Sage Journals: Discover world-class research

Abstract

Because of COVID-19, the indoor environmental quality (IEQ) in sports facilities has been a concern to environmental health practitioners. To develop an overall understanding of the available guidelines and standards and studies performed on IEQ in sports facilities, an extensive literature study was conducted, with the aim of identifying: (1) indicators that are being used to assess IEQ in different sports facilities; (2) indicators that are potentially interesting to be used to assess indoor air, in particular; (3) gaps in knowledge to determine whether sports facilities are safe, healthy and comfortable for people to stay and perform their activities. The outcome indicates that most current standards and previous investigations on IEQ in sports facilities mainly focused on dose-related indicators (such as ventilation rate), while building-related indicators (such as ventilation regime) and occupant-related indicators (such as IEQ preferences) were rarely considered. Little attention is given to the fact that ventilation systems may play an important role in the air quality of the location, and few investigations have been performed on the transmission of SARS-CoV-2. This study recommends more research into both occupant and building-related indicators as well as cross-modal effects between various IEQ factors for developing future standards on sports facilities.

Keywords

sports facilities indoor air quality indoor environmental quality ventilation comfort health

Introduction

Due to COVID-19 (Coronavirus disease 2019) in the past two years, many public buildings, including most sports facilities, were closed for a period of time due to being under lockdown. While the initial response to the spread of the coronavirus was slow, the number of deaths was increased,¹ as well as the amount of suffering from long covid.² Clearly, the risk of becoming infected with COVID-19 is higher in crowded and inadequately ventilated spaces.³ What was already actively communicated by several researchers from the start of the pandemic,⁴ namely that airborne transmission is a route of transmission requiring serious consideration, was finally acknowledged by the World Health Organization (WHO) on 30 April 2021.⁵ COVID-19 has raised the awareness of the complexity of the challenges ahead in designing adequate ventilation to keep building occupants safe, healthy and comfortable.^6,7 Considering the importance of sports activities for keeping a healthy lifestyle, the awareness of the significance of providing healthy and comfortable environments for playing sports, has increased. The question therefore arose, how can we ensure a healthy and comfortable indoor environment? On which basis can we determine whether these buildings are safe for people to stay and undertake sports activities both during a pandemic and during non-pandemic times? Specifically, what is needed to ensure a good indoor air quality (IAQ) in these sports facilities?

The quality of an indoor environment is determined by four indoor environmental quality (IEQ) factors: air quality, lighting quality, acoustical quality and thermal quality. These factors are interrelated: measures to improve IAQ might influence other IEQ factors.^8,9 Which measures can be applied to assure a good IAQ without deteriorating the other factors, is therefore an important question to answer. The health and comfort indicators that are available to assess IEQ can be divided into three groups of indicators:¹⁰ (1) the dose-related indicators, using the dose or environmental parameters, such as concentrations of certain pollutants, temperature level or ventilation rate; (2) the occupant-related indicators, focussing on occupants such as sick leave, productivity and the number of symptoms or complaints; and (3) the building-related indicators, which are concerned with buildings and its components, such as certain measures or characteristics of a building and its components, or even labelling of buildings and its components. Of these groups of indicators, the first one (dose or environmental parameter related indicators) is used most frequently in standards and guidelines. Whether these standards and guidelines for IEQ in sport facilities can be used to assure health and comfort during pandemic and non-pandemic times, is questioned. Moreover, do current guidelines and standards for IEQ take account of different interactions and different requirements for different types of sports facilities (sports halls, swimming pools, fitness centres), different occupants (sporters, spectators and personnel), events (such as sports, concerts and educational activities) and activities (e.g. swimming, football, gymnastics, fitness, spinning, dancing and yoga)? If not, what is needed to fulfil these requirements?

To answer the questions above, an extensive literature study was performed, focussing on different standards and guidelines applied in different countries and worldwide research performed on IEQ in sports facilities, with a focus on IAQ. Because sports facilities comprise of a whole range of typologies, the choice was made to consider the three most common types in the Netherlands: Gymnasia and/or sports halls, pools, and fitness centres and studios.

Methods

The literature study aimed at identifying:

1. Indicators used to assess IEQ in different sports facilities;

2. Indicators that are potentially interesting for use to assess IEQ, in particular IAQ, in different sports facilities;

3. Gaps in knowledge to determine whether sports facilities are safe, healthy and comfortable for people to stay and undertake their activities.

