Interaction between Occupational and Non-Occupational Arsenic Exposure and Tobacco Smoke on Lung Cancerogenesis: A Systematic Review

Although a higher lung cancer risk has been already associated with arsenic exposure, the contribution of arsenic and its compounds to the carcinogenic effects of other agents, such as tobacco smoke, is not well characterized. This systematic review examined the relationship between occupational and non-occupational arsenic exposure and tobacco smoking on lung cancer risk using papers published from 2010 to 2022. Two databases, PUBMED and Scifinder, were used for the searches. Among the sixteen human studies included, four were about occupational exposure, and the others were about arsenic in drinking water. Furthermore, only three case-control studies and two cohort studies evaluated an additive or multiplicative interaction. The interaction between arsenic exposure and tobacco smoke seems to be negligible at low arsenic concentrations (<100 μg/L), while there is a synergistic effect at higher concentrations. Finally, it is not yet possible to assess whether a linear no-threshold (LNT) model for lung cancer risk can be applied to the co-exposure to arsenic and tobacco smoke. Although the methodological quality of the included studies is good, these findings suggest that rigorous and accurate prospective studies on this topic are highly needed.

Interaction between occupational radon exposure and tobacco smoke: a systematic review

INTRODUCTION

: The risk of lung cancer from radon exposure was small compared to tobacco smoking (BEIR VI), but the relationship between these two carcinogenic agents has yet to be quantitatively estimated. The objective of this systematic review was to evaluate the last evidences on the role of radon occupational exposures and tobacco smoke on lung cancer risk.

AREAS COVERED

: Thirteen articles were selected using two different databases, PubMed and Scifinder, and were limited to those published from 2010 to 2021. The reference list of selected studies was reviewed to identify other relevant papers.

EXPERT OPINION

: Seven papers included in this systematic review did not deal with the multiplicative or the additive type of interaction between radon exposure and smoking habit. Six papers discussed the nature of this interaction with a prevalence of the sub-multiplicative model compared to the additive one. Altogether, smoking adjustment did not change significantly lung cancer risk. The included studies might constitute a starting point for updating the models for risk assessment in occupational and residential scenarios, promoting concomitantly the exposure reduction to radon and other cofactors, as recently introduced by Italian Legislative Decree number 101 of 31 July 2020, an application of Euratom Directive 59/2013.

Single centre experience in 1202 biological prosthesis: a comparison between sutured, sutureless and surgical transcatheter aortic valve

Background/Introduction

Different types of bio-prosthesis are now available for the treatment of aortic valve disease.

In absence of the “ideal” heart valve prosthesis, the best choice may be customized on the basis of the patient's profile.

Purpose

The aim of this study was to compare results in different subgroups of bio-prosthesis in elderly patients (&gt;75 years old) undergoing conventional or surgical trans-catheter aortic valve replacement (AVR). Primary outcome was all cause mortality, secondary outcomes were: early post-operative complications (stroke, AV-block, acute kidney injury requiring temporary dialysis), freedom from structural vascular disease (SVD) and from re-operation.

Methods

In this retrospective study we analysed 1202 patients over 75 years old, underwent AVR from 2002 to 2018. Inclusion criteria were: age &gt;75 years underwent AVR; we divided our population in 3 groups according to different strategy: primary aortic valve replacement with sutured (group 1, n=1005), sutureless (group 2, n=103) or surgical trans-catheter aortic valve replacement (group 3, n=94). Exclusion criteria: concomitant cardiac procedure other than coronary artery by-pass graft (CABG) or endocarditis.

Patient and disease characteristics are described as numbers and percentages, continuous data were expressed using mean and standard deviation. Differences between groups were evaluated using either Student t-test or Mann-Whitney U test or ANOVA test. Survival curves of the primary outcome and freedom from secondary outcomes were built with the Kaplan-Meier method.

Results

The mean age of the overall population was 80.5±3.6 years with a mean STS score of assessed at 2.79±2.2% (2.27±1.0 for standard AVR, 3.3±2.2% for sutureless and 6.4±4.5 for S-TAVR, p-value&lt;0.001). Early outcomes are depicted in figure 1. The overall 30-day mortality was 2.9%; among the different groups we observed 2.3%, 4.9% and 7.2% for sutured, sutureless and surgical-TAVR, respectively (p-value=0.01). The groups statistically differed also for permanent pacemaker implantation (sutured AVR 2.2%, sutureless AVR 4.9%, TAVR 9.6% (p-value&lt;0.001) and acute renal failure requiring temporary dialysis sutured AVR 3%, Sutureless AVR 1.9% and Surgical TAVR 9.6% (p-value=0.004). The survival rate at follow-up was significantly different among group (log-rank &lt;0.001, figure 2). Instead, freedom from reoperation was similar between cohorts (figure 2.)

