Biological monitoring of exposure to perchloroethylene in dry cleaning workers

BACKGROUND

Perchloroethylene (PCE) is the most widely used solvent in dry cleaning.

OBJECTIVES

The aim was to evaluate PCE pollution and to identify the most reliable biological indicators for the assessment of workers' exposure.

METHODS

The study was performed in 40 dry cleaning shops covering a total of 71 subjects. Environmental monitoring was carried out with personal diffusive samplers (Radiello) for the entire work shift; biological monitoring was performed by measuring PCE in urine and blood and trichloroacetic acid (TCA) in urine on Thursday evening at end-of shift and on Friday morning pre-shift.

RESULTS

The mean concentration of PCE in air was 52.32 mg/m3, about 30% of the TLV-TWA and the mean value of the PCE inpre-shift blood samples was 0.304 mg/l, slightly more than 50% of the BEI. In dry cleaning shops employing less than 3 persons PCE in air exceeded the TLV-TWA in 7.8% of cases; the size of the shops was inversely related to pollution. Statistically significant correlations were found between PCE exposure and PCE in blood end-of-shift (r = 0.67) and pre-shift (r = 0.70), and PCE in urine end-of-shift (r = 0.68); no correlation was found between exposure and PCE in urine pre-shift and urinary TCA.

CONCLUSIONS

Dry cleaning shops still register conditions of exposure and pollution by PCE, although to a lesser extent than in the past. The most reliable indicators for biological monitoring are CE in end-of-shift urine and PCE in blood both at end-of-shift and pre-shift at the end of the workweek.

[A new scale for measuring the psycho-physical effects of work-related stress in a perspective of methods integration]

BACKGROUND

This study fits into a perspective of integrated work-related stress assessment, in response to the need to limit the common method variance and the role played by individual variables in subjective measures.

OBJECTIVES

The goal of this study was to check the metric properties of a new scale of mental and physical strain developed for the evaluation of stress symptoms by the physician and to detect the antecedents of psycho-physical symptoms, in terms of both individual and work characteristics, through an integrated approach.

METHOD

The study was conducted on 409 workers involved in health surveillance activities, to whom the new scale and a subjective assessment tool were administered.

RESULTS

Confirmatory factor analysis showed that the scale is a reliable tool for hetero-evaluation of psycho-physical symptoms attributable to stress at work. Moreover, specific individual characteristics, such as the presence of prior health disorders and the female gender, and organizational features, such as the pathological work/life conflict and the workload, were found to be risk factors in relation to psychological and physical strain. Age, consumption of alcoholic beverages between meals, relationships with colleagues, and the characteristics of the workplace were instead found to be important protective factors.

DISCUSSION

The adoption of an integrated approach made it possible to improve and study in depth the ways of work-related stress assessment, highlighting the pivotal role of the occupational health physician making the evaluation.

[Drugs use assessment in a group of bus drivers]

Bus driver is one of those tasks inherent transport activity, which involves special risks to safety and health of others and for which it is necessary, according to art. 41 of Decree No. 81/08, to check the consumption of psychoactive substances during the health surveillance. This assumption was investigated in a group of 461 bus drivers of a large trucking company. In medical history, one subject reported a previous history of opiate addiction and another, in the past, occasional taking of cannabis, and at the time of the visit, in no cases the objectivity has shown intoxication or abstinence signs, or signs of parenteral injection. Laboratory tests were found positive in one case of screening texts, not confirmed by subsequent laboratory analysis and a case of positive analysis for confirmation. The worker, temporarily suspended from driving and taken over by the Service for Drug Addiction of competence, was then reinstated in his job, having held that the absence of drug addiction.

[Guides to chemical risk assessment in the construction industry]

The presence of chemical agents in construction is certainly relevant in terms of quality, quantity and toxicity. Their manipulation can result in potential exposure as inhaled and/or through the skin. It is therefore possible and necessary to identify a list of substances to be considered relevant for the risk assessment and the possible environmental monitoring to verify the adequacy of the estimate made. The many variables inherent in construction make it extremely difficult to apply the usual methods of the industrial hygiene because it would not very significant conclusions in terms of space-time representation. SIMLII in one of its guidelines have proposed a "indexes" method that can provide useful information to the figures of prevention for the actions of their competence. The subsequent introduction of the REACH Regulation and exposure scenarios may help to further sharpening the assessment of chemical hazards in construction.

[Experiences of environmental and biological monitoring in the construction industry]

After emphasizing the characteristics of the sector and the difficulty of applying traditional industrial hygiene methods for assessing exposure to chemical agents in the construction industry, we have reviewed the major experiences of environmental and biological monitoring that can be derived from the literature. Although the determination of exposure through environmental measures should be considered the most appropriate instrument, it should be paid for the study of specific activities, while it is preferable in many situations the use of simplified tools (such as algorithms and databases) that allow the risk estimation and enable the adoption of safe work procedures and environmental and individual protection devices.

