Trace elements and diabetes: Assessment of levels in tears and serum.

Tear film is critical for the well-being and homeostasis of the ocular surface. Although the composition of the tear film is well known, the composition of metallic elements have yet to be analysed. Despite trace elements metabolism has been reported to play a role in the pathogenesis of diabetes mellitus, a metabolic disease that affects several aspects of homeostasis, little is known in the literature regarding concentration and possible variation of metallic elements in tear film. We studied the concentrations of several essential and non-essential metallic elements in the tear fluid and serum of patients with type II diabetes mellitus and a group of non-diabetic controls. Serum and tear fluid were collected from 97 patients: 47 type II diabetic patients and 50 non-diabetic controls. Regarding tear film, there were statistically significant differences in Zinc, Chrome, Cobalt, Manganese, Barium, and Lead between groups; the values of all metallic elements were found to be statistically significant higher in patients with mellitus type II diabetes. Regarding serum values there was a statistically significant difference in Chrome, Cobalt, and Selenium values; the concentrations of Chrome and Cobalt were higher in the control group, while Selenium concentration was higher in diabetic patients. In patients with type II diabetes, metal elements with higher concentrations in tears compared to serum were: Lead, Barium, Manganese, Cobalt, and Chrome. In the control group, the metal elements with the highest concentration in tear film compared to serum were Chrome, Manganese, Barium, and Lead. In this study, we attempted to evaluate the possible effect of a disease, such as diabetes, on the metabolism of metallic elements. Although our evidence was very interesting, it is probably limited in its accuracy due to the fact that individuals in the control group harboured ocular pathologies. This work lays the foundation for future studies.

Extracellular histones mediate the effects of metal-rich air particles on blood coagulation.

BACKGROUND: Epidemiological studies have shown associations of particulate matter (PM) exposure with hypercoagulability and thrombosis. Extracellular circulating histones have recently been identified as novel mediators of inflammatory and procoagulant responses. The potential roles of extracellular histones in PM-related hypercoagulability have yet not been investigated. OBJECTIVES: In 63 steel workers, we evaluated the effects of exposure to PM and PM metal components on two extracellular histone modifications (H3K4me3 and H3K9ac); and the association of H3K4me3 and H3K9ac with coagulation markers. METHODS: Extracellular H3K4me3 and H3K9ac were determined in plasma through enzyme-linked immunosorbent assays. Coagulation markers included endogenous thrombin potentials (ETPs), tissue-type plasminogen activator antigen (t-PA) and D-dimer. Exposure to PM with aerodynamic diameters <1 µm (PM1) or <10 µm (PM10) and PM10 metal components were estimated for each participant. RESULTS: The coagulation marker ETP, measured in the presence of soluble thrombomodulin (ETP TM+), showed significant positive associations with PM1 (ß=107.84, p=0.03), PM10 (ß=83.06, p=0.02), and zinc (ß=75.14, p=0.03); and a marginal association with iron (ß=122.58, p=0.07). Additional PM effects were observed on t-PA, D-dimer, and ETP TM+. PM1 exposure was associated with increased plasma H3K4me3 and H3K9ac (ß=0.20, p=0.02; ß=0.16, p=0.05, respectively). H3K4me3, but not H3K9ac, was associated with zinc (ß=0.13, p=0.03) and iron (ß=0.32, p=0.01) contained in PM. ETP TM+ was increased in association with higher plasma H3K4me3 (ß=0.50, p=0.05) and H3K9ac (ß=0.54, p=0.05). CONCLUSIONS: This observational study suggests potential roles of extracellular histones in PM-induced hypercoagulability. Experimental studies are warranted to further characterize these findings.

Work- and non-work-related eye injuries in a highly industrialized area in northern Italy: comparison between two three-year periods (1994-1996 and 2005-2007).

