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Using personal dosimeters worn during two complete work-shifts, we measured occupational exposure to Extremely Low Frequency-Magnetic Fields (ELF-MF) in 290 workers employed in 56 jobs, representative of the main occupational activities in the area of Modena and Reggio Emilia (Italy). Environmental nonoccupational exposure was also monitored. In the whole sample, the mean Time-Weighted Average (TWA) exposure during work resulted 0.59 microT (SD 3.2), while the median was 0.13 microT. Exposure was lower than 1 microT in more than 90% of the workers. In one job only exposure was greater than 1 microT (job-related median TWA); in other 8 exposure was between 1 and 0.4 microT, while about 84% of the jobs presented a median TWA lower than 0.4 microT. A high variability among workers engaged in the same job resulted in various occupational tasks. Non-occupational exposure was lower than 0.4 microT in more than 98% of the examined workers. Our results show a low to moderate occupational exposure to ELF-MF in the greatest part of the workers and working activities. Also the non-occupational exposure resulted low in the large majority of the subjects. The high variability observed among workers engaged in some occupations may represent a problem in exposure evaluation. Personal monitoring is particularly useful in such a situations.

Background: Information on occupational exposure to ELF magnetic fields (MF) in workers is largely insufficient, and is mostly based on results obtained in Scandinavian countries and North America. Accordingly, the collection of further data is needed, especially in workers exposed in other countries, including in Italy., Methods: One hundred and fifty workers (84 males and 66 females) employed in 28 different jobs in the Emilia-Romagna Region of Italy were examined. Individual exposure was measured using personal monitors worn on the hip in a belted pouch during three whole work-shifts (8 hours each) of a normal working week. A sampling interval of 10 seconds was adopted, resulting in the collection of more than 8600 measurements for each worker. The individual Time-Weighted Average (TWA) occupational exposure of workers was calculated as the arithmetic mean of all measurements during each work-shift. Environmental non-occupational exposure was also measured., Results: The 50 degrees percentile of individual TWA in the whole group was 0.15 microT, and the 5 degrees - 95 degrees percentile was respectively 0.02-1.45 microT. Job-related exposure (expressed as the mean of the TWA measured in all workers engaged in that job) was highest in substation electric power plant workers (1.12 microT) and in sewing machine workers (0.84 microT), but was lower than 0.2 microT in more than the 70% of the examined jobs. Considering the geometric mean of individual TWA are 27 out of 28 the jobs inducing an exposure lower than 0.2 microT. The lowest exposure was observed in infant school teachers. A high variability was observed among different workers engaged in the same occupation, mainly in substation electric power plant workers, machine testers and grinders in the engineering industry and in sewing machine workers and quality control in garment production. A marked variability of the pattern of exposure during the work-shift was also observed The overall environmental (non-occupational) exposure was 0.044 microT, and individual exposure was lower than 0.2 microT in about 97% of the examined subjects. Occupational exposure was usually higher and was not correlated with environmental exposure., Conclusions: The results show that the occupational component of overall exposure must be considered in studies on the biological effects of ELF-MF in populations. The high variability observed among workers engaged in the same occupation and the variability of the pattern of exposure certainly constitute major problems and could be a cause of the scarce coherence of the results of epidemiological studies on biological effects of ELF-MF to date. An improvement in protocols for the evaluation of exposure in workers, including the use of personal monitoring, is certainly needed.

We present the results of a study on the prevalence of low back pain (LBP) in a group of hospital nursing personnel. In 180 subjects (89% women) a questionnaire on LBP was collected. The prevalence of LBP episodes during the last 12 months was 63,9%; no difference was observed according to the working area (medicine, surgery, emergency). The proportion of subjects with LBP tended to increase according to the previous duration of work, but not with age. The prevalence of LBP was significantly lower in nursing personnel working according the team nursing model, that is less repetitive, and involves less work load, compared to the functional nursing model. Furthermore, LBP prevalence was lower among nurses that received an adequate formation on the prevention of occupational LBP. The results of the study confirm the relevance of LBP in nursing personnel, but suggest also that an adequate preventive programme can significantly reduce the risk.

Fifty hertz magnetic fields (MFs) induced the expression of heat shock proteins (HSPs) 70 and 90 in immunocytes of the mussel Mytilus galloprovincialis. Animals exposed at 300 microT for three different times (30; 2 x 30; 3 x 30 min), did not show differences in the HSP densitometric values in comparison with non-exposed mussels. At 400 microT, exposed animals showed a time-dependent increase in HSP expression as revealed by Western blot. After exposure to 600 microT, the HSP densitometric values were significantly higher than controls but not related to exposure duration. The induction of HSPs is concomitant with the activation of p38 MAP kinase signalling pathway. The present findings suggest the possibility to modulate the expression of HSPs by an appropriate time-intensity magnetic field exposure.

We studied the reliability of biologic indices for monitoring perchlorethylene (PCE) exposure at low environmental solvent concentrations. Environmental monitoring was performed by personal sampling, biologic monitoring by measuring PCE in alveolar air (PCE-Alv), blood (PCE-B), and urine (PCE-U) in 26 low-exposed dry-cleaners. Correlation coefficients (r) between environmental PCE and PCE-B, PCE-Alv, and PCE-U were 0.94, 0.81, and 0.67 respectively. A high correlation was also found among biologic indices: r value was 0.96 between PCE-B and PCE-Alv, 0.95 between PCE-B and PCE-U, and 0.87 between alveolar PCE-Alv and PCE-U. The examined biologic indices proved sensitive enough for biologic monitoring of low exposure to PCE and can give substantially similar information in terms of exposure evaluation. PCE-Alv offers some advantages because it correlated better with exposure and is analytically simpler.

