Stories of change: the text analysis of handovers in an Italian psychiatric residential care home

WHAT IS KNOWN ON THE SUBJECT?: There is a growing emphasis on communication as a result of the move towards the more inclusive approach associated with the community-based rehabilitation model. Therefore, more importance is attached to handovers. Besides ensuring transfer of information, handovers enhance group cohesion, socialize staff members to the practices of the service and capture its organizational culture. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: While handovers are mainly used for information transfer and to manage the services' daily routine, this paper offers an insight on how handovers can be conceived as valuable instruments to document cultural and organizational change. Only a limited amount of studies has focused on handovers in mental healthcare settings, and most of them only consider the perspectives of psychiatric nurses, while embracing a broader perspective, this paper provides valuable insights into the perspectives of various service providers. The overcoming of the dichotomy deficit-based vs. recovery-oriented model is possible if professionals use handovers to reflect upon their practice and the ways in which their cultural models are affected by the environmental context. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Handovers are valuable instruments to document organizational change. It would be important for psychiatric and rehabilitation facilities to keep track of the handover records over time as they may provide insightful information about cultural change and the transformations in the core values and beliefs held by professionals.

ABSTRACT

Handovers assure a timely and correct information transfer while socializing workers to the service's culture; however, no study describes them as instruments to document organizational change and only a few have focused on psychiatric settings. Aim To investigate the change in the culture of an Italian psychiatric residential care home as perceived by its mental health workers (MHWs) over the course of two decades. Method Emotional text analysis (ETA) was used to analyse the MHWs' handovers completed from 1990 to 2011. Results The analysis generated four clusters and three main factors illustrating the change in the MHWs' representations of the residential care home and its occupants. The factors showed: (1) the shift from an individualistic, problem-focused view to an inclusive, community-based approach; (2) the presence of a descriptive as well as a specialized language; and (3) the presence of a double focus: on patients and professionals. Conclusions Handovers transcripts document the following changes: (1) a shift from a symptom-based to a recovery-oriented approach; (2) a modification of the MHWs values towards an holistic view of the patient; (3) a growing importance assigned to accountability, services integration and teamwork. The paper shows that handovers can be used diachronically to document organizational change.

Dermal exposure to polycyclic aromatic hydrocarbons in asphalt workers

OBJECTIVES

To assess dermal exposure to 16 polycyclic aromatic hydrocarbons (PAHs) in asphalt workers by applying polypropylene pads to six body sites (neck, shoulder, upper arm, wrist, groin, ankle), to identify the compounds and exposure sites most representative, and to integrate dermal exposure results with environmental and biological data.

METHODS

Twenty-four asphalt workers were recruited. Dermal exposure was assessed during a single work shift. Sixteen PAHs (from naphthalene to indeno[1,2,3-cd]pyrene) were quantified via gas chromatography-mass spectrometry. Airborne exposure, urinary PAHs and monohydroxy metabolites were also investigated.

RESULTS

Phenanthrene (PHE), present in all samples, was the most abundant compound (median 0.805-1.825 ng/cm(2)). Benzo[a]pyrene (BaP) was present in 75% of the samples (0.046-0.101 ng/cm(2)). Wrist had the highest contamination, with median PHE, pyrene (PYR), and BaP concentrations of 1.825, 0.527, and 0.063 ng/cm(2). PHE and PYR on wrist correlated with almost all 3- to 4-ring PAHs (0.405< or =r< or =0.856), but not with BaP; BaP correlated with almost all 4- to 6- ring PAHs (0.584< or =r< or =0.633). Significant correlations were observed between PHE level, airborne exposure, and the corresponding urinary PHE and monohydroxy metabolites. For PYR, significant correlations existed only between urinary PYR and monohydroxy metabolites. Multiple linear regression analysis revealed that 42% of the end-of-shift monohydroxy metabolites were the result of airborne exposure, dermal exposure, and baseline levels of biomarkers.

CONCLUSIONS

Dermal exposure to PAHs was in the low ng/cm(2) range. PHE or PYR and BaP were the most representative compounds and the wrist was the best location to perform dermal exposure assessments. Both dermal and airborne exposure contributed to the total body burden of PAHs, though the relative contribution was analyte-dependent.

An integrated approach to biomonitoring exposure to styrene and styrene-(7,8)-oxide using a repeated measurements sampling design

The aim of this work was to investigate urinary analytes and haemoglobin and albumin adducts as biomarkers of exposure to airborne styrene (Sty) and styrene-(7,8)-oxide (StyOX) and to evaluate the influence of smoking habit and genetic polymorphism of metabolic enzymes GSTM1 and GSTT1 on these biomarkers. We obtained three or four air and urine samples from each exposed worker (eight reinforced plastics workers and 13 varnish workers), one air and urine samples from 22 control workers (automobile mechanics) and one blood sample from all subjects. Median levels of exposure to Sty and StyOX, respectively, were 18.2 mg m(-3) and 133 microg m(-3) for reinforced plastics workers, 3.4 mg m(-3) and 12 microg m(-3) for varnish workers, and <0.3 mg m(-3) and <5 microg m(-3) for controls. Urinary levels of styrene, mandelic acid, phenylglyoxylic acid, phenylglycine (PHG), 4-vinylphenol (VP) and mercapturic acids (M1+M2), as well as cysteinyl adducts of serum albumin (but not those of haemoglobin) were significantly associated with exposure status (controls<exposed workers). Also, levels of VP and M1+M2 were significantly affected by smoking, and levels of M1+M2 were significantly affected by GSTM1 polymorphisms. Multiple linear regression analyses of the subject-specific (logged) metabolite levels across exposed workers showed that Sty was a significant predictor for all urinary analytes while StyOX was a significant predictor of PHG only. Interestingly, the log scale regression coefficients for Sty in these models were significantly less than one for all metabolites except M1+M2. This suggests that the natural scale relationships between levels of all Sty metabolites, except M1+M2, displayed downward concavity with increasing Sty exposure, suggestive of saturable metabolism. Levels of the protein adducts were not associated with exposure to either Sty or StyOX among exposed subjects.

Urinary hydroxylated metabolites of polycyclic aromatic hydrocarbons as biomarkers of exposure in asphalt workers

BACKGROUND

Fumes and vapours released during laying of hot asphalt mix have been recognised as a major source of exposure for asphalt workers.

OBJECTIVES

We investigated the relationships between inhalation exposure to asphalt emissions and urinary biomarkers of polycyclic aromatic hydrocarbons (PAHs) in asphalt workers (AW, n=75) and in ground construction workers (CW, n=37).

METHODS

Total polyaromatic compounds (PAC) and 15 priority PAHs in inhaled air were measured by personal sampling. Hydroxylated PAH metabolites (OH-PAHs) (2-naphthol, 2-hydroxyfluorene, 3-hydroxyphenanthrene, 1-hydroxypyrene, 6-hydroxychrysene and 3-hydroxybenzo[a]pyrene) were determined in urine spot samples collected in three different times during the work week.

RESULTS

Median vapour-phase PAC (5.5 microg m(-3)), PAHs (<or=50 ng m(-3)) and OH-PAHs (0.08-1.11 microg l(-1)) were significantly higher in AW than in CW, except in the cases of air naphthalene and 2-naphthol. Airborne levels of particle-phase contaminants were similar in the two groups and much lower than vapour-phase levels; metabolites of particulate PAHs were never found in quantifiable amounts. An appreciable increase in OH-PAH levels during the work day and work week was found in AW; median levels for 2-hydroxyfluorene, 3-hydroxyphenanthrene and 1-hydroxypyrene were, respectively, 0.29, 0.08 and 0.18 at baseline; 0.50, 0.18 and 0.29, pre-shift; 1.11, 0.44 and 0.44 microg l(-1), post-shift. Each OH-PAH exhibited a characteristic profile of increase, reflecting differences in half-lives of the parent compounds. In non-smoking subjects, positive correlations were found between vapour-phase PAC or PAHs and OH-PAHs both in pre- and post-shift samples (0.34 <or= r<or=69). Smokers exhibited 2-5-fold higher OH-PAHs than non-smokers, at any time and at both workplaces.