BACKGROUND: Ocular trauma is a major cause of monocular blindness and visual impairment in industrialized countries. OBJECTIVES: The aim of this paper was to study epidemiology, causes, and clinical features of work-related and non-work-related eye injuries in a highly industrialized area of northern Italy. METHODS: All patients hospitalized for eye injuries were enrolled. Two 3-year periods were studied (1994-1996 and 2005-2007). The variables analyzed included sex, age, social class of the patients, nature of the injuring agent (e.g., metal, plastic, etc.), place where the accident occurred (e.g., home, work, etc.), and time of the year (e.g., summer, winter, etc.). RESULTS: We enrolled 1001 men and 129 women. There were no significant differences between the two 3-year periods as regards distribution of sex, age, and location. Road-related injuries significantly decreased (p < 0.004). Comparison of injuring agents showed a decrease in metallic agents (p < 0.001) and an increase in lime agents (p < 0.001). Analysis of the type of trauma showed a decrease in blunt traumas (p < 0.001) and an increase in chemical injuries (p < 0.001) and actinic keratitis (p = 0.002). In the second 3-year period, we found a significant increase in injuries in non-Italian subjects (p < 0.001). CONCLUSIONS: Work-related injuries were the major cause of eye trauma. Road accident-related eye injuries dropped significantly in the second 3-year period. The adoption of higher safety standards, as well as information and educational campaigns, can significantly reduce work-related and non-work-related eye injuries.

A pilot risk assessment study of strontium chromate among painters in the aeronautical industry.

OBJECTIVE: A method for risk assessment of occupational exposure to strontium chromate (SrCrO4) in painters employed in the aeronautical industry is described. METHODS: Assessment was made of 21 male workers of the painting division, potentially exposed to SrCrO4 (exposed), and 20 male workers of the tests and warehouse divisions (controls). All participants completed a questionnaire about work tasks, lifestyle habits, hobbies and diet. Personal active sampling for the determination of Cr and Sr was performed both during paint-spraying and during other operations in the painting division area. On the same day as environmental sampling, urine samples were collected at the beginning and end of the work shift in exposed workers to determine urinary chromium (CrU), and only at the end of the shift in controls. In the second half of the shift, a blood sample was taken in 10 exposed workers and 10 controls, to determine Cr in plasma (CrP) and in red blood cells (CrRBC). RESULTS: During paint-spraying, Cr concentrations ranged between 1.38 and 17.10 microg/m3, versus 0.02 to 0.07 microg/mi in the painting division area, while the Sr concentration was 22.90 microg/m3 in the paint-spray booth versus 0.07 microg/m3 in the painting division area. CrU at the end of the work shift, CrP and CrRBC, did not show significant differences between exposed workers and controls. Moreover, in exposed workers there were no differences between CrU measured at the beginning and at the end of the work shift. CONCLUSIONS: This approach, consisting of simultaneous environmental and biological monitoring, suggested no absorption of chromium in the painters thanks to the efficacy of the technical, organizational and personal protection measures adopted. However, the evident exposure to high levels of SrCrO4 during paint-spraying highlights how absolutely essential it is to ensure strict compliance with all the preventive measures foreseen by the EU and national regulations for occupational exposure to carcinogens.

Immune effects of polychlorinated biphenyls, smoking and alcohol.

Polychlorinated biphenyls (PCB) have been shown to exert some immune effects. Here we analysed their effects also on immune parameters not previously studied such as TCR alpha-beta, TCR gamma-delta and regulatory T cells (Treg), taking into account the specific and cumulative interference of smoking and alcohol. The study subjects consisted of 26 male workers in a steel works factory, employed in the electrical maintenance sector, with previous exposure to a mixture of PCB (exposed subjects), and 30 male workers with no occupational exposure to PCB (controls). All subjects were given a questionnaire and peripheral venous blood samples were taken to determine serum PCB (33 congeners), total cholesterol and triglycerides, leukocytes, total lymphocytes and the T lymphocyte subpopulations (TCR alpha-beta, TCRgamma-delta, CD4+ and Treg lymphocytes). PCB, even though at a very low concentration, were significantly higher in exposed subjects than controls, and were significantly correlated with age. Monocytes% and CD4+ were significantly reduced in the exposed subjects as compared to the controls. The serum concentration of PCB positively correlated with TCR alpha-beta, and negatively with TCRgamma-delta. Treg lymphocytes showed a positive dependence on tobacco smoking, while the monocytes percentage and CD4+ showed a negative and positive dependence, respectively, on alcohol intake. Our results seem to show some effects of slight exposure to PCB in particular reducing the relative concentration of TCRgamma-delta. This effect can favour indirectly the increase in Treg induced by smoking, the anti-inflammatory or proinflammatory/fibrogenetic/angiogenetic effect of which, exerted by produced cytokines, particularly TGF-beta, deserves further clarification.

Defining reference values of trace elements in the tear film: diagnostic methods and possible applications.

