Roberta Andreoli

The Effect of Inhaled Chromium on Different Exhaled Breath Condensate Biomarkers among Chrome-Plating Workers

Chromium is corrosive, cytotoxic, and carcinogenic for humans and can induce acute and chronic lung tissue toxicity. The aim of this study was to investigate Cr levels in exhaled breath condensate (EBC) of workers exposed to Cr(VI) and to assess their relationship with biochemical changes in the airways by analyzing EBC biomarkers of oxidative stress, namely, hydrogen peroxide (H2O2) and malondialdehyde (MDA). EBC samples were collected from 24 chrome-plating workers employed in a chrome-plating plant both before and after the Friday work shift and before the work shift on the following Monday. Cr-EBC levels increased from the beginning (5.3 μg/L) to the end of Friday (6.4 μg/L) but were considerably lower on Monday morning (2.8 μg/L). A similar trend was observed for H2O2-EBC levels (which increased from 0.36 μM to 0.59 μM on Friday and were 0.19 μM on Monday morning) and MDA-EBC levels (which increased from 8.2 nM to 9.7 nM on Friday and were 6.6 nM on Monday). Cr-EBC levels correlated with those of H2O2-EBC (r = 0.54, p < 0.01) and MDA-EBC (r = 0.59, p < 0.01), as well as with urinary Cr levels (r = 0.25, p < 0.05). The results of this study demonstrate that EBC is a suitable matrix that can be used to investigate both Cr levels and biomarkers of free radical production sampling the epithelial-lining fluid of workers exposed to Cr(VI).

Comparison between exhaled and sputum oxidative stress biomarkers in chronic airway inflammation

The aim of the present study was to compare aldehyde levels resulting from lipid peroxidation in exhaled breath condensate (EBC) and induced sputum (IS) supernatant of subjects with asthma and chronic obstructive pulmonary disease (COPD). Aldehydes (malondialdehyde (MDA), acrolein, n-hexanal (C6), n-heptanal (C7), n-nonanal (C9), 4-hydroxynonenal (HNE) and 4-hydroxyhexenal (HHE)) in both biological fluids were measured by liquid chromatography-tandem mass spectrometry. MDA concentrations in sputum were 132.5 nM (82.5–268.8) and 23.7 nM (9–53.7) in EBC. Similarly, C6, C7 and C9 concentrations in IS were 1.5–4.7-fold higher than in EBC. Acrolein levels were 131.1 nM (55.6–264.6) in IS and 45.3 nM (14.4–127.1) in EBC. The concentrations of HNE and HHE in IS were not significantly different from the levels in EBC. Aldehyde levels in EBC did not show any correlation with aldehyde levels in IS or with differential sputum cellular count. In COPD, MDA in EBC, but not its IS counterpart, was negatively correlated with the severity of disease. In conclusion, the data presented here show that aldehydes can be detected in both exhaled breath condensate and supernatant of induced sputum, but that their relative concentrations are different and not correlated with each other. Therefore, with regard to lipid peroxidation products, exhaled breath condensate and induced sputum must be considered as independent techniques.

Influence of condensation temperature on selected exhaled breath parameters

BackgroundThe effects of changes in cooling temperature on biomarker levels in exhaled breath condensate have been little investigated. The aim of the study was to test the effect of condensation temperature on the parameters of exhaled breath condensate and the levels of selected biomarkers.MethodsExhaled breath condensate was collected from 24 healthy subjects at temperatures of -10, -5, 0 and +5 C degrees. Selected parameters (condensed volume and conductivity) and biomarkers (hydrogen peroxide, malondialdehyde) were measured.ResultsThere was a progressive increase in hydrogen peroxide and malondialdehyde concentrations, and condensate conductivity as the cooling temperature increased; total condensate volume increased as the cooling temperature decreased.ConclusionThe cooling temperature of exhaled breath condensate collection influenced selected biomarkers and potential normalizing factors (particularly conductivity) in different ways ex vivo. The temperature of exhaled breath condensate collection should be controlled and reported.

Biological monitoring of low benzene exposure in Italian traffic policemen.