Background: Up now no firm conclusions can be drawn on the genotoxicity of Extremely Low Frequency (ELF) Magnetic Fields (MF) in exposed workers: both an increase in chromosomal aberrations (CA) and micronuclei (MN) or no effects were observed in substation workers, while a slight increase in CA, but not in sister chromatid exchanges (SCE) or MN was reported in linesman; an increase in CA was observed in cable splicers and, more recently, in train engine drivers, but results have not been replicated., Objectives: Objective of the study was an evaluation of possible genotoxicity of occupational exposure to ELF-MF., Methods: SCE, high-frequency cells (HFC) and SCE in HFC were measured in peripheral blood lymphocytes from 70 workers exposed to various levels of ELF-MF in different occupations, not involving exposure to known mutagens or carcinogens. In all participants, individual ELF-MF exposure was measured throughout the whole work-shift for 3 consecutive days by personal monitoring., Results: Time Weighted Average (TWA) values of ELF-MF in the whole group ranged from 0.01 to 3.48 microT; the geometric mean was 0.19 mT, and only 3 subjects exceeded 2 microT. According to the individual TWA exposure, subjects were divided into two groups: low exposed (< or = 0.2 microT) and highly exposed (> 0.2 microT). The mean values of SCE, HFC and SCE in HFC were compared between low and highly exposed: no significant differences were observed. The result was further tested by selection and comparison of workers exposed up to 0.1 microT vs. exposed > 0.4 microT only, i.e. excluding intermediate exposures: again no difference in genotoxicity indices was observed. Also multivariate analysis did not show any correlation between individual ELF-MF exposure and genotoxicity indices., Conclusions: The results of our study do not give any support to the hypothesis that occupational exposure to ELF-MF up to about 2 microT, i.e. at the levels currently found in most workplaces, can exert a genotoxic effect in workers.

Objective: To study color discrimination impairment in workers exposed to elemental mercury (Hg) vapor., Subjects: Twenty-four male workers from a chloralkali plant exposed to Hg vapor, aged 42+/-9.8 years, duration of exposure 14.7+/-9.7 years, were examined. The 8h TWA air-borne Hg concentration in workplace was 59 microg/m(3); mean Hg urinary excretion (HgU) was 20.5+/-19.3 microg/g creatinine; mean Hg urinary excretion after the administration of a chelating agent, sodium 2,3-dimercapto-1-propane-sulfonate (DMPS), was 751.9+/-648 microg/48h. Twenty-four age- and gender-matched control subjects were compared. Visual acuity, alcohol intake, smoking habits, and history of diseases or drugs potentially influencing color vision were registered., Methods: The Lanthony 15-Hue desaturated test (L-D15-d) was used to assess color vision. The results were expressed quantitatively as Bowman's Color Confusion Index (CCI), and qualitatively according to Verriest's classification of acquired dyschromatopsias., Results: The CCI was significantly higher in the exposed group than in the control (mean CCI 1.15 versus 1.04; P=0.04). The proportion of subjects with errorless performance on the Lanthony test was significantly lower in the Hg exposed group compared to referents (52% versus 73%; P=0.035). The exposed group showed higher frequency of type III dyschromatopsias (blue-yellow confusion axis) in comparison with the control group (12.5% versus 8.3%), however, the difference did not reach statistical significance. Multiple regression did not show any significant relationship between the CCI, and age, alcohol consumption, or measures of exposure., Conclusion: In agreement with previous studies by Cavalleri et al. [Toxicol. Lett. 77 (1995) 351; Environ. Res. Sec. A 77 (1998) 173], the results of this study support the hypothesis that exposure to mercury vapor can induce sub-clinical color vision impairment. This effect was observed at an exposure level below the current biological limit for occupational exposure to mercury. This raises doubts on the actual protection afforded by this limit concerning the effect of mercury on color vision.

Recent research shows that occupational exposure to several solvents, metals and other industrial chemicals can impair color vision in exposed workers. Occupation-related color vision impairment usually results in blue-yellow color discrimination loss or, less frequently, a combination of blue-yellow and red-green loss. The eyes may be unequally involved, and the course is variable depending on exposure and other factors. The pathogenesis of occupational color vision loss has not been elucidated; it may be due to, e.g. a direct action of neurotoxins on receptors, possibly on the cone's membrane metabolism, and/or to an interference with neurotransmitters within the retina. Other possible pathogenetic mechanisms, such as a direct effect to the optic nerve, have also been suggested. Occupational color vision loss is usually sub-clinical, and workers are unaware of any deficit. It can be assessed using sensitive tests, such as the Farnsworth-Munsell 100 Hue (FM-100) or the Lanthony D-15 desaturated panel (D-15 d). The latter is the most widely used for studies in groups of exposed workers, and offers the possibility of a quantitative evaluation of the results by calculation of the Bowman's Color Confusion Index (CCI), or of the Vingrys' and King Smith's Confusion Index (CI). Other advantages of D-15 d are the possibility to perform the test directly at the workplace, and the reproducibility when performed in standardized conditions. In most cases, occupation-related color vision impairment is correlated to exposure levels, and has often been observed in workers exposed to environmental concentrations below the current occupational limit proposed by the ACGIH. Progression with increasing cumulative exposure has been reported, while reversibility is still discussed. Acquired color vision impairment related to occupational exposure to styrene, perchloroethylene (PCE), toluene, carbon disulfide, n-hexane, solvent mixtures, mercury and some other chemicals are discussed. Results show that color vision testing should be included in the evaluation of early neurotoxicity of chemicals in exposed workers. The D-15 d would be useful in the surveillance of workers exposed to solvents and other chemicals toxic to the visual system.

