The study of indoor concentrations of organic compounds in school classrooms and accumulated blood xenobiotic levels in children

Abstract

The analysis of multicomponent chemical composition of atmospheric air and the air of residential and public premises, including school indoor air, is an urgent task of modern hygienic studies devoted to environmental quality and risk assessment of adverse health effects of dangerous chemicals. The priority sources of air pollution inside classrooms are finishing materials (linoleum, wallpaper, varnishes, paints, etc.) and emissions of monomers from furniture made of chipboards processed with polymer resins. The article demonstrates the results of screening tests establishing the levels of airborne toxic organic compounds (phenol, formaldehyde, benzene, toluene, ethylbenzene, and xylene) both inside and outside educational premises affected by various environmental exposures (conditional areas of observation and comparison). To assess the chemical body burden, blood levels of certain chemicals were measured in schoolchildren dwelling in the observation (study) and comparison (control) areas. Blood tests were accompanied by indoor and outdoor air monitoring in the educational establishments. We examined the total of 424 children including 231 students from primary, secondary and high schools of the city of Perm (observation area) and 193 schoolchildren of grades 1–11 living in the town of Kungur (comparison area). We established that the average daily concentrations of phenol and formaldehyde in indoor air in Perm were 2.4 and 5.6 times higher (р < 0.05) than those in Kungur. Outdoor concentrations of phenol and formaldehyde in Perm were 2.6 and 3.7 times higher than those in Kungur. The analysis of blood levels of certain organic compounds in the primary, secondary and high school children in Perm showed significantly higher concentrations of phenol, benzene, and toluene (p < 0.05) (1.5, 1.1, and 1.2 times, respectively). The average blood concentration of formaldehyde in the study group was 1.3 times higher (p < 0.05) than that in children of the comparison area. No significant differences between the comparison and observation groups (p < 0.05) were found in blood levels of xylene and ethylbenzene. Children’s blood concentrations of the identified organic compounds indicate the presence of external sources of exposure to these toxicants.