Three different types of sports facilities (see Figure 1) covered in this study are:

Gymnasia and/or sports halls¹¹:

Small Gymnasia used mainly by schools, usually are older buildings (before 1990)

Sports halls, which usually include more buildings, are infrastructures dedicated to indoor team sports such as basketball, handball and volleyball, have restaurants, etc.

Pools can be used for several aquatic sports such as swimming or water polo.¹¹

Fitness centres and smaller studios can offer a range of group classes and individual workout programs.¹²

Figure 1.

Different types of sports facilities. (a) Gymnasia (b) Swimming pools (c) Fitness centres.

Related publications were collected by searching in Google Scholar, ScienceDirect, PubMed and Wiley. Conference proceedings of Indoor Air, Healthy Buildings, CLIMA and ASHRAE Annual Conferences were also included. Additionally, national and international standards, guidelines and requirements on IEQ in sports facilities were retrieved by browsing the official websites such as WHO, ISO, CEN and various national governments. The keywords used for the literature search are shown in Figure 2.

Figure 2.

Keywords for literature search.

First, six queries (i.e. locations, activities, air quality, visual quality, thermal quality and acoustical quality) were created. Then, four separate searches were conducted for the four IEQ factors. Queries ‘locations’ and ‘activities’ were included in all searches. The relationships between queries are ‘AND’, while the relatio nships between the keywords within queries are ‘OR’. In total 229 publications were found based on the search. After careful selection, 60 were included in this review (detailed information can be found in Figure 2). Selection criteria included subject area (environmental science, engineering, social science), document type (article, conference paper, book chapter and review), language (English) and year (2000–2022). Additionally, 21 national and international IEQ-related standards and guidelines were checked.

Results

Current standards and guidelines on IEQ in sports facilities

Table 1 presents the current standards and guidelines on IEQ in sports facilities used in different countries. Some countries do not have specific standards on IEQ in sports facilities, or some of them are inaccessible. For the latter countries, the general standards on IEQ in all buildings, including sports facilities were reported.

Table 1.

Standards and guidelines on IEQ in sports facilities used in different countries.

Region	Country	Standards/guidelines	Building type	IEQ-related indicators
World	World	WHO Guidelines for Indoor Air Quality: selected pollutants¹³	All buildings	Benzene, CO, formaldehyde, NO₂, PAHs, radon, trichloroethylene, tetrachloroethylene
Asian	China	JGJ 31-2003 J 265-2003 Design code for sports buildings¹⁴	Sports hall/swimming pool	Temperature/relative humidity/air velocity/fresh air volume/reverberation time/illuminance
Asian	Japan	Environmental Quality Standards in Japan¹⁵	All buildings including sports facilities	Concentrations of CO₂/NO₂/SO₂/PM/benzene/trichloroethylene/tetrachloroethylene/dichloromethane
Europe	Europe	EN15251:2007 Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics¹⁶	All buildings including sports facilities	Temperature/relative humidity/ventilation rate/CO₂ concentrations/luminance/unified glare rating/sound pressure level
	Europe	EN 12193 Light and lighting – Sports lighting¹⁷	Sport halls	Luminance levels/uniformity of horizontal illuminance/colour temperature of the lighting
		EN 12464-1:2021 Light and lighting – Lighting of work places – Part 1: Indoor work places¹⁸	All buildings including sports facilities	luminance distribution/illuminance/glare/directionality of light/colour rendering and colour appearance of the light
		NEN-EN 16798 Energy performance of buildings – Ventilation for buildings¹⁹	All buildings including sports facilities	Ventilation rate/CO₂/, temperature/relative humidity/reverberation time/horizontal illuminance/formaldehyde/glare angle
		1SO 16000-11 Indoor air – Part 11: Determination of the emission of volatile organic compounds from building products and furnishing – Sampling, storage of samples and preparation of test specimens²⁰	All buildings including sports facilities	TVOC/SVOC/VVOC/aldehydes/
	The Netherlands	Handboek Huisvesting bewegingsonderwijs (2019)²¹	Sports hall	Temperature/air velocity/horizontal illuminance/evenness/background noise level. Reverberation time/ventilation rate
		Safety requirements for swimming pools – Design and management²²	Swimming pool	Temperature/relative humidity/air velocity
		Dutch building decree²³	All buildings including sports facilities	ventilation rate per person/ventilation rate per m²/inner surface temperature factor/air speed/dilution factor/lighting intensity/exposure time for undesirable noise
	UK	Code of Practice – The management and treatment of swimming pool water²⁴	Swimming pool	Temperature/relative humidity/ventilation rate
	France	Public Health Code Sanitary rules (Code de la sante publique)²⁵	Swimming pools	Transparency/the number of total coliforms/PH/germs concentration
	Spain	Regulation of thermal installations in buildings (RITE-2007) – IDA3²⁶	All buildings including sports facilities	PMV/ventilation rate per person/CO₂/olfactory comfort/a weighted noise level/
	Spain	NIDE 2021 – Halls and pavilions²⁷	Sports halls and pavilions	Ventilation rate/CO₂/, temperature/relative humidity/sound pressure level/illuminance
	Italy	CONI standards for sports facilities²⁸	Sports hall/swimming pool	Illuminance/temperature/relative humidity/air change per hour/air velocity/background noise level/reverberation time
	Germany	DIN19643 – Treatment of water of swimming pools and baths²⁹	Swimming pools	Water quality
	Germany	VDI 2089, Blatt 1³⁰	Swimming pools	Relative and absolute humidity; ventilation
NorthAmerica	Canada	Residential indoor air quality guidelines³¹	Not specific for sports, based on residences	Various contaminants/PM_2.5/VOCs
	USA	ASHRAE 62.1-2022 Ventilation and Acceptable Indoor Air Quality³²	Sports hall/swimming pool/fitness centre	Ventilation rate
	USA	ASHRAE Handbook – HVAC applications Chapter 6 – Indoor Swimming Pools³³	Swimming Pools	Air change per hour/air velocity/relative humidity/air temperature
		ASHRAE Standard 55–2020 Thermal Environmental Conditions for Human Occupancy³⁴	All buildings including sports facilities	Temperature/relative humidity/air speed