CONCLUSIONS

Our results suggest that OH-PAHs are useful biomarkers for monitoring exposure to asphalt emissions. The work-related exposure to PAC and PAHs was low in all AW, but urinary metabolites reflected exposure satisfactorily.

Application of ultraviolet spectrophotometry to estimate occupational exposure to airborne polyaromatic compounds in asphalt pavers

An ultraviolet (UV) spectrophotometric procedure was devised for the determination of polycyclic aromatic compound-oriented organic soluble matter in vapors and particulate collected from emissions of hot asphalt mix. Ultrasonic extraction was carried out with acetonitrile, followed by UV measurements at 254 nm. Polycyclic aromatic compounds (PACs) in volatile and particulate fraction were quantified as phenanthrene or benzo[k]fluoranthene equivalents. A comparison between UV and high-pressure liquid chromatography with fluorescence detection showed that PACs were one to three orders of magnitude higher than the sum of 15 priority polycyclic aromatic hydrocarbons (PAHs); still, significant correlations were found between volatile or particulate PACs and, respectively, total volatile or particulate PAHs. Moreover, in the particulate phase, PACs correlated with total particulate matter quantified by gravimetry. The proposed procedure was employed in a field study for monitoring personal exposure to asphalt emissions of workers engaged in road construction. Observed levels of acetonitrile-soluble PACs in air samples were very low (2-20 microg/m3); however, asphalt pavers were exposed to significantly higher concentrations of volatile PACs than construction workers (geometric mean, 5.9 microg/m3 vs. 4.1 microg/m3). This method for estimating the global content of volatile or particulate PACs in air samples satisfies our requirements of simplicity and is suitable for conducting an initial screening to assess exposure to airborne polyaromatic organics in asphalt pavers.

Bronchial malondialdehyde DNA adducts, tobacco smoking, and lung cancer

Tobacco smoking is a major risk factor for lung cancer causing, among other effects, oxidative stress and lipid peroxidation. Malondialdehyde (MDA)-DNA adducts can be induced by direct DNA oxidation and by lipid peroxidation. We measured the relationship between bronchial MDA-DNA adducts and tobacco smoking, cancer status, and selected polymorphisms in 43 subjects undergoing a bronchoscopic examination for diagnostic purposes. MDA-DNA adducts were higher in current smokers than in never smokers (frequency ratio (FR) = 1.51, 95% confidence interval (CI) 1.01-2.26). MDA-DNA adducts were also increased in lung cancer cases with respect to controls, but only in smokers (FR = 1.70, 95% CI 1.16-2.51). Subjects with GA and AA cyclin D1 (CCND1) genotypes showed higher levels of MDA-DNA adducts than those with the wild-type genotype (FR = 1.51 (1.04-2.20) and 1.45 (1.02-2.07)). Lung cancer cases with levels of MDA-DNA adducts over the median showed a worse, but not statistically significant, survival, after adjusting for age, gender, and packyears (hazard ratio = 2.48, 95% CI 0.65-9.44). Our findings reinforce the role of smoking in lung carcinogenesis through oxidative stress. Subjects who carry at least one variant allele of the CCND1 gene could accumulate DNA damage for altered cell-cycle control and reduced DNA repair proficiency.

Evaluation of Exposure to PAHs in Asphalt Workers by Environmental and Biological Monitoring

In the present article we assessed exposure to polycyclic aromatic hydrocarbons (PAHs) in Italian asphalt workers (AW, n = 100), exposed to bitumen fumes and diesel exhausts, and in roadside construction workers (CW, n = 47), exposed to diesel exhausts, by means of environmental and biological monitoring. 1-hydroxypyrene (OH-Py) was determined in urine spot samples collected, respectively, after 2 days of vacation (baseline), before, and at the end of the monitored work shift, in the second part of the workweek. Median airborne levels during the work shift of 15 PAHs (both vapor and particulate phases), from naphthalene (NAP) to indeno(1,2,3-cd)pyrene, ranged from below 0.03 to 426 ng/m(3). Median excretion values of OH-Py in baseline, before- and end-shift samples were 228, 402, and 690 ng/L for AW and 260, 304, and 378 ng/L for CW. Lower values were found in nonsmokers compared to smokers (e.g., in AW 565 and 781 versus 252 and 506 ng/L in before-shift and end-shift samples, respectively). In all subjects a weak correlation between personal exposure to the sum of airborne 15 PAHs and OH-Py was observed (r = 0.30). The results of this article show that AW experienced a moderate occupational exposure to airborne PAHs, resulting in a significant increase of urinary OH-Py during the workday and the workweek. The contribution of working activities to internal dose was in the same order of magnitude of the contribution of cigarette smoking.

Aluminum determination in biological fluids and dialysis concentrates via chelation with 8-hydroxyquinoline and solvent extraction/fluorimetry

We describe a simple, rapid, and sensitive fluorescence method for measurement of aluminum (Al) in human biological fluids, in dialysis solutions, and in tap water, which uses 8-hydroxyquinoline for ion chelation. The fluorescence intensity of the toluene-extracted metal chelate (excitation wavelength, 380 nm; emission wavelength, 504 nm) remains unchanged for over 48 h at room temperature. Fluorescence intensity is a linear function of the concentration of Al in the 2-1000 microg/L range with detection limits of 0.7-2 microg/L. A large excess of other ions normally found in biological fluids does not interfere in Al determination. The method developed was successfully used in assaying Al in serum and urine of reference subjects, in serum samples from patients undergoing long-term dialysis, and in dialysis solutions. Al concentrations, measured by this fluorimetric procedure, were compared with those obtained by Zeeman graphite-furnace atomic absorption spectrometry. A correlation coefficient of 0.98 was obtained. The proposed method could be used for routine analysis in clinical laboratories for accurate determination of aluminum in aqueous or biological fluids.

Biological monitoring of exposure to polycyclic aromatic hydrocarbons by determination of unmetabolized compounds in urine

In this paper we evaluated the possibility to assess occupational exposure to polycyclic aromatic hydrocarbons (PAHs) measuring unmetabolized PAHs in urine. With this aim, 24 road paving (RP) workers, exposed to bitumen fumes, and 6 road construction workers (CW), exposed to diesel exhausts, were investigated. Median personal exposure to low boiling PAHs (from naphthalene to pyrene) during the work shift ranged from 0.5 to 369 ng/m(3), with naphthalene as the most abundant compound. Three urine samples were collected for each worker: baseline (after 2 days of vacation), before- and end-shift samples (in the second part of the work week). The following urinary compounds were measured by headspace-solid phase microextraction GC/MS: naphthalene (U-NAP), acenaphthylene (U-ACY), acenaphthene (U-ACE), fluorene (U-FLE), phenanthrene (U-PHE), anthracene (U-ANT), fluoranthene (U-FLU), pyrene (U-PYR). Urinary PAHs were detected in almost all samples. Median levels for U-NAP, U-PHE, U-PYR and U-FLE in end-shift samples were 82, 48, 54 and 21 ng/L in RP and 69, 14, 24 and 15 ng/L in CW, respectively. Significant differences in the levels of U-PHE, U-FLU and U-PYR were found between RP and CW (p<0.05). Moreover in RP samples the urinary excretion of most analytes increased during the work shift (p<0.05). These results suggest that urinary PAHs may be useful biomarkers of occupational exposure.

Polyurethane foam chips combined with liquid chromatography in the determination of unmetabolized polycyclic aromatic hydrocarbons excreted in human urine

A method suitable for the determination of unmetabolized polycyclic aromatic hydrocarbons (PAHs) excreted at trace levels (ng/L) in human urine for the monitoring of exposure of the general population to PAH contamination was developed. PAHs were determined, after enrichment by solid-phase extraction on polyurethane foam (PUF) chips, by HPLC with fluorescence detection. Different parameters affecting analyte extraction to the PUF, including urine salting-out and organic additives, and optimization of conditions for clean-up and desorption have been investigated. Optimized conditions were 40 mL acidified urine sample, added with magnesium sulfate, tetrahydrofuran and a 2 cm3 PUF chip, and extracted by shaking at 30 rpm for 1 h at ambient temperature. Desorption was performed, after a clean-up step with diluted sodium hydroxide, using a small amount of diethyl ether. The recovery of PAH congeners from spiked urines was >90% in the 2-100 ng/L range; the detection limit was 0.1-0.5 ng/L, depending on the considered PAH congener; day-to-day precision, at 50 ng/L native PAH content, was CV = 10-20%. The proposed technique provides a simple, economical and effective procedure for the determination of trace amounts of unmetabolized PAHs excreted in human urine spot samples.

