A Study on Comparison of the Metabolites Related with Working Methods and Immunity of the Toluene diisocyanate-Exposed Workers / 대한산업의학회지

ABSTRACT

Following recent advanced industrialization. the amount of polyurethane to use as thermal insulating materials, upholstery mattresses and packing materials in automotive and furniture industry is increasing world-widely, and the number of polyurethane-producing worker will be increased. Because the numerous organic solvents are used in polyurethane-producing factory, the workers in this work site is exposed to many organic solvents. Of the organic solvents. Toluene Diisocyanate(TDI) has many hazardous effects to human. The effects of TDI on human are the irritation to respiratory mucosa and gastrointestinal symptoms. Conjunctival irritation, dermal inflammation (redness, pain, vesicular formation) and gastrointestinal symptom(nausea, vomiting, abdominal pain) are reported just after short-term exposure of TDI. TDI is known to give rise to bronchial asthma, as the immune disorder. And because of strongly volatile characteristics of TDI, it is suggested as a more injurious material to human health, especially human immune system, than other organic solvents. Bronchial asthma inducing mechanism of TDI is not clearly known, but on the analogy of TDI-induced symptoms and recent studies, early-onset asthma is type I hypersensitivity reaction mediated by immunoglobulin E(IgE), and late-onset asthma is maybe type III hypersensitivity reaction by circulating IgG. And we know that the complicated human immune function is likely to move in such that mechanisms, there are not studies on immune indices evaluating the bronchial asthma-related immune function. The evaluation of change patterns of humoral immunity including IgE and IgG and cellular immunity including T-helper cell, T-suppressor cell and T-cytotoxic cell will be helpful to evaluate exposure degrees and prognosis in TDI-exposed workers. Because TDA(toluene diamine) as a biological exposure index of TDI becomes the focus of interest, we know that a study on the correlation between urinary TDA and air TDI and immunological indices will make a contribution to biological effect monitoring indicies. We examined human immunity indicators such as WBC. %Lymph (percentile of Lymphocyte in WBC). %T-cell(percentile of T-lymphocyte in total lymphocyte). CD4, CD8, C3, C4, IgA, IgG, IgM, IgE in peripheral blood to evaluate the health hazard of the TDI-exposed workers. And we examined TDA to evaluate correlation between exposure and effect. Total 90 subjects was selected, 45 workers who worked in the polyurethane-producing factories as an exposed group, and 45 cases who were office workers(10 cases), other blue collors(27 cases), and medical college students(8 cases) as a control group. And the results were as follows ; 1. The logarithm of IgE -Log10(IgE)+/-SD- in peripheral blood of a exposed group was significantly higher than a control group, 2 22+/-.62 in case group compared with 1.98+/-.53 in control group.(p0.05). 3. WBC, %Lymph, %T-cell, C3, C4, CD4, CD8, CD4/CDB ratio and IgG in case group were 6,391.1 ea/ml, 37.53%, 59.54%, 76.68 mg/dl, 30.54 mg/dl, 0.76x10(9) ea/L, 0.63x10(9) ea/L, 1.39, and 1606.29 mg/dl, respectively, and 6,974.7 ea/ml, 35.12%, 59.64%, 71.95 mg/dl, 33.94 mg/dl, 0.80x109 ea/L, 0.61x10(9) ea/L, 1.39, and 1581.51 mg/dl in control group. There was no statistical sinificance between two groups. (p>0.05) 4. In the comparison of each other companies, average of individual urinary TDA in polyurethane paint manufacturing companies is higher than that of polyurethane sponge foaming companies. And, the concentration of 2,6-TDA which is a metabolite of well-vaporized 2,6-TDI is higher than that of 2,4-TDA in the polyurethane sponge foaming companies. But, the concentration of 2,4-TDA which is a metabolite of illvaporized but well skin-absorbed 2,4-TDI is higher in polyurethane paint manufactures. 5. There were no statistical significance in the correlations between individual urinary TDA and immunologic indices.