Note: CO = carbon monoxide; CO₂ = carbon dioxide; NO₂ = nitrogen dioxide; PAH = polycyclic aromatic hydrocarbons; PH = potential of hydrogen; PM = particulate matter; PM_2.5 = particles smaller or equal than 2.5 micron; PMV = predicted mean vote; VOC = volatile organic compounds; SO₂ = sulphur dioxide; TVOC = total VOC; SVOC = semi-VOC; VVOC = very VOC.

In terms of indicators used, they are quite consistent among these standards and guidelines and most of them are dose-related indicators. Additionally, there is no significant difference between these indicators and the indicators used in other types of buildings (such as offices or schools). For IAQ, the most used indicators in these standards and guidelines are ventilation rate and concentrations of indoor pollutants, such as formaldehyde and particulate matter (PM). For thermal quality, the indicators are temperature, relative humidity and air velocity. For visual quality, illuminance level and lighting uniformity are the most used indicators, while for acoustical quality, reverberation time and background noise are widely used.

ASHRAE has revised its IAQ-related standard ASHRAE 62.1 recently and changed the title from ‘Ventilation for Acceptable Indoor Air Quality’ to ‘Ventilation and Acceptable Indoor Air Quality’,³² which reflects ASHRAE’s recognition that IAQ goes beyond ventilation control. Although the minimum ventilation rate is still the main indicator used in this standard, information about certain contaminants and contaminant sources (including outdoor air, construction processes, moisture and biological growth) are also mentioned to guide the improvement of IAQ.

Apart from the dose-related indicators for IEQ, building-related indicators, such as occupancy, dimensions of a space, type of ventilation system, maintenance and cleaning schedules, type of materials used, type of lighting system and even colours of walls, floors and ceilings, can be important for keeping a healthy and comfortable environment in sports facilities. Some of these indicators may affect the IEQ directly.

Because these standards and guidelines for building-related indicators applied in different countries were difficult to assess or are not open to the public, this study mainly focused on the standards and guidelines used in the Netherlands. As mentioned in the Dutch Building decree,²³ sports facilities are often multi-functional, such as holding exhibitions or examinations, therefore, besides the requirements for sports functions, they must meet the requirements for meeting and educational functions as well. Table 2 lists several requirements of the building-related indicators mentioned in the Dutch Building decree,²³ the Dutch Handbook housing Physical Education,²¹ the NOCNSF-US1-RU.1³⁵ and the Handbook for fitness centres³⁶ that might affect the IEQ in sports facilities.

Table 2.