Assay of urinaryα-fluoro-β-alanine by gas chromatography–mass spectrometry for the biological monitoring of occupational exposure to 5-fluorouracil in oncology nurses and pharmacy technicians

The validation of an analytical method for the measurement of the unnatural amino acid alpha-fluoro-beta-alanine (AFBA), the main metabolite of the antineoplastic drug 5-fluorouracil (5FU), in urine for the biological monitoring of the exposure of hospital workers to the drug when preparing the therapeutical doses and administering to cancer patients is described. The method employed a two-step extractive derivatization of the analyte from urine to the N-trifluoroacety-n-butyl ester derivative and detection by selected-ion monitoring gas chromatography-mass spectrometry of structurally specific fragments. The limit of detection was 20 ng/mL with quantification accuracy better than +/-20% and precision (CV%) better than +/-20% in the range 0.020-10 microg/mL. Norleucine was used as the internal standard and the sample-to-sample analysis time was less than 15 min. The validated method has been applied to the biological monitoring of some hospital workers potentially exposed to 5FU and to matched control subjects. On a total number of 65 analyzed urine samples from control and exposed subjects, only three, obtained from exposed subjects, were found to be positive, with values of 20, 30 and 1150 ng/mL, respectively.

Monitoring Low Benzene Exposure: Comparative Evaluation of Urinary Biomarkers, Influence of Cigarette Smoking, and Genetic Polymorphisms

Benzene is a human carcinogen and an ubiquitous environmental pollutant. Identification of specific and sensitive biological markers is critical for the definition of exposure to low benzene level and the evaluation of the health risk posed by this exposure. This investigation compared urinary trans,trans-muconic acid (t,t-MA), S-phenylmercapturic acid, and benzene (U-benzene) as biomarkers to assess benzene exposure and evaluated the influence of smoking and the genetic polymorphisms CYP2E1 (RsaI and DraI) and NADPH quinone oxidoreductase-1 on these indices. Gas station attendants, urban policemen, bus drivers, and two groups of controls were studied (415 subjects). Median benzene exposure was 61, 22, 21, 9 and 6 microg/m(3), respectively, with higher levels in workers than in controls. U-benzene, but not t,t-MA and S-phenylmercapturic acid, showed an exposure-related increase. All the biomarkers were strongly influenced by cigarette smoking, with values up to 8-fold higher in smokers compared with nonsmokers. Significant correlations of the biomarkers with each other and with urinary cotinine were found. A possible influence of genetic polymorphism of CYP2E1 (RsaI and/or DraI) on t,t-MA and U-benzene in subjects with a variant allele was found. Multiple linear regression analysis correlated the urinary markers with exposure, smoking status, and CYP2E1 (RsaI; R(2) up to 0.55 for U-benzene). In conclusion, in the range of investigated benzene levels (<478 micro/m(3) or <0.15 ppm), smoking may be regarded as the major source of benzene intake; among the study indices, U-benzene is the marker of choice for biomonitoring low-level occupational and environmental benzene exposure.

[Assessment of exposure to organic aromatic compounds and PAH in asphalt industry: the PPTP-POPA Study results]

Asphalt is a mixture of mineral matter and bitumen, its fumes contain about 1% of Polycyclic Aromatic Hydrocarbons (PAH), some of which are carcinogens. In the PPTP-POPA Study of Lombardy Region, a group of 100 asphalt workers (exposed to bitumen fumes and diesel exhausts) and a group of 47 ground construction operators (exposed only to diesel exhausts) were investigated to assess PAH exposure in Italy, by means of environmental-air monitoring (the 16 most relevant, according to the American Environmental Protection Agency, EPA) and biological monitoring (urinary 1-hydroxypyrene excretion). Our results show that PAH exposure in these workers is not higher than that observed in traffic policemen working in urban areas. Since dermal exposure has been suggested as a major determinant of the total PAH dose absorbed by road pavers from bitumen fumes, we assessed skin contamination by organic aromatic compounds and by sixteen PAH: in both groups, six pads were applied to each subject in different parts of the body, during the workshift. The results show that the dermal contamination in road pavers is higher than in ground construction operators and that cutaneous dose rate is higher than respiratory dose rate, whereas the amount of absorption the ratio is inverted.

Increased urinary coproporphyrin excretion observed in patients with differently staged Hodgkin's disease treated with chemotherapy

It has been reported that patients with Hodgkin's disease (HD) show altered porphyrin metabolism, and suggested that the cause is the neoplastic process itself. If this is true, disease progression should be associated with higher levels of porphyrin excretion. The aim of this study was to evaluate urinary coproporphyrin levels in patients with Hodgkin's disease at different stages. As many of the patients received chemotherapy, another aim was to verify experimentally whether chemotherapeutic agents might increase porphyrin levels in rabbits. All of the patients had above-normal urinary coproporphyrin levels. On the other hand, rabbits receiving the porphyrin precursor 5-aminolevulinic acid (5-ALA), and also treated with doxorubicin, showed very high plasma porphyrin levels. The increased levels of urinary coproporphyrins seem to be due to the disease itself, since the patients in stages III and IV had higher excretion values, presumably due to biochemical heme synthesis lesions that lead to the availability of the porphyrin precursor, as well as coproporphyrin accumulation and excretion. The altered porphyrin synthesis may be attributable to the cytotoxic oxygen species generated in the presence of NADH and iron. As the patients also received extensive chemotherapy regimes, the altered porphyrin metabolism may be affected by antineoplastic treatment generating oxygen reactive radicals. The alterations in porphyrin metabolism induced by chemotherapeutic agents appear to be demonstrated in rabbits in which doxorubicin increases porphyrin synthesis after porphyrin precursor treatment.

The use of S-phenylmercapturic acid as a biomarker in molecular epidemiology studies of benzene

S-Phenylmercapturic acid (S-PMA), is a urinary metabolite of benzene, thought to be derived from the condensation product of benzene oxide with glutathione. S-PMA may be determined by GC, HPLC (UV or fluorescence detection), GC-MS, LC-MS/MS or immunoassays. The limit of sensitivities of most of these techniques is 1 microg/l urine or below. It has been suggested that S-PMA may have value as a biomarker for low level human exposure to benzene, in view of the facts that urinary excretion of S-PMA has been found to be related to airborne benzene in occupationally exposed workers, and that only low background levels of S-PMA have been found in control subjects. We have evaluated the use of S-PMA as a biomarker, using a commercially available analytical service, in a multicentre European study of populations exposed to varying levels of benzene, in Italy (Milan, Genoa) and in Bulgaria (Sofia). These were filling station attendants, urban policemen, bus drivers, petrochemical workers and referents (a total of 623 subjects). S-PMA was measured at the end of the work shift by an immunoassay procedure. Urinary benzene (in Milan only) and the benzene metabolite trans,trans-muconic acid (t,t-MA) were measured before and after the work shift. Air-borne benzene was measured as a monitor of exposure. Urinary benzene was the most discriminatory biomarker and showed a relationship with airborne benzene at all levels of exposure studied (including groups exposed to <0.1 ppm benzene), whereas t,t-MA and S-PMA, as determined by immunoassay, were suitable only in the highest exposed workers (petrochemical industry, geometric mean 1765 microg/m3 (0.55 ppm) benzene). All three biomarkers were positively correlated with smoking as measured by urinary cotinine).