The study has been performed on tears of apparently healthy subjects who live and work in urban and rural areas, respectively. After the collection the following elements were investigated: chromium (Cr); arsenic (As); copper (Cu); zinc (Zn); selenium (Se); rubidium (Rb); barium (Ba); lead (Pb) and cobalt (Co). Significantly higher values of As were found in subjects living and working in rural areas as compared to those found in urban area residents (0.290 vs. 0.025; p<0.001). Conversely, Ba and Pb were significantly lower in rural area residents (1.10 vs. 2.50, p=0.027 and 1.70 vs. 1.10, p=0.057, respectively). Our data show that trace elements analysis in tears is possible; further studies could define if it could be a reliable biomarker in persons exposed to high concentration of trace elements due to working or environmental reasons.

[Occupational physician: a global consultant for prevention and health promotion in workplace]. / Il Medico Competente del Lavoro, consulente globale in azienda.

Work, Occupational Medicine, legislative framework are in a deep and wipe transformation. To be able to adequately the occupational physician is requested to improve and update his professional capability, in a correct relationships between laws and normative and technical good practices. Anther crucial point appears his ability to support all the aspects involving the health protection and promotion in workplaces: form project or organization of new productions, to risk evaluation and management, to health surveillance and occupational epidemiology, to legal actions. In other words the occupational physician as a global consultant for employers ad for employees. Strategic in this perspective are the instruments (guidelines, protocols, consensus documents, technical assessments) for qualifying and updating the professionals, for which the scientific societies have a central tole.

[Review from the scientific paper about the main respiratory diseases in metallurgical workers]. / Revisione dei principali contributi scientifici sulle patologie respiratorie dei lavoratori metallurgici.

The review of main scientific investigations about the work related diseases in metallurgy shows that the most studied pathologies regards lung cancer and pneumoconiosis, other cancers and cardiovascular diseases. These evidences are not univocal and have been and are critically evaluated due to the complexity and articulated structure of metals production which makes it very difficult to compare the risks and diseases among the different metallurgical activities and, in the same activity, among the different job tasks. In addition, due to the technological and organizational evolution investigations, appear to be necessary to better define the specific hazards (for example metal species, PAH and PoPs mixtures) and to put into a correct relation these and pathologies diagnosed by health surveillance procedures or epidemiological surveys, surely different from those of past decades.

[Risk assessment of biomechanical overload of the limbs and spine in workers paving roads with stones]. / Valutazione del rischio da sovraccarico biomeccanico agli arti e rachide negli addetti alla pavimentazione lapidea stradale.

Aim of this study is to assess the risk from biomechanical overload for the whole musculoskeletal system and manual handling involved in the activity of stone paving of the road. According to the guidelines of the Italian Society of Occupational Medicine and Industrial Hygiene various risk assessment methods have been used: Washington State checklist, checklist of Turin and OCRA checklist to assess the risk from biomechanical overload for the upper limb and NIOSH method with the method provided by the State of Washington to assess the risk from manual handling of loads.

[Interdisciplinary training opportunities for residents in occupational medicine: the experience of the ERC Tour 2012]. / Nuove opportunità formative interdisciplinari per i medici specializzandi: l'esperienza dell'ERC Tour 2012.

This paper describes the experience of the School of Occupational Medicine of the University of Brescia at the current edition of the New York and New Jersey Education and Research Center--Historical Perspectives Tour on Occupational Safety and Health, that involved 5 different industrial and environmental sites, appropriate for understanding the complex occupational health and safety problems. In every site, the participants have interacted with workers and professionals and discussed about the specific work processes, to better understand the risk faced by the workers, occupational pathologies that can occur, personal protective equipment used and preventive measures adopted. This experience has been successful in provide interdisciplinary educations to occupational safety and health professionals in training in order to prepare them for the collaboration and cooperation required to solve the complex occupational health and safety problems they will face in their future careers.

[Measurement of chemical agents in metallurgy field: electric steel plant]. / Misura degli agenti chimici in ambito metallurgico: acciaieria elettrica.