The effect of industrial chemicals on the sensory perception of exposed workers has received scant attention from the medical community to date, and the scientific literature is mainly limited to some case-reports or isolated studies. Possible explanations for this include the complexity of sensory perception, and the lack of agreement among researchers on methods for testing large groups of subjects. Nevertheless, some published studies showed that vision, hearing and olfactory function can be affected by various industrial metals and solvents, and some data exist also for touch and taste. This review discusses the main industrial chemicals involved. The pathogenesis of the toxicity of chemicals to sensory perception may be related to an action on receptors, nerve fibers, and/or the brain; probably, different pathogenetic mechanisms are involved. One of the main problems in this research field is that most of the studies to date evaluated the effect of a single industrial chemical on a single sense: as an example, we know that styrene exposure can impair smell and also hearing and vision but we have little idea whether different senses are impaired in the same worker, or whether each impairment is independent. In addition, workers are frequently exposed to different chemicals: co-exposure may have no effect, or result in both an increase or a decrease of the effect, as was observed for hearing loss, but studies on this aspect are largely insufficient. Research shows that both occupational and environmental exposure to industrial chemicals can affect sense organs, and suggests that the decline of perception with age may be, at least partly, related to this exposure. Nevertheless, available evidence is incomplete, and is largely inadequate for an estimation of a "safe" threshold of exposure. Good quality further research in this field is needed. This is certainly complex and demands adequate resources, but is justified by the ultimate result: the possibility to prevent an avoidable part of the decline in sensory function with age.

Using personal dosimeters, occupational exposure to ELF-MF was measured in 150 workers employed in 28 different occupations. The main results are presented. The overall arithmetical mean in the whole sample was 0.36 microT, the overall geometric mean 0.21 microT. A high variability among workers engaged in the same occupation, and among different days in the same worker, was observed. The results suggest a relatively low exposure to ELF-MF in the large part of workers. Nevertheless, the higher levels measured in some workers, and the high variability, show the need of adequate measurements of ELF-MF exposure in workers.

We present a review on the electromagnetic hypersensitivity (EHS), a fenomenon where individuals experience adverse health effects while using, or being in the vicinity, of electric, magnetic or electromagnetic field sources and devices. Apparently, symptoms can be induced by both low and high frequencies, even at low level, and can vary substantially among different individuals. Scientific data do not support the hypothesis of a causal relationship between fields and EHS, even if knowledge is largely incomplete. Further studies in this field are needed.

In industrialised countries, carpal tunnel syndrome (CTS) is considered an epidemic work-related disease. We have set up the MODS (Malattie Occupazionali Da Sovraccarico biomeccanico, biomechanical overload-related occupational diseases) collaborative group, formed by epidemiologists, ergonomists and occupational physicians to investigate CTS in Italy, applying the methods that epidemiologists commonly use to understand epidemics. Several studies are already ongoing. Two different descriptive studies based on current hospitalisation data are in the reporting phase. A pilot case-control multicentre study (260 cases and 520 controls in 13 centres) is in the final phase of data collection. A longitudinal study on a cohort of 3000 subjects exposed to different risk factors has reached the third year of follow-up. Moreover, a surveillance system has been set up to cover selected districts of the Emilia Romagna region. These studies will generate new information about the prevalence and incidence of CTS in Italy, along with identification of regional, high-risk job titles and work sectors, and the relative influence of non-occupational factors.

Objectives: We studied subjective health symptoms in a population accidentally exposed to high styrene concentrations in drinking tap water. The contamination occurred during the reparation of a water tank., Methods: Residents of 27 apartments in two buildings using the contaminated water were contacted. A questionnaire on subjective symptoms was administered to 84 out of 93 persons living in the apartments at the time of the accident. Styrene concentration was measured in samples of water collected two days after the accident. The means of exposure associated with appearance of symptoms were examined through case-control analyses., Results: Styrene in water reached concentrations up to 900 microg/L. Symptoms were reported by 46 persons (attack rate 55 %). The most frequent symptoms were irritation of the throat (26%), nose (19%), eyes (18%) and the skin (14%). General gastrointestinal symptoms were observed with 11% reporting abdominal pain and 7% diarrhea. The factors most strongly associated with symptoms were drinking tap water (OR = 7.8, 95% CI 1.3-48), exposure to vapors from the basement (OR = 10.4, 2.3-47) and eating foods prepared with tap water (OR = 8.6, 1.9-40). All residents in the ground floor reported symptoms., Conclusions: This accidental contamination led to very high styrene concentrations in water and was related to a high prevalence of subjective symptoms of the eyes, respiratory tract and skin. Similar exposures have been described in workers but not in subjects exposed at their residence. Various gastrointestinal symptoms were also observed in this population probably due to a local irritative effect.