Conclusion(s)

The outcomes of surgical AVR in a elderly population could be safely guaranteed with different biological prosthesis and operative techniques. A patient tailored approach should be always advised to improve current available transcatheter options.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Occupational exposure to graphene and silica nanoparticles. Part II: pilot study to identify a panel of sensitive biomarkers of genotoxic, oxidative and inflammatory effects on suitable biological matrices

The available biomonitoring studies on workers producing/handling nanomaterials (NMs) focused on potential effects on respiratory, immune and cardio-vascular system. Aim of this study was to identify a panel of sensitive biomarkers and suitable biological matrices to evaluate particularly genotoxic and oxidative effects induced on workers unintentionally exposed to graphene or silica nanoparticles during the production process. These nanomaterials have been chosen for 'NanoKey' project, integrating the workplace exposure assessment (reported in part I) with the biomonitoring of exposed workers reported in the present work. Simultaneously to workplace exposure characterization, we monitored the workers using: Buccal Micronucleus Cytome (BMCyt) assay, fpg-comet test (lymphocytes), oxidized DNA bases 8-oxoGua, 8-oxoGuo and 8-oxodGuo measurements (urine), analysis of oxidative stress biomarkers in exhaled breath condensate (EBC), FENO measurement and cytokines release detection (serum). Since buccal cells are among the main targets of NM occupational exposure, particular attention was posed to the BMCyt assay that represents a noninvasive assay. This pilot study, performed on 12 workers vs.11 controls, demonstrates that BMCyt and fpg-comet assays are the most sensitive biomarkers of early, still reparable, genotoxic and oxidative effects. The findings suggest that these biomarkers could represent useful tools for the biomonitoring of workers exposed to nanoparticles, but they need to be confirmed on a high number of subjects. However, such biomarkers don't discriminate the effects of NM from those due to other chemicals used in the NM production process. Therefore, they could be suitable for the biomonitoring of workers exposed to complex scenario, including nanoparticles exposure.

Non-invasive techniques to assess restrictive lung disease in workers exposed to free crystalline silica

Objectives:

To compare the reliability of spirometry and body plethysmography in detecting restrictive lung disease in clay excavation workers exposed to free crystalline silica (FCS). The exhaled breath condensate (EBC) biomarkers of oxidative stress were also assessed in order to evaluate early lung damage.

Methods:

The study involved 62 workers (58 males and 4 females) at a company that extracts and processes clay.

Results:

Body plethysmography (total lung capacity below the lower normal limit) and spirometry respectively indicated restrictive pattern prevalence rates of 22.6% and 1.6%. EBC 4-hydroxynonenale levels were not sufficiently sensitive to highlight a restrictive deficit, but did distinguish low and high rates of occupational exposure. There was no correlation between plethysmography values and the intensity or duration of exposure.

Conclusions:

Only one out of 14 cases of restrictive deficit diagnosed on the basis of body plethysmography values was also identified by means of spirometry. This finding supports the need to use body plethysmography in the health surveillance of clay workers exposed to FCS.

IL-8 and pH Values in Exhaled Condensate after Antibiotics in Cystic Fibrosis Children

Interleukin (IL)-8 is a major factor in inflammatory response and the IL-8 levels in exhaled breath condensate (EBC) may be used as a marker of airway inflammation. Airway acidification is implicated in the pathophysiology of obstructive airway diseases and pH EBC values have been used as a marker of airway acidification. The aim of our study is to investigate whether IL-8 and pH levels in EBC of cystic fibrosis (CF) children with respiratory exacerbations change after antibiotic treatment. Lung function, IL-8 and pH EBC values were measured in fifteen CF children (mean age 11 years) with acute exacerbation before (T0) and after two weeks (T1) of antibiotic treatment. IL-8 and pH values were compared by paired t-test. A p<0.05 was considered significant. IL-8 EBC levels decreased after antibiotic treatment (TO 0.36±0.03pg/ml vs T1 0.28±0.03pg/ml; p=0.03) and pH values increased (TO 7.3610.09 vs T1 7.61±0.08; p=0.04). Results suggest possible application of EBC as a non-invasive tool to monitor efficacy of antibiotic treatment in CF patients.

An investigation of multimorbidity measures as risk factors for pneumonia in elderly frail patients admitted to hospital

OBJECTIVES

To investigate the association of different chronic comorbidities, considered singularly and together in Cumulative Illness Rating Scale (CIRS) indexes, with pneumonia diagnosis in a group of elderly frail hospitalized patients.

DESIGN AND METHODS

With a retrospective cohort design, all clinical records of frail (Rockwood ≥ 5) nonterminal patients ≥ 65 years old acutely admitted over a 8-month span in an internal medicine ward were evaluated. Pneumonia status and its categorization (community-acquired, CAP, vs healthcare-associated, HCAP) were defined according to chest radiology findings and validated criteria. Chronic comorbidities, CIRS Comorbidity Score and CIRS Severity Index were collected for each participant through a standardized methodology. Multivariate logistic regression models were applied to assess the association of each comorbid condition or scores with pneumonia.

RESULTS

1199 patients (546 M, median age 81.9, IQR 72.8-87.9 years), of whom 239 with pneumonia (180 CAP, 59 HCAP) were evaluated. CIRS Comorbidity Score was significantly associated with pneumonia, both at an age- and sex-adjusted model and at a multivariate model (OR for each unitary increase 1.03, 95% CI 1.001-1.062, p=0.04), together with provenience from nursing home (OR 1.96, 95% CI 1.41-2.73, p<0.001). Among single comorbidities, only COPD (OR 2.7, 95% CI 1.9-3.6, p<0.001) and dementia (OR 2.3, 95% CI 1.7-3.3, p<0.001) were associated with pneumonia, while stroke, cancer, cardiovascular, chronic liver and kidney disease were not.

CONCLUSIONS

In a small cohort of elderly frail hospitalized patients, measures of multimorbidity, like CIRS, are significantly associated with the risk of pneumonia. COPD and dementia are the main conditions concurring to define this risk.

The association of serum procalcitonin and high-sensitivity C-reactive protein with pneumonia in elderly multimorbid patients with respiratory symptoms: retrospective cohort study

BACKGROUND

Serum procalcitonin and high-sensitivity C-reactive protein (hs-CRP) elevations have been associated with pneumonia in adults. Our aim was to establish their diagnostic usefulness in a cohort of hospitalized multimorbid patients ≥65 years old admitted to hospital with acute respiratory symptoms.

