Assessment of Levels of Natural Radioactivity in Sand Samples Collected from Ekalakala in Machakos County, Kenya

Table 6

Dose rate (nGyh⁻¹), external hazard index, and ²³⁸U/²³²Th ratio for sand samples collected from Ekalakala River.

Sample	Dose (nGyh^−1)	Hex	^238U/^232Th
1	76.9	0.39	0.81
2	73.5	0.37	0.84
3	67.4	0.34	0.86
4	61.6	0.32	0.7
5	86.9	0.45	0.63
6	46.8	0.24	0.84
7	94.2	0.47	0.73
8	80.9	0.41	1.04
9	79.3	0.40	0.91
10	53.4	0.27	0.76
11	62.4	0.32	1.1
12	75.0	0.52	0.93
13	57.8	0.38	0.75
14	57.6	0.37	0.75
15	53.5	0.35	0.81
Maximum	94.2	0.52	1.1
Minimum	46.8	0.24	0.63
Average	68.5 ± 13.3	0.37 ± 0.07	0.83 ± 0.12