[The problem of lead exposure in the Piedmont: from the workplace to the general environment]. / Il problema dell'esposizione a piombo in Piemonte: dal posto di lavoro all'ambiente di vita.

In the first part of this study, the most frequently professional lead exposure observed since 1984 at the Occupational Health Clinic of Turin University are summarized and compared with exposure observed in the past. The second part analyzes the present blood lead levels in the general (non-occupationally exposed) population observed in a screening campaign carried out in Piedmont in 1993-94 within the framework of the national programme by biology surveillance prescribed by Presidential Decree no. 496 of 1982. Results agree with literature data and show a reduction in blood lead levels markedly below the Italian legal limits. Nevertheless, lead pollution in non-exposed subjects still represents a major hygienistic problem, because a relevant number of children have blood lead concentrations above 10 micrograms/ 100 ml, which is considered a safe level for avoiding irreversible injury to nervous system.

Exposure to cobalt and nickel in the hard-metal production industry.

OBJECTIVE: The shortage of cobalt (Co) on the metal market forced the industry to add nickel (Ni) to Co as a binding agent for the sintering of hard metal. This change enabled us to study (1) the exposure to Ni powder and (2) the effect of Ni on Co uptake (and vice versa). METHODS: Equal amounts of Co and Ni were used in the mixture in a plant employing 50 workers. Both personal ambient-air samples and single-void urine samples were taken twice in the same week, i.e., on Monday and Thursday. Atomic absorption spectroscopy (AAS) was used for analyses. RESULTS: The airborne availability of Ni (mean value 41.65 +/- 6.29 micrograms/m3) was 2-fold that of Co (mean value 21.85 +/- 24.25 micrograms/m3), although the two series of data (n = 20) were significantly correlated. Even if the Co and Ni urinary concentration values (n = 45) recorded on Monday morning and Thursday evening were significantly correlated, at the end of the week there was a 3-fold increase, specifically, from 7.3 to 22.28 micrograms/l, in Co elimination (a significant difference) and a 30% increase in Ni elimination from 11.98 to 15.83 micrograms/l. Moreover, on Monday morning, 90% of Ni urinary concentration values were higher than those of Co as opposed to only 33% on Thursday evening. In the six cases in which both airborne and urine determinations were performed on the 2 days, no significant relationship was found between external exposure and biological monitoring data. CONCLUSIONS: Although Ni uptake was variable, it was generally low, whereas Co uptake was substantial, as had previously been observed in the same plant when Co was the only binder under use. It was therefore possible to rule out any influence of Ni exposure on Co uptake and to suggest the contrary, as has been demonstrated in bacterial species and in rats using everted intestinal sacs.

Asbestos bodies in bronchoalveolar lavage fluid and sputum.

The aim of the study was to determine the concordance of asbestos body (AB) detection in sputum and bronchoalveolar lavage fluid (BALF). AB were detected in the BALF of 110 former or current asbestos workers with medium weak exposure level and, for 65 subjects, in sputum. Several spontaneous sputum samples were taken from each subject. AB prevalence in BALF was rather low (48.2%) especially in subjects with former chrysotile exposure (32.5%). AB prevalence was lower in smokers (40.9%) and ex-smokers (40.7%) than in non-smokers (68.7%). In the sub-group, who underwent both sputum and BALF examination, the concordance of AB detection was observed only in 56.8% of the cases. Neither of the two methods had significant prevalence over the other but were complementary, as both are useful in increasing the probability of AB detection.

Relationship between asbestos bodies in sputum and the number of specimens.

OBJECTIVES: This study investigated the relationship between asbestos body identification and the number of sputum specimens obtained from each subject. METHODS: The presence of asbestos bodies in sputum was studied in 142 asbestos workers with former low-exposure levels; the number of specimens collected during 1-3 weeks varied from 2 to more than 4. Furthermore the persistence of asbestos bodies in the sputum of 15 asbestos workers was studied during a long-time follow-up. RESULTS: Asbestos bodies were present in at least 1 specimen in 44.4% of the 142 subjects. The cumulative percentage of asbestos body presence increased linearly, from 20% to 68%, as the number of specimens increased. CONCLUSIONS: Five specimens did not seem to be sufficient to obtain satisfactory sensitivity in a group with low exposure to asbestos. Neither the type of exposure (to chrysotile only or to chrysotile plus amphibole) nor the presence of an asbestos-related disease clearly influenced the probability of finding asbestos bodies.

Asbestos bodies in sputum of asbestos exposed workers.

The prevalence of asbestos bodies (AB) in sputum was studied in a group of 220 former or current asbestos workers, who came under observation because of a claim for compensation and who had, in most cases, high levels of exposure. Only one sputum specimen was obtained from each subject. The overall AB prevalence was 34%; it was 24.5% among workers exposed to chrysotile only, and 42% among workers also exposed to amphiboles, thus showing a statistically significant difference. No significant differences were found in AB prevalence either between current asbestos workers and former workers or between asbestosis cases and those without asbestosis. AB prevalence among current smokers was significantly lower than that observed among non-smokers and ex-smokers pooled together. The highest AB prevalence was found among currently exposed textile workers (65.7%), especially in male subjects (66.7%). As the exposure of these groups was heavy and included amphiboles, it may be concluded that although AB counts are highly specific they have low sensitivity.