METHODS

With a retrospective cohort study design, all multimorbid patients ≥65 years-old with acute respiratory symptoms admitted to an internal medicine hospital ward in Italy from January to August 2013 were evaluated. Pneumonia diagnosis, comorbidities expressed through Cumulative Illness Rating Scale (CIRS), setting of living, length of stay, serum hs-CRP and procalcitonin at admission were collected for each patient. Data were analyzed with Mann-Whitney's U test and multivariate Cox logistic regression analysis. A Receiver Operating Characteristic (ROC) curve was used to verify each biomarker's association with pneumonia diagnosis.

RESULTS

Four hundred fifty five patients (227 M) were included in the study, of whom 239 with pneumonia (138 M, mean age 80 ± 13) and 216 without pneumonia (89 M, mean age 80 ± 14). After adjustment for age and sex, median levels of hs-CRP were significantly higher in patients with pneumonia (116 mg/L, IQR 46.5-179.0, vs 22.5 mg/dl, IQR 6.9-84.4, p < 0.0001), while procalcitonin median levels were not (0.22 ng/ml IQR 0.12-0.87, vs 0.15 ng/ml, IQR 0.10-0.35, p = 0.08). The ROC analysis showed that, unlike procalcitonin, hs-CRP values were predictive of pneumonia (AUC 0.76, 95% CI 0.72-0.79, p < 0.0001, cut-off value 61 mg/L), even after adjustment for possible confounders including nursing home residence and dementia. Serum hs-CRP levels >61 mg/L were independently associated with a 3.59-fold increased risk of pneumonia (OR 3.59, 95% CI 2.35-5.48, p < 0.0001).

CONCLUSION

In elderly multimorbid patients who require hospital admission for respiratory symptoms, serum hs-CRP testing seems to be more useful than procalcitonin for guiding the diagnostic process when clinical suspicion of pneumonia is present. Procalcitonin testing might hence be not recommended in this setting.

Multimorbidity in elderly hospitalised patients and risk of Clostridium difficile infection: a retrospective study with the Cumulative Illness Rating Scale (CIRS)

OBJECTIVES

To identify the role of chronic comorbidities, considered together in a literature-validated index (Cumulative Illness Rating Scale, CIRS), and antibiotic or proton-pump inhibitor (PPI) treatments as risk factors for hospital-acquired Clostridium difficile infection (CDI) in elderly multimorbid hospitalised patients.

DESIGN

Retrospective cohort study.

SETTING

Subacute hospital geriatric care ward in Italy.

PARTICIPANTS

505 (238 male (M), 268 female (F)) elderly (age≥65) multimorbid patients.

MAIN OUTCOME MEASURES

The relationship between CDI and CIRS Comorbidity Score, number of comorbidities, antibiotic, antifungal and PPI treatments, and length of hospital stay was assessed through age-adjusted and sex-adjusted and multivariate logistic regression models. The CIRS Comorbidity Score was handled after categorisation in quartiles.

RESULTS

Mean age was 80.7±11.3 years. 43 patients (22 M, 21 F) developed CDI. The prevalence of CDI increased among quartiles of CIRS Comorbidity Score (3.9% first quartile vs 11.1% fourth quartile, age-adjusted and sex-adjusted p=0.03). In the multivariate logistic regression analysis, patients in the highest quartile of CIRS Comorbidity Score (≥17) carried a significantly higher risk of CDI (OR 5.07, 95% CI 1.28 to 20.14, p=0.02) than patients in the lowest quartile (<9). The only other variable significantly associated with CDI was antibiotic therapy (OR 2.62, 95% CI 1.21 to 5.66, p=0.01). PPI treatment was not associated with CDI.

CONCLUSIONS

Multimorbidity, measured through CIRS Comorbidity Score, is independently associated with the risk of CDI in a population of elderly patients with prolonged hospital stay.

Axillary and innominate artery cannulation during surgery of the thoracic aorta: a comparative study

AIM

The aim of this paper was to compare hospital outcomes in patients undergoing elective surgery of the thoracic aorta using the right axillary artery (RAA) and the innominate artery (IA) as a cannulation site for cardiopulmonary bypass (CPB) arterial inflow.

METHODS

Between September 2009 and October 2011, 71 patients underwent elective aortic procedures with RAA (N.=27) and IA (N.=44) cannulation. Selection of RAA vs. IA was not randomized, but rather based on surgical judgment of best indication in each patient. Pre-, intra-, and postoperative variables were compared according to cannulation site.

RESULTS

Preoperative comorbidities, underlying aortic pathology, and surgical procedures were similar in RAA and IA patients. Hospital mortality was 11.1% and 6.8% in RAA and IA patients, respectively (P=0.243). Overall, 4 brain infarctions occurred, all left sided (RAA: 3.7% vs. IA: 6.8%; P=0.508). One brachial plexus injury, and 1 arterial dissection occurred in RAA group. No cannulation-related morbidity was observed in IA patients. Theoretical CPB flow could be reached in all patients, but resistances through the cannulation sites were more favourable in IA patients.

CONCLUSION

RAA and IA were associated with similarly valid results. The choice between the two, based on the specific patient's characteristics, can improve outcomes after aortic surgery.

