Table 4.
The average content of toxic heavy metals in green tea samples according to their origin (including tea type or form).
| Parameter | Heavy Metals | ||
|---|---|---|---|
| Pb (µg/kg) | Cd (µg/kg) | Ni (mg/kg) | |
| CH (China) | |||
| Concentration | 9.37 ± 0.99 | 4.66 ± 0.61 | 5.09 ± 0.50 |
| Range | 8.30–11.23 | 3.98–5.72 | 4.32–5.80 |
| CH1 (China) | |||
| Concentration | 238 ± 46.7 | 16.9 ± 2.09 | 7.92 ± 0.83 |
| Range | 168–311 | 12.6–19.2 | 6.89–9.10 |
| I (India) | |||
| Concentration | 233 ± 40.7 | 11.7 ± 1.73 | 4.76 ± 0.59 |
| Range | 165–274 | 9.40–13.9 | 3.92–5.43 |
| SL (Sri Lanka) | |||
| Concentration | 3.24 ± 0.51 | 3.02 ± 0.28 | 3.10 ± 0.47 |
| Range | 2.45–3.88 | 2.55–3.45 | 2.37–3.76 |
| N (Nepal) | |||
| Concentration | 2.31 ± 0.14 | 4.51 ± 0.18 | 4.07 ± 0.24 |
| Range | 2.15–2.58 | 4.25–4.70 | 3.75–4.40 |
| SKJ (South Korea) | |||
| Concentration | 31.8 ± 6.83 | 4.70 ± 0.25 | 18.0 ± 0.84 |
| Range | 20.2–41.3 | 4.25–4.95 | 17.0–19.2 |
| JA (Japan) | |||
| Concentration | 20.5 ± 2.47 | 2.61 ± 0.30 | 5.28 ± 0.53 |
| Range | 17.4–24.6 | 2.23–3.13 | 4.66–5.97 |
| JM (Japan) | |||
| Concentration | 29.8 ± 5.53 | 2.39 ± 0.17 | 2.13 ± 0.1 |
| Range | 22.0–37.0 | 2.13–2.60 | 1.97–2.28 |
| JS (Japan) | |||
| Concentration | <LOD | 3.38 ± 0.22 | 4.75 ± 0.24 |
| Range | 3.10–3.80 | 4.53–5.19 | |
CH—China (original); CH1—China (blended); I—India; SL—Sri Lanka; N—Nepal; SKJ—Jeoncha (South Korea); JA—Agari (Japan); JM—Matcha (Japan); JS—Sencha (Japan).