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