Comparisons of Complete Blood Counts and Urinary Benzene Metabolites After Exposure to Benzene

Abstract

Background. The effects of low level benzene exposure are still controversial. The aim of our study was to clarify the relationship of the hematological effects of low level benzene exposure. Methods. We conducted a cross-sectional study in which 334 workers with different degrees of exposure to benzene were enrolled. According to the levels of urinary benzene metabolites concentrations, markers of benzene exposure that were determined by high performance liquid chromatography. The participants were divided into three groups: high exposure workers (n = 107), low exposure workers (n = 182), and non-exposed workers which made up the control group (n = 45). Complete blood count was measured using an automatic cell counter to determine outcomes of benzene exposure. Results. Means of urinary concentrations of hydroquinon, t,t-muconic acid, and cathecol were 0.51±0.43 mg/g cre,0.39±0.33 mg/g cre, 1.04±0.76 mg/g ere. No significant differences among groups were found. The white blood cell (WBC), lymphocyte, monocyte, eosinophil counts and hemoglobin (Hgb) levels were significantly higher in the high exposure group than in the low exposure group or control group (ANOVA, all p ＜ 0.05). After adjusting for age, sex, and habits of tobacco use and alcohol consumption, the benzene exposure significantly correlated with the Hgb level ( β=0.46,p＜ 0.05). Tobacco use significantly correlated with WBC count and Hgb level (both β= 0.01, P ＜ 0.05) Conclusions. Our study suggests that low levels of benzene exposure (＜ 5 ppm) may increase hemoglobin levels. Although of No. clinical significance, it may reflect an early hematological effect. Further longitudinal studies are needed to confirm the relationship.