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Objectives: Sevoflurane is an inhalation halogenated anaesthetic widely used in day and paediatric surgery. We were interested in evaluating biological markers of exposure to sevoflurane, which should improve the health surveillance of occupationally exposed personnel., Methods: A group of 36 subjects (13 male, 23 female) occupationally exposed to volatile anaesthetics in paediatric operating rooms was studied in a 2-week survey. Post-shift urine samples and specimens from passive samplers (for personal monitoring) were collected after 1.75-6 h morning exposure and analysed by headspace gas chromatography-mass spectrometry (GC-MS). Multiple determinations were assumed as independent values (in total, n = 78: 24 from men, 54 from women; 25 from smokers, 53 from non-smokers)., Results: Median sevoflurane external values were 0.13 parts per million (ppm) (range 0.03-18.82) (n = 78), urinary sevoflurane 0.6 microg/l urine (ND-18.5)(n = 76) and total urinary hexafluoro-isopropanol (HFIP) 0.49 mg/l urine (ND-6833.4) (n = 75). A lower limit of detection (LOD) was achieved for urinary sevoflurane (0.03 microg/l urine), allowing quantitation of all but one of the samples; >25% of urine samples were unquantifiable by HFIP and were assigned a value equal to half the LOD of 0.10 mg/l(urine). Urinary sevoflurane correlated well with breathing-zone data (r2 = 0.697 at log-log linear regression), whereas total urinary HFIP (r2 = 0.562 at log-log linear regression) seemed to be better described by a three-parameter logistic function and appeared to be influenced by smoking habits. Biological indices corresponding to National Institute for Occupational Safety and Health (NIOSH) exposure limits, calculated as means of linear regression slope and y intercept, were 3.9 mug/l(urine) and 1.4 microg/l urine for sevoflurane (corresponding to 2 ppm and 0.5 ppm, respectively), and 2.66 mg/l urine and 0.82 mg/l urine for HFIP., Conclusions: On the basis of our data, urinary unmodified, sevoflurane seems to be a more sensitive and reliable biomarker of short-term exposure to sevoflurane with respect to total urinary metabolite HFIP, which appears to be influenced by physiological and/or genetic individual traits, and seems to provide an estimate of integrated exposure.

To increase sample throughput for GC analysis of inhalation anaesthetics without affecting the separation of nitrous oxide (N2O) and halogenated anaesthetics (sevoflurane, isoflurane and halothane), we explored the effectiveness of a tailor-shortened (12 m) PlotQ capillary column and developed a high-speed version of a previously reported GC technique (involving chromatographic separation of analytes using a GC-MS system, coupled with a selected ion monitoring (SIM) method to increase sensitivity). Efficient separation and repeatable results were achieved at a reduced runtime of approximately 7 min (versus 18 min with the original method) at a carrier gas flow of 1.5 ml/min. This approach should more than double the previous throughput.

Unmodified sevoflurane and its metabolite, hexafluoroisopropanol (HFIP), have both been proposed as biomarkers of exposure in post-shift urine for operating room personnel exposed to inhalation anaesthetic sevoflurane. We used headspace sorptive extraction (HSSE) and thermal desorption-capillary GC-MS to assess sensitively both compounds in the urine matrix (after a HFIP deconjugation step). In GC-MS splitless mode, calibration plots (approximately 15-650 microg/L) were linear (r2 > 0.9910) and the limits of detection (1 microg/L for both biomarkers) showed increased sensitivity for HFIP with respect to the previously described headspace GC-MS method. The method was suitable for biological monitoring of both biomarkers of exposure to sevoflurane.

