Table 4 The correlations between Cd concentration and the number of cigarettes smoked, duration of smoking, the age of smoking initiation, and the age of the participants.
Sampling time | Fluid | npairs | ρ | p | |||
|---|---|---|---|---|---|---|---|
The correlation between Cd concentration at t0 and the number of cigarettes smoked daily according to smoking history | t0 | Serum | 11 | 0.30 | 0.367 | ||
Saliva | 8 | − 0.23 | 0.571 | ||||
The correlation between Cd concentration at t0, t1, t4, and t26, and the number of cigarettes smoked on the previous day | t0 | Serum | 10 | 0 | 1.000 | ||
Saliva | 8 | 0.56 | 0.149 | ||||
t1 | Serum | 10 | 0.16 | 0.620 | |||
t4 | Serum | 10 | 0.57 | 0.083 | |||
t26 | Serum | 10 | 0.32 | 0.478 | |||
The correlation between Cd concentration at t0, and the number of cigarettes smoked on 25th day of the study | t0 | Serum | 9 | 0.39 | 0.295 | ||
Saliva | 8 | 0.71 | 0.047 |
Fluid | Duration of smoking | The age of smoking initiation | |||||
|---|---|---|---|---|---|---|---|
npairs | ρ | p | npairs | ρ | p | ||
The correlations between the duration of smoking and the age of smoking initiation and serum and saliva Cd concentrations at baseline (t0) | Serum | 11 | − 0.57 | 0.066 | 11 | − 0.37 | 0.265 |
Saliva | 8 | − 0.13 | 0.754 | 8 | − 0.45 | 0.269 | |
Fluid | Group | ||||||
|---|---|---|---|---|---|---|---|
Non-smokers | Smokers | ||||||
npairs | ρ | p | npairs | ρ | p | ||
The correlation between the concentrations of Cd in serum and saliva before treatment and the age of the participants | Serum | 12 | 0.09 | 0.782 | 11 | − 0.71 | 0.014 |
Saliva | 7 | − 0.21 | 0.662 | 8 | − 0.36 | 0.385 | |