Occupational diseases due to allergic and toxic chemicals in health care workers: fitness for work

The purpose of this review is to suggest job fitness criteria for health care workers exposed to sensitizing or chemical agents. These recommendations are derived from a comparison between previous documents on prevention and management of allergic and chemical risks in health care settings and updated evidence; the job fitness criteria and the main documents on these topics are summarized in tables. Glove allergy, in particular latex allergy, is still a significant problem but we should remember that a wide choice of alternative materials is now easily available; many different alternative health products are also currently available when an allergy to disinfectants or detergents is diagnosed. Hence the prevention of allergic diseases is mostly based on an appropriate choice and use of the gloves and health products according to the specific tasks and possible individual susceptibility; this meets the requirements of the "good health care organization", which translates into lower costs, if possible, as well as the best protection of worker's health. Concerning chemical risk, it should be remembered that during the last 20 years the improvements made in work environments have profoundly changed the mode and the levels of exposure to chemical substances and the current recommendations concerning the management of workers exposed to anesthetic gases, antineoplastic agents and sterilizers/disinfectants significantly differ from those of early 1990s. However, the past prudential guidelines are still valid for formaldehyde.

[Manual material handling risk assessment and ergonomic improvement in foodstuff retailing company]

The aim of this study is to assess and reduce the risk due to manual material handling in a company involved in the foodstuff retailing. The risk assessment was performed by NIOSH Variable Lifing Index in 13 different occupational conditions. As result the risk was present in any case, with VLI values ranging from 2.12 to 2.81. A good risk reduction has been accomplished correcting properly the most important multiplier involved in the computation of the revised NIOSH Lifting equation (lifting frequency and weight of heavier products). Even if the performed risk reduction has been significant, the residual risk is still higher than the level of acceptability.

[Occupational exposure to ionizing radiation in hospital. Analysis of individual risk by area and occupational category]

An analysis of occupational radiation exposure from 1988-2008 of 43 medical, 41 nurses and 4 nuclear medicine technicians of interventional cardiology, nuclear medicine, radiology-neuroradiology, urology and orthopedics has been performed. The mean annual effective dose to the whole body of all monitored workers are decreasing; one vascular surgeon, has exceeded 20 mSv/year. The doses received by physicians in the hands were up in radiology, urology and cardiology. Currently, interventional cardiology-hemodynamic is the most department-average exposure. Nurses are overall less exposed, the great exposure is in nuclear medicine, where the technicians are included.

[Work-related stress: comparing two assessment methods]

Aim of the study is to compare and evaluate the possible integration of two methods of work-related stress risk assessment: the "subjective/perceptive" ISPESL-HSE and the "objective/intersubjective" VIS. Four different types of companies were examined: public education, social services, forestry work, agricultural machinery industry. Both VIS and HSE showed a different level of risk among the companies, with a good overlap of the results obtained with the two different methods of investigation. They also integrate each other in eliciting a better and more articulated study of work-related stress risk.

[The role of scientific associations in the definition of occupational limit values]

The definition and compliance with occupational limit values for pollutants in the workplace are the main tool for risk reduction and prevention of possible adverse health effects. There is no doubt that the decisions on the limit values are now closely linked to what produced in the European Community, if not at the international level. However, we believe that Scientific Associations should play a role in proposing and updating the limit values adopted by law in Italy. Become prominent interlocutors of lawmakers and institutional bodies is equally important.

[Environmental and biological limit values and reference values]

The application of air quality guidelines and limits for occupational exposure in the workplace are the main tools for risk reduction and prevention of the effects of pollutants on health of the general population and workers respectively. The Biological Reference Values (BRVs), determined in situations of non-occupational exposure, and the Biological Limit Values (BLVs) contribute to the interpretation of biological monitoring data. In the occupational field the comparison with the BRVs should be informative about the existence of exposures greater than the general population and are particularly important for substances without VLBs or whose effects include chronic diseases.

[Lesser validity of urinary benzene than S-phenylmercapturic acid for measuring occupational and environmental exposure to very low concentrations of benzene]

AIM

To study the validity of urinary benzene as a biomarker of low and very low exposure to this toxicant, as compared with t,t-muconic acid (t,t-MA) and S-phenylmercapturic acid (SPMA), also taking into account the influence of cigarette smoking and co-exposure to toluene on the urinary excretion of benzene.

MATERIALS AND METHODS

The results obtained in two different studies were compared: in the first, workers occupationally exposed to low concentrations of benzene (18 fuel tanker drivers and 23 filling station attendants) were compared with 31 controls and in the second, workers exposed to very low concentrations of benzene (the same 23 filling station attendants) were compared with the 31 controls. Exposure to airborne benzene and toluene was monitored with passive personal samplers (Radiello). Then the urine collected at the end of the work shift was analyzed for t,t-MA, SPMA and urinary benzene. All participants also filled out a questionnaire about their lifestyle habits.

RESULTS

There were no differences among the three groups in terms of age and smoking habit. Occupational exposure to benzene and toluene and the urinary concentrations of t,t-MA, SPMA and urinary benzene were higher in the fuel tanker drivers than the filling station attendants and higher in the latter than in the controls. Cigarette smoking was found to be associated with urinary excretion of t,t-MA, SPMA and urinary benzene at both low and very low exposure to benzene. The biomarkers t,t-MA, SPMA and urinary benzene were almost always correlated, for both low and very low exposure to benzene. Notably, for low exposure to benzene a dependency relation was found with the levels of t,t-MA, SPMA and urinary benzene on both cigarette smoking and airborne benzene, whereas for very low exposure to benzene there was a dependency relation of SPMA on cigarette smoking and airborne benzene, of urinary benzene only on cigarette smoking and of t,t-MA on none of the variables considered.