Objective: Information is required on levels of agreement between different sets of median nerve conduction studies (NCS) and symptoms of carpal tunnel syndrome (CTS) in at-risk subjects., Methods: We performed a reanalysis of an extensive data set from a population of 114 "highly exposed" meat workers (without prior diagnosis of CTS), who were interviewed for the presence of current symptoms typical of CTS and systematically submitted to median NCS., Results: Agreement between presence/absence of symptoms and NCS normal/abnormal findings ranged from 81% for wrist sensory latency (WSL) to 49% for motor conduction velocity wrist-to-palm (MCV-WP) in the nondominant hands (from 60% to 50%, respectively, in the dominant hands). Mean values of WSL, sensory conduction velocity-WP (SCV-WP), wrist motor latency, MCV-WP, and the SCV-WP/SCV-elbow-to-wrist ratio all showed significant differences between symptomatic and asymptomatic workers. In nondominant hands, these parameters all reached significant P values at chi-squared tests for kappa coefficients of agreement, the best kappa coefficients being 0.57 for WSL and 0.40 for SCV-WP. However, in the dominant hand only SCV-WP reached significance (kappa coefficient=0.20)., Conclusions: Given the importance of the dominant hand in working populations, these data support use of SCV-WP (or WSL) as an informative NCS parameter for occupational studies on CTS.

Objectives: To investigate whether healthcare workers routinely exposed to low-level ionizing radiation have a higher prevalence of thyroid nodularity., Methods: Presence of thyroid nodularity, as assessed by 10-MHz neck ultrasonography, was compared with accumulated radiation doses of 579 exposed university hospital workers (M:F 350:229) obliged to wear a personal dosimeter., Results: Nodules were detected in 141/579 (24.3%) subjects. Mean accumulated dose was not different among subjects with and without nodules (14.19+/-28.00 mSv vs 17.71+/-32.89 mSv; P=0.12). Duration of occupational exposure (<10 years vs 10-19 years vs >or=20 years) did not affect prevalence of nodularity. At multivariate analysis, only female gender and age were significant risk factors., Conclusions: Mildly exposed health workers do not appear to incur any excess risk of thyroid nodularity.

Objectives: Assessment of individual exposures to sevoflurane plus nitrous oxide (N(2)O) by biological monitoring of unmodified analytes in post-shift urine of exposed personnel., Methods: Anaesthetics in urine and breathing area were monitored in 124 subjects in 11 operating theatres. Passive samplers were collected after 2.5-7 h of exposure, at the same time as post-shift urinary samples, to evaluate the individual time-weighted average (TWA) exposures to sevoflurane and N(2)O. A static headspace sampler coupled with a gas chromatograph mass spectrometer was used for analytical determinations (sensitivity sufficient to reveal biological/environmental exposures of 0.1 microg/l(urine) and 50 ppb for sevoflurane, and 1 microg/l(urine) and 80 ppb for N(2)O)., Results: Median (range) post-shift urinary and environmental values were 1.2 microg/l(urine) (0.1-5.0) and 0.4 ppm (0.05-3.0) for sevoflurane ( n=107) and 10.9 microg/l(urine) (0.5-74.9) and 8.6 ppm (0.2-123.4) for N(2)O ( n=121) (all low-exposure range). At log-log regression, urinary levels closely correlated with environmental data (sevoflurane, r(2)=0.7538; N(2)O, r(2)=0.8749). Biological equivalent limits (BELs) based on National Institute for Occupational Safety and Health (NIOSH) TWA exposure limits, calculated as means of regression slope and y-intercept, were 3.6 microg/l(urine) for sevoflurane (corresponding to 2 ppm) and 22.3 microg/l(urine) for N(2)O (corresponding to 25 ppm). Individual "mixture BELs", which we calculated by applying the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) mix formula to biomarker values and using the obtained NIOSH-based BELs as a reference, closely correlated with mixture TLVs (rho=0.816, Lin's concordance test). CONCLUSIONS. We propose urinary sevoflurane as a new, specific, internal dose biomarker for routine biological monitoring of personal exposures among operating-theatre personnel, and use of reliable "mixture BELs" to provide safer levels of internal exposure for workers exposed to mixtures of sevoflurane and N(2)O, and conceivably also to other mixtures of toxicants with possible additive effects.

