Peer Review Commentary (August 2026)
Performance Evaluation of Five Different Low‑Cost Particulate Matter Sensors for Monodisperse Test Aerosols
Martin Nothhelfer1 · Ana Maria Todea1 · Dieter Bathen1,2 · Christof Asbach1
Aerosol and Air Quality Research (2025) 25:17 doi.org/10.1007/s44408-025-00019-9
Comment: A detailed laboratory review by Christof Asbach’s group. Alphasense OPCs perform best up to 1000 PNC for particle size speciation, while the Tera NextPM and Sensirion SPS30 have other advantages and are limited when particle sizing.
Associations between acute exposures to PM2.5 and carbon dioxide indoors and cognitive function in office workers: a multicountry longitudinal prospective observational study
Jose Guillermo Cedeño Laurent, Piers MacNaughton, Emily Jones, Anna S. Young, Maya Bliss, Skye Flanigan, Jose Vallarino, Ling-Jyh Chen, Xiaodong Cao and Joseph G. Allen Environ. Res. Lett. 16 (2021) 094047 doi.org/10.1088/1748-9326/ac1bd8
Comment: Cognitive ability was measured in six countries where people were exposed to different PM2.5 and CO2 concentrations. PM concentrations above 12 µg/m3 showed reduced cognitive ability and slower response times. CO2 effects were more complex but also pointed to reduced cognitive ability at higher concentrations. The authors warned that country location and lifestyles were difficult to integrate in their analysis.
Parameterising the effect of human occupancy and kinetic energy on indoor air pollution
Dimitrios Bousiotis1, Dylan S. Sanghera1, Jenny Carrington2, Glyn Hodgkiss2, Farzaneh Jajarmi2, Khalid Z. Rajab3 & Francis D. Pope1
npj Climate and Atmospheric Science (2026) 9:4 doi.org/10.1038/s41612-025-01281-9
Comment: This study emphasises the need to understand occupant activity (kinetic energy) when considering CO2, TVOC, and particle concentrations.
The National Human Activity Pattern Survey (NHAPS): a resource for assessing exposure to environmental pollutants
Neil Klepeis, William Nelson, Wayne Ott, John Robertson, Andy Tsang, Paul Switzer, Joseph Behar, Stephen Hern, William Engelmann
Journal of Exposure Analysis and Environmental Epidemiology (2001) 11, 231–252 doi.org/10.1038/sj.jea.7500165
Comment: A milestone paper that quantifies that our indoor time is 87%. Also details the level of indoor ETS exposure in 2001, though ETS concentrations are now much reduced.
Detailed Investigation of the Contribution of Gas-Phase Air Contaminants to Exposure Risk during Indoor Activities
Anna L. Hodshire, Ellison Carter, James M. Mattila, Vito Ilacqua, Jordan Zambrana, Jonathan P. D. Abbatt, Andrew Abeleira, Caleb Arata, Peter F. DeCarlo, Allen H. Goldstein, Lea Hildebrandt Ruiz, Marina E. Vance, Chen Wang, and Delphine K. Farmer
Environ. Sci. Technol. (2022) 56 (17): 12148–12157 doi.org/10.1021/acs.est.2c01381
Comment: This important HOMEChem paper catalogues specific residential VOCs and their concentrations during normal activities, focusing on cooking, including a US Thanksgiving dinner. The commitment to analytical equipment is unsurpassed; there will soon be an updated study from this impressive group.
A review of microbial and chemical assessment of indoor surfaces
Victor G. Mihucz, Aimé Ruus, Jane Raamets, Lenka Wimmerová, Teresa Vera, Rossana Bossi & Kati Huttunen
Applied Spectroscopy Reviews (2021) 57:9-10, 817-889 doi.org/10.1080/05704928.2021.1995870
Comment: This paper explains how to sample surfaces for microbiologicals and how to analyse the samples.
