Exposure to individual and multiple carcinogenic metals during paediatric age: an experience from an Italian urban scenario

BACKGROUND

Exposure to single and multiple carcinogenic metals and/or semimetals represents a major environmental risk factor for public health. In particular, children are more susceptible to environmental pollutants than adults, but specific studies are still limited. The aims of the present study were: 1) to trace the exposure and co-exposure profiles to eight known or suspected carcinogenic metals and semimetals (As, Be, Cd, Co, Cr, Ni, Pb, and Sb); and: 2) to evaluate the influence of some possible interfering/confounding factors on the exposure to these elements during childhood.

STUDY DESIGN

Cross-sectional study.

METHODS

We recruited 159 healthy Italian children attending a primary school of the urban area of Rome, Italy. Selected metals were determined by inductively coupled plasma mass spectrometry on urinary samples collected at the end of a "typical" day (one sample for each child), while information about possible confounding/interfering factors were collected via questionnaires.

RESULTS

The great part of the studied children resulted co-exposed to the monitored metals: 83.2%, 69.2%, 51.0% and 29.3% of the participants were concurrently exposed to at least two, three, four and five trace elements, respectively. Gender was the only one among the investigated variable that significantly influenced the co-exposure, with females resulting at lower risk (OR = 0.392; 95 IC = 0.156 - 0.989; p < 0.047).

CONCLUSIONS

Given the importance of protecting child's health and the risks related to the exposure to carcinogenic metals, especially when they occur simultaneously, other researches in this field are strongly recommended.

Urinary biomarkers of exposure and of oxidative damage in children exposed to low airborne concentrations of benzene

The aim of this work was to evaluate the oxidative damage to nucleic acids in children (5-11 years) associated with exposure to environmental pollutants and tobacco smoke (ETS). For each subject, urinary sampling was done twice (evening and next morning) to measure by tandem LC-MS-MS such oxidated products of nucleic acids as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo), 8-oxo-7,8-dihydroguanosine (8-oxoGuo), and 8-oxo-7,8-dihydroguanine (8-oxoGua). Methyl tert-butyl ether (U-MTBE), benzene (U-Benz), and its metabolites (t,t-muconic and S-phenylmercapturic acids, t,t-MA and S-PMA, respectively) were determined as biomarkers of exposure to air pollution, and cotinine as a biomarker of exposure to ETS. Biomarkers of exposure (S-PMA and U-MTBE) and of DNA oxidation (8-oxodGuo) were dependent on the urbanization and industrialization levels and increased in the evening sample as compared to next morning (p<0.05). In both evening and next morning samples, 8-oxodGuo and 8-oxoGuo correlated with each other (r=0.596 and r=0.537, respectively, p<0.01) and with biomarkers of benzene exposure, particularly S-PMA (r=0.59 and r=0.45 for 8-oxodGuo and r=0.411 and r=0.383 for 8-oxoGuo, p<0.01). No such correlations were observed for U-MTBE and cotinine. Multiple linear regression analyses showed that 8-oxodGuo was positively associated with S-PMA at both sampling times (β=0.18 and β=0.14 for evening and next morning sampling, respectively; p<0.02) and weakly with U-MTBE (β=0.07, p=0.020) only in the evening urines. These results suggest that the selected biomarkers of exposure to benzene, particularly S-PMA, are good tracers of exposure to complex mixtures of oxidative pollutants and that the associated oxidative damage to nucleic acids is detectable even at very low levels of exposure.

Exhaled breath analysis in suspected cases of non-small-cell lung cancer: a cross-sectional study

