General characteristics of the workers by urinary total OH-PAHs levels*.

BMI, body mass index; HF, high frequency; HRV, heart rate variability; Hsp70, heat shock protein 70; IL-6, interleukin-6; LF, low frequency; RMSSD, root mean square of successive differences in adjacent NN intervals; SDNN, standard deviation of NN intervals; TP, total power.*Values are presented as mean ± SD, n (%), or median (25th, 75th quartile) unless otherwise indicated.aΣOH-PAHs was dichotomized at the 33th percentile as either low (≤8.84 μg/mmol creatinine) or high (>8.84 μg/mmol creatinine). bP-values were calculated by χ2 test for categorical variables, and t-test for continuous variables. c HRV indices were natural log transformed.