Airway acidification in childhood asthma exacerbations

Exhaled breath condensate (EBC) is being used increasingly to sample airway lining fluid. In asthmatic patients, the concentration of pH in EBC has been found to be decreased and to be related to airway inflammation. The aim of this study was to determine exhaled pH levels during acute asthma exacerbations in relation to pharmacologic treatment in asthmatic children and compare these with control subjects. Twelve asthmatic children with asthma exacerbation and 27 healthy children were enrolled. Clinical observations and pH in EBC before and after standard treatment for asthma attack, based administration of inhaled beta2-agonist, and corticosteroid, according to international Global Initiative for Asthma guidelines, were compared with those in healthy subjects. All children performed skin-prick tests to aeroallergens. Asthmatic children underwent spirometry. Exhaled pH levels were significantly lower in children with asthma exacerbation before treatment (mean ± SD = 7.87 ± 0.66; p = 0.03) but not after treatment (8.11 ± 0.06; p = 0.40) compared with controls (8.12 + 0.19). Intragroup analyses found that condensate pH levels in asthmatic children before treatment were lower, but not significantly, than those after treatment. No correlation was found between pH values and treatment with systemic corticosteroids or lung function. Asthmatic children were atopic in 75% of cases. Levels of pH are decreased in EBC of asthmatic children with exacerbation before treatment. Larger studies are required to determine whether EBC pH levels may be a useful noninvasive biomarker to guide treatment of asthma exacerbations in childhood.

Influence of lean and fat mass on bone mineral density and on urinary stone risk factors in healthy women

Background

The role of body composition (lean mass and fat mass) on urine chemistries and bone quality is still debated. Our aim was therefore to determine the effect of lean mass and fat mass on urine composition and bone mineral density (BMD) in a cohort of healthy females.

Materials and methods

78 female volunteers (mean age 46 ± 6 years) were enrolled at the Stone Clinic of Parma University Hospital and subdued to 24-hour urine collection for lithogenic risk profile, DEXA, and 3-day dietary diary. We defined two mathematical indexes derived from body composition measurement (index of lean mass-ILM, and index of fat mass-IFM) and the cohort was split using the median value of each index, obtaining groups differing only for lean or fat mass. We then analyzed differences in urine composition, dietary intakes and BMD.

Results

The women with high values of ILM had significantly higher excretion of creatinine (991 ± 194 vs 1138 ± 191 mg/day, p = 0.001), potassium (47 ± 13 vs 60 ± 18 mEq/day, p < 0.001), phosphorus (520 ± 174 vs 665 ± 186 mg/day, p < 0.001), magnesium (66 ± 20 vs 85 ± 26 mg/day, p < 0.001), citrate (620 ± 178 vs 807 ± 323 mg/day, p = 0.002) and oxalate (21 ± 7 vs 27 ± 11 mg/day, p = 0.015) and a significantly better BMD values in limbs than other women with low values of ILM. The women with high values of IFM had similar urine composition to other women with low values of IFM, but significantly better BMD in axial sites. No differences in dietary habits were found in both analyses.

Conclusions

Lean mass seems to significantly influence urine composition both in terms of lithogenesis promoters and inhibitors, while fat mass does not. Lean mass influences bone quality only in limb skeleton, while fat mass influences bone quality only in axial sites.

Concentration of exhaled breath condensate biomarkers after fractionated collection based on exhaled CO2 signal

A standard procedure for exhaled breath condensate (EBC) collection is still lacking. The aim of this study was to compare the concentration of several biomarkers in whole (W-EBC) and fractionated EBC (A-EBC), the latter collected starting from CO2 ≥ 50% increase during exhalation. Forty-five healthy non-smokers or asymptomatic light smokers were enrolled. Total protein concentrations in W-EBC and A-EBC were overlapping (median: 0.7 mg l(-1) in both cases), whereas mitochondrial DNA was higher in A-EBC (0.021 versus 0.011 ng ml(-1)), indicating a concentration rather than a dilution of lining fluid droplets in the last portion of exhaled air. H2O2 (0.13 versus 0.08 µM), 8-isoprostane (4.9 versus 4.4 pg ml(-1)), malondialdehyde (MDA) (4.2 versus 3.2 nM) and 4-hydroxy-2-nonhenal (HNE) (0.78 versus 0.66 nM) were all higher in W-EBC, suggesting a contribution from the upper airways to oxidative stress biomarkers in apparently healthy subjects. NH4(+) was also higher in W-EBC (median: 590 versus 370 µM), with an estimated increase over alveolar and bronchial air by a factor 1.5. pH was marginally, but significantly higher in W-EBC (8.05 versus 8.01). In conclusion, the fractionation of exhaled air may be promising in clinical and occupational medicine.

Effect of Salt-Bromide-Iodine Thermal Water Inhalation on Functional and Biochemical Lung Parameters

Background. Inhalation of thermal water has been used empirically in the treatment of chronic diseases of upper and lower respiratory tract. This study investigates biomarkers of effect in exhaled breath (nitric oxide (NO)) and in exhaled breath condensate (EBC) (hydrogen peroxide (H2O2), anions, toxic heavy metals of tobacco smoke) for patients with lung diseases inhaling salt-bromide-iodine thermal water. Methods. This study enrolled two groups of patients, twenty with alveolar pulmonary diseases—pneumoconiosis—twenty-two with bronchial diseases. Patients received 12 days inhalation treatment with thermal water in Terme of Monticelli (Parma), Italy. Results. No statistically significant differences were found for NO at different flow rates in both groups of patients before and after thermal water inhalation. Also in EBC no statistically significant differences were present for H2O2 concentrations, toxic heavy metals concentrations, and anion concentrations before and after treatment. Nitrates in EBC were found to be significantly higher in patients before inhalation than in controls as well as in patients after inhalation versus controls. Conclusions. This study contributes to better quantify functional and biochemical changes in airways before and after thermal water treatment.