Lung cancer is one of the most frequently diagnosed cancers worldwide and is still the leading cause of cancer-related deaths. There is a considerable interest in finding diagnostic methods in the disease's earliest stages. A complementary approach to imaging techniques could be provided by exhaled breath gas phase and exhaled breath condensate (EBC) analysis. The aim of this study was to quantify various biomarkers in the exhaled breath gas phase and EBC in suspected cases of non-small-cell lung cancer (NSCLC). The study involved 138 subjects with suspected lung cancer, 71 of whom had a subsequent diagnosis of NSCLC. The diagnostic power of a combination of hydrogen peroxide (H₂O₂)-EBC, and exhaled pentane, 2-methyl pentane, hexane, ethyl benzene, heptanal, trans-2-nonenal in distinguishing NSCLC and non-NSCLC subjects was poor-to-fair (area under the curve (AUC) = 0.68), similar to that of smoking history alone (expressed as pack-years, AUC = 0.70); a further improvement was observed when smoking history was combined with exhaled compounds (AUC = 0.80). The diagnostic power was increased in those patients with little or no past smoke exposure (AUC = 0.92) or where past smoke exposure was up to 30 pack-years (AUC = 0.85). Exhaled substances had a good accuracy in discriminating suspected cancerous cases only in those subjects with a modest smoking history (≤ 30 pack-years), but the inclusion of other exhaled biomarkers may increase the overall accuracy, regardless of tobacco smoke.

[Interpretative strategies of lung function tests: obstructive pattern]

INTRODUCTION

Periodic spirometric assessment is critical in the health surveillance of workers who are exposed to respiratory pollutants and plays a key role in the prevention of occupational lung diseases.

OBJECTIVES

The aim of this review is to provide updates on the proper spirometry examination procedure and the criteria for data interpretation, in order to correctly diagnose obstructive impairment and longitudinal decline of pulmonary function.

METHODS

A review of the most recent scientific literature was carried out focusing on those papers dealing with spirometric techniques, choice of reference values, and criteria for data interpretation.

RESULTS

Over the years, the use of different diagnostic algorithms and reference values have led to poor clarity among users as well as diagnostic misclassifications.

CONCLUSIONS

For spirometric data reliability it is mandatory to perform appropriate pulmonary function tests, make a correct selection of reference values and use updated interpretive criteria.

Synergistic interactions between PBDEs and PCBs in human neuroblastoma cells

Polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are ubiquitous environmental pollutants. Exposure to these chemicals has been associated with developmental neurotoxicity, endocrine dysfunction, and reproductive disorders. Humans and wildlife are generally exposed to a mixture of these environmental pollutants, highlighting the need to evaluate the potential effects of combined exposures. In this study, we investigated the cytotoxic effects of the combined exposure to two PBDEs and two PCBs in a human neuronal cell line. 2,2',4,4'-Tetrabromodiphenyl ether, 2,2',4,4',5-pentabromodiphenyl ether, PCB-126 (3,3',4,4',5-pentachlorobiphenyl; a dioxin-like PCB), and PCB-153 (2,2',4,4',5,5'-hexachlorobiphenyl; a non-dioxin-like PCB) were chosen, because their concentrations are among the highest in human tissues and the environment. The results suggest that the nature of interactions is related to the PCB structure. Mixtures of PCB-153 and both PBDEs had a prevalently synergistic effect. In contrast, mixtures of each PBDE congener with PCB-126 showed additive effects at threshold concentrations, and synergistic effects at higher concentrations. These results emphasize the concept that the toxicity of xenobiotics may be affected by possible interactions, which may be of significance given the common coexposures to multiple contaminants.

Association between environmental exposure to benzene and oxidative damage to nucleic acids in children

OBJECTIVES

To evaluate the association between environmental exposure to benzene and oxidative damage to nucleic acids in children, also considering the role of Environmental Tobacco Smoke (ETS).

METHODS

396 children living in central Italy were recruited in districts with different urbanization and air pollution. All biomarkers were determined in spot urine samples by mass spectrometric techniques to assess exposure [benzene (U-Benz), and its metabolites (t,t-muconic and S-phenylmercapturic acids, t,t-MA and S-PMA, respectively), cotinine] and nucleic acid oxidation [8-oxo-7, 8-dibydro-2'-deoxyguanosine (8-oxodGuo), 8-oxo-7, 8-dihydroguanosine (8-oxoGuo), and 8-oxo-7, 8-dihydroguanine (8-oxoGua)].

RESULTS

Biomarkers of exposure and nucleic acid oxidation increased with urbanization and were correlated with each other (r > 0.18, p < 0.005). In a multiple linear regression model, benzene exposure, assessed by S-PMA and t,t-MA, was associated (p < 0.0001) with both 8-oxodGuo (R2 = 0.392) and 8-oxoGuo (R2 = 0.193) in all areas of residence, with similar slopes.