The steel industry maintains its important position in the context of the Italian production involving thousands of workers. The iron and steel processes are divided into primary steel industry, production of intermediate minerals, and secondary steel, scrap from the production of semi-finished industrial and consumer sector (metal inserted into components and metal used for dissipative uses, primarily coatings) and industrial waste. The paper presents the results of environmental monitoring carried out in some electric steel plant for the measurement of airborne chemicals that characterize the occupational exposure of workers employed in particular area like electric oven, to treatment outside the furnace, continuous casting area. For the sampling of the pollutants were used both personal and in fixed positions samplers. The pollutants measured are those typical of steel processes inhalable dust, metals, respirable dust, crystalline silica, but also Polycyclic Aromatic Hydrocarbons (PAH), polychlorinated dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).

[Epigenetic effects as mediators of procoagulant action of thin dust with high metal content. Study on occupational epidemiology]. / Effetti epigenetici come mediatori dell'azione pro-coagulante delle polveri sottili ad alto contenuto metallico. Uno studio di epidemiologia occupazionale.

Blood hypo-methylation mediates the effects of metal-rich airborne particles on blood coagulation: An occupational epidemiological study. Particulate matter (PM) exposure is associated with increased coagulation and thrombosis, but the biological mechanism has not yet been clarified. DNA methylation represents a potential mechanism because it can be modified by environmental factors. Foundry workers are exposed to PM components and showed increased cardiovascular risk. In a group of 63 steel workers we found that PM and zinc airborne levels were negatively associated with leukocyte DNA methylation in genes NOS3 and ET-1 (b = -1.1; p = 0.002 and b = -1.5; p = 0.003, for zinc exposure respectively in multivariate regression models; b = -0.9 with p = 0.01 for PM10 exposure and NOS3) and in turn, DNA hypo-methylation resulted associated with increased Endogenous Thrombin Potential (for NOS3 b = -45.0, p = 0.001; and for ET-1 b = -16.4, p = 0.03). Our study based on healthy subject exposed in occupational setting, suggests that gene specific hypomethylation contributes to environmentally-induced hypercoagulability.

[Biological monitoring of exposure to carcinogenic metallic elements and polycyclic aromatic hydrocarbons in four secondary metallurgical sectors]. / Monitoraggio biologico dell'esposizione ad elementi metallici cancerogeni e ad idrocarburi policiclici aromatici in quattro settori metallurgici secondari.

This cross-sectional study was aimed at evaluating in a large sample of male foundry workers the current exposure levels to carcinogenic compounds, including metallic elements [arsenic (As), beryllium (Be), cadmium (Cd), chromium (Cr), nickel (Ni)] and aromatic polycyclic hydrocarbons (PAH) by a biological monitoring approach, using validated biomarkers of exposure. Workers were recruited from 15 aluminium, copper alloy, electric steel and cast iron foundries and provided an end-of-shift urine sample to determine urinary concentrations of As, Be, Cd, Cr, Ni and 1-hydroxypyrene (1-OHP). Metallic elements were determined either by inductively coupled plasma mass spectrometry (Be, Cd and Cr) or by atomic absorption spectrometry (As, Ni), whereas 1-OHP was determined by high pressure liquid chromatography with fluorimetric detection. Most of the determinations fell within the laboratory's reference values. Age and lifestyle habits (smoking, alcohol, diet) played a significant interfering role.

[Risk assessment of biomechanical overload of limbs and spine in workers employed on stone paving roads, using a combination of different methods]. / Valutazione del rischio da sovraccarico biomeccanico agli arti e rachide negli addetti alla pavimentazione lapidea stradale: applicazione integrata di diversi metodi.

BACKGROUND: Few data exist on the risk of musculoskeletal disorders in road paving workers, in addition methods for risk assessment of biomechanical overload of the lower limbs and the spine are also lacking. OBJECTIVES: The aim of this study was to assess the risk from biomechanical overload for the whole musculoskeletal system and manual handling involved in the activity of stone paving of roads. METHODS: In accordance with the guidelines of the Italian Society of Occupational Medicine and Industrial Hygiene various risk assessment methods were used. RESULTS: The Washington State checklist revealed the presence of biomechanical overload of the spine in flexion. The Turin checklist showed a risk score higher than the acceptable limit for the cervical and lumbar spine and limbs (risk level similar to that obtained from the OCRA checklist for the upper limbs). The assessment of risk from manual handling of loads carried out using the NIOSH method provided a synthetic risk index whereas evaluation conducted using the Washington State method was acceptable. CONCLUSIONS: Biomechanical risk assessment showed the presence of risk for use of force and awkward postures of the wrist and elbow, which agrees with literature data. The division of tasks among workers and the distribution of breaks helped to reduce the risk to an acceptable level for limbs. All methods however showed a risk for the spine. Health surveillance showed disorders of the spine in 28% of the workers and no disorders of the upper limbs, which agrees with the risk assessment.

