Samenvatting

In this report of inhalatory exposure to fly ash aerosol on the immune system of the rat are described. Effects on both specific immunity and on non-specific defense mechanisms were noted. With regard to non-specific defense machanisms NK activity appeared stimulated in rats exposed during 4 weeks (5 dyas per week, 6 hrs per day) to 10 and 30 mg fly ash/m3 whereas at a concentration of 100 mg/m3 a decreased activity was noted. Macrophage activity in exposed rats was signigicantly increased. With regard to specific immune system, in lung draining lymph nodes a signigicant increased number of both T and B lymphocytes was observed. In serum of exposed rats a significant increase of upto 150% of the IgA content was found. From these data it can be concluded that inhaltory exposure to fly ash aerosol influences the specific and non-specific defense mechanisms