CONCLUSIONS

(i) Biomarkers of exposure to benzene increased as a function of environmental air pollution and urbanization level; (ii) U-Benz clearly distinguished both exposure to ETS and areas of residence, whereas benzene metabolites were associated only with the latter; (iii) the variance of 8-oxodGuo and 8-oxoGuo was accounted for by environmental benzene exposure, thus suggesting that benzene is a good tracer of other components of complex mixtures of pollutants causing oxidative damage to nucleic acids.

[Sleep disorders, risk of accidents and traffic accidents in a group of drivers of public transport]

In order to evaluate the prevalence of sleep disorders and visuomotor performance, a survey was conducted on 253 drivers of public transport company, aged between 25 and 64 years. Biometric data (BMI, neck circumference and waist, PA) were collected and three questionnaires were administered to investigate sleep disorders. Simple and multiple choice reaction times were administered using a computerized test battery. Records on road accidents in the period 2005-2011 and all accidents in the period 2002-2010 were analyzed. On the basis of clinical and anamnestic questionnaire, workers were divided into two groups: 194 drivers (group 1) without suspicion of sleep disorders and 59 drivers (group 2) with suspected sleep disorders, and 41 with suspected obstructive sleep apnea syndrome (OSAS). The drivers with suspicion of sleep disorders, in particular those with suspected diagnosis of OSAS, showed reaction times significantly prolonged as compared to the drivers of the group 1. In group 2, a higher incidence of (all) accidents was found, whereas the incidence of road accidents was significantly increased only in drivers with suspected OSAS. In addition to the sleep disorders, the use of drugs altering vigilance (antihistamines and benzodiazepines) were significant determinants. In-depth clinical examinations are in progress to confirm the suspected diagnosis of sleep disorders.

[New perspectives in biomonitoring of metallic elements: the example of hexavalent chromium]

Plating industry is an important productive sector in all the national territory, because of its contribution to a high number of industrial products and crafts. In the chrome plating sector there is a specific chemical risk due to the exposure to compounds containing hexavalent Chromium [Cr(VI)]. Exhaled breath condensate (EBC) has been used to study both acute and long term exposure to Cr(VI) in chrome plating workers. Cr-EBC correlates with specific oxidative stress biomarkers. Moreover, both total Cr and its hexavalent fraction can be measured in EBC, which therefore is a promising biological fluid to assess the absorbed dose at the target organ level, the pulmonary reduction kinetics of Cr(VI) and in general its local pneumotoxic effects. EBC collection and analysis could give additional information to the traditional measures performed during biomonitoring.

[Laboratory animal; allergy; asthma]

Laboratory animal allergy (LAA) may develop when susceptible persons are exposed to allergens produced by laboratory animals. LAA is associated with exposure to urine, fur, and salivae of rats, guinea pigs, dogs and rabbits. Approximately 30% of persons who are exposed to laboratory animals may develop LAA and some will also develop asthma. LAA is most likely to occur in persons with previously known allergies, especially to domestic pets. The majority of LAA sufferers experience symptoms within six months their first exposure to laboratory animals; almost all develop symptoms within three years. The most common symptoms are watery eyes and an itchy, runny nose, although skin symptoms and lower respiratory tract symptoms may also occur. Feeding and handling laboratory animals or cleaning their cages generates ten times the amount of allergens compared with undisturbed conditions. Prevention of animal allergy depends on control of allergenic material in the work environment and on organizational and individual protection measures. Pre-placement evaluation and periodic medical surveillance of workers are important pieces of the overall occupational health programme. The emphasis of these medical evaluations should be on counselling and early disease detection.

[Early molecular diagnosis of lung cancer: a method to rule out the disease]

Aim of this study was the determination of new markers for the diagnosis of lung cancer. 61 patients with non-small cell lung cancer (NSCLC) and 42 controls were enrolled. In the NSCLC patients the following markers were increased: H2O2 in exhaled breath condensate, pentane, hexane, nonenal, trans-2-heptanal, trans-2-nonenal in exhaled breath, while pentanal was decreased. Using multivariate statistical models, a sensitivity of 73.8% and a specificity of 76.8% were calculated. This study shows that with this non-invasive test followed by a most powerful test on positives (e.g. PET) it is possible to decrease the number of false positives.