Effect of exposure to detergents and other chemicals on biomarkers of pulmonary response in exhaled breath from hospital cleaners: a pilot study

PURPOSE

The main aim of the study was to provide evidence whether professional cleaning was associated with biomarkers of lung damage in non-invasively collected biological fluids (exhaled air and exhaled breath condensate--EBC).

MATERIALS AND METHODS

This cross-sectional study involved 40 cleaners regularly exposed to cleaning detergents and 40 controls. The subjects completed a standard questionnaire from European Community Respiratory Health Survey (ECRHS II) and underwent a spirometry. Fractional exhaled nitric oxide (F(E)NO) was measured online, and pH, ammonium (NH(4) (+)), H(2)O(2) and 4-hydroxynonenal (4-HNE) were assayed in EBC.

RESULTS

Among the cleaners, the frequency of asthma and rhinitis was, respectively, 2.5 and 20%. The most frequently reported symptoms were sneezing (27.5%), nasal and/or pharyngeal pruritus (25%), ocular pruritus (22.5%) and cough (22.5%). There were no significant differences in comparison with the control group. Median F(E)NO levels were higher in African than in Caucasian cleaners (21.5 [16.5-30.0] ppb and 18.0 [13.5-20.5] ppb; p < 0.05). H(2)O(2)-EBC (0.26 [0.09-0.53] μM vs. 0.07 [0.04-0.15] μM; p < 0.01), NH(4) (+)-EBC (857 [493-1,305] μM vs. 541 [306-907] μM; p < 0.01) and pH-EBC (8.17 [8.09-8.24] vs. 8.06 [7.81-8.10]; p < 0.01) were higher in the cleaners than in the controls. Finally, the cleaners showed significant correlations between pH-EBC and NH(4) (+)-EBC (r = 0.33, p < 0.05) and a weak correlation between 4-HNE-EBC and H(2)O(2)-EBC (r = 0.37, p < 0.05).

CONCLUSION

The promising role of EBC analysis in biomonitoring of exposed workers was confirmed. It was also possible to identify the potential biomarkers of exposure to alkaline products (increased ammonium-EBC and pH-EBC levels) and potential biomarkers of oxidative stress (increased H(2)O(2)-EBC levels correlated with 4-HNE-EBC levels) in workers with no signs of airway diseases.

Urea in exhaled breath condensate of uraemics and patients with chronic airway diseases

Exhaled breath condensate (EBC) is composed mainly by water and also contains non-volatile mediators, which are expired in small droplets of airway fluid. Urea has been proposed as a normalization factor for EBC non-volatile biomarkers. Aim of this study was to assess volatility and diffusivity of urea ex vivo and to measure its EBC concentrations in different clinical conditions. Volatility was assessed quantifying EBC concentrations collected at 4 different temperatures, whereas diffusivity was tested by measuring urea concentrations in both plasma and EBC from uraemic patients on intermittent haemodialysis. Urea was also measured in EBC from patients with chronic airway diseases, i.e., chronic obstructive pulmonary disease, asthma, and cystic fibrosis. The concentration of urea but not its absolute amount in EBC increased with condensation temperature. Haemodialysis influenced EBC and plasma urea concentrations in a similar way. The concentrations of urea in chronic airway diseases did not significantly differ from those of controls. Urea is a non-volatile molecule ex vivo and EBC urea depends on its concentrations in plasma. Urea concentrations in EBC are unaffected by three chronic airway diseases. We suggest that there is no need to normalize non-volatile biomarkers in EBC for urea concentrations to account for inter-individual variability. However, in repeated measurements within the same individual, the use of urea either as a normalizing factor or as covariate variable could be proposed to control intra-individual variability.

Environmental and biological monitoring of benzene exposure in a cohort of Italian taxi drivers

An integrated approach based on ambient and biological monitoring, the latter including both biomarkers of exposure and susceptibility, was applied to characterize benzene exposure in a group of 37 taxi drivers of the city of Parma (Italy). Airborne benzene concentrations were assessed by 24 h personal sampling and work-shift sampling inside the taxicab using passive samplers (Radiello). Benzene metabolites, trans,trans-muconic acid (t,t-MA) and S-phenylmercapturic acid (S-PMA), and urinary cotinine as biomarker of smoking habits were measured by isotopic dilution liquid chromatography tandem mass spectrometry in both pre-shift (PS) and end-of-shift (EOS) samples. Urinary benzene (U-B) levels were determined by solid-phase microextraction gas chromatography-mass spectrometry in EOS samples. Relevant polymorphisms of microsomal epoxide hydrolase, NAD(P)H:quinone oxidoreductase, glutathione S-transferases M1-1 (GSTM1), T1-1, and A1 were characterized by PCR-based methods. Mean airborne benzene concentration was 5.85 +/- 1.65 microg/m3, as assessed by 24 h personal sampling integrating for work-shift, indoor or general environment activities. Significantly, higher benzene concentrations were detected in the taxicab during the work-shift (7.71 +/- 1.95 microg/m3, p < 0.005). Smokers eliminated significantly higher concentrations of U-B and S-PMA than non-smokers in EOS samples [geometric mean (geometric S.D.): 2.58 (4.23) versus 0.44 (1.79) microg/l for U-B; 3.79 (1.50) versus 2.14 (1.87) microg/gcreat. for S-PMA, p < 0.002]. Within smokers, S-PMA concentrations significantly increased at the end of the work-shift compared to pre-shift values (p < 0.05). t,t-MA showed a similar behaviour, although differences were not significant. In the narrow range examined, no correlation was observed between air benzene concentration and urinary biomarkers. All benzene biomarkers but EOS t,t-MA were correlated with U-cotinine (p < 0.05). GSTM1 polymorphism significantly modulated S-PMA excretion, as subjects bearing the GSTM1pos genotype [3.61 (1.15) microg/gcreat.] excreted significantly higher S-PMA concentrations than GSTM1null subjects [2.19 (1.18) microg/gcreat., p < 0.05].