Urinary t,t-muconic acid, S-phenylmercapturic acid and benzene as biomarkers of low benzene exposure

This research compared the capability of urinary trans,trans-muconic acid (t,t-MA), S-phenylmercapturic acid (S-PMA) and benzene excreted in urine (U-benzene) to monitor low benzene exposure and evaluated the influence of smoking habit on these indices. Gasoline attendants, urban policemen, bus drivers and two groups of referents working in two large Italian cities (415 people) were studied. Median benzene exposure was 61, 22, 21, 9 and 6 microg/m3, respectively, with higher levels in workers than in referents. U-benzene, but not t,t-MA and S-PMA, showed an exposure-related increase. All the biomarkers were strongly influenced by cigarette smoking, with values up to five-fold higher in smokers compared to non-smokers. In conclusion, in the range of investigated benzene exposure (<478 microg/m3 or <0.15 ppm), the smoking habit may be regarded as a major source of benzene intake; among the study indices, U-benzene is the marker of choice for the biological monitoring of occupational and environmental exposure.

[New biomarkers of exposure]

In this paper we have defined the new biomarkers of exposure (NBE) as those biomarkers discovered in the last five years and, among previously validated biomarkers, also those applied in different ranges of doses or those determined in biological matrices which differ from matrices originally considered. We examined the results from the surveys carried out by the main Italian research units involved in biological monitoring, i.e. those from the Universities of Brescia, Milan, Naples, Padua, Parma, Pavia, Turin and Verona. The data were collected using a standardized model and included the following: type of element or organic compound, type of biomarker, analytical technique and method, their relationship with environmental monitoring data, their relationship with effect indicators or effects in general, improvement with respect to old biomarkers, reference values. Twenty two NBEs were identified: 14 elements and chemical compounds as such or as metabolites, 4 examples of mixtures, 3 of new matrices, one of speciation. Among the others, aspects such as interest in requiring NBE, quality assurance, availability, cost-benefit ratio were discussed. We conclude that development of this specific field of research appears to be a crucial point for future improvement in risk assessment and health surveillance procedures.

Comparison of DNA adduct levels in nasal mucosa, lymphocytes and bronchial mucosa of cigarette smokers and interaction with metabolic gene polymorphisms

The recent introduction of biomarkers in population studies of lung cancer has improved the traditional epidemiological approach, especially in the detection of high risk groups. Many inhalable carcinogens form DNA adducts, an initial event in lung carcinogenesis, and therefore the identification of easily accessible sources of DNA for population studies is considered a leading priority in the field. In this study we compared the frequency of DNA adducts in samples from nasal brushing, bronchial biopsy and peripheral blood lymphocytes (PBL) in a group of 55 subjects, both smokers and non-smokers, undergoing bronchoscopy for diagnostic purposes. Polymorphisms in the CYP1A1, GSTM1 and GSTT1 genes were also evaluated. The level of DNA adducts measured by (32)P-labelling assay in nasal mucosa (10(8) relative adduct level, mean +/- SD 1.10 +/- 0.66) was higher than in bronchial mucosa (0.82 +/- 0.36) and in PBL (0.54 +/- 0.39, P < 0.01). DNA adducts measured in nasal mucosa and in PBL were correlated with those in bronchial mucosa (P < 0.01 and P < 0.05, respectively). DNA adducts in smokers were significantly increased in both nasal mucosa and PBL, with a significant dose-response linear trend (P < 0.05). No significant effect on DNA adduction of the genetic polymorphisms investigated was found. Nasal mucosa brushing proved to be a suitable procedure for the (32)P-labelling assay and its use in population studies should be further explored.

Increased excretion of urine coproporphyrins during daunorubicin administration in patients affected by acute myelogenous leukemia

Increased erythrocyte porphyrin values and high urine porphyrin levels have been reported in leukemic patients, but it is not clear whether the alteration in porphyrin metabolism is due to the leukemia or its treatment. The aim of this study was to compare porphyrin levels in leukemic patients undergoing chemotherapy or not. We analysed porphyrin values in patients with acute emyelogenous leukemia, who had or had not received chemotherapy according to Gale. Erythrocyte and urine porphyrin levels were increased as a result of the leukemic process, but urine coproporphyrins were further increased by daunorubicin treatment. These higher urine coproporphyrin levels were attributed to the activity of daunorubicin, which is known to interfere with the coproporphyrinogen decarboxylation process leading to the accumulation and high excretion of coproporphyrins in urine.

[European multicenter cross-sectional study on exposure to low doses of benzene]

A cross-sectional multicenter european study has been carried out to evacuate the relations between exposure to low level of benzene and biological markers of internal dose (t,t-MA, S-PMA) and early biological effect (DNA-SSB). The research has shown significantly increased levels (adjusted for smoking habits) of the urinary excretion of t,t-MA, S-PMA and DNA-SSB in petrochemical workers (mean benzene level = 5,694 micrograms/m3) but not in filling station attendants, traffic police officers, and bus drivers compared to referent workers. Dose-response relations were detected between benzene air levels, t,t-MA, S-PMA and DNA-SSB in petrochemical workers, with significantly increased levels of DNA-SSB detected for benzene exposure levels in the range 391-1,800 micrograms/m3 (0.12-0.58 ppm).

[Assessment of exposure to polycyclic aromatic hydrocarbons during road paving]

Asphalt is a mixture of bitumen, (its fumes contain about 1% of polycyclic aromatic hydrocarbons, PAH), and mineral matter. 18 Workers were investigated during road paving to assess PAH exposure by environmental air-monitoring (the 16 most relevant, according to the American Environmental Protection Agency, EPA) and biological monitoring (urinary 1-hydroxypyrene excretion). Our results show that PAH exposure in these workers is not higher than that observed in traffic policemen working in urban areas.

[Evolution of industrial toxicology toward vanishing doses and the human genome]

BACKGROUND

This article aims to discuss the influence that the application of the recent discoveries in genomics will have on the theory and practice of industrial toxicology in developed post-industrial countries. It is stressed that the recent advances in toxicogenomics can be integrated into the existing wealth of knowledge on the toxic properties of industrial chemicals to improve the efficacy of prevention of toxicological risk.

METHODS AND RESULTS

The understanding of the biochemical and physiological mechanisms underlying susceptibility or resistance to the toxic effects of industrial xenobiotics, and in particular to carcinogens, allows us to split the epidemiologically derived relationship linking the frequency of disease in the exposed population to the level of workplace contamination into a set of sequential sub-relationships linking: a) the exposure level to that of workplace contamination; b) the internal dose to the exposure level; c) the biological effect (e.g., measured through biochemical markers of early effect) to the internal dose; d) the frequency of disease to that of observation of early biochemical effects. Each of the cited relationships is affected by a degree of uncertainty due to the variability of biological response among the examined individuals, which in turn requires a definition of the statistical limits for the association functions between the variables. As a consequence, the possibility of investigating the individual biochemical and physiological steps in the causal mechanism that links toxic exposure to disease does not necessarily lead to an increase in the information potential of biological monitoring, since the uncertainty due to inter-individual variability is amplified through the sequence of causal relationships to the point that the data from biological monitoring become valueless with regard to the prediction of the frequency or probability of disease. This is particularly true when exposure to 'low doses' is investigated, as is now increasingly frequent in post-industrial developed countries, where workplace contamination is now greatly reduced to levels which may be borderline with those in the general environment. Thus at the low-dose end of the range of contamination and exposure values there is an area where, for statistical reasons consequent to the heterogeneity of examined populations, a quantitative prediction of internal exposure due to environmental contamination, of biological adverse effects due to exposure levels and of frequency of disease due to the extent or frequency of biological effects is no longer reliably possible. This in turn impairs the preventive efficacy of biological monitoring.

CONCLUSIONS

A closer integration between industrial toxicology and state-of-the-art molecular genetics derived from the recent sequencing of the human genome is the way to overcome the limitations described. In particular, the individual subjects in the examined populations can be classified with regard to some genetically controlled characters relevant to the biotransformation of xenobiotics and to DNA repair and the statistical analysis of data can be performed on more homogeneous subpopulations, in order to decrease inter-individual variability of biochemical and physiological response. This in turn increases the predictive power of the biological markers, both of dose and effect, and improves the efficacy of prevention, e.g., by highlighting oversensitive subpopulations or lifestyles which can increase the risk of occupational and environmental disease.