Plasma membrane Ca(2+) channels in immunocytes from the mussel Mytilus galloprovincialis exposed to 50 Hz sine wave magnetic fields (MFs) of various strengths were studied. At levels of 300 microT and above, MFs reduce shape changes in immunocytes induced by the chemotactic substance N-formyl-Meth-Leu-Phe, and this effect involves L-type Ca(2+) channels. Upon the addition of the Ca(2+) blocker verapamil to molluscan immunocytes exposed to MFs results in a synergistic cytotoxic action, while in the presence of the Ca(2+) opener SDZ-202, 791, a reactivation of the cells is observed. This suggests that, as previously reported for potassium channels, the damage to Ca(2+) channels induced by short exposure to MF at appropriate intensities is not permanent., (Copyright 2003 Wiley-Liss, Inc.)

N-formyl-Meth-Leu-Phe (fMLP)-induced immunocyte shape changes in the mussel Mytilus galloprovincialis through both the phosphatidylinositol and the cAMP pathways are studied. Fifteen- and thirty-minute exposures of mussels to 50-Hz magnetic fields (MFs) at intensities of 300 and 400 microT do not provoke permanent cell damage, since immunocytes maintain the capacity to respond to fMLP. This avoidance of external insult seems to be achieved through the activation of a "stress pathway" which is not functionally detectable in nonexposed animals and which involves mitogen activated protein (MAP) kinase members. This phenomenon is clearly evident at 400 microT. Contemporaneously, a different expression of Jun transcriptional regulatory proteins is also found.

The effect of exposure to industrial metals on sensory perception of workers has received only modest interest from the medical community to date. Nevertheless, some experimental and epidemiological data exist showing that industrial metals can affect vision, hearing and olfactory function, and a similar effect is also suggested for touch and taste. In this review the main industrial metals involved are discussed. An important limit in available knowledge is that, to date, the number of chemicals studied is relatively small. Another is that the large majority of the studies have evaluated the effect of a single chemical on a single sense. As an example, we know that mercury can impair hearing, smell, taste, touch and also vision, but we have scant idea if, in the same worker, a relation exists between impairments in different senses, or if impairments are independent. Moreover, workers are frequently exposed to different chemicals; a few available results suggest that a co-exposure may have no effect, or result in both an increase and a decrease of the effect, as observed for hearing loss, but this aspect certainly deserves much more study. As a conclusion, exposure to industrial metals can affect sensory perception, but knowledge of this effect is yet incomplete, and is largely inadequate especially for an estimation of "safe" thresholds of exposure. These data support the desirability of further good quality studies in this field.

In Italy, as in other countries, an apparently increasing number of subjects is reporting a variety of subjective symptoms that the subjects themselves refer to the exposure to electric, magnetic or electromagnetic fields (EMF) from nearby electric appliances, cellular phones, antennas, etc. Terms like electricity hypersensitivity (EHS), EMF hypersensitivity, or other similar, are frequently adopted to describe such symptoms; nevertheless, up to now, these terms are not entered the medical terminology. No accepted diagnostic criteria or procedures for the diagnosis of EHS are currently available. Furthermore, apart from the subject's self-attribution of the symptoms to EMFs, no direct cause-effect relationship between EHS symptoms and electromagnetic fields has been proved; additionally, evidence of a possible pathogenetic mechanism is lacking. In this paper, two cases developing symptoms of EHS ascribed to overhead power line in the proximity of their house are discussed. Nervous system (asthenia, depression, paraesthesias etc.), cardiovascular system (cardiac palpitations) and the skin (tingling, itching, etc.), are mostly (but not exclusively) involved. Based on available scientific knowledge, the rationale for an approach to subjects claiming for EHS is discussed. The establishment of a National archive for the collection of cases is communicated.

The effect induced by exposure to 50 Hz magnetic fields (MFs) in immunocytes from the mussel Mytilus galloprovincialis is evaluated. The whole animal was exposed for 15 and 30 min to MF intensities ranging from 200 to 1,000 microT. The changes in the cellular shape of immunocytes, expressed as shape factor (SF), were studied at different times after addition of the chemotacting substance N-formyl-Meth-Leu-Phe (fMLP). Results show that MFs provoke differing delays in fMLP-induced cellular shape changes: 200 microT are ineffective, while levels from 300 microT upwards cause a significant increase in immunocyte SF values compared to controls. Reactivation of the cells is possible up to an intensity of 600 microT. The use of PCO 400, an opener of ATP-sensitive K+ channels, shows that potassium channels are involved in the effect of MFs on M. galloprovincialis immunocytes., (Copyright 2002 Wiley-Liss, Inc.)

The study evaluated occupational exposure to trihalomethanes (THMs) in indoor swimming pools. Thirty-two subjects, representing the whole workforce employed in the five public indoor swimming pools in the city of Modena (Northern Italy) were enrolled. Both environmental and biological monitoring of THMs exposure were performed. Environmental concentrations of THMs in different areas inside the swimming pools (at the poolside, in the reception area and in the engine-room) were measured as external exposure index, while individual exposure of swimming pool employees was estimated by THMs concentration in alveolar air. The levels of THMs observed in swimming pool water ranged from 17.8 to 70.8 microg/l; the mean levels of THMs in ambient air were 25.6+/-24.5 microg/m3 in the engine room, 26.1+/-24.3 microg/m3 in the reception area and 58.0+/-22.1 microg/m3 at the poolside. Among THMs, only chloroform and bromodichloromethane were always measured in ambient air, while dibromochloromethane was detected in ambient air rarely and bromoform only once. Biological monitoring results showed a THMs mean value of 20.9+/-15.6 microg/m3. Statistically significant differences were observed according to the main job activity: in pool attendants, THMs alveolar air were approximately double those observed in employees working in other areas of the swimming pools (25.1+/-16.5 microg/m3 vs. 14.8+/-12.3 microg/m3, P < 0.01). THMs in alveolar air samples were significantly correlated with THMs concentrations in ambient air (r = 0.57; P < 0.001). Indoor swimming pool employees are exposed to THMs at ambient air levels higher than the general population. The different environmental exposure inside the swimming pool can induce a different internal dose in exposed workers. The correlation found between ambient and alveolar air samples confirms that breath analysis is a good biological index of occupational exposure to these substances at low environmental levels.

