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A neuropathological examination was performed on a patient with parkinsonism induced by prolonged exposure to a mixture of aliphatic hydrocarbons, mainly n-hexane and halogenated compounds. The patient developed a rapid-course disease that progressed even after withdrawal from the toxic exposure. Pathological examination and immunohistochemical analysis of the brain revealed severe and widespread dopaminergic neuronal loss, associated with severe gliosis, in the substantia nigra, and almost complete loss of tyrosine hydroxylase immunostaining in the striatum. No Lewy bodies were detected. Neuronal loss was also observed in the periaqueductal gray matter, locus ceruleus, and pedunculopontine nucleus. These changes, combined with the moderate anemia due to marrow suppression, and the mild axonal neuropathy observed in vivo, are suggestive of a hydrocarbon toxic insult.

The risk of work-related stress has been determined in bus drivers and workers employed in the service department of two urban and suburban public transportation companies. The INAIL evaluation method (Check list and HSE indicator tool) was used. The GHQ-12 questionnaire, which is widely used to assess the level of psychological distress, was also employed. 81.9% of workers involved in the survey answered both the HSE indicator tool and the GHQ-12 questionnaire. The Check list evaluation showed an increase in quantifiable company stress indicators while close examination using the HSE indicator tool demonstrated critical situations for all the subscales, with the control subscales more problematic in bus drivers. The demand, manager's support, relationships and change subscales were most associated with psychological distress in bus drivers, while relationships, role, change and demand subscales were negatively related in workers of the service department.

Mental disorders are common in our industrialised society and inevitably affect the working population. Over the last few years greater attention has been focussed on work-related psychopathologies due to an increasing number of studies regarding workplace bullying.This study reports our observations on patients with mental disorders who came to our Occupational Health Centre because they perceived themselves to be victims of negative working conditions. An indepth analysis of their working conditions led us to the conclusion that many of these disorders were to be attributed to the workplace.Between 2004 and 2010, 449 workers attended our Occupational Health Centre, most suffering from mental disorders which they ascribed to negative working conditions. All patients had an initial consultation session with an occupational physician which focused on the environmental and relational characteristics of their place of work. Thereafter, patients underwent a second clinical evaluation with a psychologist including several psychological tests. At the end of diagnostic process, the occupational physician and the clinical psychologist drew their clinical conclusions and defined the possible relationship with the working condition.For 379 out of 449 patients/workers, a positive and causal relationship between medical disorders and working conditions was established. The mental disorders observed in these groups of workers were: mixed anxiety and depressive disorder (53.6%), depressive disorder (16.2%), adaptation disorder (15.9%), anxiety disorder (13%) and only 1.3% post-traumatic stress disorder. The working conditions favouring the mental disorders were: workplace bullying, such as person-related bullying (30.1%) and task-related bullying (14.8%), adverse situations causing work distress (38.2%) or non-specific work discomfort (16,9%).Our experience showed that not only workplace bullying can cause different psychiatric disorders but also adverse situations that favour work distress and non-specific work discomfort often give raise to the same disorders. Negative working conditions can play a significant role in the development of psychological-psychiatric disorders: such disorders related to occupational conditions are on the increase in many industrialised countries.

Pine processionary moth (Thaumetopoea pityocampa) is a lepidopteran living in the Mediterranean countries whose mature larvae have microscopic hairs that can be released and carried far from the source. The hairs are responsible of urticating symptoms on the exposed areas although systemic manifestation might be involved. The study involved 94 forestry workers (92 M, 2 F) of the Regional Forest Service of Verona and the objective was to determine the prevalence of skin and respiratory disorders due to exposure to this insect. 21 chainsaw operators and 2 labourers experienced symptoms on exposed skin areas; 3 of them reported also ocular and respiratory symptoms. The chainsaw operators resulted most at risk whereas individual already suffering from others allergies do not seem to be affected. The results highlight the importance of risk assessment to Thaumetopoea pityocampa in forestry workers and the need for instruments to assess the allergic sensitization in medical surveillance.