Determination of hexafluoroisopropanol, a sevoflurane urinary metabolite, by 9-fluorenylmethyl chloroformate derivatization

A reversed-phase HPLC method with fluorescence detection for the quantification of hexafluoroisopropanol (HFIP) in urine is presented. HFIP, a metabolite of the inhalation anesthetic sevoflurane, is excreted mainly in urine as glucuronic acid conjugate. After enzymatic hydrolysis of the glucuronate, primary amino groups of interferent urinary compounds are blocked by reaction with o-phthalic dicarboxaldehyde and 3-mercaptopropionic acid, followed by labeling of HFIP with 9-fluorenylmethyl chloroformate. The derivatization reaction proceeds in a water-acetonitrile (1:1) solution at room temperature with a borate buffer of pH 12.5 as a catalyst. A stable fluorescent derivative of HFIP is formed within 5 min. The HFIP-FMOC derivative is separated by reversed-phase chromatography with isocratic elution on an octadecyl silyl column (33x4.6 mm, 3 microm) and guard column (20x4.0 mm, 40 microm), at 35 degrees C, and detected by fluorescence detection at an excitation wavelength of 265 nm and an emission wavelength of 311 nm. The method detection limit is 40 pg, per 10-microl injection volume, corresponding to 16 microg/l of HFIP in urine. The among-series relative standard deviation is <6% at 200 microg/l (n=6). As a preliminary application, the method was used to detect HFIP concentration in the urine of two volunteers exposed for 3 h to an airborne concentration of sevoflurane in the order of 2 ppm.

[Evaluation of the neurotoxic and nephrotoxic effects following long-term exposure to metallic mercury in employed at a chlorine/sodium-hydroxide plant]

OBJECTIVES

Within the frame work of a wide multicentre study, a sub-study was developed in order to explore the occurrence of early effects on the central nervous system, on the kidney and on the neuro-immune system in the workers of a chloro-alkali production plant exposed to metallic mercury at airborne concentration levels lower than 0.025 mg/m3 (TLV-TWA). They were compared to a control population of employees of the same huge petrochemical plant with different job that did not implicate exposure to mercury vapors. Specifically, the study aimed at revealing the occurrence of early effects on the central nervous system related with mercury exposure, as can be assessed through neurophysiological and neurobehavioral tests.

METHODS

The excretion of urinary mercury was measured by atomic absorption spectrometry. The study of renal function was assessed by measurement of the urinary excretion of some high and low molecular weight protein markers (albumin, beta 2-microglobulin, retinol-binding protein, fibronectin, specific proximal tubule brush border antigens, N-acetyl-beta-D-glucosaminidase). The neurobehavioral status of the study subjects was assessed by means of several test parameters (Simple Reaction Time, Color Word Vigilance Test, Symbol Digit, Finger Tapping, Mood Scale of Kjellberg and Iwanowski, Subjective symptoms questionnaire (QSS), Luria Nebraska Motor Scale, Branches Alternate Movement Task and Tremometry).

RESULTS

The values of urinary excretion averaged 12 +/- 8 micrograms Hg/g of creatinine for the exposed workers group (n = 38), while for the reference group (n = 34 cases) urinary excretion was statistically lower, averaging 4 +/- 6 micrograms Hg/g of creatinine. Neither the parameters selected for the assessment of renal functions, nor those chosen to probe the neurobehavioral status of the probands revealed statistically reliable differences between the group of exposed workers (length of exposure: range 1-34 years) and the control group. Nevertheless, some minor but still statistically reliable correlations were found between some neurobehavioral parameters and some demographic variables describing the whole group of tested workers, but not to the level of occupational exposure to mercury.

CONCLUSIONS

The results of the study confirm the lack of toxic effects of clinical importance on the central nervous system and on the kidney for values of mercury urinary excretion lower than the suggested index of biological exposure (IBE) of 35 micrograms Hg/gram of creatinine.

[Evaluation of the dose of mercury in exposed and control subjects]

OBJECTIVES

The aim of this paper was to analyse the concentrations of HgU and HgB in three different groups: 122 workers exposed, 18 workers formerly exposed and 196 subjects not occupationally or environmentally exposed to mercury.

METHODS

All the subjects filled out a questionnaire concerning personal data, lifestyle, occupational or non-occupational exposure to Hg and medical history. The amalgam fillings area was measured by a standardised method.

RESULTS

Urinary mercury excretion was significantly greater in the group of the exposed workers respect to the group of subjects not occupationally exposed (Median value of 8.3 micrograms/g creatinine and the 5 degrees and 95 degrees percentile respectively of 2.66 e 23.50 micrograms/g creatinine against Median value of 1.2 micrograms/g creatinine and the 5 degrees and 95 degrees percentile respectively of 0.18 and 5.42 micrograms/g creatinine). U-Hg in formerly exposed workers were comparable to U-Hg in non-occupationally exposed subjects, with a median value of 1.6 micrograms/g creatinine. B-Hg values were similar in the three groups: the median value was 3.1 micrograms/l in the non-occupationally exposed, 4.0 micrograms/l in the exposed workers and 3.9 micrograms/l in the past exposed. These value were not significantly different. Among the considered variables (amalgam fillings, fish consumption, age, sex, alcohol intake, chewing-gum and smoking) dental amalgam and fish consumption were significantly related with the Hg urinary excretion and the B-Hg levels. This is particularly true considering the subjects altogether: for the exposed workers, indeed, the occupational exposure was the most relevant variable.

CONCLUSIONS

The results of the present research confirmed that the U-Hg excretion in non-occupationally exposed subjects is influenced by amalgam dental fillings. Furthermore, in our study Hg urinary excretion was significantly related with fish consumption. This fact can be explained, according to several recent experimental human and animal trials, considering that methylmercury contained in fish is partially converted, through breakage of the carbon-Hg bond, into Hg inorganic forms, which accumulate in the kidney and have a urinary excretion pathway.

Determination of monobromobimane derivatives of phenylmercapturic and benzylmercapturic acids in urine by high-performance liquid chromatography and fluorimetry

A method was developed for the determination in human urine of S-phenylmercapturic (PMA) and S-benzylmercapturic (BMA) acids, metabolites respectively of benzene and toluene. PMA and BMA were determined, after alkaline hydrolysis, to give respectively thiophenol and benzylmercaptan, and coupling of the thiol-containing compounds with monobromobimane (MB), by reversed-phase HPLC on a diphenyl-silica bonded cartridge (100 x 4.6 mm I.D., 5 microm particle size) with fluorimetric detection. Wavelengths for excitation and emission were 375 and 480 nm, respectively. The recovery of PMA and BMA from spiked urines was >90% in the 10-500 microg/l range; the quantification limits were respectively 1 and 0.5 microg/l; day-to-day precision at 42 microg/l was C.V. <7%. The suitability of the proposed procedure for the biological monitoring of exposure to low-level airborne concentrations of benzene and toluene, was evaluated by analyzing the urinary excretion of PMA and BMA in subjects exposed to different sources of aromatic hydrocarbons, namely occupationally-unexposed referents (non-smokers, n=15; moderate smokers, n=8; mean number of cigarettes smoked per-day=17 cig/day) and non-smoker workers occupationally exposed to toluene in maintenance operations of rotogravure machines (non-smokers, n=17). Among referents, non-smokers showed values of PMA ranging from <1 to 4.6 microg/l and BMA from 1.0 to 10.4 microg/l; in smokers, PMA values ranging from 1.2 to 6.7 microg/l and BMA from 9.3 to 39.9 microg/l, were observed. In occupationally exposed non-smoker subjects, BMA median excretion value (23.6 microg/l) was higher than in non-smoker referents (3.5 microg/l) (P<0.001) and individual BMA values (y, microg/l) were associated and increased with airborne toluene concentration (x, mg/m3) according to the equation y=6.5+0.65x (r=0.69, P<0.01, n=17). The proposed analytical method appears to be a sensitive and specific tool for biological monitoring of low-level exposure to benzene and toluene mixtures in occupational and environmental toxicology laboratory.

