Exposure of rome city tram drivers to airborne platinum, rhodium, and palladium.

OBJECTIVE: To investigate the exposure of tram drivers of Rome to Pt, Rh, and Pd in total suspended particulate, PM10, and PM2.5 fractions. METHODS: Sampling was performed on a tram running on about 15-km pathway characterized by a medium-high traffic car density. The analytical determination of metals was performed using inductively coupled plasma mass spectrometry. RESULTS: Mean element values (in pg/m) total suspended particulate, PM10, and PM2.5, were Pt, 20.3, 14.1, and 8.86, Rh, 3.99, 2.83, and 1.94, and Pd, 82.1, 58.0, and 15.2, respectively. CONCLUSIONS: Although the Pt, Rh and Pd levels in urban air were found to be still 8 to 11 orders of magnitude below the values thought to cause adverse effects on adult worker health, periodic environmental monitoring would be necessary to detect possible increments which could affect occupational exposure of tram drivers.

Environmental and biological monitoring of iridium in the city of Rome.

The use of iridium in the latest catalytic converters to further reduce nitrogen oxide emission in the exhaust of lean-burn engines could result in increased atmospheric levels of this element in high-density vehicle traffic areas. The objective of this study is to assess environmental Ir pollution and its urinary levels in workers and an urban control group. Environmental monitoring inside a tram consisted in air samplings of total suspended particles (TSP), PM10 and PM2.5 carried out during November 2005. Urinary Ir levels were evaluated in 64 municipal tram drivers and in 58 administrative employees as controls. Quantification of Ir in air samples and urine was performed by means of Sector Field Inductively Coupled Plasma Mass Spectrometry. Means+/-standard deviation of Ir levels in TSP, in PM10 and PM2.5 fractions were 1.43+/-1.66, 0.44+/-0.27 and 0.36+/-0.19 pg m(-3), respectively. No statistically significant differences were observed among urinary Ir values in the exposed subjects and control group. The Ir levels in Rome air are still sufficiently low, even if the increased use of new Ir-based catalysts could be of some concern in the near future. The results of our study are of interest as they are a first attempt to explore airborne levels and urinary concentrations of Ir in an urban context at medium-high density of vehicle traffic. Particular attention should be given to the fact that Ir was found in the finest dust particles as the effects of fine particles containing Ir have not yet been studied.

Biomonitoring of tram drivers exposed to airborne platinum, rhodium and palladium.

OBJECT: The aim of this study was to evaluate urinary levels of Pt, Rh and Pd in occupationally exposed subjects. METHODS: A total of 122 healthy male subjects of Rome (Italy) were studied; 64 were municipal tram drivers and 58 control subjects. Metal quantification in the urine samples was carried out by sector field inductively coupled plasma mass spectrometry. RESULTS: There were statistically significant differences between urinary Pt and Rh levels of the workers and the control group (Pt median: 1.23 versus 1.03 ng/g creatinine; Rh median: 19.16 versus 11.18 ng/g creatinine), while no difference in Pd levels was observed (Pd median: 11.47 versus 8.75 ng/g creatinine). CONCLUSIONS: Urinary Pt and Rh could be useful biomarkers for monitoring population groups occupationally exposed to these elements. Urinary concentration of Pt and Rh, though still low, could be of some concern in workers heavily exposed to urban car traffic.

Determination of airborne polycyclic aromatic hydrocarbons at an airport by gas chromatography-mass spectrometry and evaluation of occupational exposure.

The aim of this study was to determine airborne polycyclic aromatic hydrocarbons (PAHs) and biphenyl at an airport by gas chromatography-mass spectrometry and to evaluate occupational exposure by environmental monitoring. A total of 12 samplings were carried out in three areas: (1) a handling area where baggage was unloaded manually from vehicles onto conveyor belts (n=5); (2) the runway with plane and motor vehicle traffic (n=5) and (3) a departure lounge (n=2). PAHs levels were in most cases low. The higher levels found refer to naphthalene (130-13,050 ng/m3) and to its methyl-substitutes 2-methylnaphthalene (64-28,500 ng/m3) and 1-methylnaphthalene (24-35,300 ng/m3), and biphenyl (24-1610 ng/m3). A method was used to quantify twenty-four airborne PAHs, and biphenyl, and to detect a variety of other chemical compounds by means of the deconvolution program AMDIS. After sampling air on quartz filter and PUF and XAD-2 sorbents; extraction with dichloromethane, and concentration and purification on silica cartridges, analyses were carried out by gas chromatography-ion trap mass spectrometry. We used 20 deuterated PAHs to quantify both the 24 native PAHs and biphenyl. The native substances had been subdivided into small groups and in this way, their volatility was adequately reflected by the D-PAH present in each group. The limit of detection was 0.1 ng/m3 for all the PAHs, and a linear range of at least about three-fold the maximum level studied (naphthalene) was obtained both for D-PAHs and the native PAHs. A good recovery pattern was obtained for D-PAHs on quartz filters, PUF and XAD-2.

