Relationship of blood protein levels to outdoor air pollutant concentrations in a semicohort of school-age children living in urban areas differing by quality of air

Variations in some humoral immune responses to polluted air were studied in two semicohorts of children, initial age 10 years, from two urban communities differing from each other by the degree of ambient air pollution. The material for analysis (blood, saliva) was collected every autumn and spring in 3 successive years, giving a total of 6 sets of specimens for each examinee. All blood specimens were examined for the serum level of immunoglobulins (IgG, IgA, IgM), lysozyme (LYS), total serum protein (TP) and the level of the acute reactants alpha 2 macroglobulin (A2M), alpha 1 antitrypsin (A1AT), transferrin (TRF) and ceruloplasmin (CPL). The saliva specimens were examined for the level of lysozyme (sLYS) and secretory IgA (sIgA). The mean protein concentrations for each of the 6 sampling series were correlated with the mean of 24-h emission concentrations measured in the last 3 months preceding the autumn or spring sampling series. In the community area characterized by a low-degree non-industrial pollution of air the correlations of immunoglobulins to SO2 and floating particles (FP) in air were as a rule inversed while the response from TP, LYS and acute reactants was direct. In the community contaminated by industrial pollutants, correlations between proteins and SO2 were markedly weaker, but there was a significant positive correlation between H2S and levels of IgA and A2M in blood and sIgA and sLYS in the saliva. A high degree of positive correlation was also observed between H2S and levels of IgM and LYS. Inverse correlations were only between levels of LYS and FP, SO2 and H2S. Significant correlations were also between contaminant concentrations and FP. The associations found between the contaminant concentrations in air and levels of blood and saliva proteins supports the hypothesis that quality of air may have considerable impacts on defense mechanisms. Seasonal variations in the quality of air may increase the rates of childhood morbidity for acute upper respiratory tract infections.