In vitro biological effects of clay minerals advised as substitutes for asbestos.

We studied one sample of commercial sepiolite and two samples of commercial vermiculite--clay minerals proposed as replacements for asbestos--and tested in vitro their abilities to activate complement, to lyse erythrocytes, and to elicit the production of reactive oxygen species (ROS) with human polymorphonuclear leukocytes (PMN) or bovine alveolar macrophages (AM); their behavior was compared with that of asbestos fibers obtained from the Union International Contra Cancer (UICC) as reference standards, as well as with kaolinite and illite, main members of the clay mineral family. Since in short-term in vitro tests the biological activity of mineral particles seems especially related to the active sites on their surface, we first measured the specific surface area of each mineral. Sepiolite was unreactive in two of the three tests we used (complement activation and ROS production) and able to lyse a minimal percentage of red blood cells. Vermiculite was shown to be incapable of activating complement, to have a moderate hemolytic activity and a high ability to elicite ROS production, although lower than that of chrysotile. Sepiolite, therefore, might be of more interest than vermiculite, given the low level of biological effects detected during the tests used to compare both clay minerals with asbestos fibres. The ROS production does not seem to require phagocytosis. A high ROS production was observed with kaolinite: this result casts doubt on the ability of pathogenic mineral dusts in vitro to induce a greater release of ROS than nonpathogenic mineral dusts.

Factors related to the development of sensitization to green coffee and castor bean allergens among coffee workers.

BACKGROUND: Occupational allergic respiratory symptoms in coffee workers have been frequently reported, but the ultimate cause of sensitization is still debated, castor bean being considered besides green coffee beans. Atopy and cigarette smoking have been suggested as promoting factors of sensitization for several occupational allergens. OBJECTIVE: This study was carried out to assess the prevalence of allergic respiratory symptoms and of sensitization to both green coffee beans and castor bean in the whole workforce of a coffee manufacturing plant. Furthermore we wanted to ascertain both the presence of castor bean antigens in the settled dust of the green coffee beans warehouse and the possible crossreactivity between the two beans. Meanwhile, the effect of smoking and atopy was considered. METHOD: Two-hundred and eleven workers were examined. A questionnaire on oculorhinitis and asthma was administered and skin-prick tests for green coffee beans, castor bean and 15 common inhalant allergens were carried out. Isoelectric focusing, isoelectric focusing immunoblot and radioallergosorbent assay (RAST) inhibition were performed on samples of settled environmental dust from the green coffee area, as well as on castor bean and green coffee beans. RESULTS: Ten per cent of the workers complained of oculorhinitis alone and 16% of asthma (nearly always associated with oculorhinitis). The overall prevalence of skin-sensitization was: 15% for green coffee beans, 22% for castor bean, 22% for common allergens. Evidence of sensitization to occupational allergens was more common in smokers, with a more than twofold increase in relative risk. The strong association between skin positivity to common and occupational allergens suggests that atopy acts as an enhancing host factor towards occupational sensitization. The analysis of the dust confirmed the presence of castor bean antigens. CONCLUSION: Our findings indicate that castor bean is the major cause of occupational sensitization among coffee workers, whereas smoking and atopy act as enhancing factors.

Absorption and excretion of cobalt in the hard metal industry.

Absorption and excretion of cobalt in the hard metal industry was investigated by means of ambient air and urine measurements in three factories with high levels of environmental cobalt pollution. In the presence of poor hygiene conditions and permission to smoking during work, there was no relationship between cobalt ambient air and cobalt urine concentrations. Such a finding was therefore attributed to a substantial skin contact. A simple experiment of skin exposure to freshly mixed or waste powder on volunteers identified a ten-fold increase of cobalt in urine in the post-exposure samples, thus confirming the contribution of dermal exposure as a route of entry. An improvement in the hygiene of the working conditions helped to investigate the relationship between exposure and excretion level. Cobalt uptake through the different routes of entry may be substantial, and requires a more prolonged exposure-free period so that the excretion rate can be reduced to the reference population level.

Metal determinations in biological specimens of diseased and non-diseased hard metal workers.