Communication ability is essential for the Physician to the proper management of ambulatory activity and corporate training. The aim of this work is describe the communication strategies to be adopted in everyday healthcare practice. When the occupational physician relates with an employee his message must act both verbal both non-verbal. The medical history should be collected carefully and during the physical examination is important to put the employee at ease by adopting a discreet and attentive attitude. The clinical findings and the capacity to work with any limitations will be discussed at the end of health surveillance using understandable terminology to the worker. During the training-information process is important to define the primary objectives, organize the program and bring the display materials. The worker should be actively involved and encouraged to learn throughout the course information. In the text will also be shown the main aspects of information on line.

The use of nailfold capillaroscopy combined with skin thermometry in the study of microcirculation of the hands in workers exposed to hand-arm vibration is assessed. Fifty-eight subjects were studied; 40 asymptomatic forestry workers exposed to hand-arm vibration, 13 forestry workers exposed to hand-arm vibration with Raynaud-like symptoms confirmed by skin thermometry; 5 controls. Reduction of capillary density was observed in workers exposed to vibrating tools with respect to controls. Tortuosity of capillary loops was significantly more frequent in subjects exposed to vibrating tools than in controls. No statistically significant difference in capillary vessels of the hands was found between asymptomatic exposed subjects and workers affected by Raynaud-like symptoms. In our sample nailfold capillaroscopy shows good sensibilty and specificity in detecting capillary modifications secondary to exposure to hand-vibration. Weaker evidence is instead given in order to actual disturbances of hands circulation in chronic exposure to vibrating tools.

A critical review of the literature on obesity and overweight underlines that a low educational level, a low social-economic status, certain working conditions, the lack of physical activity in leisure time, together with the availability of food, are the main factors favouring increased prevalence of obesity. Certain jobs also contribute significantly to this problem. Automation, the use of machines for heavy works and sedentary activities favour body weight increase. Jobs that are a source of stress, such as work with night shift can cause metabolic disorders leading to an increased prevalence of obesity. The main aim of this article is to study the trend of body weight in different working area during ten years, comparing this parameter to different factors such as job, blood pressure, smoke, alcool and health diseases.

To evaluate noise-induced hearing loss in a group of workers at a steel engineering works over a 20 year period (1979-1999).A total of 2431 audiometric tests were performed in 708 workers (in 1979, 1984, 1989, 1994 and 1999). Audiometric tests were classified so that hearing loss could be assessed over time. Additionally, personal noise exposure was measured for each worker (average, 85 dB(A) in tests carried out in 1992, 1996 and 1999).Over 5 years of noise exposure, mean cumulative incidence of noise-induced hearing loss was 8,2%. Over 10 years ofexposure (1979-89 or 1984-94 or 1989-99), the mean incidence was 15,3%. This percentage increased to 22,9% and 25,7% when the exposure lasted 15 or 20 years respectively.The considerable incidence of noise-induced hearing loss within the wide group of steel workers examined greatly exceeds the expected incidence related to the occupational exposure limits. The Evidence Based Occupational Medicine suggests that our health surveillance was not effective enough.

The role of genetic and environmental factors, as well as their interaction, in the natural history of asthma, allergic rhinitis and chronic obstructive pulmonary disease (COPD) is largely unknown. This is mainly due to the lack of large-scale analytical epidemiological/genetic studies aimed at investigating these 3 respiratory conditions simultaneously. The GEIRD project is a collaborative initiative designed to collect information on biomarkers of inflammation and oxidative stress, individual and ecological exposures, diet, early-life factors, smoking habits, genetic traits and medication use in large and accurately defined series of asthma, allergic rhinitis and COPD phenotypes. It is a population-based multicase-control design, where cases and controls are identified through a 2-stage screening process (postal questionnaire and clinical examination) in pre-existing cohorts or new samples of subjects. It is aimed at elucidating the role that modifiable and genetic factors play in the occurrence, persistence, severity and control of inflammatory airway diseases, by way of the establishment of a historical multicentre standardized databank of phenotypes, contributed by and openly available to international epidemiologists. Researchers conducting population-based surveys with standardized methods may contribute to the public-domain case-control database, and use the resulting increased power to answer their own scientific questions.