Exposure evaluation to airborne polycyclic aromatic hydrocarbons in an italian airport.

The aim of this study was to use environmental monitoring to evaluate occupational exposure to polycyclic aromatic hydrocarbons (PAHs) and biphenyl in an Italian airport. Air was sampled using a quartz fiber filter, a polyurethane foam, and an XAD-2 layer. After extraction with dichloromethane, concentration and purification analyses of 25 PAHs (including biphenyl) were carried out by gas chromatography-ion trap mass spectrometry. In winter 2005, 12 air samples were taken at 120 L/min for 24 hours in three different areas of the airport. PAH levels were found to be generally low. In all investigated areas, the higher levels refer to naphthalene (130-13,050 ng/m), 2-methylnaphthalene (64-28,500 ng/m), 1-methylnaphtalene (24-35,300 ng/m), and biphenyl (24-1610 ng/m). However, in some instances, for compounds such as benzo[b+j+k]fluoranthene and benzo[a]pyrene, two high-boiling PAHs, the levels found (54.2 ng/ m and 8.6 ng/m, respectively) can be considered of some concern.

Occupational exposure in airport personnel: characterization and evaluation of genotoxic and oxidative effects.

Airport personnel can be exposed to several polycyclic aromatic hydrocarbons (PAHs) from jet fuel vapours, jet fuel combustion products and diesel exhaust. The aim of this study was to characterize the exposure and to evaluate genotoxic and oxidative effects in airport personnel (n=41) in comparison with a selected control group (n=31). Environmental monitoring of exposure was carried out analysing 23 PAHs on air samples collected from airport apron, airport building and terminal/office area during 5 working days. The urinary 1-hydroxy-pyrene (1-OHP) following 5 working days, was used as biomarker of exposure. Genotoxic effects and early direct-oxidative DNA damage were evaluated by micronucleus (MN) and Fpg-modified comet assay on lymphocytes and exfoliated buccal cells, and by chromosomal aberrations (CA) and sister chromatid exchange (SCE) analyses. For comet assay, tail moment (the product of comet relative tail intensity and length) values from Fpg-enzyme treated cells (TMenz) and from untreated cells (TM) were used as parameters of oxidative and direct DNA damage, respectively. We found 27,703 microg/m(3) total PAHs in airport apron, 17,275 microg/m(3) in airport building and 9,494 microg/m(3) in terminal/office area. Urinary OH-pyrene did not show differences between exposed and controls. The exposed group showed a higher mean value of SCE frequency in respect to controls (4.6 versus 3.8) and an increase (1.3-fold) of total structural CA in particular breaks (up to 2.0-fold) and fragments (0.32% versus 0.00%), whereas there were no differences of MN frequency in both cellular types. Comet assay evidenced in the exposed group a higher value in respect to controls of mean TM and TMenz in both exfoliated buccal cells (TM 118.87 versus 68.20, p=0.001; TMenz 146.11 versus 78.32, p<0.001) and lymphocytes (TM 43.01 versus 36.01, p=0.136; TMenz 55.86 versus 43.98, p=0.003). An oxidative DNA damage was found, for exfoliated buccal cells in the 9.7% and for lymphocytes in the 14.6% of exposed in respect to the absence in controls. Our findings furnish a useful contribution to the characterization of civil airport exposure and suggest the use of comet assay on exfoliated buccal cells to assess the occupational exposure to mixtures of inhalable pollutants at low doses since these cells represent the target tissue for this exposure and are obtained by non-invasive procedure.