Occupational exposure to various neurotoxic chemicals can impair color vision. We evaluated this possibility in toluene-exposed workers. Thirty-three rubber workers and 16 referents were studied. We estimated toluene exposure by measuring urinary excretion of the unmodified form of the solvent (i.e., TolU). Color vision was tested with the Lanthony D-15 desaturated panel, and the outcomes were expressed quantitatively with the Color Confusion Index and the Total Confusion Index. Toluene-exposed workers had a subclinical reduction in color vision, compared with referents. We related this effect to solvent cumulative exposure--estimated as the product of urinary excretion of unmodified toluene by previous toluene exposure duration. This approach supports the hypothesis that impairment progresses as exposure continues. In the examined group of workers, toluene exposure was within the occupational limit proposed by the American Conference of Governmental Industrial Hygienists. The observed loss in color vision raises doubts on the real protection afforded by this limit--at least for effects of the solvent on the eyes. Finally, the Total Confusion Index was a more sensitive index than the Color Confusion Index in the evaluation of toluene-related color-vision impairment, suggesting that this index should be adopted in future studies of the effects of chemicals on color perception.

The evolution of occupationally induced color vision loss was studied in workers exposed to various chemicals. Exposure was evaluated by biological monitoring or personal air samplers, and color vision using the Lanthony D-15 desaturated panel (D-15 d). The effect of short-term interruption of exposure was studied in 39 Styrene (St) exposed workers: at a first examination a dose-related color vision loss was disclosed; a re-test performed after one month's interruption of exposure did not show any improvement of the effect. The evolution during longer periods was studied in another group of 30 St workers. Exposure and color vision were evaluated, then a follow-up was done 12 months later: the exposure was unmodified or slightly decreased in 20 subjects, and D-15 d outcomes remained unchanged, while St levels had increased and color vision loss progressed in the other 10. Similar results were obtained in 33 PCE exposed dry-cleaners: no change in color perception was observed in 14 workers whose exposure decreased, while in the other 19 a rise in PCE levels was followed by a significant color vision worsening. In 21 Hg exposed workers whose mean urinary excretion of Hg was threefold the BEI proposed by ACGIH, a dose-related impairment in color perception was observed. 12 months after a marked reduction of exposure, an almost complete recovery of the impairment was observed. Our data show that an increase in exposure can induce a worsening in color vision loss. A short interruption in exposure did not reduce the effect. A more prolonged reduction of dose reversed color vision loss in Hg exposed workers, while in solvent-exposed individuals the progression deserves further evaluation. D-15 d proved a useful test for studies on the evolution of color perception in workers exposed to eye-toxic chemicals.

In the last 15 years an increasing number of studies have investigated color discrimination in workers exposed to various neurotoxins. Color vision was generally evaluated using the Lanthony D-15 desaturated panel (D-15 d), a test suited to identify mild acquired impairments, that can be easily performed at the workplace. In most studies, results were quantitatively expressed using the method of Bowman or that of Vingrys and King-Smith: the former is the most widely reported, while the latter gives information on the type of color defect. Applying D-15 d, or other color perception tests, impairment in color vision was observed among workers exposed to several solvents (styrene, perchloroethylene, toluene, n-hexane, and carbon disulfide), or to solvent mixtures, and also to metals like mercury. Chemical related color vision loss is a sub-clinical early effect, and in most studies proved dose-related. For styrene and perchloroethylene, and also for solvent mixtures, an impairment was observed at exposure levels lower than the current occupational limits, suggesting that these limits may be inadequate for a proper protection of visual function of workers.

Progression of perchloroethylene-induced color-vision impairment was studied in 33 dry-cleaner workers at 12 establishments in Modena, Italy. In an initial survey, we evaluated exposure with personal passive samplers, and we assessed color vision with the Lanthony D-15 desaturated panel. Two years later, workers were reexamined. In 19 workers (subgroup A), exposure to perchloroethylene had increased (median of 1.7 ppm versus 4.3 ppm, respectively), whereas in the remaining 14 workers (subgroup B) exposure was reduced (2.9 ppm versus 0.7 ppm, respectively). Color vision worsened in subgroup A, but no vision changes were apparent in subgroup B. The results indicated that an increase in exposure during a 2-y period, even if slight, can cause color vision to deteriorate. A similar slight reduction in exposure did not lead to color-vision improvement; perhaps this lack of improvement resulted from (a) an insufficient reduction in exposure, (b) an insufficient reduction in duration of exposure, or (c) irreversible perchloroethylene-induced color-vision loss.