[Biological monitoring and exposure to silica: application of new dose and effect biomarkers]

Si-CAE was measured in 16 composite marble industry workers furthermore, a spirometry was performed and 8oxoGua, 8oxoGuo 8oxodGuo, SP-A, SP-D, CC16 and HO-1 were dosed. A lower spirometric values (FEV1 and FVC) were observed among workers compared with controls and the following markers were increased: Si-CAE, 8oxoGuo and HO-1 expression. This study shows that exposure to silica can increase the levels of Si-CAE, which can be used to estimate the dose to the target. Finally, nonspecific spirometric abnormalities and an increase in biomarkers of effect were observed.

[Environmental and biological monitoring of exposure to monoaromatic hydrocarbons and to methyl tert-butyl ether in a group of petrol station workers]

The aim of the study was to evaluate biomarkers of exposure to gasoline in petrol station workers by a combined approach of environmental and biological monitoring. The personal exposure to benzene, toluene, ethylbenzene and xylene (BTEX) and the urinary levels of BTEX, methyl tert-butyl ether (U-MTBE), trans,trans-muconic (t,t-MA) and S-phenylmercapturic acids (S-PMA) and cotinine were determined by mass spectrometry coupled chromatographic techniques. U-MTBE levels were strictly influenced by occupational exposure to gasoline, whereas both U-B and S-PMA levels depended from smoking habits and occupational exposure.

[Acute lead poisoning: a singular case of hemolytic anemia and lead colic]

BACKGROUND

Acute lead poisoning due to food intake is exceptional in adults and often associated with mental illness

OBJECTIVES

to describe a case report of acute lead intoxication with haemolytic anemia and lead colic.

METHODS

A 41-year old male patient was admitted to hospital for abdominal pain and persistent constipation. Abdominal X-ray showed a radiopaque mass in the caecum and progressive anaemia was observed The patient was discharged with a diagnosis of bowel obstruction. Due to persistence of the symptoms he was again hospitalized; abdominal X-ray showed diffuse radiopaque particles in the colon and haemoglobin (hb) had dropped to 8.7 g/dl. Blood levels of lead and zinc protoporphryin were 106.7 microg/dl and 6.6 microg/gHb, respectively. The timely start of chelating therapy led to a rapid return to normal peripheral blood counts and a decline in blood lead levels.

RESULTS

Although acute lead poisoning due to intake with food is exceptional in adults and often associated with mental illness, in this case, it was not possible to clarify the route and vehicle of ingestion of the toxic. Lead body burden was shown as a caecal mass, probably as a result of ingesting a single bolus of lead dust which, considering the size and density of the mass, was estimated as weighing several grammes. This acute lead intake induced an acute haemolysis due to enhanced fragility of the erythrocyte membrane.

CONCLUSIONS

In the course of acute lead intoxication, the critical organ is not the bone marrow, but rather the red blood cell, leading to haemolysis and anaemia.

Feasibility and economic viability of home-based supportive care

e20741

Background: Oncological treatment is becoming more complex and more costly. When their symptoms worsen, many patients seek an Emergency Room and arrive without a good performance-status. This causes insecurity to the attending physician, and it also represents a huge chance that this patient would receive an avoidable admission. With the appropriate home-support it is possible to attend the majority of patient's demands, offering a good quality clinical support.Home administration of some drugs is more comfortable and helps to eliminate some taxes that are commonly charged by private clinics. Methods: We performed an analysis of a private healthcare company's database.To avoid seasonality and high impact on costs of terminally ill patients occurring at an analyzed month, we selected a six months interval, from January to June 2008. Results: About 500 patients are active each month at the home-care program. They received from simple monitoring to 24 hour home nursing support. Hematological malignancies, as expected, require more resources.Home based supportive care could prevent the majority of avoidable hospital admissions. Conclusions: Home based supportive care can meet the basic needs of clinical support during chemotherapy and the demands of comfort at the end of life, in order to reduce avoidable hospital admissions. This contributes to reducing the cost of treatment.

[Table: see text]

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.

[Non-invasive assessment of lung pathobiology in hairdressers]

BACKGROUND

Hairdressers are exposed to chemical agents with potentially irritant and sensitizing effects on airways.