This work describes the audiometry threshold assessment of 1000 workers employed in different artisan categories during a period of ten-year noise professional exposure. The hearing loss noise-induced rates were determined by analysing audiometric tests at the beginning of our period of study and after 5 and 10 years of noise exposure. Environmental noise exposures were on average 88 dB(A), but near 90 dB(A) in some work categories. Workers widely used hearing protection devices, nearly at 93%, during the period we studied. The Evidence Based Occupational Medicine should find out points of reference proving the efficiency and effectiveness of occupational physicians: in this case, a positive trend in the reduction of hearing loss rate will be expected to confirm the goodness of prevention practice. Our study suggests that the levels of protection so far accepted are not effective enough in order to reduce the incidence of noise-induced hearing loss in the course of the years: in despite of most accredited predicting models for hearing conservation programs, a significant percentage of workers exposed to industrial noise continues to present a high incidence of hearing loss. The Evidence Based Occupational Medicine suggests that the proposed prevention activities carried out in the described factories were not enough effective.

Person-related bullying is regarded as a form of stress capable of cause negative effects on workers' health, potentially leading to psycho-physical symptoms, alterations of mood and personality, psychiatric disorders such as anxiety-depression disorder, chronic adjustment disorder and posttraumatic stress disorder. At the Centre for the study of psychosocial risks and pathologies at work of Verona the health state of victims of person-related bullying and work-related bullying and their working conditions are periodically evaluated. On a regular bases these workers receive psychological support and, if necessary, psychiatric treatment; at the same time interventions on working environment are undertaken when possible. Verification of effectiveness is then carried out by means of interviews starting six months after the first consultation. Two questionnaires are used; a specific one for the assessment of working environment and health conditions, and Goldberg's General Health Questionnaire--G.H.Q-12. Improvement of health state related to better working conditions was obtained in general.

The aim of the study is to evaluate the prevalence of respiratory and skin symptoms among bakers in the district of Verona by means of two standardized questionnaires, a clinical one administered to the bakeries employees, either directly exposed to flour dust or not exposed, and one concerning the characteristics of the bakery environment. The study involved 613 bakery workers, 401 bakers and 212 sales personnel employed in 152 bakeries. Bakers exposed to flour dust reported nasal symptoms in 29.2% of cases, ocular symptoms in 13.2%, cough, shortness of breath, chest tightness, wheezing respectively in 8.7%, 7%, 4.5% 6.2% of cases, itch and skin burning with paleness respectively in 9.7% and 8.5%. A significantly lower prevalence of these symptoms, except skin paleness, was reported among the sales personnel. In bakers, a significant correlation was found between ocular-nasal and respiratory symptoms and family or self-reported history of atopy (p = 0.001). Reported flour dust air pollution at the workplace correlated with occupational ocular-nasal and respiratory symptoms (p = 0.001). Flour dust on skin and clothes correlated with crusts and excoriations (p = 0.01). Our study confirms the high prevalence of allergic symptoms among bakers and the need of clinical assessment.

Obesity constitutes a risk for several vascular, metabolic and neoplastic diseases. In industrialised countries, but more and more in developing countries too, the prevalence of obesity is increasing. Body Mass Index and circumference of the abdomen are the two simplest and most utilized methods of measuring the degree of obesity in an individual and of comparing selected groups with different ethnic, social, cultural and occupational features.The main aim of this article is to initiate a discussion on the possible contribution that the Occupational Health Physician can make to solving the problem of obesity, which is becoming more and more alarming in social terms. The working conditions favouring an increase in body weight and the negative effects that obesity has on various types of work are reported.A critical review of the literature on obesity and overweight stresses that a low educational level, a low socio-economic status, lack of physical activity in leisure time and certain working conditions, together with the ready availability of food, are the main factors favouring increased prevalence of obesity. Certain jobs also contribute significantly to this problem. Automation and the use of machines/robots for very heavy work in industrialised countries have the "collateral effect" of favouring body weight increase due to low energy consumption. Jobs that are a source of stress, such as work on three rotating shifts, can cause metabolic disorders leading to an increased prevalence of obesity. Contrariwise, obesity renders the individual unfit for some jobs, in fact, an increased incidence of industrial accidents has been related to obesity.The occupational health physicians engaged in surveillance of workers' health conditions can make a positive contribution to alleviating this problem by focusing their activity on the primary prevention of obesity and advising workers on how to maintain the right weight; otherwise, obese workers should be referred to appropriate medical centres.

