earthquake took place two months later.

Moreover, H. Wakita et al, Science 269, pp 60-61 (1995), reported that radon concentration in ground water increased for several months prior to this earthquake. The ground water samples were taken three miles east of the air sampling station.

Earthquakes are especially dangerous to human life because they strike quickly before emergency action can be taken. People are trapped under falling structures without having an opportunity to escape. With warning, most earthquake deaths, like most deaths from hurricanes and floods, could be avoided. These experiments indicate that ground release of radon 222 can provide warning.

•	Science and Humility
•	ORDERS OF MAGNITUDE
•	MOLECULAR CLOCKS
•	*RADON AND EARTHQUAKES*
•	GLOBAL THERMOMETERS
•	IODIDE DISTRIBUTION
•	SAN DIEGO
•	STARK RAVING MAD
•	GOOD READING

Vol. 24, No. 9

Newsletter: Access to Energy Newsletter Archive
Volume: Issues
Issue/No.: Vol. 24, No. 9

Date: May 01, 1997 01:10 PM
Title: Science and Humility