Sangyo igaku. Japanese journal of industrial health最新文献

Diseases caused by occupational exposure to sensitizing metals including platinum (Pt), rhodium (Rh), nickel (Ni), chromium (Cr), cobalt (Co), gold (Au), mercury (Hg), zirconium (Zr) and beryllium (Be) are reviewed. Allergic reactions induced by the metals are described according to the classification by Coombs and Gell. Metals with unproven sensitizing potential are not discussed if reports on these are either very rare or devoid of convincing evidence for allergic involvement. The sensitizing metals are haptens which are not themselves able to act as antigens. There is evidence that combination of the metals with circulating or tissue protein gives rise to new antigens. An alternative hypothesis is that these metals interfere with the antigen recognition step of the immune response. Immunomodulatory effects or immunotoxicity of the metals may be also involved in metal-induced hypersensitivity. Occupational exposure to Pt, Rh, Ni, Cr, and Co causes allergic asthma via type I allergic reaction in which serum from affected individuals shows specific IgE antibodies against mental-human serum albumin conjugates. Some rheumatoid arthritis patients treated with gold salt therapy develop glomerulonephritis, thrombocytopenia, or agranulocytosis, which arise from type II and/or type III allergic reactions. Occupational exposure to mercury causes glomerulonephritis in which involvement of type III reaction is suggested. Type IV hypersensitivity reaction of the skin also takes place following exposure to the metals: allergic contact dermatitis is evoked by exposure to Ni, Cr, Co, Rh, and Hg; cutaneous granuloma is formed by contact with Zr and Be. Be is also a sensitizer of the lungs, resulting in granulomatous disease. Diagnosis of metal-induced allergic diseases is made on the basis of allergological tests with metal antigens including skin tests, radioallergosorbent test for specific antibody, lymphocyte transformation test, macrophage migration inhibition test, and provocation test. Atopy is a predisposing factor and smoking is a risk factor for developing metal-induced asthma. Evidence for genetic factors in the development of metal contact dermatitis is conflicting, although animal models implicate genetic factors in skin sensitization with some metals and respiratory sensitization with Be. Skin irritation, forearm injury, complication with atopic dermatitis and concomitant sensitization to other agents are determinants for prognosis of the dermatitis. Epidemiological reports of occupational diseases from allergic reactions to metals in industries are reviewed with respect to prevalence and allergic manifestations. There is a report on a clinical trial of hyposensitization with Pt in a platinum asthma patient. Predictive methods for evaluating sensitization potential of metals have been developed and new methods, which quantify potential more objectively, are sought.

The effects of smoking and age on the results of hematologic tests were determined in a group of 429 healthy male workers. The results obtained were as follows: 1) The values of total leucocyte count (x10(9)/l), neutrophil count (x10(9)/l), lymphocyte count (x10(9)/l), monocyte count (x10(9)/l), hemoglobin (g/l), hematocrit, mean corpuscular volume (MCV; fl), mean corpuscular hemoglobin (MCH; pg), and mean corpuscular hemoglobin concentration (MCHC; g/dl) in current smokers were significantly higher than those in non-smokers. 2) Total leucocyte counts and neutrophil counts significantly increased with the number of cigarettes smoked per day in current smokers. 3) Total leucocyte counts, neutrophil counts, and lymphocyte counts significantly increased with Brinkman Index (B.I.) in current smokers. 4) The increase of age was significantly associated with the decrease of erythrocyte counts and the increase of MCV in both current smokers and non-smokers.

An experimental study on Japanese White (JW) rabbits was conducted to clarify the sex difference in FEP level. Male and female rabbits (n = 14 of each sex) were used. The animals of the same sex were divided into 3 groups; i.e., control group (5% glucose solution only, n = 4), low lead dose group (Pb 0.4 mg/kg.BW, n = 5) and high lead dose group (Pb 2 mg/kg.BW, n = 5). Lead was injected intravenously twice a week for 5 wk. The following parameters were determined once a week for 5 wk: blood lead (Pb-B), FEP, Ht, Hb, erythrocyte ALA-D activity, erythrocyte pyrimidine 5'-nucleotidase (P5N), urinary coproporphyrin (CP-U), urinary delta-aminolevulinic acid (ALA-U), iron in serum (Fe-S), and serum GOT and GTP. Average levels of FEP in female rabbits were higher than those in males between the 1st and 3rd week after the lead injection in the low lead dose groups, and in the final week in the high lead dose groups. In the periods without lead injection, the average levels of FEP in the female groups were not significantly higher than the corresponding levels in the male groups in every week except in the first week in the control. However, the mean of FEP levels in all female rabbits without Pb treatment was higher than that in male rabbits (t-test). By the analysis of variance for the gains of FEP from the initial value, only the low lead dose group showed a significant sex difference (female > male); that is, the female group tended to increase when compared with the male group. Furthermore, the week when FEP began to increase in the female groups was earlier than that in the male groups in the low lead dose group. In the high lead dose group, both sexes reacted to the lead exposure from the same early week. As for the parameters of anemia, the average levels of Ht and Hb tended to be lower in females than in males, but Fe-S levels were not affected by lead in both sexes and no consistent sex difference could be observed. By lead exposure, ALA-D and P5N were inhibited, and ALA-U was increased, but these parameters showed no evident sex difference. The average levels of CP-U tended to be higher in females than in males in the administration of low lead dose and to be inversely higher in males than in females in the administration of high lead dose.(ABSTRACT TRUNCATED AT 400 WORDS)

Biochemical examination and two-color flow cytometric analysis of lymphocyte subsets of the peripheral blood were carried out in 107 healthy males working in high noise environments. The level of hearing disorder was compared with these results. By audiometry at six frequency levels, 51 of the 107 healthy males showed hearing loss. Their mean value of hearing ability was 30 dB and/or above. Among the peripheral lymphocyte subsets, helper T cells of CD4+CD45R- were significantly increased and the CD4/CD8 ratio tended to be elevated. CD20 that indicate B cells were reduced. These results suggested a relationship between susceptibility to acoustic trauma and cell-mediated immunity.

A study was made on the cross-sectional relationship of the psychosocial work environment and personal health practices to mental health level among 15,639 male subjects aged 30-59 engaged in various kinds of occupations and firms. Mental health level was dichotomized by self-reported mental disorders. The psychosocial factors of work environment were conceptually constructed from the aspects of working conditions and occupational stress. Working conditions were assessed by work overload, work shifts and role in the organization. Occupational stress was measured by psychological work load and job characteristics (job demands and decision latitude). Various factors associated with positive health behavior--an index based on six parameters such as supper time, physical exercise, smoking, alcohol consumption, sleep, and weight--were examined. The prevalence of self-reported mental disorders was 17.5 per 1,000 population. Multiple logistic analysis showed that both psychological work load and health practice index have a significant independent effect on mental health levels after controlling for age and marital status. Limitations of the present study indicate a need for future longitudinal studies.