Methyl tert-butyl ether (MTBE) is widely used as an additive to gasoline, to increase oxygen content and reduce tailpipe emission of carbon monoxide. Our research dealt with 37 refinery workers in order to measure their occupational exposure to MTBE during two different seasonal periods. They provided blood and urine samples before and after a work shift during which they wore an active charcoal sampler for solvents. All samples were analysed by a gas-chromatograph equipped with a mass spectrometer detector. The concentration in air of MTBE was very low (median: 25 micrograms/m3 in spring and 5 micrograms/m3 in autumn). The blood and urine concentrations of MTBE at the end of the work shift were higher than those found before the shift. The increment in biological samples confirmed a small intake of MTBE by refinery workers: the biological monitoring of occupational exposure to this solvent yielded reliable results. Blood and urinary concentrations of MTBE obtained from workers split in relation to their smoking habit did not give a statistic significance to say that cigarette smoke is not a confusion factor in monitoring exposure to MTBE.

Although genomic screening studies have identified several genes associated with Parkinson's disease (PD), there is evidence that environmental factors are also involved in the pathogenesis of the disease and that hydrocarbon-solvents may be one of them. The genetic component is less evident in late-onset PD. To assess whether age and PD may affect the catabolism of the hydrocarbon n-hexane, a two-part study was performed. In the first part the urinary levels of its main metabolites, 2,5-hexanedione and 2,5-dimethylpyrroles, were measured in 108 patients and 108 healthy controls, matched by age and sex. Metabolite urinary excretion was significantly reduced in PD patients as compared with controls and was inversely related to age in both groups. In the second part the same comparison was made between 24 non-smoking and 10 smoking patients, matched to controls, after smoking of a hydrocarbon-rich cigarette. In these subjects also n-hexane and 2,5-hexanedione blood levels were measured. There was no appreciable difference in n-hexane blood levels between patients and controls in non-smokers, whereas there was a significant increase in patients over controls in smokers (p < 0.01). 2,5-hexanedione blood levels were significantly lower in patients than in healthy controls, both in non-smokers and in smokers, but the reduction was more pronounced in smokers (-46.3 % versus -10.7 %). The same was true for 2,5-hexanedione and 2,5-dimethylpyrrole urinary levels. This study suggests that aging and PD may be associated with a reduction in the capacity to eliminate the hydrocarbon n-hexane. This metabolic alteration may play a role in the pathogenesis of PD.

This article presents a review of reference values for organic solvent biomarkers. Some of these results were obtained in the research activities of the Italian Society Reference Values (SIVR). Most experiences show data obtained from control groups during occupational exposures assessment investigations. We considered only data related to the following biomarkers: immodified solvents in blood and urine, their main urinary metabolites. The reference values of the following solvents are reported: benzene, toluene, xylene, nhexane, cyclohexane, trichloroethylene, perchloroethylene, methanol, acetone, N,N-dimethylformamide, carbon disulphide. In the text also the influence of some confounding factors is discussed.

The European regulations classify gasoline as "carcinogenic agent" because of its content of benzene (0.1%). Consequently the preventive and protective actions towards the petrol station attendants prescribe, before all, the elimination of the agent or the reduction of the exposure and the risk to the minimum. Well known are currently a series of preventive measures able to produce appreciable reduction of the risk: reduction of the benzene content of gasoline, vapor recovery systems, self-areas or do-it-yourself, specific procedures for working. Exposure assessment is an essential step in order to establish the need for further preventive measure and to verify their efficacy. The exposure levels to gasoline of the petrol station attendants can be influenced by a variety of factors other than benzene air concentrations and therefore biological monitoring can give some sensible advantage in respect to air monitoring. Dosage of benzene in expired air, in urine, or in blood give a very good estimation of the exposure to benzene but they are not test largely practicable today, because analytical, economical, organizational reasons. Recent studies suggest that the dosage in urine of trans,trans muconic acid (ttMA) or phenil mercapturic acid can be useful biomarkers of recent exposure, even at low levels of exposure such as in filling stations. Exposure conditions to gasoline vapors in filling stations are rapidly changing thanks to some technological innovations and legal restrictions and the exposure levels are much below the occupational air standards, Toxicological and epidemiological data (although not yet conclusive at low doses) suggest to carry out however health and epidemiological surveillance programs for the working population. A program for the health surveillance and biological monitoring is here proposed: a clinical examination, integrated with haematological tests and biological monitoring tests, must be carried out in pre-employment and subsequently repeated yearly in the highest exposure conditions. When the exposure levels should decrease the examinations could be carried out every two years.

