group | Treatment observation cases | Concentration increases the number of cases after treatment | Concentration unchanged or reduce the number of cases after treatment | |||
The number of cases | The mean concentration (mg/L) | The number of cases | The mean concentrations (mg/L) | The number of cases | The mean concentrations (mg/L) | |
Before the treatment | 96 | 157.95 ± 31.46 | 33 | 140.39 ± 5.085 | 63 | 167.14 ± 3.60 |
After treatment | 96 | 147.26 ± 28.76 | 33 | 169.97 ± 4.79 | 63 | 135.37 ± 2.68 |
T value | - | 2.45726 | - | 24.3242 | - | 56.1865 |
P values | - | 0.01049 | - | 0.00106 | - | 0.000459 |