CONCLUSIONS

For occupational exposure to low concentrations of benzene, urinary benzene and SPMA showed a comparable validity, while for exposure to very low concentrations of this toxicant the validity of SPMA was confirmed while urinary benzene was found to be less useful. Cigarette smoking was the main factor conditioning the excretion of all the biomarkers of benzene in conditions of both low and very low exposure to the toxicant, so for the analysis of occupational exposure to benzene it is best to recommend abstention from smoking at least in the hours immediately before urine collection.

Applicability of urinary benzene to biological monitoring of occupational and environmental exposure to very low benzene concentrations

OBJECTIVE

To verify whether urinary benzene is an applicable biomarker of occupational exposure to very low concentrations of benzene, considering the influence of cigarette smoke and benzene-toluene co-exposure.

MATERIALS AND METHODS

23 filling station attendants with occupational exposure to benzene and 31 controls were analyzed. Occupational and environmental exposure was monitored and t,t-muconic acid (t,t-MA), S-phenylmercapturic acid (SPMA), urinary benzene and creatinine in the urine samples were tested.

RESULTS

Occupational exposure to benzene and toluene was significantly higher in the filling station attendants than in the controls, whereas t,t-MA, SPMA and urinary benzene were not different in the two groups. Instead, the smoker group showed significantly higher values for the above biomarkers than the non-smoker group, each of which included both exposed workers and controls. SPMA was dependent on airborne benzene and cigarette smoking, and urinary benzene only on cigarette smoking, while t,t-MA was not dependent on either of these variables.

CONCLUSIONS

At very low concentrations of occupational exposure to benzene, urinary benzene is less valid than SPMA as a biomarker, even if both are strongly influenced by smoking habit. Abstention from smoking should therefore be recommended for at least two hours before urine collection.

Personal exposure to particulate matter is associated with worse health perception in adult asthma

BACKGROUND

Epidemiological studies have shown positive associations between particulate matter (PM) air pollution and short-term mortality and morbidity for asthma. The hypothesis that lung inflammation is responsible for these effects has been tested in panel and controlled exposure studies in asthmatic adults, with inconsistent results.

OBJECTIVES

We investigated whether personal exposure to PM10 and PM2.5 were related to changes in the clinical course of asthma and to lung inflammatory responses in adult asthmatics.

METHODS

A cohort of 32 asthmatic patients was followed for 2 years. Asthma control test (ACT) and St George's Respiratory Questionnaire (SGRQ) scores, forced expired volume in the first second (FEV1), exhaled nitric oxide (Fe(NO)), and pH of exhaled breath condensate (EBC) were determined on 6 occasions during different seasons. Personal exposure to PM was measured for 24 hours prior to clinical assessments.

RESULTS

A 10 microg/m3 increase in PM10 personal exposure was associated with an increase in SGRQ scores (regression coefficient beta = 0.22; 95% confidence interval [CI], -0.005 to 4.451; P =.055) and with a decrease in ACT scores (beta = -0.022; 95% CI, -0.045 to 0.001; P = .060), whereas no associations were found between PM10 and FEV1, Fe(NO), or EBC pH. A positive association was detected between Fe(NO) and outdoor O3 (P = .042) and SO2 (P = .042) concentrations in the subgroup of nonsmoking asthmatics.

CONCLUSIONS

We concluded that increments in personal exposure to PM10 are associated with a decrease in asthma control and health-related quality of life. However, this study does not provide evidence that 24-hour exposures to PM are associated with short-term changes in lung function or inflammatory responses of the lung.

[Role and integration of technical prevention figures in the management system]

The multifarious issues of health and safety at work require multi-disciplinary skills, both in the risk assessment and in the subsequent definition and management of preventive measures, and this requires a renewed operational protocol that supports integration and co-operation between the technical prevention figures. Thus, between occupational physicians and technical advisers there should be a concrete and fruitful interaction, which should not be episodic or occasional, but a modus operandi systematic and constant. In this contribution is discussed as the technical prevention figures should be included in the Health and Safety Management System and should make a specific contribution in defining corporate policies on prevention. In particular it is outlined the role that the occupational physician may play in the development of prevention and health promotion activities within the strategies of corporate social responsibility.

[The role of the occupational physician in the chemical risk assessment]

The Author describes the process of chemical risk assessment to be implemented in the workplace, which must lead to the characterization of risk, and thus to estimate the probability of adverse health effects can occur. It is a multi-step and multi-disciplinary activity carried out in close collaboration between the Head of Prevention and Protection Service (which is able to use the accountability of managers and supervisors and the involvement of representatives of workers' safety) and occupational physician who, through its cross-training, can and should be the connective tissue of the entire operation: in fact he is the only professional figure able to link together health and safety in the workplace. The Author recalls the importance of using biological monitoring procedure, which must always be used especially when the evaluation is to use simplified measures such as algorithms.