The release of metals from metal-on-metal surface arthroplasty of the hip.

The aim of the study was to evaluate the serum and urine levels of cobalt (Co), chromium (Cr), manganese (Mn), molybdenum (Mo) and nickel (Ni) in patients who had undergone metal-on-metal hybrid surface arthroplasties on the supposition that a release of metals would occur due to the large head size of this type of implant. Metal levels were determined by using an analytical method based on sector field inductively coupled plasma mass spectrometry. Results showed a significant difference between patients and control subjects in mean levels of Co and Cr in serum (p<0.0001 and p=0.02, respectively) and in urine (p<0.0001 for both). No significant differences were observed in mean serum and urinary levels of Mn, Mo and Ni. Although the clinical consequences of these changes, if any, are unknown, further studies could be performed in a larger number of subjects implanted with a total surface arthroplasty at follow-up times over different periods.

Evaluation of occupational exposure to N-nitrosamines in a rubber-manufacturing industry.

OBJECTIVE: We sought to determine volatile N-nitrosamines levels in the air of a rubber-manufacturing industry and to measure urinary N-nitrosamines concentrations in exposed workers. METHODS: Personal monitoring of 34 workers was performed by sampling nine airborne N-nitrosamines in four factories that manufactured rubber drive belts for automotive engines. Urinary N-nitrosamine levels were determined in all workers and in a control group of 26 subjects. Analyses were conducted by capillary gas chromatography-thermal energy analyzer. RESULTS: Airborne and urinary N-nitrosamines levels were very low and, in most cases, below the limit of detection (0.06 microg/m and 0.1 microg/L, respectively). CONCLUSIONS: Although airborne and urinary N-nitrosamines levels were found to be very low, exposed workers should still be monitored constantly because some of these substances are known to be genotoxic and carcinogenic.

Dose-response relationships in human experimental exposure to solvents.

Previous studies carried out in the field of experimental toxicology have shown evidence of biphasic dose-response relationships for different experimental models, endpoints and chemicals tested. As these studies excluded humans as the experimental model, we have examined the literature of the last three decades in order to verify data concerning human experimental exposure with the aim of highlighting possible biphasic dose-response relationships. The substances used for experimental exposures included hydrocarbons, esters, alcohols, ketones, ethers, glycoethers, halogenated hydrocarbons, and carbon sulphide; the absorption route was inhalation. We did not detect any biphasic dose-response relationship and, in the studies reviewed, our examination revealed major methodological limitations that prevented us making a more detailed examination of experimental data. We concluded that the experimental data available did not allow us to support evidence of biphasic dose-response relationships in human experimental exposure to the above-mentioned chemical substances.

Treatment of Wilson's disease with zinc from the time of diagnosis in pediatric patients: a single-hospital, 10-year follow-up study.

Wilson's disease (WD) is an inherited disorder of copper metabolism characterized by a failure of the liver to excrete copper, leading to its accumulation in the liver, brain, cornea, and kidney, with resulting chronic degenerative changes. It is generally accepted that "presymptomatic" patients--in whom WD is diagnosed in childhood and who are defined as those who, although still asymptomatic, do have liver disease, as indicated by increased serum concentrations of transaminases--should be treated prophylactically. Here we report our results in 22 children treated with continuous oral zinc therapy for 10 years. Zinc sulfate was administered at a dosage of 25 mg elemental zinc twice a day until the age of 6 years, 25 mg three times a day between the ages of 7 and 16 years or until the child attained a body weight of 125 lb, and 50 mg three times a day thereafter. Five years after the start of zinc treatment, we noted highly significant decreases in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and urinary copper excretion, but white blood cell counts did not vary significantly. Six of 22 patients continued to demonstrate greater-than-normal ALT concentrations and only 1 patient demonstrated an ALT concentration more than 1.5 times the upper normal limit. Further decreases in ALT, AST, and urinary copper excretion were observed at the end of the 10-year follow-up, but these decreases were not statistically significant. Only 1 patient continued to demonstrate abnormal ALT levels. Again, white blood cells showed no significant variations. All histologic scores (steatosis, inflammation, and fibrosis) were significantly decreased after treatment. Hepatic copper content was also significantly decreased, although it remained higher than normal in all patients. The removal of toxic copper was confirmed by disappearance of Kayser-Fleischer rings in 3 patients. Zinc did not have adverse effects on growth. The efficacy of zinc in WD in presymptomatic pediatric patients has been established in previous studies, and our study adds considerably to the earlier findings because it includes a large number of very young children, as many as 11 younger than 6 years and 20 younger than 10. The excellent clinical results in all patients, coupled with the improvement in hepatic histologic findings in the vast majority, indicate convincingly that zinc treatment can control the disease effectively and safely, preventing its progression over the course of 10 years. Histologic findings reportedly improved in 3 patients treated in an earlier study, but our data are numerically much more relevant. Notably, histologic study of the liver revealed that copper concentration was reduced by treatment, suggesting that oral zinc was able not only to prevent further accumulation of copper but also to promote, at least in part, the depletion of its stores. The lack of adverse effects of zinc on growth suggests that our patients received enough anticopper therapy to prevent damage resulting from copper toxicity but an adequate amount of copper for proper growth and development. In conclusion, our findings indicate that zinc is the treatment of choice in presymptomatic pediatric patients with WD.

