Search

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 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.

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.

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.

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.

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. 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.

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.

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.

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.

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.

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.

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.

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.

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.

An environmental hygiene study was carried out in a factory making aluminium alloy wheels via pressure moulding. Physical risk factors (noise and microclimate) and chemical risk factors (respirable dust, mineral oils, solvents, fluorides, formaldehyde, CO) were assessed. Analysis of the data showed that physical risk factors were prevalent, whereas chemical pollution was insignificant due to technical improvements made by the management in the course of several redesigns of the plants.

The frequency of micronuclei (MN) and cytology of respiratory nasal mucosa cells were evaluated in 15 non-smokers exposed to formaldehyde in a plywood factory. Each subject was paired with a control matched for age and sex. Mean levels of exposure to formaldehyde ranged from about 0.1 mg/m3 in the sawmill and shearing-press departments to 0.39 mg/m3 in the warehouse area. There was a contemporary exposure to low levels of wood dust (inspirable mass ranged from 0.23 mg/m3 in the warehouse to 0.73 mg/m3 during sawing operations). Nasal respiratory cell samples were collected by an otorhinolaryngologist near the inner turbinate using a brush for endocervical cytology. After staining (Feulgen plus Fast Green and Papanicolaou's method for MN analysis and cytology, respectively), about 6000 cells were screened for micronuclei and scored in parallel for cytology according to a histopathological scale. A higher frequency of micronucleated cells was observed in the exposed group than in the controls (0.90 +/- 0.47 vs. 0.25 +/- 0.22, Mann-Whitney U test: p less than 0.01). Cytological examination indicated chronic phlogosis in the nasal respiratory mucosa of plywood factory workers, with a high frequency of squamous metaplasia cells (mean score 2.3 +/- 0.5 vs. 1.6 +/- 0.5 in the control group, Mann-Whitney U test: p less than 0.01).

Two hundred and sixty seven workers employed in the manufacture of silicon carbide (SiC) were examined to determine the effects of exposure to contaminants (SiC, quartz, and SO2) in the workplace on pulmonary function. No exposure concentrations exceeded the current permissible limits. Ten subjects (3.7%) showed rounded opacities (profusion greater than or equal to 1/0). Two subjects employed only in the final stages of the production process and not exposed to crystalline silica showed opacities (profusion q1/0 and q2/1) on x ray film suggesting a role of SiC in the genesis of interstitial lung disease. Chest abnormalities on x ray film were correlated with cumulative exposure to dust and pulmonary function was affected by cumulative dust exposure, profusion of opacities, and smoking. It is concluded that the current standards do not provide adequate protection against pneumoconiosis and chronic pulmonary disease in this industry.

Here we have outlined the data relative to an environmental survey carried out in a laparoscopy clinic at the hospital of Padua, to determine the environmental concentration of nitrous dioxide (N2O) used for intra-abdominal inflation during diagnostic laparoscopy interventions. The data obtained have revealed cases of considerable N2O environmental pollution. This above all, due to spontaneous loss of gas during the intervention and to the lack of adequate ventilation systems.

In the present study we analysed 19 workers exposed to styrene in two factories where polyester resins were used. Because of the different sizes of the pieces undergoing resin processing, the environmental styrene concentrations and urinary mandelic acid (MA) levels of the analysed subjects were quite different in the two plants examined. Cytogenetic monitoring was performed by analysis of chromosome aberrations (CAs) and micronuclei (Mn) in peripheral blood lymphocytes. Cytogenetic analysis revealed a significant increase in the percentage of aberrant cells and total aberrations in the group with higher styrene exposure (group 2) and no increase in the group with lower exposure (group 1), as compared with matched controls. Mn frequencies were not significantly increased in the two exposed populations. No correlations between length of exposure and CA or Mn frequency were found, and a weak correlation was found between exposure levels, measured as urinary MA, and Mn frequencies. Only 5 of the 12 exposed workers examined in group 2 had urinary MA levels higher than the limit recommended by the ACGIH in 1990-91 [1]. Significant increases in DNA damage are therefore already found at urinary MA levels lower than the internationally suggested exposure limits.

Ten sanitary workers exposed to concentrations of ethylene oxide below 1 ppm were studied to determine whether effects could be observed at low exposure levels. A significant increase in the number of sister chromatid exchanges in cultured lymphocytes was found only for five subjects with relatively high exposure in the sterilization area. However, it was not possible to separate clearly the effect of smoking from that of ethylene oxide exposure. No increase in the frequencies of micronuclei in lymphocytes and buccal cells was found. The level of 2-hydroxyethyl adducts to the N-terminal valines in hemoglobin responded in a reliable fashion to chronic ethylene oxide exposure and smoking. Furthermore, measurement of levels of 2-hydroxyethyl adducts to the N-terminal valines in hemoglobin made it possible to reconstruct the dynamics of a leakage of ethylene oxide which involved three workers.