N,N-dimethyformamide (DMF) is widely used in industrial processes to prepare synthetic fibres, films and leathers. The metabolic pathway of DMF in humans gives raise to several products. N-hydrowymethyl-N-methylformamide (HMMF) is the major metabolite of DMF, but appears to be N-methylformamide (NMF) on GLC analysis, because the first product decomposes to NMF when injected at 250 degrees C. In humans, an other important metabolite of DMF is the N-acetyl-S-(N- methylcarbamoyl)cysteine (AMCC) which is the mercapturic acid coming from DMF. AMCC is excreted in urine with a half-time of about 23 hours. This means that it accumulates in the body when exposures to DMF are repeated as in industrial settings. The data of the literature on the analysis of AMCC in urine both in experimental or field conditions are reported and compared with the results obtained by a physiologically "based toxicokinetic model". The findings are discussed in order to use AMCC in the biological monitoring of occupational exposures to DMF.

Background: Single cases of parkinsonism have been associated with hydrocarbon solvents. Objective: To determine whether exposure to hydrocarbon solvents is related to PD. Methods: Cohort study of 990 patients with PD according to Core Assessment Program for Intracerebral Transplantations (CAPIT) criteria, selected from 1455 consecutive subjects presenting at a referral center; case–control study assessing Unified PD Rating Scale scores (motor score as primary endpoint) in all subjects with positive history of hydrocarbon solvent exposure (n = 188), matched for duration of disease and gender to 188 subjects selected from the remaining 802 with a negative history. Two subgroups in the case–control study included the following: 1) response to apomorphine (n = 26); 2) brain MRI (n = 15). PET imaging (n = 9) was compared with that of historic controls. Results: Exposed patients were younger (61.0 ± 9.4 versus 64.7 ± 9.4 years, p = 0.002), predominantly male (76.4% versus 45.2%, p = 0.0001), less educated (8.4 ± 4.2 versus 10.1 ± 4.4 years, p = 0.0001), and younger at onset of disease (55.2 ± 9.8 versus 58.6 ± 10 years, p = 0.014). Exposure to hydrocarbon solvents directly correlated to disease severity ( r = 0.311) and inversely correlated to latency period ( r = −0.252). Nine blue-collar occupations accounted for 91.1% of exposures. Conclusions: Occupations involving the use of hydrocarbon solvents are a risk factor for earlier onset of symptoms of PD and more severe disease throughout its course. Hydrocarbon solvents may be involved in the etiopathogenesis of PD, which does not have a major genetic component.

For many years biological monitoring of occupational exposure to solvents is achieved via their specific urinary metabolites. In the last 10 years many publications have shown that the urinary concentrations of unchanged solvents are well correlated with environmental exposure and could therefore be used for biological monitoring. For acetone, methanol, methyl ethyl ketone and methyl iso butyl ketone, the American Conference of Governmental Industrial Hygienists and the Deutsche Forschungsgemeinschaft have proposed urinary concentrations of substance itself as biological exposure indices. A critical revision of the literature on this matter reveals discrepancies between the results obtained by different authors. The correlations between environmental data and respective solvents give excellent indices of correlation. However, the differences observed when comparing the regression lines obtained from different research groups are very wide. For example, for an exposure to toluene corresponding to 50 ppm, some authors found urinary concentrations equal to 35 micrograms/l, others found urinary concentration higher than 100 micrograms/l. Similarly for benzene, styrene and methyl ethyl ketone the differences were also marked. We have not identified an explanation for such different results. Biological data variability could help to explain part of these disagreements. It should also be remembered that for benzene, the analytical methodology performed in different conditions can give rise to very different results. The mechanisms of excretion of organic solvents in urine are discussed considering biological variability and analytical method problems. The current hypotheses do not allow a satisfactory interpretation of the literature results. In conclusion further experience is needed that will more clearly show which results better express the relationship between occupational exposure to organic solvents and their specific urinary concentrations.