Comparison between blood and urinary toluene as biomarkers of exposure to toluene

OBJECTIVES

To compare blood toluene (TOL-B) and urinary toluene (TOL-U) as biomarkers of occupational exposure to toluene, and to set a suitable procedure for collection and handling of specimens.

METHOD

An assay based on headspace solid-phase microextraction (SPME) was used both for the determination of toluene urine/air partition coefficient (lambdaurine/air) and for the biological monitoring of exposure to toluene in 31 workers (group A) and in 116 non-occupationally exposed subjects (group B). Environmental toluene (TOL-A) was sampled during the work shift (group A) or during the 24 h before specimen collection (group B). Blood and urine specimens were collected at the end of the shift (group A) or in the morning (group B) and toluene was measured.

RESULTS

Toluene lambdaurine/air was 3.3 +/- 0.9. Based on the specimen/air partition coefficient, it was calculated that the vial in which the sample is collected had to be filled up to 85% of its volume with urine and 50% with blood in order to limit the loss of toluene in the air above the specimen to less than 5%. Environmental and biological monitoring of workers showed that the median personal exposure to toluene (TOL-A) during the work-shift was 80 mg/m3, the corresponding TOL-B was 82 microg/l and TOL-U was 13 microg/l. Personal exposure to toluene in environmentally exposed subjects was 0.05 mg/m3, TOL-B was 0.36 microg/l and TOL-U was 0.20 microg/l. A significant correlation (P < 0.05) was observed between TOL-B or TOL-U and TOL-A (Pearson's r = 0.782 and 0.754) in workers, but not in controls. A significant correlation was found between TOL-U and TOL-B both in workers and in controls (r = 0.845 and 0.681).

CONCLUSION

The comparative evaluation of TOL-B and TOL-U showed that they can be considered to be equivalent biomarkers as regards their capacity to distinguish workers and controls and to correlate with exposure. However, considering that TOL-U does not require an invasive specimen collection, it appears to be a more convenient tool for the biological monitoring of exposure to toluene.

Matrix interferences in the analysis of benzene in urine

The analysis of benzene in urine of the general population or of exposed workers can be performed with different methods using the 'purge and trap' or 'solid-phase microextraction' techniques in combination with gas chromatographic analysis and photoionisation or mass spectrometric detection. The published results, however, are deeply conflicting. Differences in sample preparation by different research groups and our own preliminary observations prompted us to investigate pre-analytical and analytical factors potentially capable of modifying the urinary benzene quantification results. Benzene concentrations were measured in 20 urine samples in relation to different conditioning conditions (at 24, 40 and 80 degrees C) and at basic or acid pH. Urinary protein concentrations were measured in the same samples. Urine heating at 80 degrees C yields benzene concentrations on average five times higher than at 24 degrees C. On acidification of urine, the benzene released increases up to 28-fold in comparison to that obtained at uncorrected 'physiological' pH. Despite a widely scattered data distribution, a statistically significant linear correlation was found between 'heat-released' and 'acid-labile' benzene values. There was no correlation between total urinary proteins present in 'physiological' concentrations (between 12 and 110 mg/l) and the different kinds of benzene in urine. Our results could perhaps be explained if it is supposed that part of the benzene in urine is absorbed onto sediment, or bound to specific proteins, or derived from parent molecules and is released with pH modification or heat administration. Our observations may also help to explain why the urinary benzene concentrations reported by different investigators vary considerably even when environmental levels are comparable.

Gas chromatography-electron-capture detection of urinary methylhippuric acid isomers as biomarkers of environmental exposure to xylene

Methylhippuric acid isomers (MHAs), urinary metabolites of xylenes, were determined, after clean-up by C18-SPE and esterification with hexafluoroisopropanol and diisopropylcarbodiimide, by GC with ECD detection, on an SPB-35 capillary column (30 m, 0.32 mm I.D., 0.25 microm film thickness, beta = 320). S-benzyl-mercapturic acid was used for internal standardization. Chromatographic conditions were: oven temperature 162 degrees C, for 14.2 min; ramp by 30 degrees C/min to 190 degrees C, for 3.5 min; ramp by 30 degrees C/min to 250 degrees C, for 4 min; helium flow rate: 1.7 ml/min; detector and injector temperature: 300 degrees C. The sample (1 microl) was injected with a split injection technique (split ratio 5:1). MHA recovery was >95% in the 0.5-20 micromol/l range; the limit of detection was <0.25 micromol/l; day-to-day precision, at 2 micromol/l, was Cv<10%. Urinary MHAs were determined in subjects exposed to different low-level sources of xylenes: (a) tobacco smoking habit and (b) BTX urban air pollution (airborne xylene ranging from 0.1 to 3.7 micromol/m3). Study (a) showed a significant difference between urinary MHA median excretion values of nonsmokers and smokers (4.6 micromol/l vs. 8.1 micromol/l, p<0.001). Study (b) revealed a significant difference between indoor workers and outdoor workers (4.3 micromol/l vs. 6.9 micromol/l, p<0.001), and evidenced a relationship between MHAs (y, micromol/mmol creatinine) and airborne xylene (x, micromol/m3) (y = 0.085+0.34x; r = 0.82, p<0.001, n = 56). Proposed biomarkers could represent reliable tools to study very low-level exposure to aromatic hydrocarbons such as those observed in the urban pollution due to vehicular traffic or in indoor air quality evaluation.

Headspace solid-phase microextraction for the determination of benzene, toluene, ethylbenzene and xylenes in urine

A method for the determination of benzene, toluene, ethylbenzene and xylenes (BTEX) in urine of people exposed to these airborne pollutants present in the living environment, has been described. Solid-phase microextraction has been used for sampling BTEX from the headspace of urine and gas chromatography-mass spectrometry has been applied for the selective analysis of chemicals. The method has the following features: small volume of urine (2 ml) needed, linearity in the range of interest (from the limit of detection up to 5000 ng/l) with coefficient of correlation > or =0.998, limit of detection in the range 12-34 ng/l, good repeatability (coefficient of variation 2-7%), high specificity. The stability of the urine sample during storage (-20 degrees C) was evaluated: BTEX remained stable for up to 2 months. The assay has been successfully applied to the biological monitoring of two subjects environmentally exposed to airborne BTEX in an urban area.

Determination of urinary 2,5-hexanedione in the general Italian population

OBJECTIVE

Determination of the urinary levels of 2.5-hexanedione (2,5-HD) was performed in subjects belonging to the Italian general population to define the reference value for this metabolite.

MATERIALS AND METHODS

Urine samples were collected from 123 healthy Italian subjects who had not been occupationally exposed to n-hexane or methyl-n-butyl ketone (60 men and 63 women; 53 living in urban areas and 70 living in rural areas; 36 smokers and 87 nonsmokers; 65 aged above 35 years and 58 aged below 35 years). The determinations were performed by a gas chromatography method using a flame ionization detector (FID). A quality-control step was realized by analysis of 78 of these samples by high-performance liquid chromatography (HPLC) with UV detection.

RESULTS AND DISCUSSION

The distribution of 2,5-HD concentration was log-normal and the corresponding centiles at the 95% confidence interval were as follows: the 50th centile, 0.270 mg/l for men and 0.191 mg/l for women; the 75th centile, 0.352 and 0.330 mg/l, respectively, for men and women; and the 95th centile, 0.762 and 0.582 mg/l, respectively, for men and women. The reference value, calculated as the upper unilateral 95% tolerance interval at 95% of confidence, was 0.795 mg/l for men and 0.627 for women.