In 56 subjects with lead exposure that had terminated at least 3 a previously and in a reference group of nonexposed subjects, the behavior of several biochemical indicators of dose and effect were studied. The mean values for blood lead (PbB) (1.4 +/- 0.4 mumol/l), chelatable lead (PbUEDTA) (3.4 +/- 1.5 mumol/24 h) and free erythrocyte protoporphyrin (FEP) (62 +/- 25.2 micrograms/100 ml red blood cells) were found to be significantly higher in the subjects with past lead exposure than in the referents. The cut-off levels (mean + 2 SD calculated for the reference group) of PbB, PbUEDTA and FEP were exceeded in 35.7, 67.9, and 28.6% of the exposed subjects, respectively. A normalization of lead doses and indicators of effect was reached only when the exposure had not exceeded 2 a. The time elapsed after termination of exposure did not significantly reduce the PbB level and PbUEDTA excretion, whereas these parameters correlated significantly with the length of exposure. A close correlation was found between the PbB and the PbUEDTA. Due to poor sensitivity at PbUEDTA values of less than 5.3 mumol/24 h (91% of the cases), PbB and FEP were not useful for subjects whose exposure had terminated more than 3 a earlier. In these cases, only PbUEDTA was capable of revealing elevated active lead deposits.

The report concerns the AA. experience in the field of pollution due to solvents, particularly in the following industries: shoe manufacturing, graphics and the production and application of paints. The exposure risk in these 3 indutries is quantitatively and qualitatively defined based on data obtained from the gas--chromatographic analysis of 238 work environment samples. The data are evaluated with reference to limit values established by the ACGIH, the Italian Society of Occupational Medicine and the Italian Society of Industrial Hygiene. In additon to the evaluation with respect to the TLV and VLP, the hygiene parameter of TLVs for mixtures is evaluated in the field of industrial hygiene.

Exposure to toluene was studied in a group of 14 subjects working in a printing industry, who were exposed to this solvent only. Environmental monitoring was carried out using personal samplers for the whole workshift over three consecutive days. Toluene TWA concentrations ranged from 37 to 229 mg/m3. At the end of the workshift on each day of investigation, urine samples were collected for the determination of hippuric acid and ortho-cresol. Hippuric acid was also determined for urine before the workshift and on the Saturday and Monday mornings after the end of exposure; hippuric acid was also determined in 16 controls over the same five-day period. At the end of the workshift, hippuricuria levels in exposed workers always turned out to be statistically different from pre-workshift levels and those of the controls. The end-of-workshift hippuricuria levels of exposed workers were significantly correlated with the mean daily environmental concentration (TWA): in the three days of comparative study, we found r = 0.63 (P less than 0.05) on Day 1, r = 0.90 (P less than 0.001) on Day 2, and r = 0.87 (P less than 0.001) on Day 3. Ortho-cresol turned out to be correlated with daily exposure less significantly than hippuric acid: r = 0.49 (n.s.) on Day 1; r = 0.78 (P less than 0.001) on Day 2, and r = 0.65 (P less than 0.05) on Day 3. Using all available data (41 observations), a very significant correlation (P less than 0.001) was found between the TWA and both metabolites (r = 0.80 for hippuric acid; r = 0.68 for o-cresol). The values of the two metabolites in the end-of-workshift urine samples (41 observations) also turned out to be well correlated (r = 0.70; P less than 0.001). The authors conclude that hippuric acid is a valid test for evaluating even low exposures to toluene.

The purpose of the present study was to compare the most common hearing damage criteria, based upon pure tone audiometric data. We examined 1086 workers with different intensity and duration of noise exposure. After consecutive selections, 455 subjects, subdivided into four exposure groups, were studied. The 12 considered criteria showed a widespread difference in their sensitivity: the percentage of hearing impaired subjects ranged from 3.3 to 24.2% in the whole population. The most sensitive criteria evaluated the hearing loss at 2 and 4 KHz. The evaluation of the hearing loss at 3 and 6 KHz did not modify the percentage of subjects bearing an handicap. The authors suggest the average hearing loss at 2 and 4 KHz as a criterion to be used for preventing and epidemiological purposes.

Occupational exposure to ethylene oxide (ETO) was studied in ten workers employed in a hospital sterilizer unit by testing environmental air, alveolar air and blood during and at the end of the workshift. Alveolar (Ca) and blood (Cb) ETO concentrations were correlated with each other (r = 0.744, n = 36, P less than 0.001) and both with the environmental (Ci) concentrations (r = 0.947, n = 144, P less than 0.001; r = 0.827, n = 36, P less than 0.001). The alveolar retention of ETO (1-Ca/Ci) was equal to 75-80% of the inhaled ETO. In comparison with a blood/air partition coefficient equal in vitro to 90 (SD = 20), the mean Cb/Ca ratio found in the exposed workers was equal to 12-17. During work the blood ETO concentration was, on average, three times the environmental ETO concentration.