Raynaud's phenomenon may be secondary to several different pathological conditions. In some cases it is favoured by occupational exposure to vibration of the upper arms. The diagnosis of Raynaud's phenomenon requires clinical information together with specific technical investigations. This report presents the results of 232 chrono-thermometric tests performed on 157 workers exposed to vibrations during the use of different kinds of tools. Seventy-five subjects not exposed to vibrations of the upper arms but with suspected Raynaud's syndrome were also tested. Chrono-thermometry enabled us to distinguish between three different subgroups of subjects exposed to vibrations: 61 workers with "normal" chrono-thermometry, 33 subjects with "pathological" vascular reactivity to cold in some fingers and 63 workers with such reactivity in all fingers. Similarly the 75 patients not exposed to vibration could also be divided into three groups. No statistical difference was found between the chrono-thermometric results obtained from the exposed and non-exposed subjects when divided into the three subgroups. The overall analysis of the combined results of the different kinds of tests (capillaroscopy plus a vascular reactivity test) is discussed.

This study reports the results obtained with the environmental and biological monitoring of 34 workers exposed to acrylonitrile (ACN). Occupational exposure was monitored during 8-h work shifts with both active and diffusive personal samplers which yielded comparable results. The median exposure was 78 micrograms/m3. The ACN concentration in urine collected at the end of the work shifts correlated significantly with the environmental exposure. The ACN concentration in the pre-shift urine samples (median 3.6 micrograms/l) was lower than that found in the post-shift samples (median 10.9 micrograms/l), but higher than in the urine of non-exposed people (median 0.45 microgram/l). Smoking is an important confounding factor in monitoring exposure to ACN. The ACN concentration in urine provides reliable information about occupational and non-occupational exposure to ACN. Aspects of the mechanism of ACN excretion in urine are also discussed.

Environmental benzene levels were measured in 26 petrol stations using both active and passive stationary and personal samplers. Simultaneously, benzene levels were measured in the petrol station operators on blood samples collected at the end of the work shift and the following morning before starting work. The petrol stations belonged to various different oil companies and were studied both during the winter (9 stations) and in the summer (17 stations). The environmental levels measured with active samplers in the 26 stations were on average 256 ng/l, were significantly lower (98 ng/l) in winter and higher (326 ng/l) in summer. The blood levels of benzene in 77 workers at the end of the work shift were on average 548 ng/l, were significantly lower (306 ng/l) in winter and higher (651 ng/l) in summer. The following morning, blood levels of benzene were lower than those found at the end of the work shift, on average 249 ng/l in winter and 427 ng/l in summer. Smokers had higher benzene levels than non-smokers, both in winter at the end of the work shift (617/170 ng/l) and the following morning (506/137 ng/l), and in summer at the end of the shift (742/517 ng/l) and the following morning (535/233 ng/l). A comparison with a sample of 243 "normal" subjects of the general population showed that their mean blood level of benzene of 165 ng/l was significantly lower than the level found in petrol station workers the morning after the work shift (364 ng/l).

In order to investigate the effect of n-hexane and its metabolites on the Central Nervous System (CNS), we treated mice with n-hexane and 2,5-hexanedione (2,5-HD) by intraperitoneal (i.p.) administration. Gascromatographic mass spectrometric (GCMS) analyses of striatum and cerebellum revealed a consistent increase of 2,5-HD concentration at 0.5 and 2 hours after treatment and a decline to baseline levels at 24 hours. Traces of 2,5-HD were detected in the brain of control animals. Biochemical analyses revealed a precocious, short lasting, significant increase of striatal dopamine (DA) and homovanillic acid (HVA) levels. A significant increase of striatal synaptosomal DA uptake, suggesting a DA releasing effect on the dopaminergic terminals, was also observed. These results support the hypothesis of a possible role of n-hexane and its metabolites in inducing parkinsonism in humans and animals.

n-Hexane, similar hydrocarbons, and derivatives are common environmental pollutants and by-products of lipid peroxidation, and they may have a nigrotoxic effect like that of 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine. This report describes our second case of parkinsonism in a subject exposed to n-hexane. Positron emission tomography studies demonstrated regional striatal abnormalities of the nigrostriatal dopaminergic system and of glucose metabolism that were different from those found in idiopathic Parkinson's disease.