OBJECTIVES

To asses the presence of respiratory symptoms and biochemical and functional changes of the airways in a cohort of hairdressers.

METHODS

Respiratory symptoms, lung function tests, fractional exhaled nitric oxide (FE(NO)50) and selected oxidative stress biomarkers [hydrogen peroxide (H2O2), malondialdehyde (MDA) and 4-hydroxynonenal (HNE)] in exhaled breath condensate (EBC) were assessed in 23 hairdressers on a rest day (Group 1); 12 workers (Group 2) were willing to perform the same tests at the beginning (BS) and at the end of a shift (ES) on the same working day. Eighteen subjects not occupationally exposed to airways irritants formed the control group.

RESULTS

Most of the hairdressers reported respiratory symptoms during work; however, all (except one) showed normal spirometry indexes. FE(NO)50 levels were within the reference limits and did not change comparing BS vs. ES sampling. H2O2 and HNE values in EBC were higher in Group 1 (H2O2: 0,16 [0,05-0,19] microM; HNE: 0,94 [0,82-1,22] nM) than in controls (H2O2: 0,05 [0,02-0,09] microM; HNE: 0,61 [0,49-0,78] nM, p < 0,001). In Group 2, H2O2 and MDA levels were higher in EBC collected at ES (0,56 [0,23-3,62] mM and 5,21 [4,93-5,95] nM) in comparison with the BS values (0,11 [0,03-0,28] mM and 4,12 [3,46-5,16] nM, p < 0,001 and p < 0,02, respectively).

CONCLUSIONS

Increased levels of oxidative stress biomarkers are detectable in EBC of hairdressers, without impairment in respiratory function. Exhaled biomarkers of oxidative stress may be sensitive end points for evaluating early biochemical changes in the airways of hairdressers.

New techniques for assessment of occupational respiratory diseases

Recently, as several studies have demonstrated, these non-invasive techniques, such as induced sputum (IS) or analysis of the exhaled air; exhaled nitric oxide (eNO) or exhaled breath condensate (EBC) provide fairly reliable results that correlate with those of "gold standard" methods (bronchoscopy, bronchoalveolar lavage) which are more invasive and uncomfortable for patients. Although novel approaches have attracted the attention of scientists, they have not been examined in relation to occupational settings and professional diseases. The IS is a useful biological medium for the diagnosis of occupational asthma and for the assessment of exposures to harmful dust at workplaces. The eNO analysis can serve as an easy and comfortable diagnostic tool for the professional asthma after exposure to various allergens. The examination of EBC biomarkers evaluates local doses of hard metals in the lung, as well as detection of oxidative stress markers (malondialdehyde, H2O2). Due to the need to standardize the procedures for EBC collection, further studies on EBC validation and the subsequent application in the clinical and epidemiological fields are required. The techniques listed in this article may serve as optimal tools for diagnosis of occupational respiratory diseases and for screening/monitoring programs following inhalation exposures in future (ref 64).

Bronchoalveolar lavage, sputum and exhaled clinically relevant inflammatory markers: values in healthy adults

Bronchoalveolar lavage (BAL), induced sputum and exhaled breath markers (exhaled nitric oxide and exhaled breath condensate) can each provide biological insights into the pathogenesis of respiratory disorders. Some of their biomarkers are also employed in the clinical management of patients with various respiratory diseases. In the clinical context, however, defining normal values and cut-off points is crucial. The aim of the present review is to investigate to what extent the issue of defining normal values in healthy adults has been pursued for the biomarkers with clinical value. The current authors reviewed data from literature that specifically addressed the issue of normal values from healthy adults for the four methodologies. Most studies have been performed for BAL (n = 9), sputum (n = 3) and nitric oxide (n = 3). There are no published studies for breath condensate, none of whose markers yet has clinical value. In healthy adult nonsmokers the cut-off points (mean+2sd) for biomarkers with clinical value were as follows. BAL: 16.7% lymphocytes, 2.3% neutrophils and 1.9% eosinophils; sputum: 7.7 x 10(6).mL(-1) total cell count and 2.2% eosinophils; nitric oxide: 20.2 ppb. The methodologies differ concerning the quantity and characteristics of available reference data. Studies focusing on obtaining reference values from healthy individuals are still required, more evidently for the new, noninvasive methodologies.