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 microg/m(3) (Day 1) and 2 microg/m3 (Day 2). Personal exposure to ambient concentrations of benzene, toluene, ethylbenzene and xylene (BTEX) was assessed by using Radiello((R)) 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] microg/m(3), as assessed by personal sampling. Urinary concentrations of biomarkers in the whole group were 41.8 [34.1-89.8] microg/g creatinine for t,t-MA, 0.67 [0.23-1.32] microg/g creatinine for S-PMA, and 0.16 [0.13-0.26] microg/l for U-B. Smokers eliminated significantly higher concentrations of unchanged BTEX and benzene metabolites than non-smokers (p < 0.05). When traffic policemen were distinguished into indoor (n=31) and outdoor workers, no significant differences were observed for either airborne benzene or urinary biomarkers. Significantly lower concentrations of S-PMA and U-B were determined in samples collected at Day 1 as compared to Day 2 (p < 0.0001 and p = 0.003, respectively) suggesting that these biomarkers are enough sensitive and specific to detect changes in airborne benzene concentration even at few microg/m(3).

Determination of naphthalene metabolites in human urine by liquid chromatography-mass spectrometry with electrospray ionization

The use of a liquid chromatography-electrospray mass spectrometry system was investigated for the quantitative analysis of naphthalene metabolites (alpha-naphthol, alpha-naphthylglucuronide and beta-naphthylsulphate) in untreated urine samples. Chromatography was carried out under ion-suppressed reversed-phase conditions, by using high-speed (3 cm, 3 microns) columns and formic acid (2 mM) as a modifier in the mobile phase. The ionization was obtained in the negative-ion mode. Linearity, sensitivity and precision of the method were explored by operating in selected-ion monitoring mode. The method was applied to the quantitative analysis of naphthalene metabolites in untreated urine samples from workers in a naphthalene producing plant. Solid-phase extraction was used for sample clean-up and trace enrichment. Liquid chromatography-tandem mass spectrometry experiments were performed for confirmation purposes.

Atmospheric pressure chemical ionization liquid chromatography/mass spectrometry in cholesterol oxide determination and characterization

An atmospheric pressure chemical ionization liquid chromatography/mass spectrometry (APCI-LC/MS) system was evaluated for the analysis of cholesterol oxidation products (COPs). High performance liquid chromatography separation of these compounds was performed under reversed-phase chromatographic conditions at 1 mL/min flow rate. Useful mass spectra for confirmation and quantitation purposes were obtained with positive-ion detection. The influence of several parameters, such as the temperature of the heated nebulizer interface, the voltage applied to the orifice and to the ring electrode on the mass spectra of the analytes, was studied and optimized in order to obtain the best sensitivity. Linearity, sensitivity and precision of the method were determined operating in the selected-ion monitoring mode. Detection limits were in the range 0.2–0.8 ng for all the compounds with linear calibration graphs in the 0.1–10 mg/L concentration range. The method was applied to the quantitative analysis of COPs in lyophilized beef preparations, and results were compared with those obtained using LC/UV and LC/MS with particle beam interface.

Liquid chromatography-electrospray tandem mass spectrometry of acidic monoamine metabolites

A new method based on liquid chromatography-tandem mass spectrometry has been developed for the determination of monoamine metabolites, i.e., homovanillic acid (HVA), vanilmandelic acid (VMA), 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) in human urine. Analytes were separated on a C16 amide (5 cm, 5 microm) column and ionized by negative ion electrospray. Operating in the selected-reaction monitoring mode, linearity was established over three-orders of magnitude and limits of detection were in the range 30-70 microg/l. Precision calculated as RSD was within 0.8-5.2% for all intra- and inter-day determinations. The method was applied to the quantitative analysis of monoamine metabolites in 700 urine samples from occupationally (adults) and environmentally (both children and adults) exposed people living in areas with different soil contamination from lead. The urinary excretion of monoamine metabolites was significantly higher (P<0.001) in the subgroup of children living in polluted areas as compared to the control group (HVA, 6.03 vs. 4.57 mg/g creatinine; VMA, 5.33 vs. 4.37 mg/g creatinine; 5-HIAA 3.24 vs. 2.45 mg/g creatinine). In adults belonging to both groups of subjects occupationally and environmentally exposed, no differences were detected in the urinary concentration of monoamine metabolites. However, adults showed lower values of HVA (2.57 mg/g creatinine), VMA (2.17 mg/g creatinine) and 5-HIAA (2.09 mg/g creatinine) as compared to children groups.