Requirements of building-related indicators for sports facilities in Dutch standards and guidelines.

Standards/Guidelines	Articles	Indicators	Functions	Requirements
Dutch building decree²³	1.2	Minimum number of persons per m² of a staying area	Sports	0.05
			Watching sport	0.75
			Education	0.33
	4.7	Height of staying area	Sports	2.1 m
	4.7		Education	2.1 m
Handboek Huisvesting bewegingsonderwijs (2019)²¹	6.1	Floor area of the gym	School gym	252 m²
	6.1	Height of the gym	School gym	5 m
	2.3	Maximum group size	School gym	30 students +1 teacher
NOCNSF-US1-RU.1³⁵	Normblad 3/4: Competition	Dimensions: minimum “free” height	Sport halls competition badminton, basketball, handball, volleyball, hockey	5.5 m 7 m
NL-Actief: Concept Handbook³⁶	10.2.4	Flooring material	Fitness facilities	Cleanable, no source for moulds, non-hygroscopic (no carpet)
	10.2.4	Flooring walls ceiling	Fitness facilities	Colour reflection factor between: 0.25 and 0.40 0.45 and 0.60 0.60 and 0.80
	11.1	Ventilation	Fitness facilities	Quality and distribution of air are important

Besides the above-mentioned standards and guidelines, in several European countries labelling schemes are available for assessing whether a certain product stays below emission limits for certain VOCs, carcinogens and odours. For example, the AgBB protocol for flooring materials,³⁷ which is a regulatory scheme, and the voluntary scheme M1 (Emission Classification of Building materials) of Finland.³⁸ Most of these labelling schemes are based on the protocol described in ISO 16,000-Part 11.²⁰

IAQ in sports facilities

IAQ is an important factor to consider in sports facilities, however, no consensus exists as to which parameters are of greatest concern to occupants, whether trainers or spectators alike, as these parameters can be different from location to location. Some of the most prevalently monitored parameters in sports facilities, in different countries, are CO₂, relative humidity, PM, certain VOCs and NO₂. Additionally, ventilation requirements are frequently considered, such as air changes per hour, the maximum air velocity, and, less frequently, the ventilation per unity of surface and the perceived air quality in the facility.

A review of studies performed in three diverse types of sports facilities is presented: sports halls, swimming pools and fitness centres. Specifically, the review includes the indoor air quality requirements for sports halls, swimming pools and fitness centres, respectively, with a focus on the main problems found at each type of location and the methods used for assessment as well as the common indicators for assessment.

Table 3 presents the pollutants monitored in the indoor air quality studies that are reviewed in this paper. Six main pollutants are commonly investigated in sports halls (NO_x, magnesia alba, acetone, CO₂, formaldehyde and VOCs), four in fitness centres (PM₁₀, VOCs, fungi and yeasts, and bacteria) and four in swimming pools (PM_2.5, VOCs, fungi and yeasts, and water disinfection by-products), regardless of the ventilation system present at each type of location.

Table 3.

Main pollutants, their sources, effects on humans, location and ventilation system, per type of sports facility presented in the reviewed studies.

Pollutant	Source	Ventilation type	Facility type	Effects on human health	Ref.
NO_x	Outdoor traffic	NaturalMechanical	Sports halls	CoughShortness of breathTirednessNausea	^39,40
Magnesia alba	Occupant use	NaturalMechanical	Sports halls	Skin and respiratory irritantCoughWheezeChest tightness	^39,41,42
Acetone	PolishWaxDetergentsCleaners	Natural	Sports halls	Eye and respiratory irritantHeadacheDizzinessLight headednessNervous system effects	^39,40
CO₂¹	OccupancyAthletesSpectatorsPersonnel	NaturalMechanical	Sports halls	TinglingDizziness (high exposure)	⁴³
Formaldehyde	Composite woodProducts with urea-formaldehyde resinFinishingsTobacco smoke Combustion processes Pressed wood adhesives	Natural	Sports halls	Eye, nose and throat irritation (low exposure)RashesShortness of breathWheezing (high exposure)	³⁹
PM₁₀	Climbing chalk (magnesia alba)Resuspension from physical activityCleaning activities	NaturalMechanical	Sports hallsFitness centres	CoughAsthma exacerbationBronchitis	^41,44-46
PM_2.5	Resuspension from physical activities	Mechanical	Swimming pools	Eye, nose, throat, lung irritantCoughSneezeRunny noseShortness of breath	^47-49
VOCs	Cleaning activitiesDisinfection by-productsAlcohol-based disinfectant	NaturalMechanical (influenced by the efficiency of air filtration)	Sports halls Swimming poolsFitness centres	Eye, nose and throat irritation Shortness of breathHeadachesFatigue NauseaDizziness Skin problems	^39,40,48-50
Fungi and yeasts	High humidity Activities (perspiration, respiration)	Natural (fitness centres) Mechanical (swimming pools)	Swimming pools Fitness centres	Respiratory disorders Allergies	⁵¹
Bacteria	Air velocity Relative humidity High temperatures	Mechanical	Fitness centre	Respiratory disorders	⁵²
Trichloramine Trihalomethanes Chloroform Bromoform Bromodichloromethane	Water disinfection with bleach	Mechanical ventilation (HVAC)	Swimming pools	Shortness of breath Eye, nose, throat irritation	^53-55