Color vision was evaluated in twenty-one mercury exposed workers and referents matched for sex, age, tobacco smoking, and alcohol habits. The Lanthony 15 Hue desaturated panel (D-15 d) was applied. In the workers, mean urinary Hg (HgU) was 115+/-61.5 microg/g creatinine; in all but one the values exceeded the biological limit (BEI) proposed by the American Conference of Governmental Industrial Hygienists. A dose-related subclinical color vision impairment was observed in Hg-exposed workers compared to the referents. Just after the survey, working conditions were improved. Twelve months later the workers were reexamined. Mean HgU was 10.0 microg/g creatinine and in no subjects was the BEI exceeded. Color perception was significantly improved compared to the first examination and, furthermore, no differences were observed between exposed workers and referents. The results add evidence that the color vision loss observed during the first part of the study was related to Hg exposure and, moreover, show that this effect is reversible. These data indicate that metallic Hg can induce a reversible impairment in color perception. This suggests that color vision testing should be included in studies on the early effects of Hg. The possibility of applying the D-15 d as an early effect index in the biological monitoring of Hg exposed workers should also be entertained., (Copyright 1998 Academic Press.)

The aim of our study was to evaluate the modification of serum concentration of aminoterminal propeptide of type III procollagen (PIIINP) in 70 patients with previous transmural myocardial infarction. In 38 patients (group 1 ) PIIINP levels increased at 6 and 12 months after infarction; in 32 patients (group 2) PIIINP increased at 6 months, returning to baseline at 12 months. At the same time we observed a significant left ventricular enlargement and worsening of the performance in group 1, whereas in group 2 an improvement was seen in left ventricular volumes and performance. In conclusion, rearrangement of collagen myocardial matrix plays an important role in left ventricular postinfarction modification. This process can be easily followed over time in a noninvasive manner by dosing serum PIIINP concentrations.

The levels of aminoterminal propeptide of type III procollagen (PIIINP) can be used as an index of collagen breakdown. The aim of our study was to evaluate modifications in serum concentration of PIIINP (PIIINPs) in patients with a first episode of myocardial infarction. We examined 70 patients admitted at our Institution for acute myocardial infarction and 10 normal subjects. PIIINPs dosage was obtained by radioimmunoassay method utilizing a commercial available kit. All patients underwent three PIIINPs dosages: within 24 hours after admission, at 6 and 12 months after myocardial infarction. Control values were 0.4 +/- 0.1 U/ml. In 38 patients (Group I) PIIINPs levels increased at 6 and 12 months after infarction: 0.53 +/- 0.2, 0.75 +/- 0.2 and finally 0.76 +/- 0.1 U/ml. In the remaining 32 patients (Group II) PIIINPs values increased at 6 months and then returned to baseline at 12 months: 0.56 +/- 0.2, 0.75 +/- 0.1 and then 0.46 +/- 0.1 U/ml. The end-diastolic volume index did not change significantly in Group I (from 93.7 +/- 21 to 79.7 +/- 20 ml/m2) while it decreased after 12 months in Group II (from 88.9 +/- 13 to 58.6 +/- 11 ml/m2; confidence interval 95% from 2 to 55 ml/m2; p = 0.03). Similarly, there was no significant variation in end-systolic volume index (ESVI, from 39.7 +/- 11 to 36.9 +/- 11 ml/m2) and ejection fraction (from 60 +/- 10 to 59 +/- 15%) in Group I; while in Group II ESVI decreased significantly (from 33.6 +/- 13 to 20 +/- 5 ml/m2, confidence interval 95% from 3 to 24 ml/m2; p = 0.02) and ejection fraction improved (from 62 +/- 11 to 72 +/- 15%; confidence interval 95% from -20 to -1%; p = 0.04). In conclusion, patients with elevated levels of PIIINPs at 12 months did not improve ventricular function while patients with PIIINPs returning to baseline at 12 months had an improvement. Our results suggest an active participation of newly formed collagen in post-infarct ventricular remodeling. Therefore PIIINPs may be a marker of this process.

Occupational exposure to perchloroethylene (PCE) was studied in a total of 106 workers in 78 dry cleaning shops in the province of Pavia, Northern, Italy. Environmental monitoring was performed by personal passive sampling. The median time weighted average (TWA) level of PCE was 57 mg/m3, i.e., about 30% of the current Threshold Limit Value (TLV) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH). However, in 12 workers exposure exceeded this limit. Biological monitoring was performed via measurement of urinary trichloroacetic acid (TCA), i.e. the exposure index currently used in Italy, and urinary excretion of unmodified perchloroethylene (PCE-U) in samples collected at the end of the half-shift. Median levels of TCA and PCE were 1.03 mg/l and 17.7 micrograms/l respectively. The correlation coefficient between environmental TWA concentrations of perchloroethylene and PCE-U was 0.755 (0.809 after logarithmic transformation), compared to 0.660 for TCA values. The subjects were then classified as "low exposed" and "heavily exposed" according to whether personal exposure was lower or higher than 57 mg/m3, the median TWA value of the whole group. PCE-U levels were significantly correlated to exposure in both subgroups whereas TCA was correlated only in the "heavily exposed subjects", but not in those with lower exposure. The results of the study show that in the majority of dry cleaning shops exposure to PCE was well below the current occupational limits. Nevertheless surveillance of dry cleaners is recommended as nearly 10% of the workers exceeded the environmental and biological limits. Urinary excretion of unmodified PCE appears to be a very reliable indicator for biological monitoring of PCE exposure in dry cleaning and is also significantly correlated to exposure at low levels. The estimated biological equivalent exposure level (BEEL) for PCE-U, corresponding to the current TLV-TWA proposed by the ACGIH, is 55 micrograms/l. Urinary TCA seems to be less suitable for assessment of individual exposure to perchloroethylene in dry cleaners as it is poorly representative of exposure to low levels of the solvent, which is a very common occurrence in this occupational group nowadays.

