Assessment of Natural Radioactivity Levels and Radiation Hazards in Agricultural and Virgin Soil in the State of Kedah, North of Malaysia

Table 1

Gamma-ray energy and emission rate for ²³⁸ U, ²³²Th, and ⁴⁰K radionuclides.

Element	Nuclide	Half-life	Gamma-ray energy; (keV)	Emission rate	Sources/origin
^238U	^214Pb	26.8 min	351	35.8	^238U (^226Ra) series
	^214Bi	19.9 min	609.3	45.4	^238U (^226Ra) series
			1764.5	15.3
^232Th	^228Ac	6.15 h	338.4	11.4	^232Th series
			911.1	25.8
			968.9	17.4
	^212Pb		238.63	46.6
	^208Tl		583.19	85.0
^40K	^40K	1.28 × 10^9 yr	1460.8	10.7	Primordial