Saturday, March 07, 2009

Danger of Benzene in the Street

Toxicology LettersVolume 181, Issue 1, 10 September 2008, Pages 25-30
Biological monitoring of low benzene exposure in Italian traffic policemen
Paola Maninia, b, , , Giuseppe De Palmac, Roberta Andreolia, b, Diana Polib, Marta Petyxd, Massimo Corradia, Antonio Muttia and Pietro Apostolic
aLaboratory of Industrial Toxicology, Department of Clinical Medicine, Nephrology and Health Sciences, University of Parma, Via Gramsci 14, 43100 Parma, Italy
bISPESL-National Institute for Occupational Safety and Prevention, Research Center at the University of Parma, Via Gramsci 14, 43100 Parma, Italy
cDepartment of Experimental and Applied Medicine, Occupational Medicine and Industrial Hygiene, University of Brescia, Piazzale Spedali Civili 1, 25123 Brescia, Italy
dISPESL-National Institute for Occupational Safety and Prevention, Department of Occupational Medicine, Via di Fontana Candida, 00141Monteporzio Catone, Rome, Italy

A comparative evaluation of urinary biomarkers was carried out to characterize benzene exposure in a group of 100 traffic policemen of the city of Parma (Italy). All subjects were monitored once, in two consecutive days characterized by similar climatic conditions but preceded by two windy days. Benzene ambient concentration measured by municipal air monitoring stations was 1 μg/m3 (Day 1) and 2 μg/m3 (Day 2). Personal exposure to ambient concentrations of benzene, toluene, ethylbenzene and xylene (BTEX) was assessed by using Radiello® passive-diffusive samplers in a subgroup of 24 workers. Benzene metabolites, t,t-muconic acid (t,t-MA) and S-phenylmercapturic acid (S-PMA) were determined by isotopic dilution liquid chromatography–tandem mass spectrometry on spot urine samples collected at the end of the shift. Urinary benzene (U-B) was determined by solid-phase microextraction gas chromatography–mass spectrometry. Airborne benzene concentration expressed as median [and interquartile range] was 6.07 [0.28–9.53] μg/m3, as assessed by personal sampling. Urinary concentrations of biomarkers in the whole group were 41.8 [34.1–89.8] μg/g creatinine for t,t-MA, 0.67 [0.23–1.32] μg/g creatinine for S-PMA, and 0.16 [0.13–0.26] μg/l for U-B. Smokers eliminated significantly higher concentrations of unchanged BTEX and benzene metabolites than non-smokers (p < n =" 31)" p =" 0.003,">>>>>>>>>>>>>>>>>>>>>
BrooklynDodger(s) comment: The investigators were interested in the biomonitoring, but the Dodger(s) is(are) interested in how much benzene vapor was in the air on the average. The median exposure, converted to the ppm units for vapor exposures, was about .002 ppm or 2 pbb. EPA risk estimate, based on a Crump estimate in 1994, puts this risk somewhere above 1/100,000 and less than 1/10,000. The Dodger(s) isn't(aren't) sure whether more recent mortality studies wouldn't push the risk higher

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