Adam Muszyński

Background: Children spend a large part of waking hours in schools, which makes indoor air quality (IAQ) in classrooms a crucial determinant of their health, well-being, and cognitive performance. In Poland, most school buildings rely on gravity ventilation and have high children density in their classrooms. This leads to widespread and, to date, insufficiently studied indoor air quality problems.,Objectives: This study aimed to characterize, based on long-term, continuous measurements in 23 classrooms, indoor carbon dioxide (CO2) concentrations in Polish schools, to identify diurnal and seasonal patterns, and to assess ventilation adequacy relative to international guidelines.,Methods: Continuous CO2 monitoring using Kaiterra devices was conducted at 23 classrooms across seven primary schools in the Warsaw metropolitan area from January 2024 to December 2025. Hourly means of CO2 concentrations were analyzed for school days (06:00 – 15:59) and non-school days, assessing diurnal, seasonal, and inter-facility variability.,Results: Mean school-day CO2 concentrations ranged from 642 to 1,191 ppm, with 90th percentile values exceeding 1,600 ppm in most schools and peaking at 2,135 ppm. Maximum hourly values reached 2137-5306 ppm. December concentrations were 2-3 times higher than respective levels in June, which reflects strong seasonal variation of this parameter. Non-school day low concentrations (421-470 ppm) confirmed that classrooms occupancy was the main decisive factor for this parameter.,Conclusions: This longitudinal study showed that CO2 concentrations in Polish schools were often elevated, particularly in the heating season, showing that natural ventilation alone is insufficient. Targeted, evidence-based strategies are needed to ensure consistently healthy indoor air across classrooms in Polish schools.

Indoor spaces contain diverse microbial communities that shape human health. These microorganisms are particularly relevant to respiratory diseases, including asthma and allergies. Despite growing recognition of the importance of indoor microbial exposures, research in this field is slowed by differences in methods. These inconsistencies make it difficult to compare results and draw conclusions. This systematic review analyses 106 studies published between 2000 and 2025 that investigated indoor microbiomes in dust, air, and other matrices across homes, schools, and other built environments. We assessed sampling strategies, DNA extraction protocols, sequencing technologies, and bioinformatic pipelines, identifying trends, inconsistencies, and areas requiring harmonisation. Passive sampling, particularly dust collection, was the most common approach, while Illumina‐based 16S rRNA and ITS amplicon sequencing dominated molecular analyses. However, variations in targeted gene regions, extraction kits, and analytical tools limited cross‐study comparability. Ecological findings revealed consistent detection of bacterial taxa such as Staphylococcus , Streptococcus , and Corynebacterium , and fungal taxa including Cladosporium , Aspergillus , and Penicillium , with diversity shaped by building characteristics, ventilation, humidity, occupancy, and presence of pets. This review highlights the need for standardised protocols in indoor microbiome research to facilitate reproducibility, enable meta‐analyses, and inform health‐related guidelines for indoor environments.

NDOOR AIR QUALITY ASSESSMENT IN A HIGHER EDUCATION LIBRARY: IMPLICATIONS FOR ENVIRONMENTAL QUALITY IN EDUCATIONAL SPACES Brisa Braga,, Ermelinda Pereira, Susana Capitão, Fabiana Tiago, Paula Baptista, Manuel Feliciano HIGH-RESOLUTION MONITORING OF HYGROTHERMAL AND INDOOR AIR QUALITY: ARE MEDITERRANEAN SCHOOLS HEALTHY? Carmen María Calama-González Jesús Llanos-Jiménez; Rocío Escandón; Rafael Suárez INTELLIGENT LOW-COST MONITORS FOR INDOOR AIR QUALITY MONITORING IN SCHOOLS Hiten Chojer ; J.P. Sá,; P.T.B.S Branco,; F.G. Martins,; S.I.V. Sousa, HIGH SCHOOL STUDENTS’ RESEARCH ON ENERGY EFFICIENCY AND ENVIRONMENTAL QUALITY IN A SECONDARY SCHOOL BUILDING Miguel Díaz Sofía Zaragoza METHODOLOGY FOR CHARACTERISING INDOOR AIR QUALITY IN EUROPEAN SCHOOLS USING CONTINUOUS MONITORING AND GO-AQS INDICATORS Jose Fermoso; Sandra Rodríguez-Sufuentes; Alicia Aguado; Artur Badyda; Adam Muszynski; Piotr Kepa, Mariusz Rogulski, Alexandra Kristian CHILDREN’S RIGHTS TO SAFE, HEALTHY AND SUSTAINABLE EDUCATIONAL BUILDINGS IN SPAIN Enrique Hernández-Diez; Margherita Mini and Claudia Ponce de León Rodríguez URBAN CLASSROOMS AS POLLUTION AMPLIFIERS: FULL-YEAR EXPERIMENTAL EVIDENCE Alberto Leal Matilla; Alicia Zaragoza Benzal; Alexandra Míguez Souto; Daniel Ferrández Vega E+V MORE VENTILATED SCHOOLS: IMPROVING THE IAQ OF EDUCATIONAL CENTERS Fabian López Plazas; Eva Crespo Sánchez; Mònica Ubalde-López; Gloria Carrasco-Turigas; Silvia Gómez Araujo; Pablo Gonzalez Ruiz ENHANCING LEARNING ENVIRONMENTS THROUGH ADDITIONAL ACOUSTIC METRICS INTEGRATING IEQ PERSPECTIVES Juan Negreira; Nicolás Bermejo-Presa; Isabel Sánchez-Camacho ASSESSMENT OF INDOOR ENVIRONMENTAL QUALITY (IEQ) UNDER EPBD 2024 IN A ZERO EMISSION BUILDING. CASE STUDY Julio San José-Alonso, ; Yolanda Arroyo, ; Francisco J. Rey-Martínez, Luis J. San José-Gallego,; Alberto Rey ; Carmen A. García-García , and Javier M. Rey-Hernández ,. CITIZEN SCIENCE TO UNDERSTAND CHILDREN’S THERMAL COMFORT AND HEAT ADAPTATION PRACTICES AT SCHOOL Mar Satorras; Joana Ortiz; Carlos Chang; Elena Domene ENVIRONMENTAL MONITORING THROUGH IOT AND DIGITAL TWINS: A FRAMEWORK FOR INTELLIGENT BUILDING MAINTENANCE STRATEGIES Carmen Gómez, Francisco Castilla, Alejandro Lucas and Antonio Adán EVALUATING NATURE-BASED SOLUTIONS IN EDUCATIONAL ENVIRONMENTS: A METHODOLOGICAL MATRIX FOR EUROPEAN CASE STUDIES Hugo Canahua LIGHT AND TRANSPARENCY AS ENVIRONMENTAL VALUE. THREE EDUCATIONAL FACILITIES DESIGNED BY TRAZA ARQUITECTURA Francisco Felipe Muñoz Carabias; Manuel Rodrigo Gutiérrez de la Cámara FROM GIANT REED WASTE TO HEALTHY CLASSROOMS: LIME BASED ARUNDO DONAX L. PANELS FOR LOW EMISSION INTERIORS Jonathan Ruiz-Jaramillo; Carmen M. Muñoz-González; Ana Morales-Guisande; Milagrosa Borrallo-Jiménez