¹As an indicator of human bio-effluents.

Table 4 presents the requirements of dose-related ventilation indicators for assessing sports facilities presented in standards and guidelines of the Netherlands, CEN and ASHRAE. Similar as the information shown in Table 1, ventilation rate is the most used indicator for assessing IAQ.

Table 4.

Requirements of dose-related IAQ indicators for sports facilities.

Standards/Guidelines	Articles	Indicators	Functions	Requirements
Dutch building decree²³	Article 1.2 Number of persons	Capacity (persons/m² of staying area)	Sports	0.05
	Article 1.2 Number of persons	Capacity (persons/m² of staying area)	Watching sports	0.75
	Article 3.29 Ventilation in staying area, staying space, toilet space and bathroom space	Ventilation	Sports	0.7 dm³/s⋅m² or 7 dm³/s
			Toilet	7 dm³/s
			Bathroom	14 dm³/s
	Article 3.33 Location of the opening	Dilution factor	sports	0.01
Handboek Huisvesting bewegingsonderwijs (2019)²¹	6.8 Ventilation	Ventilation rate	sports hall for education	40 m³/h/p 7 m³/h/m²
Handboek Huisvesting bewegingsonderwijs (2019)²¹	8.1 Changing room and washroom	Ventilation rate (ACH)	showering	10 h⁻¹
NOCNSF-US1-RU.1³⁵	Normblad 3/4: Competition	Ventilation rate	sport halls: players spectator	40 m³/h p 20 m³/h p
NL-Actief: Handbook³⁶	11.3	Ventilation rate (ACH = air changes per hour)	fitness facilities	6 h⁻¹ (summer); 4 h⁻¹ (winter)
			Fitness lessons	8 h⁻¹ (summer); 6 h⁻¹ (winter)
			spinning	10 h⁻¹ (summer); 8 h⁻¹ (winter)
			body & mind	6 h⁻¹ (summer); 4 h⁻¹ (winter)
EN15251:2007¹⁶	Table B.2	Ventilation rate	Auditorium	15 L/s/m² (Ⅰ) 10.5 L/s/m² (Ⅱ) 7 L/s/m² (Ⅲ)
EN15251:2007¹⁶	Table B.4	CO₂	All buildings including sports facilities	350 ppm (Ⅰ)¹500 ppm (Ⅱ)800 ppm (Ⅲ)>800 ppm (Ⅳ)
NEN-EN 16798 Energy performance of buildings – Ventilation for buildings¹⁹		CO₂	All buildings including sports facilities	550 ppm (Ⅰ)¹800 ppm (Ⅱ)1350 ppm (Ⅲ)
ASHRAE 62.1-2022 Ventilation and Acceptable Indoor Air Quality³²	Table 6-1	Ventilation rate	Gym, sports area	10 L/s/p; 0.9 L/s/m²
			Spectator area	3.8 L/s/p; 0.3 L/s/m²
			Swimming pool	2.4 L/s/m²
WHO Guidelines for Indoor Air Quality: selected pollutants¹³		Benzene	There is no known exposure threshold for the risks of benzene exposure. Therefore, from a practical standpoint, it is expedient to reduce indoor exposure levels as much as possible
		CO		15 min: 100 mg/m³1 h: 35 mg/m³8 h: 10 mg/m³24 h: 7 mg/m³
		Formaldehyde		0.1 mg/m³ (30-min average concentration)
		Naphthalene		0.01 mg/m³ (annual average concentration)
		NO₂		1 h average: 200 μg/m³ annual average: 40 μg/m³
		PAHs		0 (all levels are considered to be relevant to health
		Radon		Non-smoker: 0.6 × 10⁻⁵ Bq/m³; smoker (15–24 cigarettes per day): 15 × 10⁻⁵ Bq/m³
		Trichloroethylene		4.3 × 10⁻⁷ μg/m³
		Tetrachloroethylene		Annual average: 0.25 mg/m³

¹recommended CO₂ concentrations above outdoor concentration.