Exposure to cytostatic drugs was assessed in a group of 9 nurses employed in a hospital cancer therapy department by measuring the post-shift levels of urinary mutagens and cis-platinum. A slight but significant increase in urinary mutagenic activity compared to 11 controls was observed in the non-smokers: the mean values of mutagenic activity on the Ta100 strain in the presence of both microsomal and deconjugating enzymes were 4418 +/- 1186 and 2468 +/- 1681 respectively. Conversely, the urinary platinum concentration was below the detection limit of the analytical method (10 micrograms/l) in all samples. The increased urinary mutagenic activity in the exposed group can probably be attributed to the absorption of cyclophosphamide either during preparation and administration of the drug, or due to accidental contact with contaminated biological fluids, in view of the fact that the level of mutagens in urine samples from cyclophosphamide-treated patients is extremely high (up to 319,478 revertants/g creatinine in the case we examined).

The effects of lead on porphyrin metabolism and peripheral nervous system were studied in a group of 38 subjects who had not been exposed for a period of time, ranging from 3 to 27 years. The mean values for blood lead (PbB), chelated lead(PbUEDTA), and free erythrocyte protoporphyrin (FEP) were found to be significantly higher in the subjects with past lead exposure than in controls. In all cases the neurological examination was negative. The mean values for maximum motor conduction velocity (MMCV) and conduction velocity of the slower fibers (CVSF) of the ulnar and peroneal nerves were found to be significantly lower in the subjects with past lead exposure than in the control group of 23 subjects standardized for age. Signs of partial denervation were present in four cases, with two presenting a decrease of the motor conduction velocity (MCV) as well. No correlation was found between electrophysiological findings and biochemical indicators of dose and effect. The length of exposure showed a significant negative correlation only with the MMCV of the ulnar nerve. A significant difference from controls standardized for age was observed only in subjects with exposure of more than 6 months for all the electromyographic (EMG) parameters. It does not appear that the EMG findings could depend upon modest lead deposits still present in the organism; they should rather give evidence to the permanent effect of alterations that occurred during the prolonged exposure to lead.

Industrial exposure to toluene was studied in a group of 18 subjects working in a printing plant, exposed only to this solvent. Environmental monitoring was carried out using personal samplers for the whole work-shift. Urine samples were collected for the determination of hippuric acid and ortho(o)-cresol before toluene exposure, at the end of the work-shift, and 5, 9, and 17 h after the end of the work-shift. The values of two metabolites in all the urinary samples were corrected for g creatinine and specific gravity (1.024). Toluene time weighted average (TWA) concentrations ranged from 51 to 221 mg/m3 (7-h samples; two samplings lasting 3.5 h each). Urinary hippuric acid and o-cresol values at the end of the work-shift were significantly higher than the prework-shift values. Both hippuricuria and o-cresoluria end-of-work-shift values, corrected for creatinine and specific gravity, were significantly related to the mean daily environmental concentration of toluene, the correlation being weaker for o-cresol. Correlation coefficients were 0.88 and 0.84 for hippuric acid and 0.63 and 0.62 for o-cresol after correction for creatinine and specific gravity, respectively. No significant relationship was observed between environmental exposure and the values of the two urinary metabolites 5, 9, and 17 h after the end of the work-shift. Extrapolated values from the linear regression analysis at 375 mg/m3 were in good agreement with the biological exposure index (BEI) suggested by ACGIH for hippuric acid.(ABSTRACT TRUNCATED AT 250 WORDS)

Numerous n-heptane metabolites have been identified and quantified by gas chromatography and mass spectrometry in some tissues and in the urine of Sprague Dawley rats exposed for 6 h to 1800 ppm n-heptane. 2-Heptanol and 3-heptanol were the main biotransformation products of the solvent. 2-Heptanone, 3-heptanone, 4-heptanol, 2,5-heptanedione, gamma-valerolactone, 2-ethyl-5-methyl-2,3-dihydrofuran and 2,6-dimethyl-2,5-dihydropyran were also found as metabolites of n-heptane. In five shoe factory workers and in three rubber factory workers the mean exposure to technical heptane was measured (n-heptane ranged between 5 and 196 mg/m3). In the urine collected at the end of their work shift some n-heptane biotransformation products were found: 2-heptanol, 3-heptanol, 2-heptanone, 4-heptanone and 2,5-heptanedione. 2-Heptanol was the main n-heptane metabolite and its urinary concentrations ranged between 0.1 and 1.9 mg/l. Urinary 2,5-heptanedione was detectable only in some samples and at very low concentration (0.1-0.4 mg/l). These data suggest that n-heptane can be considered as a neurotoxic product, since it gives rise to 2,5-heptanedione, but the small amount of the urinary metabolite is very unlikely to cause clinical damage to the peripheral nervous system.