Methylmercury at low doses modulates the toxicity of PCB153 on PC12 neuronal cell line in asynchronous combination experiments

Me-Hg and PCB153 are known neurotoxic contaminants which tend to accumulate in food, particularly in fish. Aim of this study was to perform asynchronous and combined exposure to Me-Hg and PCB153 in a neuronal rat cell line (PC12) to better characterise the antagonism observed at some combination concentrations. PC12 cells were treated with three concentrations of Me-Hg (0.1-0.5-1.0 microM) and PCB153 at one concentration (175 microM) in single and combined asynchronous exposures, using viability (MTT assay) as end-point. At all concentrations used, a statistically significant antagonistic effect was observed when Me-Hg preceded PCB153 exposure, while effect was additive when PCB153 preceded Me-Hg exposure. The antagonism is particularly evident at low concentrations of Me-Hg (0.1 microM). In conclusion, combined asynchronous exposure showed that whereas Me-Hg can modulate PCB153 toxicity, the opposite seems not to be true. Therefore, the use of asynchronous exposure could be a promising approach to study the mechanisms of toxicity of binary mixtures.

Gene-environment interactions in parkinsonism and Parkinson's disease: the Geoparkinson study

OBJECTIVES

To investigate associations of Parkinson's disease (PD) and parkinsonian syndromes with polymorphic genes that influence metabolism of either foreign chemical substances or dopamine and to seek evidence of gene-environment interaction effects that modify risk.

METHODS

A case-control study of 959 prevalent cases of parkinsonism (767 with PD) and 1989 controls across five European centres. Occupational hygienists estimated the average annual intensity of exposure to solvents, pesticides and metals, (iron, copper, manganese), blind to disease status. CYP2D6, PON1, GSTM1, GSTT1, GSTM3, GSTP1, NQO1, CYP1B1, MAO-A, MAO-B, SOD 2, EPHX, DAT1, DRD2 and NAT2 were genotyped. Results were analysed using multiple logistic regression adjusting for key confounders.

RESULTS

There was a modest but significant association between MAO-A polymorphism in males and disease risk (G vs T, OR 1.30, 95% CI 1.02 to 1.66, adjusted). The majority of gene-environment analyses did not show significant interaction effects. There were possible interaction effects between GSTM1 null genotype and solvent exposure (which were stronger when limited to PD cases only).

CONCLUSIONS

Many small studies have reported associations between genetic polymorphisms and PD. Fewer have examined gene-environment interactions. This large study was sufficiently powered to examine these aspects. GSTM1 null subjects heavily exposed to solvents appear to be at increased risk of PD. There was insufficient evidence that the other gene-environment combinations investigated modified disease risk, suggesting they contribute little to the burden of PD.

Environmental risk factors for Parkinson's disease and parkinsonism: the Geoparkinson study

OBJECTIVE

To investigate the associations between Parkinson's disease and other degenerative parkinsonian syndromes and environmental factors in five European countries.

METHODS

A case-control study of 959 prevalent cases of parkinsonism (767 with Parkinson's disease) and 1989 controls in Scotland, Italy, Sweden, Romania and Malta was carried out. Cases were defined using the United Kingdom Parkinson's Disease Society Brain Bank criteria, and those with drug-induced or vascular parkinsonism or dementia were excluded. Subjects completed an interviewer-administered questionnaire about lifetime occupational and hobby exposure to solvents, pesticides, iron, copper and manganese. Lifetime and average annual exposures were estimated blind to disease status using a job-exposure matrix modified by subjective exposure modelling. Results were analysed using multiple logistic regression, adjusting for age, sex, country, tobacco use, ever knocked unconscious and family history of Parkinson's disease.

RESULTS

Adjusted logistic regression analyses showed significantly increased odds ratios for Parkinson's disease/parkinsonism with an exposure-response relationship for pesticides (low vs no exposure, odds ratio (OR) = 1.13, 95% CI 0.82 to 1.57, high vs no exposure, OR = 1.41, 95% CI 1.06 to 1.88) and ever knocked unconscious (once vs never, OR = 1.35, 95% CI 1.09 to 1.68, more than once vs never, OR = 2.53, 95% CI 1.78 to 3.59). Hypnotic, anxiolytic or antidepressant drug use for more than 1 year and a family history of Parkinson's disease showed significantly increased odds ratios. Tobacco use was protective (OR = 0.50, 95% CI 0.42 to 0.60). Analyses confined to subjects with Parkinson's disease gave similar results.