[Comparison of the training schemes of the specialization schools of the public health area: a rational basis for a proposal of a core curriculum for the university training programme contained in article 38 of Legislative Decree (D.Lgs) 81/2008]

A document by the B. Ramazzini College of University Teachers of Occupational Medicine of the Italian Society of Occupational Health and Industrial Hygiene (S.I.M.L.I.I). The aim of this document was to compare the professional competence, training profile and core curricula of the three main specialization courses in the Public Health postgraduate medical area, i.e., Occupational Medicine, Hygiene and Preventive Medicine, and Forensic Medicine, such as contained in the Ministerial Decree (D.M) of 1 August 2005. We set out to identify, using clear and objective criteria, the knowledge and skills that specialists in Hygiene or Forensic Medicine must develop, in accordance with Art. 38 of the new Italian law on safety ahd health at work (D.Lgs 81/2008), in order to be authorized to perform occupational health activities as "Competent Physicians" (CP). The comparison revealed significant differences in structure and content among the three courses. In particular, compared to the course in Occupational Medicine, the courses in Hygiene and in Forensic Medicine both lack clinical training, including diagnostic and therapeutic skills, risk-oriented occupational health activities, biological monitoring, assessment of individual susceptibility, and clinical or instrumental procedures to prevent and detect occupational diseases. Furthermore, the specialization course in Hygiene lacks any training regarding the criteria and methods for assessing the individual worker's fitness for work, while the course in Forensic Medicine lacks any training in occupational risk assessment and management. From this comparison, a list was derived of the education and training debits that specialists in Hygiene or Forensic Medicine should cover (credits) in order to be authorized to perform CP activities as indicated by the new law. A core curriculum is proposed here, based on the corresponding credits, for use as a reference.

Reference values of urinary trans,trans-muconic acid: Italian Multicentric Study

This article reports the results of a study, conducted in the framework of the scientific activities of the Italian Society for Reference Values, aimed at defining reference values of urinary trans,trans-muconic acid (t,t-MA) in the general population not occupationally exposed to benzene. t,t-MA concentrations detected in 376 subjects of the resident population in three areas of Italy, two in central (Florence and southern Tuscany) and one in northern Italy (Padua), by three laboratories, compared by repeated interlaboratory controls, showed an interval of 14.4-225.0 microg/L (5th-95th percentile) and a geometric mean of 52.5 microg/L. The concentrations measured were influenced by tobacco smoking in a statistically significant way: Geometric mean concentrations were 44.8 microg/L and 76.1 microg/Ll in nonsmokers (264 subjects) and smokers (112 subjects), respectively. In the nonsmoking population, a significant influence of gender was found when concentrations were corrected for urinary creatinine, geometric mean concentrations being 36.7 microg/g creatinine in males (128 subjects) and 44.7 microg/g creatinine in females (136 subjects). The place of residence of subjects did not seem to influence urinary excretion of the metabolite, although personal inhalation exposure to benzene over a 24-h period showed slightly higher concentrations in Padua and Florence (geometric means of 6.5 microg/m(3) and 6.6 microg/m(3), respectively) than in southern Tuscany (geometric mean of 3.9 microg/m(3)). Concentration of t,t-MA in urine samples collected at the end of personal air sampling showed little relationship to personal inhalation exposure to benzene, confirming the importance of other factors in determining excretion of t,t-MA when concentrations in personal air samples are very low.

[Occupational health and safety management systems: scenarios and perspectives for occupational physicians]

This paper analyzes the role of the occupational physicians, taking into account the new Italian legislation within the frame of CSR, that puts in a new light the physicians inside the Organizations. In this context, Occupational Medicine and Workplace Health Promotion play a central role in most of the items of the Occupational Health and safety management systems, from H&S politics to training, from First Aid to audit and revision systems. From this innovative perspective, the authors try to identify the occupational physician's new challenges and opportunities.

Occupational exposure to electromagnetic fields in physiotherapy departments

To assess occupational exposure to electromagnetic fields, 11 microwave (MW), 4 short-wave diathermy and 15 magneto therapy devices were analysed in eight physiotherapy departments. Measurements taken at consoles and environmental mapping showed values above European Directive 2004/40/EC and ACGIH exposure limits at approximately 50 cm from MW applicators (2.45 GHz) and above the Directive magnetic field limit near the diathermy unit (27.12 MHz). Levels in front of MW therapy applicators decreased rapidly with distance and reduction in power; this may not always occur in work environments where nearby metal structures (chairs, couches, etc.) may reflect or perturb electromagnetic fields. Large differences in stray field intensities were found for various MW applicators. Measurements of power density strength around MW electrodes confirmed radiation fields between 30 degrees and 150 degrees , with a peak at 90 degrees , in front of the cylindrical applicator and maximum values between 30 degrees and 150 degrees over the whole range of 180 degrees for the rectangular parabolic applicator. Our results reveal that although most areas show substantially low levels of occupational exposure to electromagnetic fields in physiotherapy units, certain cases of over-occupational exposure limits do exist.

[Evaluating patients manual handling hazards in nursing personnel of a hospital]

Low back pain (LBP) and shoulder and arm disorders are common among workers exposed to risk due to manual weight lifting, and this health care problem is also very costly. We also know that nursing personnel exposed to manual patient handling activity report high number of work-related musculoskeletal disorders. The objective of our study was to evaluate the relationships between work and musculoskeletal disorders in personnel exposed to manual patient handling activity. 160 health care workers of an hospice exposed to patient handling were compared to a control group of 172 people not exposed to the handling risk. In our study we considered only subject with pathology already diagnosed, withdrawing people with disturbs but without clinical trials. The statistical evaluation using the chi2 test has not shown any meaning in the comparison between the two groups, we have calculated the Odds Ratio risk for discal hernia and protrusion finding a risk between low and modest (1.52). We think that the least prevalence of musculoskeletal disorders to the back in the group exposed to manual patient handling activity, could be explained partly with the "healthy worker" effect and partly with the workplace improvement. That is demonstrated also with the M.A.P.O. index scoring between 0 and 1.5 (negligible risk).