IAQ in sports halls (schools/public)

Several studies focus on the difference between indoor and outdoor air by monitoring NO₂. Generally, NO₂ is found to be higher outdoors, due to the presence of nearby traffic. Furthermore, TVOC tend to spike during the cleaning activities and decrease overnight. Acetone is another pollutant found to be higher in sports halls. The source of acetone has been assumed to be wood polishers and waxers, certain detergents, glues and cleansers.^39,40

Another pollutant that is prevalent in sports halls is magnesia alba. Using this chemical, magnesium carbonate hydroxide is popular amongst athletes for drying their hands in different disciplines (climbing, bouldering, weight lifting, gymnastics, etc.).^41,42 Magnesia alba is attributed as the main reason for the high particle levels of PM₁₀ in sports halls.³⁹ In most studies conducted in large sports halls, whether in schools, universities or public spaces, PM₁₀ was found to be an important pollutant and seemed to be mainly dependent on the activities exercised in the halls, occupancy rates and cleaning activities. Additionally, there are specific activities that stimulate the resuspension of particles (from PM_2.5 to PM₁₀), namely those that make use of foam mats.^41,44,45

Other researchers focused on the infection risk of diseases in sports halls with different ventilation systems (split-airco unit and central air conditioning). In one study the risk of influenza and tuberculosis was analyzed by assessing CO₂ concentration levels and by using the Wells-Riley model. Results showed that regardless of the ventilation, the risk of infection was highest during the evenings, with the highest occupancy levels. The researchers suggested that sports halls are in need of efficient ventilation systems, that can maintain CO₂ concentration at a low level to reduce the risk of viral infection.⁴¹

Suggestions to improve the IAQ in sports facilities include adequate mechanical ventilation with appropriate filters, suitable cleaning practices and limited occupancy. It is also suggested that because in these locations people increase their breathing rate, air quality requirements should be stricter.⁵⁶

IAQ in swimming pools

Swimming pools can present a different challenge to the IAQ of a space, caused by the large volume of high humidity and temperature. Both personnel and athletes in swimming pools and aquatic centres can suffer from eye, nose and breathing symptoms, due to the chlorinated chemicals in the air released from the chlorination of water and exposure to disinfectants and their by-products. The exposure of such pollutants can occur through ingestion of the swimming water, inhalation of the compounds or by skin contact.⁵⁷ Swimming pool chlorination can cause the emission of trichloramine and trihalomethanes, such as chloroform.^53,54 PM_2.5 concentrations in swimming pool halls tend to be higher than in other sports facilities, likely due to the chlorination used in the disinfection process of the water.⁴⁷ Furthermore, chloroform is the main emission coming from pool water into the air; while other VOCs are negligible.

Other pollutants that have been found in swimming pool halls and aquatic centres are fungi and yeasts in suspension, in the air, water or on surfaces, and can represent a health risk to swimmers and personnel. These yeasts and fungi were of the species Penicillium, Aspergillus, Cladosporium and Alternaria, which were detected in the air and surfaces sampled in ten pools in Italy.⁵¹

Suggested solutions for the control of the emission of trichloramine and trihalomethanes to keep concentrations below 0.3 mg m^-³ are to separate solid particles from the swimming water to form loose aggregations or soft flakes (flocculation), the use of adequate ventilation with appropriate filters, control of water flow and filtering, regulating water quality and ensuring good public hygiene to avoid urea, a dominant organic compound also found in swimming pools, present in sweat and urine.^53,55 Similarly, one study found that the concentrations of urea tend to be higher with higher occupancy and usage of the swimming pools. VOCs emitted from disinfectant by-products also tended to be higher on Mondays and gradually decreased over the week, due to volatilization.⁵⁰