[Biological monitoring of environmental benzene exposure in traffic wardens]

Vehicle exhausts are a well known source of aromatic hydrocarbon pollution in urban environments. The paper reports the results of environmental and biological monitoring of benzene exposure in traffic wardens carried out over a 5-hour workshift. Subjects (n = 131) were grouped according to smoking habits and job task as follows: group (A) 52 nonsmoking office workers, (B) 43 nonsmoking outdoor workers, subdivided into (B1) 36 working on foot and (B2) 7 cyclists; (C) 20 smokers office workers, (D) 16 smokers outdoor workers, subdivided into (D1) 11 working on foot and (D1) 5 cyclists. The median indoor environmental benzene concentration (26 micrograms/m3, n = 50) was significantly lower than the outdoor concentration (45 micrograms/m3, n = 43) (p < 0.01); median exposure value of cyclists was 78 micrograms/m3 (n = 12). For biological monitoring, urinary excretion of trans,transmuconic acid was determined in spot samples collected at 7:30 h (MAit) and 12:30 h (MAft). The MAftA median value (63 micrograms/l, range 2-242 micrograms/l) was not statistically different from MAftB (74 micrograms/l, range 15-216 micrograms/l), while the MAftB2 value of 96 micrograms/l was higher than both MAftB1 (71 micrograms/l) and MAftA. In group (B) there was a relationship between airborne benzene levels and MAftB excretion (y = 17.2 + 1.1x, r = 0.62, n = 35, p < 0.01). The influence of smoking on urinary MA excretion was studied by comparing the results obtained in all nonsmokers (AB) with smokers (CD). MAftCD (192 micrograms/l) was significantly higher than MAftAB (69 micrograms/l) (p < 0.01). In smokers, statistically significant relationships were observed between urinary excretion of MAft (y, microgram/l) and cotinine (x, microgram/l) (y = 83 + 0.08x, r = 0.73, n = 23, p < 0.01), and smoking (x, number cigarettes/day) (y = 87.4 + 4.4x, r = 0.53, n = 29, p < 0.01). Comparison between MAft and MAit median excretion values, calculated for each of the 6 exposure groups, showed that MAft was always higher than the corresponding MAit value. A rough estimate of the total dose of benzene ("index of exposure", EI) inhaled by each subject during the 5-hour working shift as a consequence of air pollution and smoking was also made. Considering the entire group of subjects, a significant association was observed between EI and MAft values (y = 43.4 + 0.39x, r = 0.65, n = 104, p < 0.01). Individual values of MA it were correlated with MAft according to the equation y = 43.6 + 0.82x (r = 0.62, n = 105; p < 0.01) and were also positively associated with EI values (y = 42.3 + 0.20x; r = 0.55; n = 74; p < 0.01). In conclusion, the results suggest that the measurement of urinary MA excretion is a poor indicator for assessing environmental benzene exposure at levels below 100 micrograms/m3, such as those seen in this study; MA can however be reliably used as a biomarker for higher exposures such as those, for example, due to smoking.

Fast liquid chromatographic determination of urinary trans,trans-muconic acid

trans, trans-Muconic acid (1,3-butadiene-1, 4-dicarboxylic acid, MA), a minor urinary metabolite of benzene exposure, was determined, after clean-up by solid-phase anion-exchange chromatography, by reversed-phase HPLC on a C18 column (5 x 0.46 cm I.D., 3 microns particle size), using formic acid-tetrahydrofuran-water (14:17:969) as mobile phase and UV detection at 263 nm. The recovery of MA from spiked urine was > 95% in the 50-500 microgram/l range; the quantification limit was 6 micrograms/l; day-to-day precision, at 300 micrograms/l, was C.V. = 9.2%; the run time was less than 10 min. Urinary MA excretion was measured in two spot urine samples of 131 benzene environmentally exposed subjects: midday values obtained in non-smokers (mean +/- S.D. = 77 +/- 54 micrograms/l, n = 82) were statistically different from those of smokers (169 +/- 85 micrograms/l, n = 30) (P < 0.0001); each group showed a statistically significant increase between MA excretion in midday over morning samples. Moreover, in subjects grouped according to tobacco-smoke exposure level, median values of MA were positively associated with and increased with daily smoking habits.

[Biological monitoring of exposure to solvents: a method for the gas-chromatographic determination of aromatic hydrocarbons in the blood and urine]

A gas chromatographic procedure with dynamic head-space purge and trap preconcentration (HSGC) and FID detection for blood and urinary benzene, toluene, ethylbenzene and xylenes (BTEX) determination at low level exposure is described. Critical steps (sample collection, calibration, HSGC conditions, contamination control) are discussed. The calibration curve is linear in the range 50 ng/l-500 micrograms/l; the calculated detection limit is 50 ng/l for all the considered aromatic hydrocarbons (AH) both in blood and urine; the within-day precision, calculated as variation coefficient (CV) at 400 ng/l and 40 micrograms/l (n = 6) was respectively CV = 13% and CV = 6% for all the studied analytes. The recovery rate was in the range 29-70%, depending on the hydrocarbon and matrix (blood or urine) considered. The procedure was applied to the biological monitoring of 151 workers occupationally or environmentally exposed to BTEX. Occupationally exposed subjects showed blood AH levels of 2-4 order of magnitude higher than environmentally exposed subjects. In white-collar workers exposed to BTEX urban pollution a significant difference in blood and urine levels of AH was observed between nonsmokers and smokers. Nonsmokers showed blood AH median values of respectively benzene = 241 ng/l, toluene = 759 ng/l, ethylbenzene = 140 ng/l, xylenes = 604 ng/l. Significatively higher BTEX blood values were observed in smokers after a median consumption of 5 cigarettes in 5 hours; observed median values were respectively: benzene = 365 ng/l toluene = 1327 ng/l, ethylbenzene = 233 ng/l, xylenes = 794 ng/l.

Biological and environmental monitoring of exposure to airborne benzene and other aromatic hydrocarbons in Milan traffic wardens

Environmental and biological monitoring of airborne aromatic hydrocarbons has been performed in 20 policemen working as traffic wardens exposed to motor vehicle exhausts and in 19 peers employed as clerks. Airborne benzene, toluene, ethylbenzene and xylene concentrations, measured during the workshift, resulted in significantly higher outdoor than indoor concentrations (benzene and related aromatic hydrocarbons mean values, respectively of 53 and 350 micrograms/m3 vs. 29 and 180 micrograms/m3). Blood benzene, toluene, ethylbenzene and xylene concentrations did not differ significantly between indoor and outdoor workers; no differences were found between values obtained at the beginning (07:30 h) and the end of shift (00:30) in either group. Blood hydrocarbon concentrations seem to reflect airborne pollution, whilst the blood benzene concentration determined after the workshift poorly reflects airborne benzene morning peaks. Endshift blood benzene mean concentration in smokers (462 ng/l, n = 9) differs significantly from non-smokers (292 ng/l, n = 39).

[The biological monitoring of occupational exposure to anesthetic gas and vapors: the determination of nitrogen protoxide, halothane and isoflurane in the urine]

A gas-chromatographic method has been developed for measuring urinary nitrous oxide, halothane and isoflurane concentrations. A volume of head-space gases obtained from biological samples is analyzed by ECD-GC on a steel column (2 mm ID) serially packed with Porapak Q (1.2 m) and MS-5A (0.30 m), operated at 160 degrees C. The detection limit (ranging from 0.03 micrograms/l for halothane to 1 microgram/l for nitrous oxide), between-day precision (CV < 6%) and working linear range (up to 100 micrograms/l for halothane and 2000 micrograms/l for nitrous oxide) were determined. A two-year experience in biological monitoring of occupationally exposed surgical staff with the proposed method is reported and confounding factors are discussed. The method is easy to perform, free from interferences and suitable for use in routine analysis in toxicological laboratories.

[Measurements and environmental and biological monitoring of occupational exposure to inhalation anesthetics]

This paper reports the data of nitrous oxide (N2O) environmental pollution in 269 operating rooms of 47 hospitals in Italy in 1989-91. In 40% of the operating rooms the N2O concentrations are lower than 50 ppm, limit value proposed by Health Council for new operating rooms. In 65.4% of the operating room studied, N2O mean environmental concentrations are lower than 100 ppm, value proposed by the above-mentioned Health Council as limit value for the already existing operating rooms. Concerning the biological monitoring, the authors report several N2O data in urine (2193), whose levels confirm the data obtained with environmental monitoring. The authors believe that they presently have reliable methods to perform biological and environmental monitoring: the two techniques are complementary in the assessment of the exposure. The method of measuring N2O concentrations as exposure index, both for the environmental and biological monitoring, is considered very useful to simplify the performance of the analyses. In order to assess exposure more precisely, it is however necessary also to determine the environmental and/or biological measure of the other different anaesthetics used.

