The pH value of drinking water in longevity areas of South China are 6.62 ∼ 8.01 with a median of 7.42, indicating drinking water in longevity areas of South China are slightly alkaline. The TDS of drinking water in longevity areas in South China ranges between 35.43 and 1,014.66 mg/L, varying from fresh water (TDS < 1,000 mg/L) to brackish water (1,000 < TDS <2,000 mg/L). The TH of drinking water is 20.14 ∼ 594.13 mg/L, varying from soft water (TH < 75 mg/L) to high-grade hard water (TH > 450 mg/L). The order of relative abundance of major cations of drinking water in longevity areas of South China is Ca > Na > Mg > K (on a mg/L basis), while that of anions is HCO−3 > SO2−4 > NO−3 > Cl. The concentration of micro-elements varies greatly (Table 4). The sum concentration of micro-elements (SCME) is 138.26 ∼ 2,269.66 μg/L with a median of 358.28 μg/L, and the top three micro-elements in decreasing order according to median value are Fe (108.66 μg/L) > Sr (82.1 μg/L) > Zn (7.97 μg/L). The ranges of the sum concentration of essential micro-elements (SCEE: Fe, Zn, Cu, Mn, Cr, Mo, Co, Ni, V, Se) and sum concentration of hazardous elements (SCHE: As, Cd, Pb) are more than one magnitude with a median of 160.17 μg/L and 1.26 μg/L, respectively. The ranges of the ratio of SCEE in SCME (SCEESCME) and the ratio of SCHE in SCME (SCHESCME) are within two magnitudes with a median of 0.4 and 0.035, respectively.
Statistical summary of micro-elements in drinking waters of China
| . | Longevity in South n = 40 . | Non-longevity in South n = 74 . | Non-longevity in North n = 14 . | GB 5749-2006 . | . | |||
|---|---|---|---|---|---|---|---|---|
| Elements . | Range . | Median . | Range . | Median . | Range . | Median . | (MHPRC 2006) . | WHO (WHO 2011) . |
| Se | <0.01 ∼ 7.29 | 0.12 | 0.02 ∼ 2.28 | 0.47 | <0.01 ∼ 9.07 | 0.25 | 10 | 10 |
| As | 0.12 ∼ 56.33 | 1.09 | 0.05 ∼ 7.46 | 0.72 | 0.92 ∼ 40.6 | 16.95 | 10 | 10 |
| Al | <0.1 ∼ 109.02 | 6.04 | 0.86 ∼ 1,127.24 | 26.99 | 1.44 ∼ 52.17 | 5.8 | 200 | 200 |
| B | <0.1 ∼ 209.4 | 4.9 | <0.1 ∼ 80.7 | <0.1 | 15.4 ∼ 222.2 | 90.75 | 500 | 500 |
| Ba | 1.75 ∼ 56.98 | 6.62 | 0.63 ∼ 195.04 | 22.71 | 19.99 ∼ 359.69 | 52 | 700 | |
| Be | <0.1 ∼ 0.07 | <0.1 | <0.1 ∼ 1.35 | <0.1 | <0.1 ∼ 0.28 | 0.01 | 2 | |
| Cd | <0.1 ∼ 1.66 | 0.02 | <0.1 ∼ 0.51 | 0.02 | 0.01 ∼ 0.13 | 0.04 | 5 | 3 |
| Co | 0.01 ∼ 0.56 | 0.07 | <0.1 ∼ 18.24 | 0.03 | 0.03 ∼ 0.63 | 0.07 | ||
| Cr | <0.1 ∼ 50.71 | 5.93 | 0.4 ∼ 39.22 | 3.27 | 3.49 ∼ 17.42 | 9.65 | 50 | 50 |