Recently. we proposed the use of a run-only headspace-GC-MS method for the biological monitoring of ppb concentrations of unmodified volatile anaesthetics (isoflurane, sevoflurane and halothane, plus nitrous oxide) in post-shift urine of operating theatre personnel. The adoption of enflurane (a volatile anaesthetic no longer used in clinical practice) as a poper and viable internal standard improves intra-day and inter-day accuracy in halide quantitation, providing a GC-MS reference method useful in the practice of biomonitoring of exposure of operating theatre personnel to modern volatile anaesthetics (isoflurane. sevoflurane, halothane).

Benzene is a widespread pollutant of which the main source in the outside environment is automotive traffic. Benzene is also present in cigarette smoke, and small quantities exist in drinking water and food; all of these sources contribute to pollution of indoor environments. Benzene exposure may be studied with biologic indicators. In the present study, the authors evaluated whether differences in urinary concentrations of trans,transmuconic acid (t,t-MA) were detectable in a sample of 150 children and if the chemical was correlated with environmental exposures to low levels of benzene. The children attended primary schools that had significantly different-but low-environmental benzene levels. Analysis of urinary t,t-MA was achieved with high-performance liquid chromatography (photodiode array detector), and analysis of passive air samplers for benzene was performed with gas chromatography-mass spectrometry. Statistical analysis (Kruskal-Wallis test) indicated that differences in urinary levels of t,t-MA in children from urban and rural areas were not statistically significant (p = .07), nor were there significant differences between children with and without relatives who smoked (p = .69). As has been shown in other studies of children and adults, results of our study evidenced (1) the difficulty of correlating concentrations of urinary biomarkers with environmental exposure to benzene at a parts-per-billion level (i.e., traffic and environmental tobacco smoke) and, consequently, (2) the lack of specificity of t,t-MA as a biological indicator for the study of a population's exposure.

Background: Bakers' allergic diseases are a well known occurrence. Wheat flour is the most important allergen responsible for rhinoconjunctivitis and IgE mediated asthma. The good correlation between atopy, wheat flour sensitization and allergic diseases is also well known. In a previous study we described the results concerning sensitivity to wheat flour in a group of 300 bakers, followed up for 8 years. In this study we showed that the same subjects who were sensitive to wheat flour had no symptoms., Aim: The aim of this study was to carry out the metacholine test for bronchial hyperreactivity in a group of 14 bakers selected from the group of 300 previously studied., Methods: The subjects underwent: pulmonary function test, IgE test, skin prick test with grass pollen, Dermatophagoides farinae, Dermatophagoides pteronissinus, wheat flour, and the metacholine test., Results: The results of the metacholine test showed only one positive case in a subject with positive skin prick test. This agreed with the assumptions of our previous study that showed a sensitization (10%) to wheat flour but a low prevalence of allergic symptoms., Conclusions: Limited to the subjects studied, the results indicate an absence of a relationship between positive prick tests and aspecific bronchial hyperreactivity. Recent research that suggest a probable different genetic control of atopy, bronchial hyperreactivity and asthma is discussed. In our opinion effective primary and secondary prevention could account for this absence of relationship.

Benzene is a widespread pollutant whose main source in the environment is automotive emission. There is increasing interest in the exposure of the population to this pollutant as benzene is present also in the indoor environment due to cigarette smoke, drinking water, and food. The aim of this study was to evaluate, in an adult nonsmoking population not occupationally exposed to benzene, whether it is possible to detect differences in the urinary concentration of trans,trans-muconic acid (t,t-MA) between low and high environmental exposure to benzene. A study sample of 31 employees working in pharmacies in a large town in Italy with low environmental exposure to benzene (4.8 microg/m3) was compared to a high (8.1 microg/m3) benzene exposure group. Analysis of urinary t,t-MA was carried out by high-performance liquid chromatography (HPLC; photodiode array detector); analysis of environmental benzene samples was by gas chromatography/mass spectroscopy (GC-MS). The statistical analysis revealed no significant differences in urinary levels of t,t-MA of subjects with high (mean concentration: 157.9 microg/g creatinine) versus low exposure (mean concentration: 114.2 microg/g creatinine). Data show that it is difficult to correlate urinary t,t-MA with benzene exposure at parts per billion levels.