A tobacco-related carcinogen: assessing the impact of smoking behaviours of cohabitants on benzene exposure in children

Background Secondhand smoke (SHS) represents a major preventable cause of morbidity for communities, especially for children, who are more susceptible than adults to the adverse effects of passive smoking. SHS contains several carcinogens, including benzene. Objective To investigate the role of household characteristics and the smoking behaviours of cohabitants in predicting SHS-derived benzene exposure levels. Methods In this cross-sectional study, 122 children (aged 5–11 years old) were selected from a school in rural Italy. Characteristics of their home environment and the smoking habits of the childrens cohabitants were obtained via questionnaire, and urinary unmodified benzene (u-UB) and cotinine (a specific nicotine metabolite) levels were determined from spot urine samples. Results Significant differences between SHS-exposed and SHS-unexposed children were found with respect to u-UB levels (median values 359.50 and 92.50 ng/litre, respectively; p<0.001). The excretion of u-UB increased significantly in parallel to increased SHS exposure as follows: unexposed to SHS (median value 92.50 ng/litre)<cohabitant(s) smoker(s) not smoking inside the home (282.00 ng/litre)<cohabitant(s) smoking inside the home only when children are out (314.50 ng/litre)<cohabitant(s) smoking inside the home even when children are in (596.00 ng/litre). The difference between groups was significant (p=0.019). Conclusions Although smoke-free legislation has transformed the smoking behaviours of some, domestic environments remain an important source of SHS exposure for children. This fact holds true even in the case of parents and other cohabitants who believe they are fully protecting children by smoking only outdoors or at home only when the children are not present. These findings should be included in Italian community-level health promotion interventions for discouraging tobacco use.

Urinary trans, trans-muconic acid and S-phenylmercapturic acid are indicative of exposure to urban benzene pollution during childhood ☆

The aims of the study were to evaluate the feasibility of urinary trans, trans-muconic acid (u-t,t-MA) and urinary S-phenylmercapturic acid (u-SPMA) as markers of exposure to urban benzene pollution for biomonitoring studies performed on children and to investigate the impact that creatinine correction may have on the classification of children exposure status. U-t,t-MA, u-SPMA, u-cotinine, and u-creatinine levels were measured in urine samples of 396 Italian children (5-11 years) living in three areas with different degrees of urbanisation (very, fairly and non-urban). The median u-SPMA levels significantly increased with increased urbanisation: non-urban (0.19 μg/L; 0.22 μg/g creatinine)<fairly urban (0.28 μg/L; 0.28 μg/g creatinine)<very urban group (0.92 μg/L; 0.90 μg/g creatinine). Differences in the levels of u-t,t-MA excretion related to the degree of urbanisation were revealed only by multivariate analyses. Neither u-SPMA nor u-t,t-MA levels were influenced by environmental tobacco smoke (ETS) exposure. Athletic activity during the sampling day was negatively associated with u-SPMA in the model built with u-SPMA adjusted for creatinine, but not in the model where unadjusted u-SPMA was used. This finding demonstrates that u-creatinine correction may alter the results when an independent variable is unrelated to the chemical concentration itself but is related to the u-creatinine levels. These results suggest that both u-SPMA and u-t,t-MA are indicative for assessing environmental benzene exposure in children (exposed and unexposed to ETS) when urine sample is collected at the end of the day. However, u-SPMA is more reliable because u-t,t-MA, also a metabolite of sorbic acid, is less specific for exposure to low levels of benzene. To avoid the possible confounding effect of creatinine correction, it is better to use u-creatinine as additional independent variable in multiple linear regression analyses for evaluating the independent role of the covariates on the variability of u-t,t-MA and u-SPMA levels.

Quantitative determination of urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine, 8-oxo-7,8-dihydroguanine, 8-oxo-7,8-dihydroguanosine, and their non-oxidized forms: daily concentration profile in healthy volunteers.

We developed a new method for the simultaneous quantitative determination of 8-oxo-7,8-hydro-2′-deoxyguanosine (8-oxodGuo), 8-oxo-7,8-dihydroguanine (8-oxoGua), 8-oxo-7,8-dihydroguanosine (8-oxoGuo), and the corresponding non-oxidized forms, 2′-deoxyguanosine (dGuo), guanine (Gua) and guanosine (Guo), in human urine samples by liquid chromatography–tandem mass spectrometry. Differences in the ionization of analytes in different urine batches with variable matrix effects were effectively compensated for by internal standardization with stable isotope-labelled analytes. The method was sensitive enough to allow the determination of background levels of these biomarkers and was applied to characterize the inter- and intraindividual variability of biomarkers in the diurnal profile of concentrations in 24 healthy volunteers. When normalized for creatinine, none of the biomarkers was affected by sampling time, thus ruling out any circadian rhythm for nucleic acid oxidation in urine.