Styrene represents nowadays one of the most used organic solvent. The current exposure limit proposed for this chemical differs significantly from country to country: the Threshold Limit Value-Time Weighted Average (TLV-TWA) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH) is 50 ppm while the German, Finnish and Swedish occupational exposure limit is 20 ppm. Nevertheless, effects on the nervous system were recently reported in workers exposed at TWA styrene levels below the current TLV. Neuro-optic pathways have been shown to be particularly vulnerable to organic solvent exposure. Analysis and measurements of visual functions can provide important information on early neurotoxic effects. Previous studies support the hypothesis that styrene exposure can induce a dose-dependent color vision loss. The aim of this study is to assess a threshold level below which no detectable effect occurs for color vision. We applied a sub-application of the change point problem in two-phase regression considering one phase as a constant line. In accordance with this model the maximum-likelihood technique was used as a method to examine the dose- effect relationship between external styrene exposure and chromatic discrimination. The present article presents a joint analysis of data from two previously published studies, one carried out in Canada and the other in Italy. The age and seniority of the workers from both countries were remarkably similar, as were the process type, the chemicals used and the work-tasks of exposed subjects. The mathematical method presented here shows the existence of a statistically significant threshold. This finding shows that, in fiberglass-reinforced plastics industry, visual color impairment could be significantly detected above 4 ppm (upper limit of the confidence interval at 5% = 26 ppm). The exact clinical meaning of this effect, and also the progress of the impairment in exposed workers, is still to be assessed in further studies. The results of our study support the need of a reduction of the occupational limits for styrene in workplaces to values close to or lower than German, Finnish or Swedish exposure limits.

Perchloroethylene exposure in 28 dry-cleaning establishments and in 25 homes occupied by dry cleaners in Modena, Italy, was investigated. Environmental air samples and alveolar air samples from dry cleaners (n = 60) and from their family members (n = 23) were collected. The degree of perchloroethylene on the dry-cleaning premises varied widely from establishment to establishment. Spot sampling ranged from 0.6 to 75 mg/m3, whereas sampling by personal passive dosimeters ranged from 2.6 to 221.5 mg/m3 (8-h time weighted average values). Perchloroethylene in alveolar air samples collected at the end of the work day correlated closely with the 8-h time weighted average values (r = .750, p = .001), and correlated also with alveolar air samples collected at home in the evening (r = .665, p = .001) and the following morning (r = .549, p < .001). Perchloroethylene levels inside the homes of dry cleaners appeared significantly higher than in 29 houses selected as controls (Mann Whitney U test, p < .001). Perchloroethylene in alveolar air samples collected at home suggests that nonoccupational exposure to perchloroethylene for family members of dry cleaners exists.

We evaluated the influence of the body burden of styrene on biological indices of exposure and the effects of this solvent on colour perception. The exposure of 19 workers was followed during a working week by personal sampling and biological monitoring. Although no significant difference in daily exposure was observed, pre-shift values of urinary styrene and urinary mandelic acid increased significantly during the week, and the regression line between external dose and biological exposure indices changed correspondingly. These data suggest that body burden can influence the results of biological monitoring of styrene. The effect of styrene on colour vision was evaluated in two further groups: 73 exposed workers and 53 referents and 36 pairs of workers and controls. A dose-related impairment was observed, which appeared to be synergistic with age and was not significantly improved by a one-month interruption of exposure. Our data show the need to improve biological monitoring of exposure to styrene and, in particular, to establish dose-effect and dose-response relationships between exposure and early effects. Urinary excretion of styrene and colour vision assessment represent, respectively, promising indices of exposure to and an effect of styrene.

Fifty-six males workers exposed to rock wool during production, and 20 referents were examined. Exposure, evaluated by personal sampling, ranged from 0.05 to 0.74 fibres/ml (median 0.15). The subjects underwent a medical examination, chest X-ray according to ILO recommendations and pulmonary function tests. In all subjects the serum levels of type III procollagen N-terminal propeptide (PIIINPs) were determined. No evidence of pulmonary fibrosis, nor work-related lung diseases were observed. PIIINPs mean values in the exposed (9.8 ng/ml; 2.8 S.D.) were slightly higher, but not significantly different when compared to referents (8.5 ng/ml; 2.5 S.D.). No significant correlation between PIIINPs and rock wool exposure (both airborne levels and exposure duration) was observed. Furthermore, peptide levels were not related to pulmonary function test results. Our results suggest that occupational exposure to rock wool fibres lower than 0.75 fibres/ml for less than 20 years does not induce definite cases of pulmonary fibrosis nor an increase of type III collagen synthesis in the lung.

We investigated the occurrence of color vision loss in 75 styrene-exposed workers and in 60 referents. Color vision was evaluated by adopting the Lanthony D 15 desaturated panel, a test specifically suited to detect mild acquired dyschromatopsia. The results of the test were expressed as Color Confusion Index. Styrene exposure was evaluated with both environmental and biological monitoring. Airborne levels of the solvent were 3.2 to 549.5 mg/m3. In styrene-exposed workers color vision was significantly impaired when compared with referents matched for age. A significative correlation was found between environmental and urinary levels of styrene and Color Confusion Index excluding the influence of age in multiple regression analysis, indicating the possibility of a dose-effect relationship. The findings suggest that styrene can induce an early appearance of a dose-dependent color vision loss.