In two previous papers we reported allergic diseases in workers employed in breeding insects for biological pest control. It was found that Ephestia kuehniella, Orius laevigatus and other insects caused allergic rhinoconjunctivitis and asthma. The aim of this new study was to assess the relationship between the implementation of the recommended preventive measures and the decrease in sensitization in exposed workers. We performed a four-year follow-up of exposed workers, using the prick test and RAST with specific allergens and pulmonary function test at the end of the work shift. The results showed a decrease in skin test sensitization for Orius and Ephestia, a decrease in allergic diseases in the previously studied workers, and no symptoms in recently employed workers. These results confirm the validity of the recommended preventive measures: semi-closed cycles, gloves, protective masks, overalls and sunglasses.

The aim of this study was to propose a protocol for assessment of markers of infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) in exposed health care professionals and to define criteria for evaluation of fitness for the job of the infected personnel. The study comprised 800 persons involved in operative procedures, including 414 surgeons, 275 nurses, and 111 anaesthetists. A graduated protocol was created for monitoring markers of HBV and HCV infection. A well-defined combination of markers of antigen-antibody systems enabled identification of four groups of persons with HBV infection differing in fitness for work: 1) HBsAg-positive, HBeAg-positive, HBV DNA-positive; 2) HBsAg-positive, anti-HBe-positive, HBV DNA-positive; 3) HBsAg-positive, anti-HBe-positive, HBV DNA-negative; and 4) anti-HBs-positive, anti-HBc-positive, anti-HBe-positive group. For HCV infection, two groups with different job fitness were identified: 1) anti-HCV-positive, HCV RNA-negative and 2) anti-HCV-positive, HCV RNA-positive. Screening of hospital personnel at risk to HBV and HCV infection requires a well-defined protocol which may help to evaluate the fitness of the infected personnel for a specific job.

This study would examine the efficiency of different diagnostic tools, imaging and functional, in the study of pulmonary system of workers exposed to silicotigen dusts. 24 male miners were examined with chest H.R.T.C., spirometry with study of DLCO and of total lung capacity. 13 of 24 miners were submitted to pulmonary ventilatory scintigraphy (99mTcDTPA). All 24 miners were previously yet submitted to two follow-up by means of chest radiography in conformity with ILO guidelines. The chest radiography, even evaluated in conformity with ILO guidelines, is subject to remarkable differences when performed and reported by different operator. Useful data are provided by functional studies. H.R.T.C. is necessary to evaluate the degree of parenchymal involvement and for medicolegal porpoises. Scintigraphy with 99mTc DTPA need of further studies in the evaluation of exposure to silicotigen dusts.

Normal flexion of the fingers involves an involuntary contraction of the pronator and lumbrical muscle. In individuals whose profession involves constant flexing of the fingers those muscles become hypertrophied, impinging on the carpal tunnel. The narrowing of the carpal tunnel yields well to ultrasonography. The objective of this investigation was to find an ultrasonographic index of occupational carpal tunnel syndrome. Thus "Index M" denotes the variation obtained in the "M Space" before and after flexion-extension of the fingers. The study included 45 subjects performing tasks which involved the risk of cumulative trauma disorders. The subjects were tested using the electromyography and ultrasonography. The method was based on relation between the decrease in conduction of the median nerve measured by electromyography and the ultrasonographically measured variation of "M Space" in terms of sensitivity and specificity. The sensitivity of ultrasonography was 85%, as it confirmed the pathologic findings determined by electromyography ("M Index" positive) in twenty-two out of 26 hands, but the specificity was not statistically significant. Ultrasonography seems to have found very important application as a screening technique in occupational medicine. It is non-invasive, sensitive, easily repeated, and costs little.

