Antonio Accorsi

Lack of correlation between environmental or biological indicators of benzene exposure at parts per billion levels and micronuclei induction

Despite growing concern for possible carcinogenic effects associated with environmental benzene exposure in the general population, few studies exist at parts per billion (ppb) levels. We investigated the existence of a relationship between airborne/biological measurements of benzene exposure (i.e., personal/area sampling and unmodified urinary benzene/trans,trans-muconic acid; t,t-MA) and micronuclei induction (cytochalasin B technique) among exposed chemical laboratory workers (n=47) and traffic wardens (n=15). Although urinary t,t-MA (106.9+/-123.17 microg/L(urine)) correlated (R(2)=0.37) with urinary benzene (0.66+/-0.99 microg/L(urine)), neither biological measurement correlated with environmental benzene exposure (14.04+/-9.71 microg/m(3); 4.39+/-3.03ppb), suggesting that, at ppb level (1ppb=3.2 microg/m(3)), airborne benzene constitutes a fraction of the total intake. Traffic wardens and laboratory workers had comparable numbers of micronuclei (4.70+/-2.63 versus 5.76+/-3.11; n.s.), similar to levels recorded in the general population. With univariate/multivariate analysis, no association was found between micronuclei induction and air/urinary benzene exposure variables. Notably, among the personal characteristics examined (including age, gender, smoking, drinking, etc.), high body mass index correlated with micronuclei induction while, among females, use of hormonal medication was associated with less micronuclei. Thus the present study provides no evidence that ppb levels of environmental benzene exposure appreciably affect micronuclei incidence (against the background of other relevant factors). However, this should not be taken as an argument against efforts aiming to reduce environmental benzene pollution.

Exposure of personnel to sevoflurane during paediatric anaesthesia: influence of professional role and anaesthetic procedure

Background and objective: This study was performed to determine the individual exposure of paediatric operating theatre personnel to sevoflurane and to evaluate the impact of inhalation induction and various airway approaches on exposure to airborne sevoflurane. Methods: Mean individual environmental (workplace air) exposure to sevoflurane and a biomarker of exposure (urinary sevoflurane) were monitored in 36 subjects (10 anaesthetists, 10 surgeons, 12 nurses and 4 auxiliary personnel) working in two paediatric operating rooms. Results: Environmental and urinary values were significantly greater in anaesthetists compared with other groups, with median values of 0.65 ppm (interquartile range 1.36; 95th percentile 4.36) for breathing zone sevoflurane and 2.1 μgL−1 urine (interquartile range 2.6; 95th percentile 7.6) for urinary sevoflurane. Anaesthetists exceeded the 2 ppm maximum allowed environmental concentration recommended by the National Institute for Occupational Safety and Health in 4 of 22 cases (18.1%). A positive correlation was found between the number of patients undergoing inhalational induction each day and mean values of breathing zone and urinary sevoflurane. An increase in the number of daily laryngeal mask insertions, or the use of rigid bronchoscopy, are statistically related to higher environmental and urinary values (P < 0.01 and <0.00001 for breathing zone sevoflurane, P < 0.05 and <0.01 for urinary sevoflurane, respectively). Conclusions: Anaesthesia with sevoflurane can pose a hazard of chronic exposure with anaesthetists having the highest risk. Endotracheal intubation offers considerable protection against exposure. Routine anaesthesia using a standard facemask, a laryngeal mask or rigid bronchoscopy are risk factors for increased anaesthetic exposure.

FAILURE OF URINARY trans,trans-MUCONIC ACID AS A BIOMARKER FOR INDOOR ENVIRONMENTAL BENZENE EXPOSURE AT PPB LEVELS

Benzene is a widespread pollutant whose main source in the environment is automotive emission. There is increasing interest in the exposure of the population to this pollutant as benzene is present also in the indoor environment due to cigarette smoke, drinking water, and food. The aim of this study was to evaluate, in an adult nonsmoking population not occupationally exposed to benzene, whether it is possible to detect differences in the urinary concentration of trans,trans-muconic acid (t,t-MA) between low and high environmental exposure to benzene. A study sample of 31 employees working in pharmacies in a large town in Italy with low environmental exposure to benzene (4.8 µg/m³) was compared to a high (8.1 µg/m³) benzene exposure group. Analysis of urinary t,t-MA was carried out by high-performance liquid chromatography (HPLC; photodiode array detector); analysis of environmental benzene samples was by gas chromatography/mass spectroscopy (GC-MS). The statistical analysis revealed no significant differences in urinary levels of t,t-MA of subjects with high (mean concentration: 157.9 µg/gcreatinine) versus low exposure (mean concentration: 114.2 µg/gcreatinine). Data show that it is difficult to correlate urinary t,t-MA with benzene exposure at parts per billion levels.

Lack of sensitivity of urinary trans, trans-muconic acid in determining low-level (ppb) benzene exposure in children

Abstract Benzene is a widespread pollutant of which the main source in the outside environment is automotive traffic. Benzene is also present in cigarette smoke, and small quantities exist in drinking water and food; all of these sources contribute to pollution of indoor environments. Benzene exposure may be studied with biologic indicators. In the present study, the authors evaluated whether differences in urinary concentrations of trans, trans-muconic acid (t,t-MA) were detectable in a sample of 150 children and if the chemical was correlated with environmental exposures to low levels of benzene. The children attended primary schools that had significantly different—but low—environmental benzene levels. Analysis of urinary t,t-MA was achieved with high-performance liquid chromatography (photodiode array detector), and analysis of passive air samplers for benzene was performed with gas chromatography-mass spectrometry. Statistical analysis (Kruskal-Wallis test) indicated that differences in urinary levels of t,t-MA in children from urban and rural areas were not statistically significant (p = .07), nor were there significant differences between children with and without relatives who smoked (p = .69). As has been shown in other studies of children and adults, results of our study evidenced (1) the difficulty of correlating concentrations of urinary biomarkers with environmental exposure to benzene at a parts-per-billion level (i.e., traffic and environmental tobacco smoke) and, consequently, (2) the lack of specificity of t,t-MA as a biological indicator for the study of a populations exposure.

Enflurane as an internal standard in monitoring halogenated volatile anaesthetics by headspace gas chromatography–mass spectrometry

Recently. we proposed the use of a run-only headspace-GC-MS method for the biological monitoring of ppb concentrations of unmodified volatile anaesthetics (isoflurane, sevoflurane and halothane, plus nitrous oxide) in post-shift urine of operating theatre personnel. The adoption of enflurane (a volatile anaesthetic no longer used in clinical practice) as a poper and viable internal standard improves intra-day and inter-day accuracy in halide quantitation, providing a GC-MS reference method useful in the practice of biomonitoring of exposure of operating theatre personnel to modern volatile anaesthetics (isoflurane. sevoflurane, halothane).