Concentrations of free and acid-labile carbon disulfide in human blood were determined by gas chromatography mass-spectrometry. Carbon disulfide was measured in the blood of 62 subjects not occupationally exposed to the solvent, and in 27 subjects treated with disulfiram (which is partially biotransformed into carbon disulfide). In blood, a small part of carbon disulfide is free (it can be analysed without any blood treatment); most carbon disulfide is bound ("acid labile" carbon disulfide), and requires acid hydrolysis to become free and detectable. During the first phase of our study, stored samples of blood (storage at 4 degrees C for 15-40 days) were used. Later, we analysed fresh blood samples. A significant decrease in carbon disulfide was found in stored samples in comparison to fresh samples. During storage, free and acid-labile carbon disulfide in blood decreased respectively to 26% and 27% of the initial concentration within a month. In fresh samples, free carbon disulfide concentrations in blood showed a median of 139 ng/l in normal subjects. Acid-labile carbon disulfide concentrations were much higher (median 2743 ng/l). Free and acid-labile carbon disulfide in blood were closely correlated (r = 0.9358). Blood samples stored at -80 degrees C maintained a constant concentration of carbon disulfide over almost three weeks.

Case report of a plumber's fatal work accident. Investigations on the causes of death made at post mortem showed that the worker had absorbed a large quantity of freon 22 (chlorodifluoromethane) which is known to be a narcotic agent and capable of inducing cardiac arrhythmia. It is believed freon inhalation was the cause of loss of consciousness with consequent death from drowning in the water issuing from the pipes. It is concluded that preventive measures need to be reinforced by adequate information to the workforce on the risks connected to this type of gas.

In order to study solvent exposure in shoe factories, 43 kinds of glues and 22 solvent products used in footwear manufacturing were analyzed. A gas chromatographic spectrometric method was used to identify the mixtures of solvents contained in glues and their diluents. Acetone, ethylacetate and cyclohexane were the solvents more frequently found in glues. Cyclohexane represented on average about 40% of the solvent mixture. Methyl ethyl ketone, 3-methylpentane and 2-methylpentane were often present in glues (45-52% of the samples), but only in a few cases were they associated with n-hexane. N-hexane and methylcyclopentane were found in 32% of the glue samples. N-hexane represented 47% of the solvents only in one glue. Most of the glues contained less than 10% n-hexane. Other solvents (dichloropropane, toluene, trichloroethane, butyl acetate, iso-butyl acetate and 2,2-dimethylbutane) were found in few glue samples or in low percentages. The 22 solvents used as glue diluents were mainly acetone, ethylacetate, dichloromethane and methyl ethyl ketone. The results suggest that solvent exposure in shoe factories has changed compared with data reported about 10 years ago. Biological monitoring of shoe factory workers should measure exposures to the specific solvents found in each factory, especially acetone, cyclohexane, ethylacetate and methyl ethyl ketone.

Benzene was measured in blood and alveolar air of a group of 168 subjects, consisting of 34 chemical industry workers exposed to benzene and 134 definitely not occupationally exposed to benzene. A gas chromatographic method was used with mass spectrometry and cryogenic trap. The results of the biological measurements were compared with the environmental levels of benzene in the room where samples were taken and at the worksite during the previous day's shift. All environmental air samples showed measurable levels of benzene, which agrees with the observations of many authors, according to which benzene is a common pollutant also of the living and external environments. Benzene in blood measured on morning samples was correlated with the previous day's exposure. In the group of non-exposed, both blood and alveolar concentrations of benzene were significantly higher in the 68 smokers than in the 66 non-smokers and the biological levels of benzene were inversely correlated with the time that had elapsed since the last cigarette smoked. In the chemical workers, the high biological levels of benzene due to occupational exposure largely exceeded the variations in concentration due to cigarette smoking and cancelled out the differences between smokers and non-smokers. It can therefore be assumed that smoking was not influential and did not interfere with the interpretation of the results in the occupationally exposed workers. Lastly, cigarette smoking, as a cyclical and additional factors of exposure, seems to be responsible for the disturbance in the relationships between biological benzene levels and ubiquitous environmental pollution, a relationship that was only observable in non-smoking subjects not occupationally exposed, but not in the group of smokers.