| Cu | <0.1 ∼ 4.25 | 0.19 | <0.1 ∼ 7.47 | <0.1 | 0.28 ∼ 4.34 | 0.74 | 1,000 | 1,000 |
| Li | <0.1 ∼ 36.71 | 0.82 | 0.05 ∼ 9.55 | 1.21 | 2.09 ∼ 37.22 | 13.49 | ||
| Mn | <0.1 ∼ 34.92 | 0.79 | <0.1 ∼ 1,213.4 | 1.01 | 0.05 ∼ 76.66 | 1.74 | 100 | 400 |
| Ni | <0.1 ∼ 3.53 | 0.53 | <0.1 ∼ 12.9 | <0.1 | <0.1 ∼ 2.76 | 0.64 | 20 | 70 |
| P | <0.1 ∼ 227.1 | 23.3 | <0.1 ∼ 851.6 | <0.1 | 8.7 ∼ 265.8 | 37.5 | ||
| Pb | <0.1 ∼ 0.73 | 0.04 | <0.1 ∼ 5.03 | 0.05 | <0.1 ∼ 0.17 | 0.01 | 10 | 10 |
| Tl | <0.1 ∼ 0.2 | 0 | <0.1 ∼ 0.18 | 0.01 | <0.1 ∼ 0 | <0.1 | 0.1 | |
| V | <0.1 ∼ 7.27 | 0.15 | <0.1 ∼ 35.91 | <0.1 | 0.45 ∼ 43.08 | 25.66 | ||
| Cs | <0.1 ∼ 0.85 | 0.02 | 0 ∼ 0.81 | 0.06 | 0 ∼ 0.02 | 0.01 | ||
| Ga | <0.1 ∼ 4.45 | 0.26 | 0.13 ∼ 12.36 | 1.28 | 0.49 ∼ 8.36 | 1.73 | ||
| In | <0.1 ∼ 0 | <0.1 | <0.1 ∼ 0.01 | <0.1 | <0.1 ∼ 0.01 | <0.1 | ||
| Rb | <0.1 ∼ 78.88 | 1.26 | 0.55 ∼ 43.35 | 3.37 | 0.09 ∼ 1.29 | 0.39 | ||
| U | <0.1 ∼ 3.54 | 0.17 | 0 ∼ 9.84 | 0.03 | 0.12 ∼ 15.8 | 0.62 | 15 | |
| Bi | <0.1 ∼ 0.01 | 0 | <0.1 ∼ 0.07 | 0 | <0.1 ∼ 0.01 | 0 | ||
| Sr | 20.3 ∼ 621.2 | 82.1 | <0.1 ∼ 607.3 | 7.45 | 177 ∼ 2,005 | 748.65 | ||
| Mo | <0.1 ∼ 5.1 | 0.15 | <0.1 ∼ 5.85 | 0.07 | 0.93 ∼ 7.6 | 5.69 | 70 | 70 |
| Zn | 1.08 ∼ 1,951.63 | 7.97 | <0.1 ∼ 517.29 | 13.89 | 0.33 ∼ 197.49 | 11.99 | 1,000 | 3,000 |
| Fe | <0.1 ∼ 278.78 | 108.66 | <0.1 ∼ 214.85 | 42.04 | 33.63 ∼ 423.76 | 80.1 | 300 | 3,000 |
| SCME | 138.26 ∼ 2,269.66 | 358.28 | 36.58 ∼ 2,691.33 | 204.53 | 592.78 ∼ 3,205.63 | 1,171.79 | ||
| SCEE | 29.73 ∼ 2,209.73 | 160.17 | 9.13 ∼ 13,84.48 | 75.16 | 60.51 ∼ 550.99 | 158.65 | ||
| SCHE | 0.2 ∼ 56.35 | 1.26 | 0.07 ∼ 7.54 | 0.96 | 1.13 ∼ 40.7 | 17.12 | ||
| SCEESCME | 0.03 ∼ 0.98 | 0.40 | 0.04 ∼ 0.8 | 0.35 | 0.07 ∼ 0.23 | 0.14 | ||
| SCHESCME | 0.0007 ∼ 0.053 | 0.0035 | 0.0002 ∼ 0.027 | 0.004 | 0.0004 ∼ 0.058 | 0.0107 | ||
| . | Longevity in South n = 40 . | Non-longevity in South n = 74 . | Non-longevity in North n = 14 . | GB 5749-2006 . | . | |||
|---|---|---|---|---|---|---|---|---|
| Elements . | Range . | Median . | Range . | Median . | Range . | Median . | (MHPRC 2006) . | WHO (WHO 2011) . |
| Se | <0.01 ∼ 7.29 | 0.12 | 0.02 ∼ 2.28 | 0.47 | <0.01 ∼ 9.07 | 0.25 | 10 | 10 |
| As | 0.12 ∼ 56.33 | 1.09 | 0.05 ∼ 7.46 | 0.72 | 0.92 ∼ 40.6 | 16.95 | 10 | 10 |
| Al | <0.1 ∼ 109.02 | 6.04 | 0.86 ∼ 1,127.24 | 26.99 | 1.44 ∼ 52.17 | 5.8 | 200 | 200 |
| B | <0.1 ∼ 209.4 | 4.9 | <0.1 ∼ 80.7 | <0.1 | 15.4 ∼ 222.2 | 90.75 | 500 | 500 |
| Ba | 1.75 ∼ 56.98 | 6.62 | 0.63 ∼ 195.04 | 22.71 | 19.99 ∼ 359.69 | 52 | 700 | |