The aim of this study was to assess whether a sample of 37 anaesthetists occupationally exposed only to N2O showed any deterioration in vigilance and/or mood. The anaesthetists were examined with three neurobehavioural tests (Simple Reaction Time and Colour Word Vigilance to measure the vigilance and Mood Rating Scale to evaluate the level of stress and arousal) and underwent N2O biological monitoring (to correlate the test results with the N2O exposure) on the first and on the last day of the work week, before and after work in the operating room. No significant relationship was found between the biological monitoring and the test results. The only significant statistical difference was found between the beginning and the end of each workday in the arousal level, regardless of the result of the biological monitoring.

The articles describes a case of radial artery thrombosis by repeated microtrauma. It describes, by one side, the occupational history, the personal habits and the typical movement and condition of the hands while working, on the other, the clinical and diagnostic picture of radial artery thrombosis. Then it shows the correlation between occupational factors and radial artery thrombosis and so the occupational genesis (repetitive microtrauma) of the disease.

The authors illustrate the application possibilities in occupational and preventive medicine of a recently computerized system for the evaluation of peripheral ventilatory non-homogeneities with or without alveolar air trapping. The method consists of an improved individual multiple breath by breath test utilizing the analysis of the respiratory gases CO2 and He. It is based on the results of previous experimental measurements performed simultaneously in different pulmonary sectors an depends on the technical possibility of signalizing out-of-phase expired CO2-He mixtures at the end of the inert gas clearance when in subjects with peripheral respiratory disorders the two gases CO2 and He arrive at the mouth at different times, during the same expiration and cause different, opposite signals. The applied physiological reliability of the measurements was experimentally verified, their technical specificity was recently established. The use of a new computerized system allows actually automatic, on-line measurements under the control of the operator, following a standardized method. The resolution power of the signals is very high. The calculation of the results is performed by the software. The system is easy to transport and can be used in the field for screening on large groups of persons in preventive medicine inquiries and during occupational medicine checks. Quite recently it has been usefully employed during an investigation on 200 subjects, occupationally exposed (policemen of the city traffic department of the town of Bologna).

Some activities performed by healthcare workers may still involve total or partial exposure to ionising radiation exceeding the limit values. In addition to the appearance of crystalline lens opacities which may lead to rays-cataract, recent studies have indicated possible induction of ocular hypertonia in occupationally exposed subjects. The aim of this study was to establish the actual prevalence of ocular hypertonia and crystalline lens opacities in a group of healthcare workers exposed to ionising radiation. The collected data failed to show significant risk of ocular hypertonia and suggested that crystalline lens opacity was not an important indicator of exposure. Notwithstanding, preventive and periodic (every 5 years) ophthalmologic control may prove helpful for medicolegal purposes. Namely, such control would record congenital crystalline lens opacities in many individuals and would thus rule out unjustified claims of occupational disease due to exposure to ionising radiation. Additionally, ophthalmologic control should focus on different and probably more important ocular risks for the radiologists such as the ocular fatigue resulting from a prolonged use of a video display terminal or other diagnostic screens or electrodiaphanoscopes.

The aim of the study was to evaluate ultrasound technique in preemployment medical assessment of the risk for low-back pain. Volunteers for the study were recruited among agricultural workers employed in the "Agraria Department" of the University of Bologna, Italy. The group consisted of 90 subjects, 52 male and 38 female, aged 25 to 58 years. The subjects filled in a questionnaire on medical history of low-back pain and were examined using an ultrasonograph equipped with a high linear frequency probe (3.5 MHz). The oblique parasagittal diameter of the lumbar spinal canal was measured by transabdominal ultrasonic imaging in the lumbar (L4-L5) and lumbosacral (L5-S1) region. Individuals with significantly narrower canals (< 14 mm) had an increased risk of low-back pain. The paper concludes that ultrasound imaging could become a valuable screening tool in industry, permitting selective job placement for workers at high risk for disorders of the back.