Environmental exposure to commercial hexane (n-hexane, 2-methylpentane, and 3-methylpentane) was tested in several work places in five shoe factories by taking three grap-air samples during the afternoon shift. Individual exposure ranges were 32-500 mg/m3 for n-hexane, 11-250 mg/m3 for 2-methylpentane, and 10-204 mg/m3 for 3-methylpentane. The metabolites of commercial hexane in the urine of 41 workers were measured at the end of the work shift. 2-Hexanol, 2,5-hexanedione, 2,5-dimethylfuran, and gamma-valerolactone were found as n-hexane metabolites and 2-methyl-2-pentanol and 3-methyl-2-pentanol as 2-methylpentane and 3-methylpentane metabolites. The presence of metabolites in the urine was correlated with occupational exposure to solvents. n-Hexane exposure was correlated more positively with 2-hexanol and 2,5-hexanedione than with 2,5-dimethylfuran and gamma-valerolactone. A good correlation was also found between total n-hexane metabolites and n-hexane exposure. 2-Methyl-2-pentanol and 3-methyl-2-pentanol were highly correlated with 2-methylpentane and 3-methylpentane exposure. The results suggest that the urinary excretion of hexane metabolites may be used for monitoring occupational exposure to n-hexane and its isomers.

The n-hexane concentration was determined in upper factory environmental air and in worker alveolar air. The relationship between the hexane alveolar concentration, and the hexane environmental concentration (Ca/Ci) was found to be steady during the 4,5 hours exposure and independent of the alveolar ventilation and hexane environmental concentration. These results suggest the hypothesis that alveolar TLV's can be fixed for hexane and other solvents.

Nine cases of local neuropathy are described in shoe-manufacture workers. Clinical and electrophysiological examination excluded diseases such as toxic polyneuropathies due to n-hexane. Specific lesions of the ulnar nerve were located near the elbow where the forced and uncomfortable posture facilitated the compression of the nerve in the cubital tunnel. The severity of the neuropathies ranged from relatively slight, with paresthesia of some of the fingers, to evident hypotrophy of the inter-osseous muscles of the hand. All the 9 cases sewed shoe uppers using sewing machines operating 25 cm above the arm support, thus obliging the operator to work with one or both elbows resting on the support, with the arms and shoe-upper held up. Five cases presented a neuropathy of the right arm, 3 of the left arm, and in one case the lesions were bilateral. The features of the work station are described and the possible promoting factors and the ergonomic pathogenesis of these neuropathies are discussed.

A case of occupational arsine poisoning is described that occurred in a small family workshop during blackening operations on zinc/aluminium alloy manufactured parts with acid solutions. This report shows that occupational poisonings wrongly believed to have disappeared can still occur, especially in small and often unsafe working environments.

A new thermic desorption method for some organic solvents from the passive dosimeters (Mod. TK 200) is described. The single active carbon leaft after solvent absorption have been put at 200 C into a oven connected with the gas-chromatograph injector. After 10 minutes of "static thermic desorption", the carrier flow (nitrogen), which usually goes through the gas-chromatograph in injector and columns, is diverted into the desorption oven and into the gas-chromatograph injector by means of a manual valve. After 5 seconds the initial route of the carrier is restored and the fraction of the solvents dragged by the carrier is analyzed. Subsequently each active carbon leaf is desorbed several times to study the trend of desorption rate of the solvent from the passive dosimeters. The data obtained from n-hexane, 2-methylpentane, 3-methylpentane, methyl ethyl ketone, cycloexane and trichloroethilene seem to suggest that the "static termic desorption, is an useful method, although further investigations are needed.