Effects of occupational trichloroethylene exposure on cytokine levels in workers.

OBJECTIVE: We sought to investigate trichloroethylene-induced alterations of the immune system in humans. METHODS: The levels of interleukin-2, interleukin-4, and interferon-gamma in sera obtained from workers exposed to trichloroethylene were determined and compared with those of internal and external control subjects. RESULTS: In workers with a mean urinary trichloroacetic acid concentration of 13.3 +/- 5.9 mg/g creatinine, exposed to a mean environmental trichloroethylene level of 35 +/- 14 mg/m, we observed a significant increase in sera interleukin-2 and interferon-gamma levels and a reduction in interleukin-4 concentrations compared with those of workers from the internal and external control groups. CONCLUSIONS: This study provides the first report on quantitative immune changes induced by occupational exposure to low levels of trichloroethylene and strongly suggests that exposure to this substance alters immunohomeostasis in humans with possible effects on health.

Biomonitoring of titanium, mercury, platinum, rhodium and palladium in dental health care workers.

BACKGROUND: In dentistry, titanium, mercury, platinum, rhodium and palladium are used to produce dental fillings. Therefore, dental workers who apply such materials may be exposed to these metals. METHODS: The study concerned 40 healthy subjects-20 controls and 20 dental health care workers-to determine serum and urinary levels of the aforementioned metals by inductively coupled plasma mass spectrometry. RESULTS: Mean urinary and serum titanium did not reveal statistically significant differences in the two groups. The very low urinary and serum levels of mercury, platinum, rhodium and palladium prevented us from making a statistical evaluation between the two groups. CONCLUSIONS: We did not find a significant increase in serum and urinary titanium levels in dental health care workers. Measurement of mercury, platinum, rhodium and palladium in urine and serum was not useful in determining occupational exposure.

Genotoxic risk and oxidative DNA damage in workers exposed to antimony trioxide.

The growing use of antimony (Sb) compounds in industry and the consequent increase in the number of exposed workers make it important to carry out a health risk assessment. The main goal of this study was to assess the genotoxicity of Sb(2)O(3) in occupationally exposed workers. Genotoxicity was evaluated by the sister chromatid exchange (SCE) and micronucleus tests, and the enzyme (Fpg)-modified comet assay. In addition, antimony exposure levels were established by environmental monitoring with personal air samplers. We studied 23 male workers assigned to different fire retardant treatment tasks in the car upholstery industry and a control group of 23 healthy nonexposed males. The exposed workers were divided into two groups on the basis of their tasks and the work cycle: Group A comprised finishing and intermediate inspection operators who directly handled a mixture containing Sb(2)O(3); Group B were jet operators, not directly exposed to the compound. Environmental monitoring detected low Sb exposure levels but significant differences between the two groups, with Group A having the higher exposure level. Cytogenetic analyses showed no difference between exposed workers and controls for micronuclei and SCE. The enzyme-modified comet assay showed a probable relation between moderate levels of oxidative DNA damage and exposure to antimony, with a significantly higher proportion of workers in Group A having oxidative DNA damage compared to controls. The results support the theory that oxidative DNA damage is involved in the genotoxicity of antimony and indicate the need for further research in this field.