Antagonistic effects of methyl-mercury and PCB153 on PC12 cells after a combined and simultaneous exposure

The study of interactions for those substances which tend to accumulate in food and affect the nervous system appears to be a fundamental point to characterize the combined exposure in vitro. In this study we included two food contaminants which are known neurotoxicants: methyl-mercury (Me-Hg) and the ortho-substituted PCB 153. PC12 cells were treated with Me-Hg (range 1e-7, 2e-6 M) and PCB153 (range 1e-5, 4e-4 M) in single and combined synchronous experiments and a mathematical model was set up according to the Loewe additivity criterion to evaluate the level of interaction between toxicants, using viability as end-point. At some concentrations (Me-Hg 5e-7 M and PCB153 1e-4 and 2e-4 M; Me-Hg 1e-6M and PCB153 5e-5 M; Me-Hg 1e-7 M and PCB153 4e-4 M), a statistically significant antagonist effect was observed. No interaction was observed for other combinations. The analysis of other toxicological parameters known to be modified in single exposure experiments (TBARS and intra-cellular dopamine) confirmed the viability results. The results of our work represent a starting point to generate novel information on the interactions between PCB153 and Me-Hg in vitro, as well as a new relevant experimental and mathematical approach useful to investigate the effects of different toxicant mixtures.

Longitudinal monitoring of lung injury in children after acute chlorine exposure in a swimming pool

RATIONALE

Acute exposure to chlorine gas results in respiratory impairment, but few data are available on the pathobiology of the underlying lung damage.

OBJECTIVES

To assess lung function and potential lung damage pathways in the acute phase and longitudinally over a 15-mo follow-up after acute chlorine exposure.

METHODS

Ten previously healthy children were accidentally exposed to chlorine gas at a swimming pool because of an erroneous servicing procedure. The fraction of nitric oxide in exhaled air (Fe(NO)), exhaled breath condensate compounds, and serum Clara cell-specific protein CC16 were repeatedly measured.

MAIN RESULTS

In the acute phase, all patients had respiratory distress (one child required mechanical ventilation) and reduced lung function (median and interquartile range: FVC, 51 [43-60]% predicted; FEV(1), 51 [46-60]% predicted). This was accompanied by low Fe(NO) (4.7 [3.9-7.9] ppb), high exhaled breath condensate leukotriene B(4) (LTB(4)) levels (24.4 [22.5-24.9] pg/ml), and increased serum CC16 levels (mean +/- SEM, 23.4 +/- 2.5 microg/L). Lung function returned to normal in 15 d (FVC, 97% predicted [82-108], and FEV(1), 92% predicted [77-102]). Fe(NO) reached normal values after 2 mo (12.6 [11.4-15] ppb), whereas LTB(4) levels were still increased (12 [9.3-17.1] pg/ml).

CONCLUSION

Children acutely exposed to chlorine in a swimming pool presented a substantial lung function impairment associated with biochemical exhaled breath alterations, represented mainly by an increase in LTB(4) and a reduction in Fe(NO). Although lung function and Fe(NO) improved within a few weeks, the increased levels of exhaled LTB(4) persisted for several months.

Biomarkers of neutrophilic inflammation in exhaled air of cystic fibrosis children with bacterial airway infections

Leukotriene B(4) (LTB(4)) and interleukin-8 (IL-8) are inflammatory mediators involved in the neutrophil response to pulmonary bacterial colonization in cystic fibrosis (CF). The aim of this study was to investigate whether the LTB(4) and IL-8 levels in exhaled breath condensate (EBC) could be related to the type of bacterial colonization in CF patients. The pH level in EBC was analyzed as an estimate of airway acidification. Forty children were evaluated: 10 CF patients with P. aeruginosa, 10 CF patients with S. aureus, 10 not colonized CF patients, and 10 healthy children. LTB(4) and IL-8 in EBC were analyzed by specific enzyme immunoassay kits (EIA). The pH of EBC was measured with a pH-meter after deareation by bubbling with argon. Exhaled LTB(4) was higher in CF children with P. aeruginosa compared to those with S. aureus (P < 0.01), not colonized (P < 0.001), and healthy children (P < 0.01). Exhaled IL-8 was elevated in CF patients colonized by P. aeruginosa compared with other subgroups (vs. not colonized, P < 0.05; vs. healthy children, P < 0.001). IL-8 levels were higher in CF children with S. aureus than in healthy children (P < 0.05). There was an increase in IL-8 levels in not colonized CF patients compared with healthy children (P < 0.05). EBC pH was higher in healthy children compared to CF patients not colonized (P < 0.05). Our data suggest that EBC is suitable for evaluating neutrophil inflammatory mediators (LTB(4), IL-8, and pH) involved in the response to pulmonary bacterial colonization in CF children.