Indoor air quality (IAQ) is influenced by a wide range of chemical, biological and physical agents that can negatively impact physical, immunological and mental health. Adverse health effects depend on the type and concentration of pollutants, duration of exposure, and individual susceptibility. The availability of data on IAQ is limited, as are standardized approaches for evaluating its health impact. This expert review aims to describe the most important indoor air determinants affecting health, and present the IDEAL cluster, which comprises seven EU‐funded scientific projects on the topic of IAQ and human health. Across the IDEAL projects, knowledge is generated on exposure to a wide range of indoor air pollutants, including well‐known hazards and more explorative chemical and microbiological determinants. The projects will also contribute to the implementation of low‐cost and/or real‐time sensors on IAQ, as well as advanced chemical and microbiological analyses, and evaluate various interventions to improve IAQ. Several of them focus on particularly vulnerable groups. Raising public awareness and implementing measures to reduce pollutant levels are essential for safeguarding health, particularly in urban areas with elevated pollution levels.

Three semi-technical scale biofilters were applied to treat waste gases at different industrial sites in Poland: a mechanical–biological treatment plant of municipal solid waste, a wastewater treatment plant and a food industry plant. Two types of materials were used as beds in the biofilters: stumpwood chips and pine bark, and stumpwood chips, pine bark and compost from green waste. Both bed materials supported the microbial growth and high numbers (10⁶–10⁸ cfu/g dry mass (DM)) of culturable bacteria, and fungi in beds were observed. There was no correlation between the number of microorganisms (cfu/g DM) and the respiratory activity in the biofilter beds. However, microbial respiration activity corresponded with microbial abundance expressed as microbial equivalents (ME), which was calculated based on adenosine triphosphate (ATP) determination. The biofilters either reduced or increased bioaerosol emissions from industrial plants, depending on the microbial content in the waste gases. A high microbial content in the waste gases made the effect of microbial emission from the biofilter bed negligible. The type of biofilter bed and number of microorganisms in the bed also influenced the final bioaerosol emission, but these factors were relevant for biofilters that treated waste gases with low microbial concentrations.

The aim of the study was to assess the bioaerosol removal efficiency by a semi-technical scale combined biofilter used to treat waste gas from a food industry plant. Two types of biofilter beds were tested: stumpwood chips and pine bark (CB) and stumpwood chips, pine bark and compost (CBC). Two types of membranes (covering the surface of the bed) were examined as the second stage of treatment: Pro Eko Tex UV (M1) and Pro Eko Tex UV 6 (M2). A conventional open biofilter (without membranes) was an emitter of microorganisms. There was no statistically significant difference between the number of bacteria emitted from CB or CBC beds, but fungal concentration was three times higher in gas treated by the CBC bed. The use of the membranes as the second stage of gas treatment significantly reduced the bacterial emission (74–78%) from the biofilter regardless of the bed and the membrane tested. The M1 membrane was also efficient in fungi removal from the treated gas by 80–97%. However, the M2 membrane could have been slowly colonized by fungi and have become an additional emitter of fungi in the system.