Research Article Time-Resolved Characterization of Indoor Air Quality due to HumanActivityandLikelyOutdoorSourcesduringEarlyEvening Secondary School Wrestling Matches Derek G. Shendell , 1,2 Lauren N. Gonzalez, 1,2 Joseph A. Panchella, 3 and Jason Morrell 3 1 Rutgers School of Public Health (SPH), Department of Environmental and Occupational Health and Justice, Piscataway, NJ, USA 2 NJ Safe Schools Program, Rutgers SPH, Piscataway, NJ, USA 3 West Deptford School District, West Deptford, NJ, USA Correspondence should be addressed to Derek G. Shendell; shendedg@sph.rutgers.edu Received 23 February 2021; Revised 13 May 2021; Accepted 27 May 2021; Published 8 June 2021 Academic Editor: Marco Dettori Copyright © 2021 Derek G. Shendell et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Despite positive health outcomes associated with physical activity as well as individual and team sports, poor indoor air and environmental quality can adversely affect human health, performance, and comfort. We conducted a 14-month field case study incorporating two winter sports regular seasons (12/2017–2/2019) including analyses of particulate matter (PMx) in air and in dust, carbon dioxide (CO 2 ), temperature, and relative humidity (RH%) during secondary or high school wrestling activities in southern New Jersey, USA. After planning and piloting methods during the first winter sports regular season (12/2017–2/2018), during the second winter sports regular season (1–2/2019), we conducted a purposeful simultaneous real-time sampling midgymnasium adjacent to the wrestling mats. Gymnasium occupancy ranged 100–500 people. Data collected included inhalable PM 10 resuspended from floor mats, fine respirable PM 2.5 , and indoor CO 2 , temperature, and RH%. Short-term real-time elevated PM 10 levels were directly compared with simultaneously documented wrestling match bouts, e.g., student-athlete takedowns and pins. PM 10 and PM 2.5 levels were compared with other known documented activities indoors (e.g., snack bar) and sources outdoors (e.g., adjacentparking lot and major freeway). To understand CO 2 , temperature, and RH% data, we characterized the HS gym mechanical ventilation system—no doors or windows outdoors—and recorded occupancy during match hours. Indoor CO 2 levels ranged ∼700–1000ppm during match #1 on 1/23/2019 but ranged from ∼900 to 1900ppm during match #2 on 1/30/2019, with >1000 ppm for the majority of the time (and throughout the entire varsity match when occupancy was at maximum). Future research should further characterize PM 10 constituents in mat dust and indoor air with larger samples of schools and matches. 1. Introduction Children are more vulnerable to poor indoor air and en- vironmental quality in schools [1–5]. Indoor air quality (IAQ) or indoor air and environmental quality in schools have been extensively studied, with a focus on classrooms (e.g., Heudorf et al.) [1] or university sports facilities, in- cluding those used for gymnastics [2]. When exercising, the velocity of airflow increases, meaning particulate matter (PM) present in the air can penetrate deeper into the respiratory tract [6]. Levels of airborne PM in commercial and university gyms have been quantified by groups based in Europe [2, 7]. School gym- nasiums in Prague, Czech Republic, [8] and Cassino, Italy [9], have been studied during normal use, but specific time- course studies examining PM levels during specific sports activities in secondary schools are rare. Poor IAQ has been repeatedly associated with adverse effects on human health and performance and thermal com- fort. Temperature (T), relative humidity (RH%), and carbon dioxide (CO 2 ) contribute to IAQ. Increased respiration during exercise signifies quicker, deeper breaths in and increased CO 2 Hindawi Journal of Environmental and Public Health Volume 2021, Article ID 5580616, 9 pages https://doi.org/10.1155/2021/5580616