Serum immunoglobulin and complement C3 levels in workers exposed to lead.

Serum immunoglobulin and complement C3 levels were measured in workers exposed to lead at a secondary lead refinery and a solder factory. In the first survey, significant correlations were found between blood lead and IgA with a correlation coefficient of 0.296, and between blood lead and IgE with a correlation coefficient of 0.314. No other significant correlations were found among the indicators of lead exposure and humoral immunity. In the second survey, no significant correlations were found between blood lead and IgG and IgA. A significantly higher number of subjects with IgE of more than 400 IU/ml was found in the group with blood lead of more than 60 micrograms/100 g.     

Serum type III procollagen peptide: indicator for pulmonary fibrosis: II. Application in 80 asbestos insulation workers

An assay for type III procollagen peptide (P-III-P) was applied to serum from 80 asbestos insulation workers in order to evaluate its relationship with pulmonary and pleural fibrosis. The serum peptide levels of 16 control workers were 7.8 +/- 2.0 ng/ml (mean +/- SD). An association between the serum values of P-III-P and the profusion of small irregular opacities on chest X-rays was noted. The levels in the group with moderate interstitial pulmonary fibrosis [profusion category 2(2/1, 2/2, and 2/3)] and with marked interstitial pulmonary fibrosis [profusion category 3(3/3)] were 9.9 +/- 2.3 ng/ml (n = 5) and thus tended to be higher than those of 16 control workers (p less than 0.1). On the other hand, there was not correlation between serum peptide levels and pleural lesions nor between the former and duration of asbestos exposure. From the results of the investigation [part I of which is reported elsewhere (Okazaki et al, 1986)] this assay may be useful for detecting individuals with a more marked tendency for progression of interstitial pulmonary fibrosis due to asbestos exposure in insulation work.     

Serum immunoglobulin levels in workers exposed to benzene,toluene and xylene

Summary Immunoglobulin levels in the sera of 35 workers occupationally exposed to benzene, toluene and xylene were studied by means of a simple radial immunodiffusion. The immunoglobulin levels were compared with those of a control group of 42 healthy adults. A statistically significant decrease was observed in the IgG and IgA levels, accompanied by an increase in the IgM level. It is possible that this observation reflects a suppressive action of benzene on immunoglobulinproducing cells, resulting in the inhibition of DNA synthesis.     

Exposures and mortality among chrysotile asbestos workers. Part II: mortality

A retrospective cohort mortality study was conducted among a cohort of 1,261 white males employed one or more months in chrysotile asbestos textile operations and followed between 1940 and 1975. Statistically significant excess mortality was observed for all causes combined (standardized mortality ratio [SMR] = 150), lung cancer (SMR = 135), diseases of the circulatory system (SMR = 125), nonmalignant respiratory diseases (SMR = 294), and accidents (SMR = 134). Using estimated fiber exposure levels in conjunction with detailed worker job histories, exposure-response relationships were investigated. Strong exposure-response relationships for lung cancer and asbestos related non-malignant respiratory diseases were observed. Compared with data for chrysotile miners and millers, chrysotile textile workers were found to experience significantly greater lung cancer mortality at lower lifetime cumulative exposure levels. Factors such as differences in airborne fiber characteristics may partially account for the large differences in exposure response between textile workers and miners and millers.     

Immune response in shipyard workers with x ray abnormalities consistent with asbestos exposure.

The association of cellular and humoral immune responses with asbestos exposure was studied in two groups of 150 workers each from a shipyard population and compared with a population of Red Cross blood donors. One of the shipyard groups had both chest x ray evidence of asbestos exposure and work assignments that necessitated direct handling of asbestos. The other shipyard group had normal chest x ray films and no job assignments involving the direct handling of asbestos. Cellular immune responses studied were mitogen activation and measures of T helper and T suppressor cells. Humoral immune measures were IgG, IgA, and IgM. In shipyard workers with asbestos related x ray abnormalities there was a significant increase in pokeweed mitogen stimulation. In both shipyard groups compared with Red Cross blood donors were found (1) significantly higher IgG and IgA levels and (2) greater numbers of T helper and T suppressor cells; because of the disproportionately large number of T suppressor cells, Th/Ts ratios were lower than in the Red Cross controls. Observations of differences in humoral and cellular immune response may point the way to the early diagnosis of the clinical manifestation of asbestos related disease.     