Measurements of Hydroxyl Radical Concentrations during Indoor Cooking Events: Evidence of an Unmeasured Photolytic Source of Radicals
Emily Reidy, Brandon P. Bottorff, Colleen Marciel F. Rosales, Felipe J. Cardoso-Saldaña, Caleb Arata, Shan Zhou, Chen Wang, Andrew Abeleira, Lea Hildebrandt Ruiz, Allen H. Goldstein, Atila Novoselac, Tara F. Kahan, Jonathan Abbatt, Marina Vance, Delphine K. Farmer, Philip S. Stevens
Environ. Sci. Technol. (2022) doi.org/10.1021/acs.est.2c05756
Comment: Another paper from the HOMEChem project. The researchers struggled to measure the short-lived radicals generated during cooking, but when possible, they found that formaldehyde, OH radicals, and other reactive species will react with cooking vapours and aerosols, creating undesirable byproducts we should avoid. This paper is focused on radical chemical reactions.
Emissions of soot, PAHs, ultrafine particles, NOx, and other health-relevant compounds from stressed burning of candles in indoor air
Christina Andersen, Yuliya Omelekhina, Berit Brøndum Rasmussen, Mette Nygaard Bennekov, Søren Nielsen Skov, Morten Køcks, Kai Wang, Bo Strandberg, Fredrik Mattsson, Merete Bilde, Marianne Glasius, Joakim Pagels, Aneta Wierzbicka
Indoor Air (2021) 31(6): 2108–2123 doi.org/10.1111/ina.12909
Comment: This Swedish and Danish study found that candle burning emits significant volumes of black carbon, soot, and ultrafine particles. Pillar candles were tested, and soot and UFP emissions varied depending on the manufacturer. Candles are a serious health concern.
Natural Ventilation Reduces Cooking-Related PM2.5 Peaks Indoors
Yizhou Su, Yuqing Dai*, Zongbo Shi, Yirui Jiang, Lingchen Kong, and Christian Pfrang*
ACS ES&T Air (2026) 3 (2): 590–599 doi.org/10.1021/acsestair.5c00427
Comment: Published as part of the ACS ES&T Air special issue “Indoor Chemistry in the Context of a Changing Climate.” This study concludes that we should maximize ventilation when cooking to reduce PM — an intuitive conclusion backed by quantitative data.
Influence of Cleaning on Indoor Air Concentrations of Volatile and Semivolatile Organic Compounds in Residences
Nathan M. Sweet*, David M. Lunderberg, Betty Molinier, Eva Y. Pfannerstill, Erin F. Katz, Pawel K. Misztal, Yingjun Liu, Caleb Arata, Kasper Kristensen, Yilin Tian, William W. Nazaroff, and Allen H. Goldstein
Environ. Sci. Technol. (2025) doi.org/10.1021/acs.est.4c11274
Comment: A very detailed analysis of home cleaning, determining which specific chemicals are emitted during cleaning and their penetration into surfaces, re-emitting later.
Indoor Air Quality in Offices
Andrea Cattaneo, Andrea Spinazzè, and Domenico M. Cavallo
Handbook of Indoor Air Quality (2022) doi.org/10.1007/978-981-10-5155-5_77-1
Comment: This chapter from the 2022 Handbook of Indoor Air Quality provides a good overview of air quality problems in offices.
The INGENIOUS Project: Towards understanding air pollution in homes
Nicola Carslaw, Jennifer Aghaji, Sri Hapsari Budisulistiorini, David C. Carslaw, Lia Chatzidiakou, Rachael W. Cheung, Terry J. Dillon, Pete Edwards, Denisa Genes, Chiara Giorio, Jacqueline F. Hamilton, Erika Ikeda, Roderic L. Jones, James Lee, Alastair C. Lewis, Ashish Kumar, Rosemary McEachan, Gordon McFiggans, Tim Murrells, Nicholas Pleace, Athina Ruangkanit, Yunqi Shao, Simon P. O’Meara, David R. Shaw, Marvin Shaw, Dagmar Waiblinger, Tom Warburton, Sarah West, Chantelle Wood, Tiffany Yang
Environmental Science: Processes & Impacts doi.org/10.1039/D4EM00634H
Comment: This paper consolidates the work from the INGENIOUS project focusing on residential IAQ, reminding us that most indoor pollutants originate from our indoor activities.
Indoor air pollutants in an enclosed classroom: Impacts on cognitive performance and physiological mediation pathways
X. Gong, Y. Wan, D. Jiang, Z. Jiao
Measurement (2026) doi.org/10.1016/j.measurement.2026.121168
Comment: The authors have attempted to set CO2 and other limits for classrooms based on cognition studies. Worthwhile work, though not fully conclusive.
