Abstract: Air pollution is caused by the increased concentration of any of its constituent above the normal value and this type of situation prevails in highly industrialized areas. SO2 is among the air pollutants which produces bad effects on human health. The value of IgG in industrial workers were high and IgM was low which might be due to repeated exposure to SO2 pollutant, IgM production was switched over to IgG which results in high level of IgG and low level of IgM. IgA level was low, which might be due to the transportation of circulatory lgA to the epithelial surface for defence.