Study of the aerogenic impact of formaldehyde on the health of child population

Introduction. Formaldehyde is a widespread environmental contaminant hazardous for human health; it belongs to the second hazard category for its inhalation exposure. Aerogenic inhalation exposure results in elevated risks of adverse effects on human health. Children are susceptible to such adverse effects produced by formaldehyde.

Materials and methods. We performed chemical-analytical studies on formaldehyde contents in ambient air, inside pre-school children facilities and schools, and biological media of children living in a large industrial city (the test group) and a rural area (the reference group) in the Western Urals.

Results. In the city, formaldehyde contents were 1.5 times higher in ambient air and 2.9 times higher inside pre-school children facilities and schools than in rural areas. Indoor air creates a more significant burden as per formaldehyde against ambient air, and its share is equal to 93% in the city and 87% in the rural area. The average group concentration of formaldehyde in blood was four times higher in the test group than the same parameter in the reference one. We also detected that formaldehyde contents were 7.6 times higher than the regional background level in the blood of children from the test group and 1.8 times higher in children from the reference group. We analyzed somatic morbidity as per nosologic categories and revealed that priority pathologies caused by exposure to formaldehyde were diagnosed 1.1–1.9 times more frequently in the test group than in the reference one (р<0.05). Regarding specific nosologies, priority nosologies were 1.8–9.7 times more frequent in the test group than in the reference group (р<0.05). We created statistically significant models showing dependence between a potential growth in morbidity with respiratory diseases, immune and nervous system diseases among children with elevated concentrations of free formaldehyde in the blood (R²=0.13–0.97; F=45.4–4,074; р≤0.001).

Limitations. In the study, the possibility of an increase in the incidence of the child population, associated with the possible influence of factors not studied in this work, cannot be ruled out. However, the revealed relationships between the content of formaldehyde in the blood and the somatic status of children according to the criterion of the probability of an increase in the number of diseases from an increased content of formaldehyde in the blood may suggest one of the reasons for the increase in the frequency of respiratory diseases, disorders of the immune system, diseases of the blood and blood-forming organs in children under aerogenic exposure to formaldehyde.

Conclusion. Having examined formaldehyde contents in air in the city and rural area, we established that toxicant concentrations were higher inside pre-school children facilities and schools in the city than in the rural area. High formaldehyde contents in the blood of children living in sizeable industrial cities occur predominantly due to aerogenic exposure to formaldehyde in indoor air and lead to more probable associated diseases of the respiratory, immune, and nervous systems.

Contribution:

Ulanova T.S. — concept and design of the study, editing;

Luzhetskiy K.P. — concept and design of the study, editing;

Karnazhickaja T.D. — writing text, collection and statistical processing of material;

Starchikova M.O. — writing text, statistical processing of material;

Pustobaeva M.S. — analysis of formaldehyde in blood by HPLC. All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Acknowledgement. The study had no sponsorship.

Received: July 6, 2021 / Accepted: November 25, 2021 / Published: March 10, 2022