Biological monitoring of Co, Ta and W, using mainly neutron activation analysis, was carried out on the urine, blood, pubic hair and toe nails of 251 subjects occupationally exposed to hard metal dusts (23 individuals were diagnosed as 'diseased subjects', affected by asthma and/or lung fibrosis). Airborne dust at hard metal workplaces were also analyzed for Co and W content. Cobalt and tungsten exposure at workplaces varied widely and frequently exceeded the TLV (0.05 mg Co/m3). Cobalt in urine (CoU), which is better than Co in blood (CoB), could represent a valuable indicator in discriminating between exposed groups, but is of little value as an indicator of exposure for single individuals. The high concentrations of cobalt in public hair (CoH) and toe nails (CoN) could also be valuable indicators of exposure although they are not useful, however, in establishing quantitatively the levels of cobalt accumulation. Tungsten and tantalum in pubic hair (WH and TaH) and toe nails (WN and TaN) also seem to be useful indicators in proving hard metal exposure qualitatively. The determination of these two elements, rather than cobalt, in the bronchoalveolar lavage (BAL) is very useful in complementing the diagnosis of hard metal disease proving hard metal exposure. The analysis of the BAL subfractions showed that W and Ta were firmly incorporated into the macrophage fraction while Co was distributed between cellular fraction and supernatant, which suggests a different mobility of hard metals in pulmonary tissue. The metal concentrations determined when submitted to statistical analysis indicated a positive correlation with P < 0.001 for the pairs (CoB-CoU), (Co-W) in urine, and (Co-W) in toe nails. Multielement analysis of biological specimens from diseased subjects suggests that hard metal disease does not relate to Co, W and Ta levels in the specimens considered. The disease does not depend on sex, age, working age and length of hard metal exposure. These findings support the theory on the possible haptenic properties of Co which may induce hypersensitivity and immuno-related toxic effects.

The prediction of recommended energy expenditure for an 8 h work-day using an air-purifying respirator.

Thirty railway workers executed maximal, or near maximal, stress tests with and without the use of a half mask air-purifying respirator (Spasciani 85 A1 P1) fitted with two combined filters for simultaneous protection from organic vapours and particulate matter. The pressure-flow characteristics of inspiratory and expiratory resistance at airflows in the range 0-90 l.min-1 were established by a continuous flow method on one test mask. Significant differences were found by paired t-test between the two exercises (with and without use of mask), showing reduced values with use of the mask, for breath frequency, ventilation rate, oxygen uptake, carbon dioxide production, maximal oxygen uptake, percentage of maximal voluntary ventilation used at the maximal exercise ventilation. No significant differences were found for tidal volume, respiratory quotient, heart rate, systolic blood pressure, oxygen uptake at anaerobic threshold, and duration of exercise. The predicted energy expenditure recommended for an 8 h work shift, corresponding to 40% of maximal oxygen uptake, is found to be reduced working with respirator and is significantly different from that observed during stress test without mask. The average ventilation rate at this workload is below 25 l.min-1, with predicted inspiratory mouth pressure equal to, or less than, 20 mm H2O. This maximal inspiratory mouth pressure is proposed as a safety limit for prolonged work using a respirator, with a recommended energy expenditure close to 40% of maximal oxygen uptake.

Exposure to metals that have recently come into use.

The possibility of deriving normal biological values for some rare metals is investigated. The metals under study are gallium, germanium, indium, niobium and tellurium, i.e. a group of metals with increasing utilization in the electronics industry. So far some data are unavailable for some of the elements, e.g. daily intake, oral absorption and half-life time for gallium, and body burden for gallium and germanium. Reliable values of blood concentration are available only for gallium, niobium and tellurium. The problem related to a proposed urinary biological limit value for tellurium is also discussed.

Airborne fibrous and non-fibrous particles in a silicon carbide manufacturing plant.

Silicon carbide (SiC) fibre generation is reported to occur during commercial SiC crystal production. Dust levels and fibre concentrations were measured by static sampling in an Italian plant operating 24 Acheson furnaces. X-ray Diffraction (XRD) was used to assess the quartz content in the dust collected. Optical microscopy (OM) and scanning electron microscopy (SEM) were used for fibre counting and identification of fibres. Only alpha-quartz was identified, but airborne concentrations were found to be higher than the concentration of crystalline silica reported in other similar studies. Two types of fibre, coarse and fine, were identified by OM and SEM: for both, only the peak of silicon (Si) was evident at energy dispersive X-ray analysis (EDXA). Coarse fibres are irregular in shape, with a diameter greater than 5 microns. Fine (respirable) fibres are straight, regular in shape, with a typical diameter between 1 and 2 microns. Fine fibre concentration does not appear to be related either to total dust or to total fibre concentration. It cannot therefore be predicted from the nature of the various processes involved.

A new case of occupational asthma from reactive dyes with severe anaphylactic response to the specific challenge.

A case of occupational asthma in a wool and cotton dyer handling reactive dyes is described. The patient was skin positive, but asymptomatic to house dust mites. A bromoacrilamidic dye (Lanasol Yellow 4G) has been identified through chamber inhalation challenge as being responsible for the sensitization. A very short (4-minute) exposure produced a severe immediate obstructive ventilatory defect followed by arterial hypotension and urticaria. Bronchial hyperresponsiveness as tested through metacholine challenge was absent both in basal conditions and after the dye challenge. Both prick and patch test for the dye were positive in the absence of any sign of contact dermatitis.

[Arterial hypertension and work activities]. / Ipertensione arteriosa e attività lavorativa.

Human work may be a causative agent in arterial hypertension (A.H.), for example through the action of toxic or physical agents such as lead and noise. The working environment is also a useful place for A.H. screening and assessment of therapeutic compliance. However, new cases of A.H. should be treated and followed up in order to avoid increased absenteeism. The choice of therapeutic drugs should take account of the type of job (i.e., amount of energy expenditure, sensorial charge, hot environment) and the shift, so as to achieve a single daily administration (for example using combined drugs). Hypertensive subjects could be advised against night work.