Methyl-tertiary-butyl ether (MTBE) inhibits growth and induces cell transformation in rodent fibroblasts.

Methyl-tertiary-butyl ether (MTBE) is a ubiquitous oxygen-bearing additive used to reduce engine knocking and obtain cleaner gasoline combustion. Conflicting data have been reported about a possible carcinogenic role of MTBE in humans. In this study we evaluated the effects of MTBE on cell growth and transformation in rodent fibroblasts. We found that MTBE inhibits cell proliferation in a dose- and time-dependent pattern with an IC50 of about 0.84 mM. We also studied the effects of MTBE on cell cycle distribution. The most striking effect was a reduction in the percentage of cells in the G2/M-phase which was associated with an increase of cells in the S-phase of the cell cycle, as assessed by flow cytometry. At a dose corresponding to IC50, a subdiploid peak indicative of apoptosis, was also evident. MTBE was also able to induce cell transformation in vitro. In conclusion, our results suggest that MTBE can affect cell growth and induce cell transformation in cultured rodent fibroblasts.

External and internal dose in subjects occupationally exposed to ochratoxin A.

OBJECTIVES: Ochratoxin A (OA) is a ubiquitous mycotoxin that can contaminate foods, drinks, and animal feeds worldwide. Humans and animals can therefore absorb this toxin via the gastrointestinal tract after ingestion of contaminated products. OA is known to exert toxic effects, particularly on the renal system, and the International Agency for Research on Cancer (IARC) classified it as a "possible human carcinogen" (Group 2B). The measurement of OA serum levels is an effective method of evaluating internal doses. Inhalation of airborne OA can represent a source of additional exposure. We determined the levels of serum OA in workers exposed to airborne dust originating from the handling or processing of contaminated foods. METHODS: We carried out area and personal sampling for airborne OA determination in three industries where coffee, cocoa beans, and spices, foods highly susceptible to contamination, were being processed. OA levels in the serum of six healthy workers employed in these factories were measured in samples collected at the end of the work shift. RESULTS: Airborne OA measured in the three industries, both by personal and area sampling, ranged from < 0.003 to 8.15 ng/m(3), while the levels measured in the breathing zone of the six workers who agreed to biological monitoring varied from 0.006 to 0.087 ng/m(3). OA serum levels ranged from 0.94 to 3.28 ng/ml, the latter values rather largely exceeding those of the control group (0.03 to 0.95 ng/ml). CONCLUSIONS: Our findings suggest that occupational exposure to this mycotoxin may represent a health risk for workers, especially if preventive and protection measures are not adopted in the workplaces. Airborne exposure levels can result in an increase of OA levels in serum, and this finding suggest that environmental and biological monitoring should be undertaken in workplaces where OA-contaminated products are handled or processed.

Biomonitoring of a worker population exposed to low antimony trioxide levels.

Antimony trioxide (Sb2O3) is used as a flame retardant in the textile industry. We carried out a study in a factory for the evaluation of antimony (Sb) occupational exposure and urinary levels in workers exposed to Sb2O3. Urinary levels and airborne Sb2O3 personal exposure values were very low when compared to international occupational standards (500 microg/m3, as Sb). The range of forty-two personal exposures was 0.01-0.55 microg Sb/m3, while twenty-four area samplings ranged from < 0.01 microg Sb/m3 to 1.45 microg Sb/m3. The mean urinary Sb levels at the beginning (n = 39) and end of the shift (n = 39) were 0.31 +/- 0.25 microg/L and 0.35 +/- 0.29 microg/L respectively, without any significant statistical difference. When the workers were divided into two subgroups according to "higher" and 'lower" exposure levels, a statistical difference (P < 0.001) was observed between the mean Sb urinary levels of the two subgroups during the workweek, both at the beginning and end of the shift. A statistical difference was also observed between the above mentioned subgroups and the controls (n = 15). No correlation was found between personal Sb2O3 exposure and the difference in urinary Sb levels at the beginning and end of the workshift on the day the flame retardant was utilized. This lack of correlation could be due to low airborne Sb2O3 levels and Sb dietary intake, estimated as 3 microg/day in UK, but not yet fully investigated in Italy. Any accidental occupational Sb per os exposure however low, could further enhance the lack of correlation.