THE IMPORTANCE OF VENTILATING CLASSROOMS IN THE PREVENTION OF RESPIRATORY INFECTIONS AMONG STUDENTS: CURRENT CONCEPTS

Abstract

The review examines the role of classroom ventilation in preventing respiratory infections among students and compares international evidence with the regulatory framework of Uzbekistan. Exhaled respiratory aerosol accumulates in poorly ventilated rooms, so the dose inhaled by occupants depends on how quickly indoor air is replaced with outdoor air. Observational studies in schools and workplaces link higher ventilation rates to less illness absence and a lower incidence of respiratory infection: in California classrooms each additional 1 L/s per person was associated with 1.6% lower illness absence, and in Italian schools mechanical ventilation above 10 L/s per student was associated with at least 80% lower risk of SARS-CoV-2 infection than natural ventilation. Carbon dioxide monitoring is a practical proxy for ventilation adequacy, although absolute CO2 thresholds alone do not describe infection risk. Direct evidence for university classrooms is scarce; in a survey of four Russian universities, 32.1% of classrooms reached 1000 ppm CO2 or more. The Uzbek sanitary rules for higher education institutions require natural ventilation with at least one air change per hour and airing during breaks; an illustrative calculation puts this at roughly 0.75–1.8 L/s per person, several times below the 10 L/s per person given in the WHO roadmap. The need for local measurements, CO2 monitoring and revision of the norms is discussed. The review is based on 20 sources, including books, WHO guidance, scientific publications of 1955– 2024 and Uzbek legal acts.