%0 Journal Article
%T A case study of benzene urinary biomarkers quantification: the comparison between pre- and post-shift samples improves the interpretation of individual biological monitoring data
%A Miraglia N
%A Genovese G
%A Basilicata P
%A Pieri M
%J Prevention and Research : International Open Access Journal of Prevention and Research in Medicine
%D 2013
%I Prevention and Research
%R 10.7362/2240-2594.121.2013
%X Background: Benzene is a common industrial chemical and a component of tobacco smoke and of gasoline. It is widely used as chemical intermediate and is a constituent of crude oil and fuels with a large distribution in the environment owing to vehicles engine emissions. Besides, smoking tobacco is regarded as another major source of environmental benzene exposure. As a consequence, benzene is an ubiquitous pollutant of the outdoor and indoor human environment, and the occupational/environmental exposure concerns a large population. Data from epidemiological studies evidence benzene toxicity to humans. In fact, it is classified as a carcinogen (group A1) by the American Conference of Governmental Industrial Hygienists (ACGIH), suggesting a threshold limit value-time weighted average (TLV-TWA) of 0.5ppm.Hence health risks prevention strategies allowing to discriminate between occupational and non-occupational exposure are essential. Objective: Evaluation of occupational exposure to benzene by comparison between urinary biomarkers levels in pre- and post-shift samples in biological monitoring (BM) investigations. Methods: The biological monitoring of 14 (smoker and non-smoker) workers of a refueling station was performed. Urinary benzene (UB) and trans,trans-muconic acid (t,t-MA) were used as biological markers. The determinations of UB and t,t-MA were performed by head space-solid phase microextraction followed by gas chromatography/mass spectrometry operating in Selected Ion Monitoring mode and High Performance Liquid Chromatography/UltraViolet detection, respectively. Urinary creatinine levels were also determined.Urine collection was initially performed after work-shift (first BM campaign) as suggested by ACGIH. Given difficulties in interpreting data without statistical basis, the urine collection was repeated before and after the work-shift (second BM campaign). Results and Discussion: During the first BM campaign, contrasting results were found. Some workers showed low UB concentrations with respect to t,t-MA ones and vice versa, and although most investigated subjects presented UB and t,t-MA levels below Biological Equivalents (BEs) values and ACGIH¡¯s BEI, various exceptions were found, either with exceeding UB or with exceeding t,t-MA levels.According to the ACGIH, the high biomarkers levels found in post-shift urine would have suggested an occupational exposure to benzene. Nevertheless, ACGIH¡¯s BEI are defined on statistical basis and should not be used when individual data are interpreted, in fact results obtained by monitoring post-shift urine o
%K benzene
%K biological monitoring
%K pre-shift urine
%K ubiquitous chemical agents
%U http://www.preventionandresearch.com/a-case-study-of-benzene-urinary-biomarkers-quantification-the-comparison-between-pre-and-post-shift-samples-improves-the-interpretation-of-individual-biological-monitoring-data.html