The authors describe a clinical case of occupational asthma due to dioctyl-phthalate in a worker using a conveyor belt for bottle stoppers. The dioctyl-phthalate is used for the production of PVC and as a compound of many other substances. The literature describes many cases of occupational asthma do to phthalate anhydride but few cases do to dioctyl phthalate. The clinical history, the environmental monitoring data, the pulmonary function tests such as bronchodilatation test by salbutamol, peak flow meter daily monitoring for three weeks, and stop and start work test showed a good correlation with the work and the worker's asthma. The authors emphasize that a detailed clinical history and a careful analysis of the production cycle are very useful and, as simple and non invasive tests, can play an important role in the diagnosis of occupational asthma.

Carpal tunnel syndrome (CTS) is a syndrome whose diagnosis is well established. One cause could be occupational factors, while others have no relation to work or the work environment. We present in this article a case report regarding a worker affected by CTS, which is of interest concerning the sensitivity of ultrasonography and electroneurography, applied as diagnostic methods, related in our protocol to the variations in occupational exposures. The case reports an agricultural worker, whose tasks required repetitive and high frequency movements of the hand-arm. Diagnosis of CTS used ultrasonography and electroneurography techniques. In our opinion, the clinical evolution of CTS encompasses three "work-related" phases (preclinical phase; phase of nerve compression; phase of irreversible damage). Ultrasonography provides greater information about the evolution of CTS, as well as other cumulative trauma disorders, and is able to discern tendinitis of flexors causing a compression on the median nerve in the carpal tunnel.

Work-related upper limb disorders are one leading occupational diseases in many industrialized countries. The paper reviews the evidence of work-relatedness of the most common upper limb disorders (namely carpal tunnel syndrome, hand-wrist and shoulder tendinitis, trapezius myalgia, hand hammer syndrome). Attention is drawn to the difference in the number of reported cases in Italy and other countries, assuming, as an underlying cause, underreporting of such conditions in Italy.

A retrospective cohort mortality study was carried out in 20 industrial factories in the Local Health Unit Bologna Sud (Emilia Romagna, Italy), where different rubber and plastics products were manufactured. The cohort consisted of 925 subjects (578 males and 347 females) employed for at least six months continuously; follow-up was between the beginning of operation of each factory, ranging between mid fifties and mid seventies, and 31 December 1989. For those exposed more than one year cause specific Standardized Mortality Ratios (SMRs) were computed using regional rates for comparison, 90% confidence intervals (CI) were calculated assuming the Poisson distribution. Among the 748 subjects employed for more than one year (457 males and 291 females) there were no lost to follow-up, 54 individuals were dead (41 males and 13 females) and for three subjects the cause of death was unknown. The results showed that all causes mortality was above expectancy in the total cohort (SMR = 123; 54 Obs; 90% CI = 97-154), among males (SMR = 117; 41 Obs; 90% CI = 89-152) and females (SMR = 143; 13 Obs; 90% CI = 85-228). Increased mortality for all malignant tumours was observed in the total cohort (SMR = 150; 25 Obs; 90% CI = 104-209) and for both genders. All nine lung cancer cases were observed among males, the SMR was equal to 218 and was statistically significant; seven cases occurred at duration of exposure less than 10 years and six at latency up to 20 years. The interpretation in terms of causality of the present investigation is limited by the small number of observations and by exposure definition solely in terms of employment in the study factories; nonetheless the results are indicating the existence, in this group of rubber and plastics product makers, of an adverse health effect which deserve further investigation.

The authors described two cases of airborne contact dermatitis caused by 2-amino-2-methyl-1-propanol (AMP 100) in two subjects with periorbital erythema and itching skin. The AMP 100 has been used to replace ammonia as a hair dye component in the cosmetic industry with the purpose to eliminate its smell. Patch tests proved positive only to dilutions of 10% and 20% in the two described patients, as well as in other six asymptomatic subjects operating in the same working environment. The authors have diagnosed an irritative airborne contact dermatitis by AMP 100.

On the basis of the results of a previous study and immuno-allergological tests, a group of workers employed in breeding insects for biological pest control were studied to ascertain whether any new sensitizations to arthropods recently included in the work cycle occurred and whether any new allergic diseases were observed. The results confirmed a high sensitization to Ephestia kuehniella and to Orius, the latter probably due to contamination; sensitization to Tetranicus urticae and to Planococcus citri were observed, although to a lesser degree. It is concluded that the insects used in biological pest control are highly allergogenic and that the protective devices used up to the present were ineffective; the authors therefore recommend the use of closed or semi-closed cycles along with local ventilation equipment.