Serum immunoglobulin,complement C3, and salivary IgA levels in lead workers

Sera of 72 lead workers and of 53 reference subjects were examined for levels of immunoglobulins IgM, IgG, and IgA, and complement C3 by radial immunodiffusion. Salivary IgA levels were determined in 33 lead workers and 40 reference subjects. On the average the lead workers had lower serum complement C3 and immunoglobulin levels, as well as lower salivary IgA levels, than the reference subjects. A significant negative correlation was found between blood lead concentrations (PbB) and the serum levels of complement C3 and IgG in the group of lead workers, as well as in the total population examined. However, a significant positive correlation was observed between PbB and serum IgA in the group of lead workers. The results obtained in this study are discussed in relation to numerous reports in the literature showing that lead exerts adverse effects on the immune system in animals.     

Serum type III procollagen peptide in asbestos workers: an early indicator of pulmonary fibrosis.

Serum type III procollagen peptide (PIIIP) concentrations were determined in 36 male workers exposed to asbestos fibres in the production of asbestos cement items and in 13 healthy male controls. Mean (SD) PIIIP serum concentrations were 9.3 (1.5) ng/ml (range 7-12) in the controls and 13.7 (3.5)ng/ml (range 7.5-20) in the asbestos workers; the difference was statistically significant (p less than 0.01). The exposed workers were subdivided according to presence or absence of radiological signs of asbestosis and intensity and duration of exposure. PIIIP serum values of workers with asbestos related interstitial fibrosis were the highest of the groups at 14.6 (2.3) ng/ml. In workers with heavy exposure the PIIIP values were significantly related to duration of exposure (r = 0.95; p less than 0.01). PIIIP serum values may be a useful index for the early diagnosis of asbestos induced pulmonary fibrosis and its use should be considered as part of the biological monitoring of exposed workers.     

Work-related injuries in young workers: an Italian multicentric epidemiological survey

Emergency departments records from 33 hospitals were reviewed to disclose work-related injuries occurred in teen-subjects living in 14 Italian cities. During January-June 2000, 317 work-related injuries were reported. Male subjects, 17 year old, working in the industrial field, resulted the most affected, probably due to the fact that among young workers this sex and age class is the most represented one. Cluster analysis identified two groups of work-related injuries: one includes mainly transportation injuries causing lower extremities or multiple body sites traumas. The other is more strictly related to specific working tasks and includes mostly traumas and cut wounds in hand/wrist and head, together with eye lesions. A more intensive supervision on the use of protective equipment, a more appropriate training in hazard recognition and safe work practices, including operation of vehicles in the work site, must be implemented to reduce work-related injuries.     

Serum immunoglobulin levels and malaria antibodies in Burkitt's lymphoma.

Data are presented to support a relationship between malaria infection and Burkitt's lymphoma in African children. IgG, IgM and IgA levels were measured in sera from Burkitt's lymphoma patients and from sex- and age-matched, nearest-neighbour controls. All three classes of immunoglobulins were present in significantly lower amounts in the sera from Burkitt's lymphoma patients than in the sera from controls. The mechanism of this apparent B-cell suppression is not yet clear. Malaria-specific IgG and IgM antibody titres were determined in the indirect immunofluorescence test. No significant difference in the IgG malaria-specific antibodies was detected between the two groups of sera. Malaria antibody levels measured using IgM specific conjugates were significantly lower in the sera from Burkitt's lymphoma patients in reactions with Plasmodium falciparum antigen. No significant difference was observed when P. malariae was used. Confirmation of this finding would serve as a positive link between Burkitt's lymphoma and P. falciparum infection.     

An environmental survey in chrysotile asbestos milling processes in India.

Environmental monitoring to determine airborne asbestos fiber levels has been carried out in four different mills processing chrysotile asbestos in the Cuddapah District (Andhra Pradesh) of India. The "membrane filter method" comprising standard asbestos sampling techniques, acetone-triacetin method for sample preparation, fiber counting, and sizing using the phase contrast optical microscope were adopted in the study. Fiber concentrations both with respect to personal exposures and processing areas were found in most of the cases to be much higher than the prescribed Threshold Limit Value (TLVs) of the developed and developing countries for chrysotile asbestos. By optical microscopy, fiber length distribution showed 70% of fibers in the milling processes were in size range > 5-10 microns, whereas in > 10-20 and > 20 microns, 20% and 8%, respectively. Fiber identification for major elemental content, also done by using scanning electron microscope equipped with an energy dispersive X-ray analyzer, indicated the presence of tremolite along with chrysotile. The study stresses the urgent need to adopt suitable engineering controls at the dust generating sources to reduce the fiber level in the mill environment below the threshold limit.     

