Bronchial asthma due to inhaled chloroplatinate

Platinum and its compounds have characteristics that make them excellent oxygen sensors, and in recent years they have come to be used in large amounts in the manufacture of internal combustion engines. Recently, there have been detected among workers engaged in making platinum oxygen sensors, dermatitis and bronchial asthma which appear to be ascribable to exposure to chloroplatinate. This is a study of their etiology from the viewpoint of industrial hygiene and clinical medicine. The results obtained are as follows: 1. Platinum-induced allergic disorders developed in a worker who applies about 50% chloroplatinate to zirconia porcelain. Although the concentration of platinum in the air was 2 μg/m3 or less as determined by ACGIH, the worker was directly exposed to the dried powder of ammonium chloroplatinate with relatively high concentration; while the exposure was intermittent and topical, it resulted in aspiration of the powder. 2. Bronchial asthma observed in 2 of 16 workers (12.5%) was reactive in a skin drop test with 1% chloroplatinate, and typical bronchial asthma was induced in an environmental provocation test carried out in a room where platinum sensors are made. Parameters obtained from periphero-hematological and immuno-serological tests were within the normal range. 3. The main symptoms revealed by physical examination of workers exposed to chloroplatinate contact dermatitis in 11 (78.6%), pharyngeal irritation in 6 (42.9%), nasal obstruction in 2(14.3 %), frequent sneezing, coughing, and sputum in one each. Diameter of the redness developed in a skin drop test with 1 % chloroplatinate administered to 14 workers was 10 mm or more in 7 cases (50%). VC, %VC, FEV 1.0, FEV 1.0%, PF/Ht, V25/Ht and MMF were within the normal range in a pulmonary function test. Although periphero-hematological test results and leukograms were within the nomal range, an immunoglobulin test revealed abnormally high IgE level in one patient. There was also observed an increased IgE level in one anamnesis of bronchial asthma. Immunoglobulin levels other than IgE were approximately within normal range.