This review is partly composed of the presentation "Cytokine alteration and speculated immunological pathophysiology in silicosis and asbestos-related diseases" delivered during the symposium "Biological effects of fibrous and particulate substances and related areas" organized by the Study Group of Fibrous and Particulate Studies of the Japanese Society of Hygiene and held at the 78th Annual Meeting in Kumamoto, Japan. In this review, we briefly introduce the results of recent immunological analysis using the plasma of silica and asbestos-exposed patients diagnosed with silicosis, pleural plaque, or malignant mesothelioma. Thereafter, experimental background and speculation concerning the immunological pathophysiology of silica and asbestos-exposed patients are discussed.

It is common knowledge that exposure to asbestos causes asbestos-related diseases, such as asbestosis, lung cancer and malignant mesothelioma, not only in people who have had long-term contact with asbestos in their work environment but also in residents living near factories that handle asbestos. Since the summer of 2005, these revelations turned into a large medical problem and caused and social unrest. We have focused on the immunological effects of both asbestos and silica on the human immune system. In this brief review, we introduce immunological alterations found in patients with malignant mesothelioma and describe the experimental background in which these were found. Analyzing the immunological effects of asbestos may improve our understanding of the biological effects of asbestos.

OBJECTIVETo evaluate the effect of exposure to rush-mat dust on the health of workers.

METHODSA cross sectional study of 661 workers (349 men, 312 women) from 35 rush-mat plants was carried out by using occupational health investigation, questionnare and physical examination.

RESULTSThe geometric mean total dust concentration in the workshop was up to 20.00 mg/m3, and the geometric mean respirable dust concentration reached 8.22 mg/m3. The mean free SiO2 concentration of accumulated dust was 25.6%. The prevalence of radiographic small opacities profusion category > or = 1/0, according to the China Classification for pneumoconiosis (GB 5906-2000), and compared with the ILO 1980 system, was 2.57%. Even more, one man had category 2 pneumoconiosis with progressive massive fibrosis. However, the incidence of pneumoconiosis (1/0 at least) was correlated with work duration and dust concentration(r = 1.156, P < 0.001; r = 0.106, P = 0.006, respectively). Some positive correlations were found between the incidence of cough or expectoration and occupational exposure (r = 0.085, P = 0.028; r = 0.094, P = 0.016, respectively).

CONCLUSIONTo our knowledge, this is the first report of rush pneumoconiosis in China. The results have offered the possibility of a dose-response relationship between rush-mat dust and pneumoconiosis. More investigation in this area is need.

Aluminum Silicates ; Chemical Industry ; Cross-Sectional Studies ; Dust ; Female ; Humans ; Male ; Occupational Exposure ; adverse effects ; Pneumoconiosis ; etiology