Radiological changes in asbestos cement workers.

OBJECTIVE--To explore associations between exposure to asbestos cement dust and radiographic findings in lung parenchyma and pleura. METHODS--Radiographs from 174 blue collar workers and 29 white collar workers from an asbestos cement plant formed one part of the study. Progression of small opacities was further studied in those 124 blue collar workers, for whom two radiographs taken after the end of employment were available. The median readings from five readers who used the full ILO 1980 classification were used. As exposure indices, time since start of employment, duration of employment, cumulative exposure, and average intensity of asbestos exposure were used. The influence of age and smoking was also considered in multiple logistic regression analyses. RESULTS--Small opacities (profusion > or = 1/0) were closely correlated with time related exposure variables, and showed weaker association with intensity based exposure variables. The odds ratio (OR) for small opacities was equal to 2.8 (90% CI 1.2, 6.7) in the > 30 f(fibre)-y/ml group, compared with those in the 0-10 f-y/ml group. Progression of at least two minor ILO categories after the end of employment was seen in 20%. Also, pleural thickening was closely related to time. By contrast, costophrenic angle obliterations were not associated with the time related variables, but closely associated with the intensity of asbestos exposure, and tended to occur during employment. The OR was 4.5 (90% CI 1.3, 15) in the > 2 f/ml group, compared with those in the 0-1 f/ml group. CONCLUSIONS--In these workers, exposed mainly to chrysotile but also to small amounts of amphibole, the risk of radiographically visible parenchymal abnormality was substantially increased and strongly dependent on time related exposure variables. Progression was found long after the end of exposure. The findings on costophrenic angle obliterations, supposed to be sequelae of benign pleural effusions, were consistent with an immediate reaction triggered by intense asbestos exposure.     

Immune response in shipyard workers with x ray abnormalities consistent with asbestos exposure

The association of cellular and humoral immune responses with asbestos exposure was studied in two groups of 150 workers each from a shipyard population and compared with a population of Red Cross blood donors. One of the shipyard groups had both chest x ray evidence of asbestos exposure and work assignments that necessitated direct handling of asbestos. The other shipyard group had normal chest x ray films and no job assignments involving the direct handling of asbestos. Cellular immune responses studied were mitogen activation and measures of T helper and T suppressor cells. Humoral immune measures were IgG, IgA, and IgM. In shipyard workers with asbestos related x ray abnormalities there was a significant increase in pokeweed mitogen stimulation. In both shipyard groups compared with Red Cross blood donors were found (1) significantly higher IgG and IgA levels and (2) greater numbers of T helper and T suppressor cells; because of the disproportionately large number of T suppressor cells, Th/Ts ratios were lower than in the Red Cross controls. Observations of differences in humoral and cellular immune response may point the way to the early diagnosis of the clinical manifestation of asbestos related disease.     

Serum type III procollagen peptide in asbestos workers: an early indicator of pulmonary fibrosis

Serum type III procollagen peptide (PIIIP) concentrations were determined in 36 male workers exposed to asbestos fibres in the production of asbestos cement items and in 13 healthy male controls. Mean (SD) PIIIP serum concentrations were 9.3 (1.5) ng/ml (range 7-12) in the controls and 13.7 (3.5)ng/ml (range 7.5-20) in the asbestos workers; the difference was statistically significant (p less than 0.01). The exposed workers were subdivided according to presence or absence of radiological signs of asbestosis and intensity and duration of exposure. PIIIP serum values of workers with asbestos related interstitial fibrosis were the highest of the groups at 14.6 (2.3) ng/ml. In workers with heavy exposure the PIIIP values were significantly related to duration of exposure (r = 0.95; p less than 0.01). PIIIP serum values may be a useful index for the early diagnosis of asbestos induced pulmonary fibrosis and its use should be considered as part of the biological monitoring of exposed workers.