[Environmental and biological monitoring of exposure to polycyclic aromatic hydrocarbons in workers of an electric steel foundry]

AIMS

To assess and classify exposure to Polycyclic Aromatic Hydrocarbons (PAHs) in some specific working areas of a steel foundry operating with a continuous casting process and evaluate biomonitoring data in different job tasks.

METHODS

Exposure to dusts and six PAHs classified as carcinogenic by EU directives was studied in a cohort of 35 male foundry workers (aged 41.1 +/- 6.9 years), who were examined both prior to and at the end of the work-shift (06:00 a.m.-02:00 p.m.) in two different periods. The urinary excretion of 1-hydroxypyrene (1-OH-P) was measured as a biomarker of exposure to pyrene.

RESULTS

PAHs concentrations ranged from 461.8 to 935.6 ng/m3 near the continuous casting area, whereas lower values were measured near the ladle furnace. End of shift 1-OH-P values were higher in 11 non-smoking workers involved in continuous casting process as compared to those employed in mantenance and furnace areas (median of the second determination: 5.70 microg/g creatinine--range: 1.24-21.24 vs 1.17 microg/g creatinine--range: 0.23-4.49; p< 0.001). 1-OH-P excretion was significantly correlated with both the sum of six carcinogenic PAHs and pyrene airborne concentrations. In two biomonitoring sessions, 9.1% and 34.3% of the workers respectively showed end-of-shift 1-OH-P values exceeding the occupational exposure limit (OEL) (4.4 microg/g creatinine or 2.3 micromol/mol(-1) creatinine) recommended for coke-oven workers.

CONCLUSIONS

1-OH-P is a useful biomarker in assessing PAH exposure and is associated with job category at a Steelplant. Due to exposure variability, to assess risk associated with PAHs exposure, biological monitoring should be carried out periodically.

[Heme oxygenase 1 expression in foundry workers]

Heme oxygenase 1 (HO-1) catalyses the oxidation of heme to biliverdin, and its expression is induced by oxidative stress. This study was aimed at assessing the role of metabolic polymorphisms (CYP1A1, CYP1B1, GSTM1, GSTP1, EPHX) in the modulation of HO-1 gene expression in 37 foundry workers. Blood and urine samples were obtained at the beginning (BS) and at the end (ES) of work shift, in February (T1) and June (T2). Urinary 1-hydroxypyrene (1-OHP) was measured as a tracer of PAH exposure. HO-1 gene expression in ES samples normalized to BS values (HO-1 ES/BS) was higher at T2 respect to T1. HO-1 gene induction was related to ES 1-OHP when considering either T2 samples or the combination of the two samplings. HO-1 ES/BS was significantly increased in subjects with at least a mutant allele for GSTP1 as compared to subjects with GSTP1AA genotype (1.23 +/- 0.002 vs 0.88 +/- 0.002, p < 0.05). Only in subjects with at least one vari.nt allele for GSTP1, a positive correlation between HO-1 ET/IT expression and 1-OHP FT levels was observed (r2 = 0.21, p = 0.016). The present study demonstrates a correlation between PAH exposure, as assessed by urinary 1-OHP, and the induction of HO-1 expression. Such a correlation seems to be limited to subjects bearing variant alleles for GSTP1. At the same exposure levels, these subjects showed a greater expression of HO-1 FT as compared to subjects with GSTP1 wild type genotype, possibly due to a higher oxidative stress in the subjects expressing the mutant GSTP1-1 isoform, which could imply a limited scavenging capacity.

Acid-base equilibrium in exhaled breath condensate of allergic asthmatic children

BACKGROUND

The dysregulation of airway pH control may have a role in asthma pathophysiology. The measurement of exhaled breath condensate (EBC) pH and ammonia levels may be used as a noninvasive method to study acid-base status in the airway of asthmatics.

METHODS

Exhaled breath condensate from 29 allergic stable asthmatic children and 13 healthy controls was collected by cooling exhaled air during tidal breathing. Ammonia was measured by high-performance liquid chromatography with fluorescence detection. pH was measured after deaeration of EBC samples by bubbling with argon. The children also underwent FENO measurement.

RESULTS

Both pH and ammonia values in EBC were significantly lower in the asthmatics than in the control group [pH: ICS-treated (median and interquartile range) 7.70 (7.62-7.74), steroid-naive 7.53 (7.41-7.68), controls 7.85 (7.80-7.90), P <0.01 and P <0.001, respectively; ammonia: ICS-treated 476.17 microM (282.50-594.80), steroid-naive 253.24 microM (173.43-416.08), controls 788.30 microM (587.29-1310.39), P < 0.05 and P <0.001, respectively]. Both pH and ammonia values were higher in ICS-treated than in steroid-naive asthmatic children. There was a significant correlation between EBC pH and ammonia concentrations.

CONCLUSIONS

These data show that EBC pH values of stable asthmatic children are lower compared with those of healthy controls and positively correlated with ammonia concentrations, supporting the hypothesis that airway acidification may have a role in the pathobiology of allergic asthma.

[Data quality and the interpretation of biological monitoring results]

Quality assurance criteria are not uniformly applied to routine biological determination, in particular with regard to the biomonitoring of exposure to organic solvents. Quality assurance is not an abstract concept but rather a flexible tool which can be adapted to different situations, such as the measurement of different exposure levels or the use of different analytical methods, for a range of purposes (routine determination, risk assessment procedures, research). The occupational health physician should be actively involved in the definition of quality objectives, as well as in checking that they have been implemented. This paper deals with some general issues regarding quality assurance, and in particular with certain requirements of analytical quality (analytical uncertainty, imprecision, bias) and its implementation (quality control, reference materials, standardization, reference values), contextualized to the biological monitoring of organic compounds and the relative metabolites.