A state-of-the-art, systematic review of indoor environmental quality studies in work-from-home settings
Sanyogita Manu, Tobias Maria Burgholz, Fatemeh Nabilou, Kai Rewitz, et al.
Building and Environment (May 2024) doi.org/10.1016/j.buildenv.2024
Comment: A thorough literature review of thermal comfort when working from home, alongside productivity and ergonomics.
Field testing a rule-based ventilation controller designed to reduce energy use and improve indoor air quality in buildings
Theresa Pistochini, Graham Jaeger, Christopher Cappa, Matthew Ellis, Deborah Bennett
Science and Technology for the Built Environment (2026) 1–22 doi.org/10.1080/23744731.2026.2664366
Comment: The authors present an IAQ-energy system that relies on IAQ and thermal comfort parameters to optimize IEQ. A solid design study.
Challenges in developing ventilation and indoor air quality standards: The story of ASHRAE Standard 62
Andrew Persily
Building and Environment Volume 91 (September 2015): 61–69 doi.org/10.1016/j.buildenv.2015.02.026
Comment: Andy Persily has been involved with ASHRAE 62 from the beginning and reviews the development and decisions of this important standard.
Improving Indoor Air Quality through Standardization
John Saffell, Sascha Nehr
Standards (2023) 3: 240–267 doi.org/10.3390/standards3030019
Comment: A review of all CEN, ISO, and ASTM standards affecting IAQ up to 2023.
A review of relevant parameters for assessing indoor air quality in educational facilities
Pedro T.B.S. Branco, Sofia I.V. Sousa, Marzenna R. Dudzińska, Duygu Gazioglu Ruzgar, Mustafa Mutlu, Georgios Panaras, Giannis Papadopoulos, John Saffell, Ana Maria Scutaru, Christian Struck, Annemarie Weersink
Environmental Research Volume 261 (November 2024): 119713 doi.org/10.1016/j.envres.2024.119713
Comment: A literature review by members of INDAIRPOLLNET COST Action WG5, covering available literature for nurseries, primary, secondary, and university educational facilities.
A review of critical residential building parameters and activities when investigating indoor air quality and pollutants
María Teresa Baeza-Romero, Marzenna R. Dudzińska, Mehdi Amouei Torkmahalleh, Nelson Barros, Ann Marie Coggins, Duygu Gazioglu Ruzgar, Ivana Kildsgaard, Motahareh Naseri, Li Rong, John Saffell, Ana Maria Scutaru, Amelia Staszowska
Environmental Research Volume 261 (November 2024): 119713 doi.org/10.1016/j.envres.2024.119713
Comment: Another review article from INDAIRPOLLNET COST Action WG5, focusing on parameters and activities in the residential built environment.
Sampling and analysis techniques for inorganic air pollutants in indoor air
Florentina Villanueva, Milagros Ródenas, Aimé Ruus, John Saffell, Marta F. Gabriel
Applied Spectroscopy Reviews Volume 57 (2022) Issue 7 doi.org/10.1080/05704928.2021.2020807
Comment: A review of current research and commercially available analytical methods with comments on deployment for inorganic gases. Produced as part of the INDAIRPOLLNET COST Action group.
Measurements of the Limit of Detection for Electrochemical Gas Sensors
J. R. Saffell, N. A. Martin
Journal of Testing and Evaluation 52, no. 5 (September 2024): 2675–2684 doi.org/10.1520/JTE20230675
Comment: The UK National Physical Laboratory tested Alphasense NO2 A43F sensors in a controlled chamber to determine ozone filter capacity and measure the limit of detection (LOD) for these electrochemical sensors. Statistical analysis showed that the sensor RMS noise was 1.45 ppb, yielding an LOD of 4.5 ppb NO2.
Considerations of Thermodynamics and Kinetics for the Effects of Relative Humidity on the Electrolyte in Electrochemical Toxic Gas Sensors
Michael L. Hitchman, John R. Saffell
ACS Sensors (2021) 6: 3985–3993 doi.org/10.1021/acssensors.1c01339
Comment: Chemical and thermodynamic analysis of electrochemical gas sensors, focusing on the impact of humidity on the electrolyte and sensor performance. Written for chemists and low-cost electrochemical sensor developers.