[Influence of cigarette smoking on the excretion of urinary benzene in filling-station attendants]

The influence of cigarette smoking on concentrations of urinary benzene, a sensitive and specific biomarker proposed for biological monitoring of exposure to very low doses of benzene, was investigated in 24 filling-station attendants and 31 workers non occupationally exposed to benzene. Environmental monitoring was performed by personal passive samplers "Radiello", and a spot urine sample was collected at the end of the work shift, from all subjects, for the determination of urinary benzene. Exposure to benzene resulted significantly higher in filling-station attendants (mean 23.3 +/- 17.0 microg/m3; range 4.5-66.3 microg/m3) than in controls (mean 4.6 +/- 2.6 microg/m3; range < 3-11.5 microg/m3), while concentrations of urinary benzene did not show any significant difference between the two groups. Considering all subjects as a single group, it was observed that urinary benzene concentrations were positively correlated with the number of cigarettes smoked during the sampling time (rho = 0.38; p = 0.047) and with airborne benzene levels (rho = 0.32; p = 0.019), and negatively correlated with the time elapsed between the last smoked cigarette and urine collecting (rho = -0.40; p = 0.045). Multiple regression analysis confirmed the influence of cigarette smoking on urinary benzene concentrations. In conclusion, our study showed the validity of urinary benzene as a biomarker for biological monitoring of exposure to very low doses of benzene, although cigarette smoking determined a prevalent etiological role at the low environmental benzene concentrations observed.

[Characterization of airborne particles and exposure assessment]

The Authors draw the attention on the critical topics of the occupational exposure assessment according to the criteria of the UNI EN 689/1997: air sampling strategy to characterize spatial and time variability of pollutant concentrations. They present a preliminary scheme to identify the sources and the chemical agents in the workplace and lead into discussion of critical topics on sampling strategy, instruments and analysis for the measurement, the particle size distribution and the chemical characterization of inorganic particles (silica, ultrafine particles), organic (wood dusts) and fibers (asbestos, synthetic fibres).

[Tannin and gallic acid as marker of exposure to hardwood dust]

The total tannin concentration was determined, using two different SPF methods, in 35 dust powdered wood species, both hard and softwood. Using direct reading-method (280 nm) the concentration varied from 2485 mg/g for Swedish pine to 35,843 mg/g for European oak (quercus robur, hardwood). The data obtained with the second method (Folin-Chocalteau) were well correlated (y = 0.9885x + 4.3373; r = 0.84; n=35) with the data obtained with the first method. The measured concentrations are usually higher in hardwood than softwood tested. Finally, a simple HPLC-DAD method was tested for gallic acid (GA), recently proposed as a marker for oak dust.

[Validation of PM10 and PM2.5 personal samplers: comparison between PEM and CEN-ARPAV selectors]

In order to validate specific personal selectors for the collection of fine particles, 65 double measurements of PM10 and PM2.5 were carried out at the same collection site; thus allowing a comparison between two different methods of sampling. The first method was that normally used by ARPAV in order to sample the above-mentioned granulometric fractions in outdoor environment. The second method was chosen by us for personal sampling (PEM working at 2 l/min and at 4 l/min). In both cases the filters gravimetric analysis conformed to the expectations of D.M. 60 of 2/4/2002. The comparison between the two methods showed a good correlation in both the granulometric fractions: correlation coefficients r for the PM2.5 are equal to 0.96 and 0.99 for the PEM working at 2 l/min and at 4 l/min respectively; r for the PM10 are equal to 0.98 and 0.99 for the PEM working at 2 l/min and at 4 l/min respectively. The analysis of results in terms of fine particles concentration and difference between methods against their mean, shows a slight overestimate of the particles concentration with PEM working at 2 l/min, compared to those working at 4 l/min. Nevertheless, considering the good results obtained even with a flow of 2 l/min, we believe that using PEM working at 2 l/min to monitoring 24 hours-personal exposure assures an improved capacity in the battery-operated pumps.

[New biomarkers of exposure]

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

[Implementation of parliamentary act D. Lgs 25/02 and definition of "moderate risk"]

This paper describes the position of the Joint Working Group of the Italian Association of Industrial Hygienists (AIDII), the Italian Society of Occupational Health and Industrial Hygiene (SIMLII) and the Italian Society of Toxicology (SITOX) on "Analysis of Parliamentary Act D.Lgs 25/02 and role of the Scientific Societies in the definition of Limit Values". The positive aspects of the new law which implements the European Directive 98/24 are discussed, including the abolition of the rigid periodicity of medical examinations as stated by the old rule D.P.R. 303/56. The Authors also address various parts of the law which appear to be unclear and controversial and highlight the expected difficulties arising for the employers and the safety and health professionals during the application of this new piece of legislation. Moreover, a number of discrepancies are noted between the new Italian law and the original Directive or other current Italian rules such as i. the translation of the term "slight risk", as from the original Directive, into "moderate risk", and the resulting non compulsoriness of health surveillance and biological monitoring of the workers in presence of a "moderate risk", ii. the concurrent exclusion, under the same circumstances, of the occupational physician from risk assessment procedures and iii. the upward modification of the previously established (D.Lgs 277/91) occupational exposure limits for lead. Moreover, the Authors examine and criticize--both in semantic and in toxicological terms--a recent proposal for the definition of "moderate risk" made by an ad hoc Consulting Committee of the Labour Ministry, in which the term "moderate" has been interpreted either as "low" or as "irrelevant for health effects", clearly two very different meanings. Besides, it would be inappropriate to define the conditions of a moderate risk based only on the level of exposure to the chemical (expressed as a fraction of the corresponding limit value), without considering the two other components of risk assessment for that chemical (hazard and susceptibility). Even worse would be the use of simplified models based on "algorithms", which might be useful in a preliminary phase of risk assessment, but easily could lead to an under- or over-estimation of risk, particularly when used by non professionals. In conclusion, the Working Group recommend that the new law be amended in order to clarify its most controversial aspects, whose misinterpretation could severely jeopardize the protection of the workers' safety and health at work.