[Indicators of pulmonary epithelial damage among workers at a foundry exposed to airborne pollutants]

Foundry ambient air contains very high concentrations of noxious substances, such as particulate matter and gaseous pollutants, which can target the respiratory epithelium. Serum concentrations of the 16-kDa Clara cell protein (CC16-S) may reflect both the integrity of the epithelial barrier and smoke-induced Clara cell toxicity. To evaluate whether CC16-S is a sensitive biomarker of early respiratory disturbances, it was determined in a group of 35 foundry male workers (aged 41.1 +/- 6.9 years) examined both prior to and at the end of their work-shift (06:00 a.m.-02:00 p.m.). Exposure to inhalable/respirable dusts and PAH was characterized; urinary excretion of 1-hydroxypyrene (1-OH-P) and naphtol was measured to assess exposure to pyrene and naphthalene, respectively. CC16 serum levels decreased at the end of the shift (10.7 +/- 3.82 micrograms/L vs. 8.39 +/- 3.05 micrograms/L; p < 0.01); such decrements were significantly larger in more exposed workers. Although smokers had lower baseline values as compared to non smokers, both subgroups showed an average decrease of 30% in CC16-S concentrations at the end of shift. CC16-S was also negatively correlated with 1-OH-P, but not with naphtol concentrations. Decreased CC16-S levels can result from citotoxicity and would represent an useful biomarker of pneumotoxicity in foundry workers exposed to complex mixtures.

Aldehydes and glutathione in exhaled breath condensate of children with asthma exacerbation

Oxidative stress is implicated in the pathogenesis of asthma, and clinical studies show an imbalance in the level of oxidants to the level of antioxidants in subjects with asthma. Aldehydes and glutathione are examples of biomarkers of oxidant-induced damage and antioxidant status in asthma, respectively. In the study, we applied analytical techniques based on liquid chromatography for the assessment of aldehydes and glutathione in the exhaled breath condensate of children with asthma and in control subjects without asthma. Twelve subjects with asthma were evaluated at exacerbation and after 5 days of therapy with prednisone. At exacerbation, malondialdehyde levels were higher in patients with asthma (30.2 +/- 2.4 nM) than in control subjects (19.4 +/- 1.9 nM, p = 0.002) and were reduced after steroid therapy (18.5 +/- 1.6 nM, p = 0.001). At exacerbation, glutathione levels were lower in subjects with asthma (5.96 +/- 0.6 nM) than in control subjects (14.1 +/- 0.8 nM, p < 0.0001) and were increased after the therapy (8.44 +/- 1.2 nM, p = 0.04). Malondialdehyde and glutathione both in subjects with asthma and control subjects were negatively correlated (r = -0.5, p = 0.001). The study shows that aldehydes and glutathione are detectable in the exhaled breath condensate of children with asthma and healthy children and that their levels are modified during asthma exacerbation and after a 5-day course of therapy with oral prednisone.

Biomarkers of oxidative stress after controlled human exposure to ozone

This study was aimed at evaluating whether controlled short-term exposure to ozone (O(3)) induces changes in biomarkers of lung inflammation and oxidative stress in exhaled breath condensate (EBC) and blood of healthy subjects. Twenty-two volunteers were exposed to 0.1 ppm of O(3) for 2 h while performing moderate intermittent exercise. EBC and blood were collected before, immediately after and 18 h after exposure. Changes in biomarkers were measured both in EBC and blood, without significant alterations of lung function tests. Changes in EBC, but not in blood, were mainly accounted for by a subgroup of 'susceptible' individuals bearing the wild genotype for NAD(P)H:quinone oxidoreductase (NQO1) and the null genotype for glutathione-S-transferase M1 (GSTM1). Thus, a single 2-h exposure to 0.1 ppm of O(3) induces changes in biomarkers of inflammation and oxidative stress. Polymorphic NQO1 and GSTM1 act as modifier of the lung response to O(3).

Chiral separation of amino acids by copper(II) complexes of tetradentate diaminodiamido-type ligands added to the eluent in reversed-phase high-performance liquid chromatography: a ligand exchange mechanism

In this paper we report a study on the mechanism of the enantiomeric separation of unmodified D,L-amino acids in RP-HPLC by copper(II) complexes of two tetradentate diaminodiamido ligands, (S,S)-N,N'-bis(phenylalanyl)ethanediamine (PheNN-2) and (S,S)-N,N'-bis(methylphenylalanyl)ethanediamine (Me2PheNN-2), added to the eluent. The aim is to investigate whether and how a copper(II) complex with no free equatorial positions can perform chiral discrimination of bidentate analytes such as unmodified amino acids. The problem is approached in a systematic way by: (a) varying the different chromatographic parameters (pH, selector concentration, eluent polarity); (b) performing chiral separation with the selector adsorbed on the stationary phase; (c) studying the ternary complex formation of these ligands with D- and L-amino acids in solution by glass electrode potentiometry and electrospray ionization MS. All the experimental data are consistent with a mechanism of chiral recognition, based on ligand exchange, which involves as selectors the species [Cu2L2H(-2)]2+ and [CuLH(-2)] and proceeds by displacement of two binding sites from the equatorial positions, giving rise to the ternary species [CuLA]+ and [CuLH(-1) A]. The most important factor responsible for chiral discrimination seems to be the affinity of the diastereomeric ternary complexes for the stationary phase since no enantioselectivity is observed in solution.