[Acute exposure to vanadium-containing dusts: the health effects and biological monitoring in a group of workers employed in boiler maintenance]

The authors describe an episode of acute intoxication due to inhalation of vanadium-containing dusts in a group of 10 workers during maintenance work inside a boiler of an oil-fired electricity power station. Historical, clinical and biological monitoring data concerning the acute exposure phase and subsequent checks are presented. The appearance of irritative symptoms of the upper airways, green tongue (in 6 out of 10 subjects) and the values of urinary excretion of vanadium (means = 92, D.S. = 47 micrograms/l: limits 20-270 micrograms/l) indicated acute vanadium exposure. With the use of appropriate individual protection devices and shorter shifts, 2 weeks after the episode there was a complete remission of the symptoms and a return of urinary vanadium concentrations to 38, D.S. = 26 micrograms/l. Checks made 6 months, 1 and 2 years later did not reveal any alterations in the general blood chemistry parameters and the urinary vanadium concentrations were below 1 microgram/l (reference value). As already often reported in the literature, this episode confirms the danger involved in working in the presence of fuel oil residues or ashes and the need to adopt appropriate prevention measures.

[Determination of blood bile acids using high pressure liquid chromatography: comparison of chromatographic, enzymatic and immunoenzymatic methods]

A method has been developed for measuring serum conjugated bile acids by HPLC. Serum samples, to which the internal standard is added, are purified by a solid phase procedure and injected on a reverse phase C18 column. Elution is accomplished by means of a flow gradient and peaks are detected at 198 nm. The detection limit ranges between 0.05 and 0.20 mumol/l for different analytes; between-day precision (CV 5.8%), working linear range (up to 50 mumol/l) and recovery (87%) were established. Comparison of the results obtained with HPLC, enzymatic and immuno-enzymatic methods gave high correlation coefficients. The method was applied for diagnostic purpose to a group of subjects suffering from various liver diseases. Also, 106 healthy workers, not occupationally exposed to known or potentially hepatotoxic agents, were studied in order to establish reference values for use in biological monitoring of chronic low level exposure to solvents. The method has the advantage of a more simple procedure compared to previously reported HPLC methods and appears to be well suited for routine use in toxicological and clinical test laboratories.

[Application of high-pressure liquid chromatography in the analysis of urinary metabolites of aromatic solvents]

The introduction of HPLC methods in industrial toxicology represents a valuable tool for the routine monitoring of workers occupationally exposed to aromatic solvents. The HPLC method described here permits the simultaneous determination of metabolites of ethylbenzene, styrene, toluene, xylene isomers, benzene, phenol and cresol isomers in diluted urine samples. Pretreatment of urine samples with steam distillation is necessary only for determination of phenol and cresols because of their low concentrations. A comparison between a GLC and the HPLC procedure for mandelic and phenylglyoxylic acids confirmed the satisfactory performance of the HPLC method.

[Biological limits of exposure: evolution of interpretative and methodologic criteria]

Biological monitoring is an extremely efficient investigation tool in evaluation of exposure to exogenous substances, in both occupational and environmental settings. However, although biological tests have been widely acclaimed as the ideal approach to or as a completion of environmental measurements, they have had difficulty in becoming firmly established due to a number of limitations of various nature. Besides the numerous uncertainties in the set-up phase, which depend on the choice of indicators or criteria for their use, difficulties are still incurred in making a univocal interpretation of the results. These difficulties are due to the limited pharmaco-kinetic information available on the various substances and to the wide variability in individual biological response. The possibility of extrapolating Biological Exposure Limits (BELs) from the corresponding TLV-TWA, by means of calculations based on the experimental regressions observed between internal and external dose indices, has up to now been considered a dubious operation from a formal point of view and merely indicative for practical purposes. This paper examines the possibility of establishing BELs that are fixed taking account of the influence of the various biological variables, thus permitting a more correct, objective and generalised use of biological indicators in current practice. From the regression function and relative tolerance limits, intended as a range of values within which regression values can be expected to be found with a probability that can be fixed a priori, it is possible to calculate 3 BEL values for each environmental TLV-TWA concentration. The question of which of these different values should be selected as a BEL for practical purposes must be solved on the basis of a series of observations related to the type of investigation being performed and the context in which the results are to be used. It should be emphasized that each BEL value has its own particular sensitivity and specificity, i.e., the possibility of correctly classifying the exposure conditions in relation to the environmental values. If sensitivity and specificity values are known, it is possible to calculate the predictive value of the biological measurements compared to the environmental measurements; if numerical data on these parameters are available, account can be taken of the variability of the results in a rigourously scientific manner.(ABSTRACT TRUNCATED AT 400 WORDS)

[Biological monitoring of occupational exposure to airborne pollutants]

Biological monitoring of inert substances requires knowledge of the mechanisms regulating respiratory absorption. The authors examine the influence of parameters such as work load, exposure duration and biotransformation on the respiratory absorption of inert airborne pollutants in the workplace. Attention is also given to the possibility of using biological thresholds or Biological Equivalent Limits (BELs).

Behaviour of plasma and urinary aluminium levels in occupationally exposed subjects

Aluminium in urine (AlU) and in plasma (AlP) was determined in seven subjects occupationally exposed to environmental concentrations of aluminium below or equal to the TWA (5 mg/m3). The AlU levels in these workers were markedly higher than those found in the control group. The levels of the indicator were definitely higher at the end of the shift than at the beginning of the same working day; also, the AlU levels were higher on Friday morning than on Monday morning. After an interruption in work of two weeks, the values of the indicator underwent a marked reduction and were then only slightly higher than those of the control group. Occupational exposure to fumes produced higher AlU levels than exposure to dusts, and in the subjects exposed to fumes the AlU levels were clearly influenced by the degree of exposure. The levels of aluminium in plasma in the exposed workers on the other hand, hardly differed from the levels found in the control group. These data appear to indicate that, whereas AlU allows daily and weekly exposure to be evaluated, AlP cannot be used as an indicator of occupational exposure, at least in the case of brief exposures to environmental concentrations below or equal to the TWA.

The speciation of the chemical forms of arsenic in the biological monitoring of exposure to inorganic arsenic

Total As content may be determined in blood and urine by means of an AAS method that involves reduction of As to its volatile hydride and ashing at 600 degrees C with MgO and Mg (NO3)2. Separation of inorganic As (InAs), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMAA) by ion-exchange chromatography, followed by direct AAS analysis, allows the determination of each As species in the urine. In a reference population of 148 subjects with only normal environmental exposure to As, total As concentration in the urine averages 17.2 +/- 11.1 micrograms/l. Urinary As consists of 10% each of InAs, MMAA and DMAA, the remaining 70% consisting of other forms of organic As. Blood As concentration averages 5.1 +/- 6.9 micrograms/l and correlates significantly with the urinary concentration of InAs and the sum of its metabolites (InAs + MMAA + DMAA). Inorganic arsenic undergoes methylation in the organism. After ingestion of high quantities of As2O3, the time course of excretion of its metabolites indicates that As methylation occurs by a saturable mechanism. In workers exposed to As2O3, InAs, MMAA and DMAA are the only chemical forms of As excreted in the urine that are relevant to a study of occupational exposure. Blood As concentration is proportional to exposure and correlates only with urinary DMAA excretion; DMAA seems to be the most appropriate single indicator of exposure. At high levels of exposure (total As excretion above 200 micrograms/l), As accumulates in the organism and DMAA excretion reflects its accumulation. At low levels of exposure (total As excretion below 50 micrograms/l) a short-term accumulation does not occur and the best biological indicator of exposure is InAs excretion. Seafood ingestion brings about a marked increase in urinary excretion of total As that lasts for 24-48 h and is not accompanied by any increase in InAs, MMAA or DMAA excretion. Organic As from seafood does not mix with the pool of inorganic As in the organism and may be separately detected in urine. In the biological monitoring of human exposure to As, particularly in the case of high urinary values, the speciation of the chemical forms of As in urine is necessary in order to establish with certainty the source, industrial or alimentary, of exposure.