Table 4.
The difference of the gross α and β radioactivity concentrations of drinking water samples in different periods (× 10–2 Bq/L).
| Gross α | Gross β | |||
|---|---|---|---|---|
| Range | Mean ± SDa | Range | Mean ± SD | |
| Raw water | ||||
| Dry season | 0.8–7.4 | 3.0 ± 2.8 | 11.8–30.0 | 20.6 ± 5.8 |
| Wet season | 0.8–8.2 | 2.3 ± 2.5 | 4.2–31.0 | 17.8 ± 7.9 |
| p value | 0.505 | 0.452 | ||
| Factory water | ||||
| Dry season | 0.8–5.4 | 1.5 ± 1.5 | 6.3–24.8 | 19.4 ± 6.3 |
| Wet season | 0.8–2.7 | 1.2 ± 0.8 | 6.5–25.2 | 16.9 ± 5.7 |
| p value | 0.573 | 0.463 | ||
| Tap water | ||||
| Dry season | 0.8–2.6 | 1.2 ± 0.8 | 1.4–32.8 | 16.2 ± 9.9 |
| Wet season | 0.8–2.3 | 1.4 ± 0.7 | 8.1–24 | 18.2 ± 5.2 |
| p value | 0.665 | 0.348 | ||
aSD standard deviation of the activity concentration.