CONCLUSIONS

The association of pesticide exposure with Parkinson's disease suggests a causative role. Repeated traumatic loss of consciousness is associated with increased risk.

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

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

Recent developments in human biomonitoring: non-invasive assessment of target tissue dose and effects of pneumotoxic metals

Tobacco smoke and polluted environments substantially increase the lung burden of pneumotoxic chemicals, particularly pneumotoxic metallic elements. To achieve a better understanding of the early events between exposure to inhaled toxicants and the onset of adverse effects on the lung, the characterization of dose at the target organ would be extremely useful. Exhaled breath condensate (EBC), obtained by cooling exhaled air under conditions of spontaneous breathing, is a novel technique that could provide a non-invasive assessment of pulmonary pathobiology. Considering that EBC is water practically free of interfering solutes, it represents an ideal biological matrix for elemental characterization. Published data show that several toxic metals and trace elements are detectable in EBC, raising the possibility of using this medium to quantify the lung tissue dose of pneumotoxic substances. This novel approach may represent a significant advance over the analysis of alternative media (blood, serum, urine, hair), which are not as reliable (owing to interfering substances in the complex matrix) and reflect systemic rather than lung (target tissue) levels of both toxic metals and essential trace elements. Data obtained among workers occupationally exposed to either hard metals or chromium (VI) and in smokers with or without chronic obstructive pulmonary disease (COPD) are reviewed to show that--together with biomarkers of exposure--EBC also allows the simultaneous quantification of biomarkers of effect directly sampled from the epithelial lining fluid, thus providing novel insights on both kinetic and dynamic aspects of metal toxicology.

[Research and formal demonstration of evidence of efficiency in occupational medicine]

There is an increasing pressure on occupational health professionals to ensure that their practice is based on a quality standard and an evidence of appropriateness. The efficacy-effectiveness of their activity strictly depends on their intellectual and professional integrity, their technical and legal competence, but also on the quality of the relations with the company organisation they are able to establish. We asked to some occupational physician when they considered their interventions in the workplace to be efficacious. Then, accordingto our epexrience, we propose some effectiveness indicators, particular concerning health surveillance and health educttaon, that should be evaluated to verify the health professional agccvity agreement to quality standards.

[Chronobiological evaluation of effects biomarkers and sampling]

Occupational exposure to oxidants is often associated with an increase in the levels of oxidative DNA damage in urine. Besides 8-hydroxy-2'-deoxyguanosine (8-oxo-dG), other products of position-8 guanine oxidation have been identified in urine, including 8-hydroxy-guanine (8-oxo-G) and 8-hydroxyguanosine (8-oxy-Guo). The aim of the present study was the characterization of these effect biomarkers in terms of inter- and intra-individuals varaibility, as well as in terms of their excretion profile during a 24 h-period. Urine samples were collected from 11 volunteers (6 samples/day). Urine concentrations of 8-oxo-G, 8-oxo-Guo, and 8-oxo-dG were determined by liquid chromatography-tandem mass spectrometry. The inter-individual variability, expressed as variation coefficient, was 85-150% for 8-oxo-G, 20-45% for 8-oxo-Guo, and 30-45% for 8-oxo-dG. The statistical anaysis for repeated measurements showed that none of the biomarkers was affected by significant variation during the day (one-way ANOVA, p < 0.05), thus excluding the existence of a circadian rhythm. We conclude that the sampling time is not critical for the assessment of oxidative DNA damage in urine.