Allergic asthma and rhinoconjunctivitis have been reported in workers who are constantly in close contact with arthropods during the course of breeding and research. We investigated a group of ten people working with beneficial arthropods in a "bio-factory." The following tests were carried out: skin prick test with allergens present in the workplace, baseline pulmonary function test, aspecific bronchial provocation test with ultrasonically nebulized distilled water, and pulmonary function test after workplace exposure in two subjects. The results demonstrated a good correlation between skin prick test, previous RAST positive reactions, clinical symptoms, and exposure. Pulmonary function test after workplace exposure proved positive in one asthmatic subject and in one subject with rhinoconjunctivitis. It is concluded that the evidence supports the occupational nature of these allergic diseases and that there is a need for careful surveillance and environmental monitoring within the workplace.

For some years, biological pest control has been re-evaluated as an alternative to the indiscriminate use of pesticides. The number of "bio-factories" in Europe has been constantly increasing and today more than 100 technicians work in mass rearing of arthropods. Seven cases of asthma and allergic rhinitis are reported in 13 workers engaged in the production of beneficial arthropods. The subjects suffered from attacks of asthma and rhinitis when they came into contact with eggs and scales or waste of Chrysoperla carnea, Leptinotarsa decemlineata, Ostrinia nubilalis and Ephestia kuehniella. These attacks occurred after an average exposure period of 18 months. A RAST test, prepared by Lofarma, was carried out on subjects' serum against the above-mentioned allergens and was positive in all symptomatic subjects (7 of 13) and negative in the others. This demonstrates IgE direct sensitization mediated by complete antigens.

In compliance with the mandatory medical surveillance of workers exposed to tetrachloroethylene (PCE) in Italy, isoenzyme fractioning of serum gamma-glutamyltransferase (GGT) was performed on 141 workers of both sexes and on 130 control subjects. None of the workers showed any clinical symptoms of liver disease and their enzymatic profiles, including AST, ALT, 5'-NU, ALP, and GGT, were within the normal reference limits. A statistically significant increase in total GGT serum level was found in the exposed subjects, which was associated with an increase in one of the two fractions normally present in healthy individuals (GGT-2), as well as with the appearance and progressive increase of the level of a fraction (GGT-4) considered to be an expression of hepato-biliary impairment. Further research is ongoing among these workers, which will clarify whether or not electrophoretic GGT tests may be useful in detecting liver function changes due to occupational exposure to PCE.

In response to a request from the personnel of a credit bank that had been moved into a new building, an evaluation was made of employee health complaints. The prevalence of symptoms was determined using a self-administered questionnaire. Ventilation effectiveness, contaminant concentrations (which included chemicals and bioaerosols) and microclimate were studied to establish their relationship to environmental discomfort and to the health problems mentioned by the employees. Indoor air quality--which was assessed in different seasons--revealed relatively high levels of carbon dioxide and bioaerosols in areas occupied by employees as compared with other places. Temperature and humidity were considered to be satisfactory. Although a causative agent was not isolated, the authors conclude that an ineffective rate of room air exchange, possibly in interaction with chemical contaminants, may be responsible for the discomfort and, perhaps, for the health symptoms experienced by workers in fully enclosed rooms.

Blood levels of DDT, DDE, and other DDT metabolites were determined in a group of workers with previous occupational exposure to DDT as spraymen. The larger part of total DDT was in the form of metabolite DDE, which is thought to be introduced into the human body primarily from external sources. Total DDT blood level was correlated positively with both age and occupational exposure (R = 0.58 and 0.52, respectively), and linear regressions between storage and these variables were demonstrated. Although the storage of these compounds in body fat was not studied, the analysis of covariance showed a significant increase of DDT blood level in the group of workers with longer occupational exposure, which was not dependent on age.