Finally, in the latest studies regarding SARS-CoV-2 in swimming pools, the virus has been found susceptible to being inactivated in chlorinated swimming pool water. More specifically, its infectious concentration seems to reduce after 30 s. However, the inactivation in chlorinated swimming pool water is less effective as the water’s pH increases.⁵⁸

IAQ in fitness centres

Fitness centres are a smaller type of sport facility than the aforementioned ones and might therefore present different risks to their occupants. Moisture resulting from the perspiration from physical activities may increase microbiological proliferation in fitness centres.⁵²

In a study in which different fitness centres were compared based on their ventilation types (mechanical ventilation, natural ventilation and outdoor centre), the relative humidity, PM₁₀, bacteria and fungi were found to be statistically different. More specifically, fitness centres with mechanical ventilation or air conditioning systems showed increased concentrations of PM₁₀ levels.⁴⁶ In another study mechanical ventilation was compared with natural ventilation in terms of bacterial concentrations in fitness centres. The results showed that naturally ventilated fitness centres can have higher concentrations of bacteria than mechanically ventilated ones. Also, mechanically ventilated centres can have higher bacterial concentrations than outdoors, due to the occupants’ activities. Fungi levels were, however, lower in mechanically ventilated centres, while naturally ventilated ones had much higher levels.⁵² Moreover, in a study on 11 fitness centres in Lisbon,⁴⁸ regardless of the ventilation (mechanical, hybrid, natural), high levels of CO₂ were found, indicating insufficient ventilation. The location of air intakes, in the case of mechanical ventilation, seemed to play a key role in the CO concentrations found (traffic being the source). Furthermore, VOCs spiked beyond limit values during the cleaning activities.⁴⁸ Additionally, PM_2.5 concentration levels tended to increase as the occupants increased their physical activity level indoors.^48,49

SARS-CoV-2 was also investigated in fitness centres in Oslo, Norway, in a randomized controlled trial. Although the study did not report on the type of ventilation system present in the targeted fitness centres, the authors suggest that good hygiene from occupants, along with physical distancing and low occupancy, can reduce the risk for infection in fitness centres.⁵⁹

Other IEQ factors in sports facilities

Apart from air quality, other IEQ factors (i.e. thermal quality, acoustical quality and lighting quality) are also important to the occupants’ wellbeing in sports facilities, including but not limited to sports practitioners, spectators and employees. All the IEQ factors can affect occupants’ performance, health and comfort. Therefore, requirements are included in standards and guidelines to control these IEQ factors sports facilities.^21,33,60 Also, for these IEQ factors in sports facilities several studies have been performed to determine the effect on health and comfort of the occupants.^61–63 Several suggestions for improvement have been made.

Thermal quality in sports facilities

Standards and guidelines for thermal quality are different for different sports facilities. As shown in Table 5, the requirements for relative humidity and air temperature in swimming pool centres are relatively higher than for other sports facilities.³³ While the requirements for air velocity in sports halls, especially during table tennis or badminton, are relatively lower to avoid the effect of airflow on the movement of a small object, such as a ping pong ball or a shuttlecock during play.^63–66 In addition to these dose-related indicators, the adaptive thermal comfort model also plays an important role in determining thermal quality in an indoor environment.⁶⁷ This model takes occupants-related indicators, such as clothing and metabolic rate into consideration. Based on this model, both the ASHRAE Standard 55³⁴ and the ISO 7730 standard⁶⁸ were adapted.

Table 5.

Requirements of dose-related indicators for thermal, acoustical and lighting quality in sports facilities.

Indicators	Sports hall¹	Swimming pool²	Fitness centres⁵
Thermal quality
Air temperature	18–20°C³ ≤ 25°C	The difference with water temperature ≤ 4°C; ≤ 30°C⁴	High intensity: 15–18°C Normal intensity: 18–21°C light intensity: 20–25°C
Relative Humidity		40–80%; 60% recommended	< 60% recommended; < 70% requirement
Air velocity	≤ 0.2 m/s	≤ 0.5 m/s⁴	≤ 0.2 m/s
Acoustical quality
Reverberation time	≤ 1.8 s⁶⁹ ≤ 1.0–2.3 s²¹	1.5–2.0 s	0.6–2.3 s (depends on the volume of the space)
Background sound pressure level	40 dB(A)	—	40 dB(A)
Maximum sound pressure level		—	65 dB(A)
Average absorption coefficient (α)	≥0.25	—	—
Lighting quality
Horizontal illuminance	500 lux	200 lux (on the water surface)	300 lux
Evenness	≥ 0.7	≥ 0.7	0.7
Daylight	≥ 5% of the floor surface	—	—
Colour temperature of lighting	—	—	3000 K or 4000 K
Colour rendering index R_a	—	—	minimum 80

¹Refers to Dutch Handbook Housing Physical Education²¹.