| Be | <0.1 ∼ 0.07 | <0.1 | <0.1 ∼ 1.35 | <0.1 | <0.1 ∼ 0.28 | 0.01 | 2 | |
| Cd | <0.1 ∼ 1.66 | 0.02 | <0.1 ∼ 0.51 | 0.02 | 0.01 ∼ 0.13 | 0.04 | 5 | 3 |
| Co | 0.01 ∼ 0.56 | 0.07 | <0.1 ∼ 18.24 | 0.03 | 0.03 ∼ 0.63 | 0.07 | ||
| Cr | <0.1 ∼ 50.71 | 5.93 | 0.4 ∼ 39.22 | 3.27 | 3.49 ∼ 17.42 | 9.65 | 50 | 50 |
| Cu | <0.1 ∼ 4.25 | 0.19 | <0.1 ∼ 7.47 | <0.1 | 0.28 ∼ 4.34 | 0.74 | 1,000 | 1,000 |
| Li | <0.1 ∼ 36.71 | 0.82 | 0.05 ∼ 9.55 | 1.21 | 2.09 ∼ 37.22 | 13.49 | ||
| Mn | <0.1 ∼ 34.92 | 0.79 | <0.1 ∼ 1,213.4 | 1.01 | 0.05 ∼ 76.66 | 1.74 | 100 | 400 |
| Ni | <0.1 ∼ 3.53 | 0.53 | <0.1 ∼ 12.9 | <0.1 | <0.1 ∼ 2.76 | 0.64 | 20 | 70 |
| P | <0.1 ∼ 227.1 | 23.3 | <0.1 ∼ 851.6 | <0.1 | 8.7 ∼ 265.8 | 37.5 | ||
| Pb | <0.1 ∼ 0.73 | 0.04 | <0.1 ∼ 5.03 | 0.05 | <0.1 ∼ 0.17 | 0.01 | 10 | 10 |
| Tl | <0.1 ∼ 0.2 | 0 | <0.1 ∼ 0.18 | 0.01 | <0.1 ∼ 0 | <0.1 | 0.1 | |
| V | <0.1 ∼ 7.27 | 0.15 | <0.1 ∼ 35.91 | <0.1 | 0.45 ∼ 43.08 | 25.66 | ||
| Cs | <0.1 ∼ 0.85 | 0.02 | 0 ∼ 0.81 | 0.06 | 0 ∼ 0.02 | 0.01 | ||
| Ga | <0.1 ∼ 4.45 | 0.26 | 0.13 ∼ 12.36 | 1.28 | 0.49 ∼ 8.36 | 1.73 | ||
| In | <0.1 ∼ 0 | <0.1 | <0.1 ∼ 0.01 | <0.1 | <0.1 ∼ 0.01 | <0.1 | ||
| Rb | <0.1 ∼ 78.88 | 1.26 | 0.55 ∼ 43.35 | 3.37 | 0.09 ∼ 1.29 | 0.39 | ||
| U | <0.1 ∼ 3.54 | 0.17 | 0 ∼ 9.84 | 0.03 | 0.12 ∼ 15.8 | 0.62 | 15 | |
| Bi | <0.1 ∼ 0.01 | 0 | <0.1 ∼ 0.07 | 0 | <0.1 ∼ 0.01 | 0 | ||
| Sr | 20.3 ∼ 621.2 | 82.1 | <0.1 ∼ 607.3 | 7.45 | 177 ∼ 2,005 | 748.65 | ||
| Mo | <0.1 ∼ 5.1 | 0.15 | <0.1 ∼ 5.85 | 0.07 | 0.93 ∼ 7.6 | 5.69 | 70 | 70 |
| Zn | 1.08 ∼ 1,951.63 | 7.97 | <0.1 ∼ 517.29 | 13.89 | 0.33 ∼ 197.49 | 11.99 | 1,000 | 3,000 |
| Fe | <0.1 ∼ 278.78 | 108.66 | <0.1 ∼ 214.85 | 42.04 | 33.63 ∼ 423.76 | 80.1 | 300 | 3,000 |
| SCME | 138.26 ∼ 2,269.66 | 358.28 | 36.58 ∼ 2,691.33 | 204.53 | 592.78 ∼ 3,205.63 | 1,171.79 | ||
| SCEE | 29.73 ∼ 2,209.73 | 160.17 | 9.13 ∼ 13,84.48 | 75.16 | 60.51 ∼ 550.99 | 158.65 | ||
| SCHE | 0.2 ∼ 56.35 | 1.26 | 0.07 ∼ 7.54 | 0.96 | 1.13 ∼ 40.7 | 17.12 | ||
| SCEESCME | 0.03 ∼ 0.98 | 0.40 | 0.04 ∼ 0.8 | 0.35 | 0.07 ∼ 0.23 | 0.14 | ||
| SCHESCME | 0.0007 ∼ 0.053 | 0.0035 | 0.0002 ∼ 0.027 | 0.004 | 0.0004 ∼ 0.058 | 0.0107 | ||
Unit: μg/L, except SCEESCME and SCHESCME.
∼: approximate.
n: number of samples.
SCME: sum concentration of micro-elements; SCEE: sum concentration of essential micro-elements (Fe, Zn, Cu, Mn, Cr, Mo, Co, Ni, V, Se); SCHE: sum concentration of hazardous elements (As, Cd, Pb); SCEESCME: ratio of SCEE in SCME; SCHESCME: ratio of SCHE in SCME.