[Heme oxygenase 1 expression in foundry workers]

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

Analysis of oxidative stress in SK-N-MC neurons exposed to styrene-7,8-oxide

Styrene-7,8-oxide (SO) is the main metabolite of styrene, a neurotoxic volatile organic compound used industrially. Here we report the novel observation that several markers of oxidative stress were affected in SK-N-MC cells exposed for 16 h to concentrations of SO that induce apoptotic cell death. The production of Thiobarbituric Acid Reactive Substances (TBARS), rose from 69.1 +/- 15.7 nmol/g protein (control) to 119.3 +/- 39.2 and 102.0 +/- 17.3 nmol/g protein after exposure to 0.3 and 1 mM SO, respectively. Carbonyl group levels were significantly enhanced by SO at both concentrations. The lower dose also decreased sulphydryl groups. SO caused a marked oxidative DNA damage, as shown by a fivefold increase in 8-hydroxy-2(')-deoxyguanosine (8-OHdG). In addition, SO exposure resulted in alterations of scavenging abilities, given the reduction of both glutathione (GSH) and glutathione-S-transferase (GST) activity. Induction of expression of the oxidative stress response gene heme-oxygenase-1 (HO-1) and an increased HO-1 activity were also observed. These data provide compelling evidence that oxidative stress significantly contributes to SO toxicity in neuronal cells.

[Neuroendocrine and renal effects of inorganic lead]

In this study 371 workers occupationally exposed to inorganic Pb (range of blood lead concentrations, PbB: 100-800 microg/l) were examined in order to assess neuroendocrine and renal effects, with regard to exposure levels and ALAD polymorphism. Plasma prolactin, urinary excretion of plasmaproteins and renal tissue constituents were measured. None of such markers differed significantly between workers stratified according to PbB levels, except for heat-stable isoenzyme NAG-B: its very low prevalence of values above the upper reference limit increased significantly with increasing PbB. No significant differences were found in indicators by ALAD genotype. Our findings did not provide evidence of any renal and neuroendocrine effects in workers exposed to the current lead levels.

[Report on the activities carried out in the research project of the Ministry of Instruction, University, and Research entitled "Environmental and occupational exposure to inorganic lead: assessment of toxic effects of current doses and related preventive measures"]

It is here presented the project sustained by the Ministry of Public Instruction, University and Research "Environmental and Occupational Exposure to Inorganic Lead: assessment of human health effects due to current doses and preventive measures" ruled out between 2001 and 2003. The aim of the study was to investigate about the toxic effects related to current occupational exposures to inorganic lead (particularly those effects concerning blood pressure, carcinogenic risk, nervous and immunological systems), to identify hypersusceptibility conditions, particularly the ALAD genetic polymorphism and to evaluate the role of traditional biomarker and the possibility of introducing new ones. In the present article the procedures followed during the project lasting and the contribution of each Unit are described. The results of the research, presented in detail in the current issue, do confirm the inadequacy of the biological exposure index nowadays ruled by Lex 25/2002.

[Lead and blood pressure]

Evidence, even if not univocal, of increase of systolic and diastolic blood pressure for Pb doses lower than 30 microg/dl stimulated studies in the last years and opened a discussion on a possible relapse in morbility and mortality, since hypertension is an important factor of cardiovascular risk. In this study, it was possible to investigate the relationship between lead and blood pressure of 303 subjects occupationally exposed to this metal with blood-Pb between 10 and 80 microg/dl and 206 subjects belonging to the general population with blood-Pb between 0.5 and 9 microg/dl. In both groups it resulted a positive and statistically significant correlation between blood-Pb values and systolic and diastolic blood pressure values, in detail in hypertensive subjects, belonging to the not-occupationally exposed group, this effect is proportionally higher. The effect of lead on blood pressure appears therefore proved, as confirmed by previous literature, but taking into consideration three specific information. It presents itself in a large range of doses, it is quantitatively very modest, it appears more evident at low doses, thus we could hypothesize different mechanisms for different doses.

[Lead: indicators of dose and effects on heme]

In the present study the role of the traditional biomarkers of exposure and effect on haeme system during lead exposure was analysed: the opportunity of introducing new biomarkers such as lead and delta-aminolevulinic acid in plasma was also evaluated, especially by considering the current levels of exposure. The population in study was constituted by 371 males owning to different production fields and selected by five national units. The results suggest caution in the use of lead in plasma as a biomarker of lead exposure in the biological monitoring procedures, mainly in reason of its great variability affecting in particular the sampling time and the pre-analytical treatment of the sample. The other biomarkers were well correlated between them and with the exposure biomarkers for lead in blood >300 microg/L, suggesting the BEI to which the protection of workers exposed to lead would be guaranteed (instead the actual of 600 microg/L).