Relationship of Indoor Aerosol Pollution and Morbidity of Children in Primary Schools of Vilnius

Objective. Identify relationship of indoor aerosol pollution and morbidity in primary school children.

Materials and methods. Indoor aerosol pollution was measured in 7 schools in Vilnius (Lithuania) in 2017-2018. Retrospective analysis of 6-11 years old patients health history (number of upper and lower respiratory infections) from records of outpatient clinics was performed. 953 pupils from primary schools were involved. Total aerosol particle number concentration (PNC) in the size range of 0.01 – 1.00 µm was estimated using a Condensation Particle Counter (CPC, TSI model 3007). Particle number and mass concentrations in the size range of 0.3 – 10 µm were measured using an Optical Particle Seizer (OPS, TSI model 3330).

Results. The median values of PNC (CPC) and (OPS) in schools varied in the range of 1965 – 10194 part/cm³ and 16 -210 part/cm³, respectively. The maximum values of PNC (CPC) and (OPS) in schools varied in the range of 12379 – 30999 part/cm³ and 215 -1334 part/cm³, respectively. Morbidity positive correlation with the indoor aerosol pollution was obtained with the PNC (OPS) in the size range of 0.3 – 1.00 μm (95 ‰). Correlation coefficients determined for the seasonal morbidity and PNC data were equal to 0.45, 0.51 and 0.6 for autumn, winter and spring, respectively. Seasonal dependence of the morbidity on the PNC can be expressed by linear function with a constant term responsible only for morbidity due to the outdoor exposure and a term proportional to PNC in the size range of 0.3 - 10 µm. A value of the proportionality coefficient was estimated to be equal to 0.02, 0.12 and 0.03 for autumn, winter and spring, respectively.

Conclusion. Relationship between indoor aerosol pollution in schools and seasonal morbidity of primary school children was found. This study shall be continued involving a larger number of schools.