[Devices for the reduction of N2O pollution during conscious sedation in dentistry]

We considered data of environmental monitoring during three working days in a dentist's office who habitually employs nitrous oxide (N2O): conscious sedation is used to alleviate anxiety and to diminish or eliminate dental pain. Three different nose masks were tested to determine influence on environmental pollution by N2O. The study shows that the levels of N2O always remains low with the use of proper dental procedures, although the chose of the type of nose mask can further diminish air pollution and the exposure of dental personnel.

[Reference values of solvents and metabolites in biological samples]

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.

[Diseases in hospital workers]

Occupational diseases and labour accidents in health care workers (Azienda Ospedaliera di Padova) were evaluated from 1990 to 2000; the information collected is compared with the same data of Regione Veneto and INAIL. 262 occupational diseases were found; nurses are more affected than other health care workers. In both reports (Azienda Ospedaliera di Padova and Osservatorio epidemiologico della Regione Veneto) half of the occupational diseases and injuries are represented by allergic disease. Low back pain is also equally represented in Azienda Ospedaliera and in Osservatorio epidemiologico results (5.3% and 6.6% respectively). Among the labour accidents reported to INAIL from 1994 to 2000, 25% of them were represented by falls and slips, 23% by car accidents, 17% were caused by tools, 17% by movement of goods and persons, 8% by contact with splinters, liquids, dusts, 5% by assaults and 5% by contact with blood or body fluid. The latter result is widely underestimated in the INAIL report, because these events usually produce a temporary inability of less than 3 days; in fact, they represent more than half of the labour accidents treated at the Azienda Ospedaliera di Padova. Medical surveillance (in exposure to aldehydes, anaesthetic gases, chemioterapic drugs) has shown many other occupational health problems that often need specific structural intervention (restructuration and restoration of workplaces in health care environments), and work organization changes.

[Occupational exposure to electromagnetic fields in physiotherapy departments]

An assessment of the electromagnetic fields emitted from short and ultrashort wave diathermy sources and from magneto therapy operating at a frequency of 50 Hz was made to evaluate the occupational exposure to the operators. Operators were exposed to electromagnetic fields which rarely exceed the recommended limits of International Commission on Non-Ionizing Radiation Protection (ICNIRP) and American Conference of Governmental Industrial Hygienists (ACGIH). Only a measurement of electromagnetic fields near short wave diathermy equipment operating at a frequency of 27.12 MHz exposed operators to levels above those recommended by ICNIRP at a distance of 1 metre. Magnetic fields of magneto therapy exceeded residential exposition of 1 microtesla, at a distance of 4 metres.

[Occupational exposure to anesthetic gases at several hospitals]

We considered data of samples collected in the period 1994-2001 in 83 operating rooms of 13 different public and private hospitals in Veneto Region. The anaestetic gases more used in operating rooms were nitrous oxide, isoflurane and, more recently, sevflurane. The mostly polluted positions were those in proximity of anaesthesiologic devices; the gases average concentrations were low in all hospitals examined, although some operating rooms demonstrated concentrations of anasthetic gases exceeding limit values. Lastly, the professional figures had different exposure to the various anaesthetic gases.

[Evaluation of the effects following low doses of inorganic mercury from environmental and occupational exposures]

AIMS

This paper reviews the studies, both in vivo and in vitro, carried out for the project on low-dose effects of inorganic mercury, financed by the Italian Ministry of Universities and Scientific and Technological Research.

RESULTS, COMMENTS AND PROPOSAL

The results offer both innovative aspects and potential practical applications. Particular attention is drawn to the reliability of biomarkers of exposure [mercury in urine (HgU) and blood (HgB), possibility of speciation] as well as to the availability of guidance values for risk assessment (reference value, action level, biological threshold value). In the general population, HgU and HgB levels are significantly related to the presence of dental amalgams and to fish consumption; nevertheless, such exposure levels do not elicit adverse health effects on renal, immune and nervous functions, according to the markers evaluated in the studies. The present biological threshold values for occupational exposure appear adequate to prevent health effects, considering the immune system, kidney and central nervous system as the target organs. However, possible effects of low doses of mercury on immune and neuroendocrine functions should be further examined; moreover, consideration should be given to the risk of consuming fish species with high Hg content, particularly concerning the renal and central nervous system effects. Finally, further studies should be planned on other potentially important effects, that could not be considered in this study, such as those on prenatal development, the cardiovascular system and the thyroid gland.

Adjustment to concentration-dilution of spot urine samples: correlation between specific gravity and creatinine

OBJECTIVE

Spot urine samples were investigated to determine correlations between urinary creatinine and specific gravity, and intra- and inter-day variations other than gender- and age-dependence of urinary concentrations.