Biological monitoring as a valid tool to assess occupational exposure to mixtures of 2,4-:2,6-toluene diisocyanate.

BACKGROUND AND OBJECTIVES: Despite its advantages over environmental monitoring, biological monitoring of exposure to 2,4-:2,6-toluene diisocyanate (TDI) mixtures is still underused. The present study was designed in order to evaluate the feasibility and reliability of biological monitoring in a factory producing polyurethane foam blocks. METHODS: Airborne TDI isomers were sampled by both static and personal pumps and determined by HPLC with fluorimetric detection. Specific metabolites 2,4- and 2,6-toluenediamine (TDA) were determined by gas chromatography-mass spectrometry on hydrolysed urine samples collected from 16 workers at the beginning of the workweek and both before (BS) and at the end (ES) of the 4th workday. Additional samples were collected at the end of the 1st half-shift and at the beginning of the 2nd half-shift in 5 workers. RESULTS: In the foam production shop, TDI values were on average about 20 microg/m3, with higher levels in the 2nd half-shift and peak levels in workers operating along the polymerization tunnel. Average TDI levels were significantly correlated with ES TDA concentrations (p < 0.0001). TDA showed a fast urinary elimination phase leading to progressively higher TDA levels either during the shift (5 workers) and at the end-of-shift. A slower elimination phase with a weekly accumulation was demonstrated by values at the beginning of the workweek (higher than in unexposed subjects) and by their elevation in subsequent BS samples. CONCLUSIONS: The study demonstrates the feasibility and reliability of biological monitoring in workers exposed to 2,4-:2, 6-TDI mixtures. This approach can provide information about both the daily and weekly exposure levels.

Environmental factors affecting the urinary excretion of inorganic arsenic in the general population.

OBJECTIVE: To assess the critical issues concerning the use of urinary inorganic arsenic (iAs), including As3, As5, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), as biomarker of internal dose in order to monitor environmental and occupational exposure to inorganic As, considering the influence of diet and drinking water on excretion of iAs. METHODS: The design protocol stipulated collection of weekly urine samples from 6 male subjects for 5 consecutive months. In all the urine samples, iAs was determined by Hydride Generation-Atomic Absorption Spectrophotometry (HG-AAS). In the subjects with iAs higher than 35 microg/L, Biological Exposure Index (BEI) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH), urinary arsenic speciation was performed by HPLC-ICP-MS. Exposure to airborne As was evaluated monthly using personal environmental samplers worn for 8 hours. Throughout the study, the participants filled out a daily food diary, also detailing types of water drunk. RESULT: Exposure to airborne As was invariably below the limit of detection, equal to 1 ng/m3. A total of 77 urine samples were collected. iAs was always detectable and was higher in 7 urine samples, obtained from 5 of the 6 subjects examined, than the BEI. Among foods with a high As content, the intake of seafood and fish within 72 hours before providing the sample seems to be the principal source of the iAs concentrations, while the intake of rice or drinking water showed no influence on this biological marker. Instead, drinking wine within 24 hours before urine sample collection can cause a significant increase in the excretion of iAs. CONCLUSIONS: In populations that eat large amounts of fish and seafood, the use of iAs to monitor occupational and environmental exposure to inorganic As seems to present some problems, and urinary As speciation may be essential at least in cases with As measurements above the biological limit values. In any case, a diet sheet reporting all foods eaten within 3 days of urine collection seems to be an indispensable tool to ensure a correct interpretation of the results.

Cobalt, chromium and molybdenum ions kinetics in the human body: data gained from a total hip replacement with massive third body wear of the head and neuropathy by cobalt intoxication.

