期刊名称:African Journal of Environmental Science and Technology
电子版ISSN:1996-0786
出版年度:2011
卷号:5
期号:7
页码:464-472
DOI:10.5897/AJEST11.054
语种:English
出版社:Academic Journals
摘要:Exposure to high-concentration of benzene in polluted air has been associated with bone marrow deficiency, aplastic anemia and leukemia. However, epidemiological studies have reported conflicting data following human exposure to benzene levels below 1 ppm (that is, 3.2 mg/m3). Therefore we investigated the influence of outdoor air benzene on peripheral blood cells among exposed motor-bike-taxi drivers (MBTD) in whichspecific IgG antibodies against reactive benzene metabolites, such as hydroquinone (HQ) and para-benzoquinone (p-BQ) are identified and quantified for further use as biomarker of exposure. We compared 144 MBTD with 30 unexposed age and sex-matched controls. The mean age ± SD (95% CI) were: MBTD 39.5 ± 7.82 (38.2 - 40.7) and village residents 40.3 ± 10.56 (39.1-43.0). Personal benzene exposure was assessed using GABIE diffusive samplers. The levels of specific IgG antibodies to HQ and p-BQ were determined by ELISA. The peripheral blood cells were counted by an automated analyzer. Benzene, Toluene and Xylene levels were much higher in MBTD in comparison to the control group. Benzene exposure levels ranged from 0.012 to 0.550 ppm in MBTD. Their average exposure level per one week was 0.126±0.206 ppm. Accordingly, MBTD had significantly higher levels of specific IgG antibodies to HQ and p-BQ compared to the controls (p< 0.001). WBC, lymphocytes, eosinophils and platelets were significantly decreased in MBTD, whereas RBC and other blood cell numbers remained unchanged. Total WBC, lymphocytes and eosinophils counts were decreased among exposed MBTD compared to unexposed controls. We suggest the use of these blood parameters together with specific IgG antibodies to HQ and p-BQ as biomarkers in biological monitoring of low level benzene exposure. Larger studies are however required to validate this new approach of health survey in workers exposed to benzene.
关键词:Benzene; motor-bike-taxi drivers; specific immune responses; peripheral blood cell count