METHODS

Urinary creatinine concentrations and specific gravity were determined in 534 spot samples (385 from men and 149 from women). Subjects' ages ranged between 18 and 68 years. Spot urine samples were also collected from 14 male subjects before and after a 1-week work-shift for the evaluation of intra- and inter-day variations of creatinine and specific gravity.

RESULTS

In spot samples, creatinine concentrations ranged between 0.16 and 4.36 g/l and specific gravity between 1.002 and 1.037. A high correlation (r = 0.82, P < 0.001) was observed between creatinine and specific gravity; male subjects showed significantly higher values of creatinine (P < 0.001) than did female subjects (1.90 +/- 0.74 and 1.41 +/- 0.72 g/l, respectively) and specific gravity (1.023 +/- 0.006 and 1.020 +/- 0.007, respectively). In addition, creatinine but not specific gravity significantly decreased (P < 0.02) in subjects older than 50 years, compared with those under 40.

CONCLUSIONS

Results confirm the gender-dependence of creatinine concentrations in spot specimens and also show age-dependence, indicating the need for these aspects to be considered when the range of acceptable samples is to be set. No significant intra- or inter-day variations were observed for the two parameters. Lastly, the possibility of a comparison of differently adjusted values was indicated by a conversion formula derived from adjustments to creatinine and the corresponding specific gravity of a hypothetical urinary value, as follows: specific gravity adjusted values = 1.48 x creatinine adjusted values.

[Organization of health and safety activities in health care centers]

The paper proposes a model for health and safety organization in health care units and hospitals which takes account of the risk assessment procedures required by law and the quality assessment of the measures thus taken. A redefinition is given of the role of Medical Director and of the functions, aims and standards on which health and safety service and the services of an authorized occupational health physicians must be based.

[Risk assessment in health care facilities]

Risk assessment in health care facilities. The risk assessment is an important procedure in occupational medicine, also due to the international and domestic regulations and recommendations. In hospitals and other health care facilities too, the risk assessment could enable the identification of hazards, the characterization of risk and thus the programme of adequate preventive measures. In this paper some theoretical and methodological aspects of risk assessment practice and related documentation in health care facilities are focussed and the strict relation between preventive activities, quality system and accreditation standards for hospitals and other health services is finally discussed.

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS AND DISCUSSION

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

[Urban air pollutant exposure among traffic policemen]

Exposure to dusts and benzene was studied in 65 traffic policemen. Samples of total dusts showed that mean personal exposure was 0.44 (SD = 0.30) mg/m3, with peaks of about 2 mg/m3. Exposure to 1-nitropyrene (1-NP), the main compound occurring in emissions from diesel engines, which was estimated from concentrations in dusts collected with high-flow samplers, was 0.28 (SD = 0.19) ng/m3 (range: 0.06-1.24 ng/m3). The mean concentration of benzene in the breathing zone was 41 (SD = 20) micrograms/m3, although a level of 100 micrograms/m3 was slightly exceeded in one subject. In urine samples collected before and after workshifts, two biological indicators of exposure to benzene were measured, urinary benzene and urinary trans, trans-muconic acid (MA). The mean values of urinary benzene before and after workshift were similar (98, SD = 81 and 83, SD = 55 ng/l; n = 63; Wilcoxon's T-test = not significant), while a moderate increase in the metabolite was observed (MA = 0.08, SD = 0.11; 0.11, SD = 0.09 mg/g creatinine, in pre- and post-shift samples respectively; Wilcoxon's T-test, z = 3.00; p < 0.01). The levels of exposure to dusts and 1-NP deriving from diesel engine emissions were comparable to those of other occupational groups with this type of risk (garage mechanics, workers operating diesel engine machinery, etc.). Traffic police exposure to benzene was similar to that of the whole population of Padova (40 micrograms/m3, mean annual 24-hour value). However, the values of urinary MA, like those reported by other authors for non-smoker controls, increased after the workshift, indicating low occupational exposure to this pollutant. It should be noted that traffic police exposure to benzene is much lower than that of other occupational categories, e.g., fuel pump distributors.

Otoneurological study in workers exposed to styrene in the fiberglass industry

Twenty workers exposed to styrene and acetone in small fiberglass factories were monitored for 8 h using passive dosimeters. Urine samples were collected at the end of the workshift and before the start of work on the next morning. The 8-h time-weighted average exposure values for styrene and acetone ranged from 14 to 416 mg/m3 and from 70 to 277 mg/m3, respectively. The sum of styrene metabolites, mandelic acid and phenylglyoxylic acid (MA + PGA), in the next-morning urine samples ranged from 81 to 943 mg/g creatinine. Different test sensitivity was identified in the otoneurological battery: it was low for audiometric tests and ABR, and relatively high for vestibular tests. The vestibular system seems partially sensitive to the toxic effects of styrene in the absence of clinical signs and symptoms. The actual exposure levels for styrene cannot be considered devoid of functional subclinical consequences.