INTRODUCTION: A patient with a total hip replacement developed optic, acoustic and peripheral neuropathy from metal ions intoxication, due to the wear products released from the prosthesis. Subsequently the kinetics of the metal ions was studied. MATERIALS AND METHODS: Massive wear and acute intoxication allowed a study of the metal ions kinetics and of EDTA treatment. RESULTS: Plasma and other organic fluids were saturated by each of the metal ions released from the exposed surface according to the solubility of each ion; a larger fraction of Co ions was bound within red cells, while the plasmatic fraction appeared more movable. In a patient with a prosthesis subjected to wear, the ions released are from the prosthetic and from the debris surface (spread in the body). The latter is a function of the number and size of particles. DISCUSSION: Revision of the prosthesis from the point of view of the metal ions kinetics corresponded to a reduction of the releasing surface because of debris washed out by irrigation and tissue excision; however, the metal particles spread by lymphatic circulation continued to release ions even though the source of wear had been removed. Early diagnosis of high metal wear can be ascertained with mass spectrometry and after revision high levels of metal ions can only be reduced with repeated chelating treatment. It is preferable not to revise fractured ceramic components with a polyethylene-metal articulation.

[Neurotoxic effects of cobalt: an open question]. / Effetti neurotossici del cobalto: una questione aperta.

Increased cobalt levels have been associated with neurological diseases (hand tremor, incoordination, cognitive decline, depression, vertigo, hearing loss and visual changes) in addition to "classic" and known cardiac diseases (arrhythmias and cardiomyopathies) and allergic or endocrine symptoms. Cobalt neurotoxicity is reported in isolated cases: old occupational or iatrogenic exposures and more recent releases of metallic ions by prosthesis. The studies of these cases have revealed a typical symptomatology of cobalt probably due to its ability to induce oxidative stress and mitochondrial alterations.

[Road map for health and safety management systems in healthcare facilities, according to the OHSAS 18001:2007 standard]. / ROAD MAP per i Sistemi di Gestione in Sanità, secondo lo Standard OHSAS 18001:2007.

The 81/2008 Act has defined a model of a health and safety management system that can contribute to prevent the occupational health and safety risks. We have developed the structure of a health and safety management system model and the necessary tools for its implementation in health care facilities. The realization of a model is structured in various phases: initial review, safety policy, planning, implementation, monitoring, management review and continuous improvement. Such a model, in continuous evolution, is based on the responsibilities of the different corporate characters and on an accurate analysis of risks and involved norms.

[Pinch assessing in bio mechanical analysis: methodological and applicative aspects dealt by using the new P force Met portable instrument]. / Stima della presa in pinch: approfondimento degli aspetti metodologici ed applicativi mediante l'impiego di un nuovo apparato portatile, P force Met.

BACKGROUND AND OBJECTIVES: Definition and significance of term pinch and related force exerted are still open outside the ergonomic field of interest too. The lack of consent appears relevant in upper limb biomechanical risk assessment. Aim of this study is to focus methodological aspects and applications of pinch, analyzing four actions by a new portable instrument able to measure strain exertion during pinch action. METHODS: A portable apparatus named P-forceMet, produced by OT bioelettronics, Turin (Italy) had been used. It measures the force generated by voluntary muscle contraction both in maximal condition (MCV) and in specific working conditions (Spontaneous Force, SF). We examined four groups of 27 subjects exerting forces of different entity required in 4 technical actions: tightening bolts, writing with a pen, use a brush to spread sealer, wiring cables. The workers were asked to exert the MCV and value was registered to be compared with force simulated on the instruments taking into account the specific experienced action. Data from force analysis by Borg scale and data about upper limb disorders had also collected, as well as the results of risk assessment by checklist OCRA application. RESULTS: Comparing MCV and SF we demonstrated different levels of measured forces: from 2-3% when using the pen to write to 8-12% for cabling and brushing activities to 31% for manual tightening. These results were in good agreement with evaluations by Borg scale, while risk assessment by check list OCRA were discordant (sealing and cable wiring were sometimes at level of mild to medium risk mainly due to posture evaluation of pinch). Workers engaged in writing, sealing and cabling did not suggest disorders to wrist-hand. CONCLUSIONS: Actions with pinch are numerous in working activities and if defined "at risk" only because they require posture of opposition of the first two fingers, we could not classify correctly to the real bio mechanical overload. This study carried out using an instruments able to measure the force exerted during pinch operations demonstrates that the force (and then of possible strain) is diferent in the four activities. It confirms the importance of critical evaluation of different hazards and of their interaction in causing the functional or organic disorder. In our case a remarkable difference of force was demonstrated by instrument p-force in actions involving the same hazard related to posture. Further investigation appears to be necessary to eliminate the residual subjective component of this force measurement method due to the necessity of simulating the force requested by specific action.