Screening and post-screening of air pollution markers in mixed saliva of preschool children

Abstract

Introduction. salivary diagnostics is a promising area that requires further research.The aim of the study. The two-stage study is aimed at identifying reliable biochemical and immunological markers of the influence of atmospheric air pollution in saliva samples in preschool children.Material and methods. Mixed saliva samples were taken from 112 children aged 5-7 years in 6 kindergartens located at distances of 1.7-5.9 km from the complex of agricultural processing enterprises. At the screening stage, the intensity of luminol-dependent chemiluminescence (LC), levels of secretory IgA (sIgA), IL-8, uric acid, activities of α-amylase, and lysosomal enzyme N-acetyl-β-d-glucosaminidase (NAG) were determined in saliva samples; at the post-screening stage, IL-1b and IL-6 were added.Results. In children at the screening stage only those markers that can be considered as indirect signs of phagocyte activation were associated with exposure levels to industrial zone emissions by significant equations: CL (y=6.98-0.17 x; p=7.2*10-9); IL-8 (y=776.2-83.2 x; p=3*10-4); NAG (y=13.94-0.93 x; p=0.037). To check whether this coincidence is random, we selected two additional markers in the form of functional “fork”: IL-1β (leukocyte pyrogen) and IL-6 (cofactor of B-lymphocyte differentiation). Methods of regression, correlation, and cluster analysis confirmed all 4 “phagocytic” markers significantly to increase along the gradient of industrial emissions and form a single cluster, cross-linked with significant correlation coefficients. IL-6 saliva content was associated with exposure levels by a rise-fall relationship, and, contrary to conventional beliefs, had no connection with sIgA content. The last finding may be related to the lack of ability of IL-6 and defensins to induce sIgA in mice [Boyaka et al., 2001].Conclusion. The survey results suppose that emission gradient from the industrial zone contains PM and does not contain haptens or immunotoxic compounds. Post-screening can be a useful technique when using saliva samples as insufficiently studied objects.