High-performance liquid chromatographic determination of urinary 2,5-hexanedione as mono-2,4-dinitrophenylhydrazone using ultraviolet detection

The good correlation between exposure to n-hexane and 2,5-hexanedione urinary excretion confers on this diketone an important toxicological meaning. this paper proposes a reversed-phase HPLC method which includes, after acid hydrolysis, a derivatization step of 2,5-hexanedione with 2,4-dinitrophenylhydrazine at 70 degrees C for 20 min. The reaction conditions, such as temperature, reagent concentration and time, are optimized so as to allow the condensation of a single carbonyl group. A linear response was obtained in the 0.19-20.0 mg/l range with a detection limit of 0.03 mg/l, corresponding to a signal-to-noise ratio of 3. A phosphate buffer (pH 3.3)-acetonitrile mixture (50:50) as the eluent and UV detection at 334 nm were used.

[Exposure to glues containing technical heptane: a clinical and electrophysiological study]

Polyneuropathy caused by n-hexane contained in glues was, until recently, the typical occupational disease of shoemakers. Glues no longer contain large concentrations of this solvent, and in some cases, it as been completely replaced by other hydrocarbons. The authors investigated the health status in a group of shoemakers using glues containing 35% technical heptane. The same glue, not containing n-hexane, was used by a shoemaker who worked at home; she developed an otherwise unexplainable peripheral polyneuropathy. For each of the 16 subjects, the following procedures were carried out: environmental sampling, biological monitoring for Mek and heptane metabolites, a neurological and electromyographic examination. No neurological abnormalities were found in the workers that could be attributable to occupational exposure, probably due to the low level environmental contamination (< 100 mg/m3 n-heptane) found in the 7 factories and workshops studied where acceptable hygiene conditions existed. The time course and ratio of urinary metabolites of heptane were also studied, the latter showing a predominance of 2- and 3- heptanol in the initial phase and 2-5 heptandione at the end of the work week; probably, the presence of other solvents, such as Mek, can modify the ratio of metabolites and consequently the formation of neurotoxic compounds could result.

Does n-heptane cause peripheral neurotoxicity? A case report in a shoemaker

Subjective and electrophysiological signs relating to the central and peripheral nervous systems developed in a shoemaker, a few months after beginning work at home. Signs of central nervous system involvement rapidly disappeared after the end of the exposure, whereas those of mild peripheral neuropathy lasted for several months. The glue used contained a variety of solvents including ethylacetate, cyclohexane, methylcyclohexane, methylethylketone and others; n-hexane was not detected, whereas, unusually, n-heptane was. This exposure was reproduced experimentally in the same work room and the solvent air level did not exceed the American Conference of Governmental Industrial Hygienists threshold values. A tentative conclusion is that the toxic effects on the peripheral nerve are likely to be due to n-heptane.

[Interference of acetone in styrene metabolism in subjects exposed to both solvents]

Thirty-seven workers exposed to styrene and acetone in fiberglass industry were monitored on Monday and Thursday for 8 hours (two subsequent samplings of 4 hours each) using passive dosimeters (mod. TK200). The charcoal disks of the passive dosimeters were analysed by gas-chromatography. Urine samples were collected at the end of the workshift and before the start of the workshift the next morning (Tuesday and Friday). Mandelic acid (MA) and phenylglyoxylic acid (PGA) were measured in the urine, using a HPLC method; values were expressed in mg/g of creatinine. The 8-h TWA exposure values ranged from 10 to 522 and 13 to 1581 mg/m3 on Monday and 8 to 423 and 10 to 579 mg/m3 on Thursday for styrene and acetone, respectively. Styrene TWA exposure values significantly correlated with the sum of metabolites at the end of workday (r = 0.72 on Monday and r = 0.91 on Thursday) and also the next morning (r = 0.88 on Tuesday and r = 0.85 on Friday). A calculated styrene exposure level of 213 mg/m3 (ACGIH-TLV) was associated with an excretion of metabolites (MA+PGA) higher on Thursday (814 mg/g creat.) than on Monday (600 mg/g creat.). The same observation was made on Friday (409 mg/g creat.) as compared with Tuesday (302 mg/g creat.). In conclusion, the TLV of styrene was associated with different values of metabolites at the beginning and at the end of the work-week. Moreover our data show that the simultaneous exposure to acetone does not modify the excretion of MA.

Biological monitoring of workers exposed to styrene and acetone

Twenty-two workers exposed to styrene and acetone in two fiberglass industries were monitored on Monday and Thursday for 8 hours using passive dosimeters. Urine samples were collected at the end of the workshift and before the start of the work on the next morning (Tuesday and Friday). The charcoal disks of the passive dosimeters were analysed by gas-chromatography. Mandelic acid (MA) and phenylglyoxylic acid (PGA) were measured using a HPLC method; values were expressed in mg/g of creatinine. The 8-h TWA exposure values for styrene and acetone ranged respectively from 22 to 522 mg/m3 and 40-1581 mg/m3 on Monday; 25-423 mg/m3 and 55-579 mg/m3 on Thursday. Styrene TWA exposure values significantly correlate with the sum of metabolites at the end of workday (r = 0.70 on Monday and r = 0.95 on Thursday) and also at the next morning (r = 0.86 on Tuesday and r = 0.85 on Friday). A styrene exposure level of 213 mg/m3 (ACGIH-TLV) was associated with an excretion of metabolites (MA+PGA) higher on Thursday (803 mg/g creat) than on Monday (570 mg/g creat). The same result was found on Friday (459 mg/g creat) compared with Tuesday (305 mg/g creat). Moreover our data show that the simultaneous exposure to acetone does not modify the excretion of MA. In conclusion the TLV of styrene is associated with different values of metabolites at the beginning and at the end of the work-week.