The effect of tricresylphosphate (TCP) was studied in vitro and in vivo on the rat liver and brain enzymes acetylcholinesterase (ACC), butyrylcholinesterase (CHE), arylesterase (ARE), aliesterase (ALI), and the microsomal nicotinamide-adenine dinucleotide phosphate oxidase (NADPH2-oxidase) system. The results show that, in the male rat, TCP given intraperitoneally induces an increase in liver microsomal ARE AND NADPH2-oxidase and a decrease in ALI and cholinesterase; no activation of ARE and NADPH2-oxidase is observed in female rats.

Determination of ethylene oxide (EtO) in the working environment and induction of sister chromatid exchanges (SCE) and unscheduled DNA synthesis (UDS) in peripheral lymphocytes of 10 exposed sanitary workers and 10 control subjects matched for sex, age, and smoking habits are reported. The relationship between the external dose of EtO and the frequency of SCE was determined in the above group and in a group of 41 sanitary workers previously studied. The 10 newly examined workers were exposed to EtO concentrations (1.84 ppm as time-weighted average) intermediate between the high (10.7 ppm) and low (0.35 ppm) levels of exposure of the two previously examined groups (19 and 22 workers, respectively). A statistically significant (p less than 0.002) increase of SCE frequency was observed between the present control and exposed groups. The inducibility of unscheduled DNA synthesis by gamma rays was lower in the lymphocytes of the exposed workers than in controls, but the difference was not statistically significant. A significant relationship between the frequency of SCE and the level of EtO exposure for the three exposed groups was demonstrated by two different statistical methods. It is suggested that the present Italian threshold limit value for EtO (3 ppm) may not protect the exposed workers against possible genotoxic effects and that even a chronic exposure to 1 ppm may not be devoid of genotoxic risk.

Evaluation of the current risk of lead poisoning in the ceramics industry. Scand j work environ health 9 (1983) 463-469. The authors evaluate the current possibility of lead poisoning in the production of ceramic tiles, an industrial sector which has always been considered dangerous due to the use of lead-rich glazes. The study was conducted in nine plants, four of which were repeatedly monitored (five checks on 94 exposed subjects). The other five plants (for a total of 221 exposed subjects) were only checked once. An analysis of all the results showed a clear reduction in mean blood lead levels, which the authors believe was due to the use of glazes with less lead. The results obtained were generally satisfactory; they indicated a definite improvement in the situation with respect to the authors' previous investigations, even for jobs in which workers were more frequently exposed. The data overlap those observed in the production of artistic pottery, which has always been considered less dangerous.

Occupational toluene exposure was studied during the workshift and the morning after by the analysis of environmental air, alveolar air, and blood. Environmental toluene exposure was measured by both continuous and instantaneous sampling. Instantaneous environmental toluene concentrations correlated better with alveolar toluene concentrations (r = 0.94; n = 155) than with blood toluene concentrations (r = 0.71; n = 52). Continuous environmental toluene concentrations correlated better with blood toluene concentrations (r = 0.84; n = 65) than with alveolar toluene concentrations (r = 0.52; n = 46). During the workshift and the morning after, blood and alveolar toluene concentrations correlated significantly with each other (r = 0.75; n = 66 and r = 0.67; n = 52). In a group of workers who were exposed to a mean environmental toluene concentration of 146 micromilligrams the concentrations of toluene in the alveolar air and blood the morning after were 3.2 micromilligrams (SD = 1.7) and 27.5 micromilligrams (SD = 12.7) respectively. With regard to the morning after toluene determinations, blood concentrations correlated (r = 0.52; n = 52; p less than 0.001) better than the alveolar concentrations with the corresponding afternoon values (r = 0.36; n = 52; p less than 0.01). The decline of the toluene concentrations from the end of one workshift to the start of the next exposure indicated a mean toluene half life of 3.8 hours in the alveolar air and of 4.5 hours in blood and therefore the 17 hour interval between two consecutive workshifts was insufficient for the complete elimination of absorbed toluene.

Among 1216 workers who were employed in a polyvinyl chloride production factory and who had had no previous dust exposure elsewhere, 20 cases of pneumoconiosis were found. Chest x-ray abnormalities were characterized by limited profusion, irregular type and low gravity. All 20 workers had been exposed to high PVC dust levels. The chest x-ray changes were observed after a minimum exposure of five years and, in a small percentage of cases, were associated with slight restrictive respiratory function impairments. Moreover, in the whole group of workers 388 cases (31.9%) were found with non-specific x-ray abnormalities mainly related to age and smoking.