The mortality experience of 4,580 male farmers licensed to buy and use pesticides in Northern Italy was examined from 1974 to 1987. The historical cohort was determined from the registers of the agricultural inspectorate offices. The vital status at the end of the study period was ascertained by municipality records and only 4 subjects were lost to follow-up. Death certificates were obtained for 100% of the 565 identified deaths. External comparison on to the Italian male population was supplemented by regional comparison. Mortality deficits were observed for all causes, all neoplasms and most specific malignancies. A non-significant mortality excess due to brain cancer, compared both to national and regional populations, was found (11 cases, Standardized Mortality Ratio 169 and 139, respectively). The excess of brain cancer became statistically significant in the age group 65-75 years. Caution must be used in the interpretation of our findings. Nevertheless, it seems reasonable to hypothesize an association of the observed excess of brain cancer with the occupational and/or environmental exposure of the cohort.

We examined 101 students (40 men, 61 women) aged 16-19 years, working 1-3 hours daily with video display terminals (VDT) with luminous green characters on dark background. McCollough visual aftereffect (ME) was reported, almost occasionally, in 80.2% of the examined group. 68% of the students referred daily ME appearance. Usually the effect appeared after 1 hour or less of VDT work and might persist for 1 hour or more. ME prevalence and persistence were significantly greater in women than in men. Apparently no relations were observed between ME prevalence and VDT work hours of visual defects. ME prevalence and persistence were significantly related to VDT induced visual asthenopia symptoms, but not with ocular asthenopia. According to our results, ME appearance may represent an early index of individual susceptibility to visual asthenopia induced by green characters VDT and/or be itself a precocious visual asthenopia symptom.

Occupational accidents represent an important problem in Occupational Medicine, not fairly investigated till now; as a consequence, data on the matter are lacking. The frequency of accidents is higher in the building, metal and wood industry. As regard to mycro-accidents, information are deeply lacking, and any comparison among different occupational groups is difficult, even if for some workers the risk is high. A very important issue concerning labour injuries is at present time represented by the risk of occupational HIV infection. From this point of view, we can distinguish three groups of workers: 1) health care workers (the group at highest risk); 2) other workers at risk of direct contact with infected blood, such as low-enforcement and correctional-facility officers; 3) workers not at risk of blood contact for occupational causes. Only in the first group some cases of seroconversion (18 until 1988) have been documented. The risk of occupational infection by HIV seems currently low, but a great effort must be devoted to accidents prevention, especially in relation to the great increase of seropositivity prevalence in the population.

Platelet adhesiveness was studied in 83 workers exposed to CS2 and 47 controls. Results show an increase of platelet adhesiveness statistically significant in workers in comparison with controls and in workers with high exposure vs. workers with mild exposure. Authors suggest the usefulness of platelet adhesiveness evaluation for prevention and early diagnosis of CS2 intoxication.

After briefly recalling the professional pathology characteristics of workers exposed to nitro derivatives and the perplexities surrounding the actual pathogenetic mechanism of the "Withdrawal hazard", the AA report the results of an investigation carried out among the workers of a dynamite producing plant. In the study, the NG and EGDN environmental levels were checked and the workers were submitted to ECG tracings, ECG D according to Holter, and monitoring of postural pressure changes both during exposure to the substances and during time-outs. The results obtained showed that the concentrations found in the plant were practically within the recommended TLV values, with no pathological modifications of the parameters examined. The AA put forward a pathogenetic hypothesis based on these findings and analyzing epidemiologic data on coronary sudden death as well as the mechanisms regarded as responsible for the disorders described in the literature in professionally exposed subjects. According to such hypothesis, the "Withdrawal hazard" (if any) would not be due to the cessation of the vasodilation effect of the nitro derivatives but would be a "rebound" phenomenon following the NG - and EGDN - inhalation induced stimulation to the production of endothelial prostaglandins, and of EDRF in particular, in exposed workers. The withdrawal of nitro derivatives inhalation would thus eliminate a vascular and coronary protection mechanism in the case of pathogenetic noxae at cardiovascular level. Such an interpretation would at last account for the time elapsing between cessation of work and occurrence of the disorders, which would not be justified by the cessation of the mere vasodilating action, since this wears out within a few hours.(ABSTRACT TRUNCATED AT 250 WORDS)

The study covered a group of female VDT operators assigned to data entry and data acquisition. Subjective VDT-related symptoms of asthenopia were assessed by means of a questionnaire. All operators were examined by an ophthalmologist. Visual acuity was measured using vision tables with optotypes. In order to achieve an objective assessment of VDT-induced visual fatigue, refractive power was measured at the beginning and at the end of the shift, using an infra-red autorefractometer. Changes in refractive power were then related to VDT work and asthenopia symptoms. Visual acuity defects were observed in 63.5% of the operators; in 36% of the cases the subjects were either unaware of the defects or the defects were not adequately corrected. 62.5% of the operators complained of subjective asthenopia symptoms. Asthenopia was not related to the number of hours at the VDT. The results suggest that ametropic subjects are likely to be more susceptible to visual fatigue than emmetropic subjects, since there was a tendency for the prevalence of asthenopia to increase in the former group. A significant decrease in refractive power (temporary myopization) was observed in 20% of the operators at the end of the shift at the VDT: all these subjects also complained of asthenopia, compared to 50% of the workers without end-of-shift myopization. The difference between the groups was highly significant (p less than 0.01); contrarywise, none of the subjects without asthenopia developed myopization. On the basis of these results, it can be concluded that end-of-shift myopization, as measured by an automatic refractometer, may be used as a reliable objective measurement of VDT-related visual fatigue.