²Refers to Safety requirements for swimming pools design and management⁶⁰.

³Desired operating temperature for educational use.

⁴Refers to ASHRAE handbook³³.

⁵NL-Actief Handbook.³⁶

Additionally, requirements for different areas in the same facility might be different.^70–72 Usually, requirements for air velocity, air temperature and relative humidity in the playing area are stricter than those for other areas, because those parameters can influence athletes’ performance. For example, a low air temperature in a gym impaired women’s exercise performance,⁷³ while a high air temperature was found to decrease football players’ performance.⁶¹ Then, studies have shown that air temperature affects the attention of teenagers more than that of adults,⁷⁴ which resulted in a quite narrow temperature range, 18–20°C, recommended for physical education in sports halls.

To fulfil different thermal requirements in different zones in the same sports facility for different thermal demands of occupants, areas should be divided based on different requirements and have possibilities to control the temperature separately.⁷⁰ Computational fluid dynamics (CFD)-simulations have been used to predict the air distribution in sports facilities during the design process to improve thermal comfort.^70,75,76 In addition, considering the different thermal demands caused by different sports activities and levels among different people in the same sports building, locally controlled or personally controlled thermal systems, such as personal ventilation, have been suggested.⁷⁷ An additional advantage of localized airflow or personal ventilation is the potential for saving energy.^77,78

Next to the impact on performance and comfort, indoor thermal quality may also affect the spread of COVID-19.^79,80 In a large-scale study involving almost 70,000 cases in China and more than 700,000 cases in USA, significant negative relationships were found between temperature/relative humidity and the effective reproductive number (which is an index for transmissibility). This means that a high temperature and a high relative humidity might have the potential to reduce the transmission of SARS-CoV-2 (spread of COVID-19).⁸¹ A similar relationship between temperature and transmissibility was found by Oliveiros et al.,⁸² however, in terms of the effect of humidity, the result was the opposite. They concluded that a high temperature could delay the spread of COVID-19, while a high humidity could benefit it. In both studies,^81,82 the impact of thermal conditions on the transmission of SARS-CoV-2 was small, and lots of other factors could also have significant impacts. In recent studies performed by Morris et al.,⁸³ SARS-CoV-2 survived longest at low temperatures and extreme relative humidities, both low and high.

Acoustical quality in sports facilities

Acoustical quality in sports facilities is also very important, and a great challenge for acoustical experts to improve because the noise type (airborne or structure-borne) and frequency can vary a lot depending on the sports activity.⁸⁴

Reverberation time (RT) is one of the major parameters used to evaluate acoustical performance in buildings. In the Netherlands, 1.8s has been seen as the threshold of a good acoustical environment in sports halls.⁶⁹ However, according to Nijs and Schuur,⁶⁹ this is not a hard rule. The optimal value of RT depends on the volume of the hall. For big halls, an RT between 2.0 and 2.5 s is still acceptable, while for small halls, this value might drop to 1.5 s. They, therefore, suggested to use the mean value of absorption coefficient s(α) as the parameter to assess the acoustical quality of a sports hall.⁶⁹ Likewise, in the Dutch guidelines for gymnasiums and sports halls for educational school use,²⁰ no fixed value for RT is given. Instead, a minimum average absorption coefficient of a sports area is set at 0.25, and a list of maximum RTs is given for different sizes of the sports hall.

In primary schools, acoustical problems have been identified as the biggest problems,⁸⁵ similar to findings in school gyms.⁶² In a series of field studies conducted by Carvalho and Barreira⁶² at 68 Portuguese high school gymnasiums, almost no sound-absorbing materials were present, the measured RTs were quite high (median 4.8s), and speech intelligibilities monitored were low. These gymnasiums failed to provide a healthy and comfortable environment for both students and teachers. The sound levels (median 80 dB) they were exposed to might even be harmful to them. Most teachers reported to be strongly bothered by the noise during the classes. To protect the health of these physical education teachers, the Dutch Royal Association for Physical Education (KVLO) recommended separating the school sports hall into three parts, while no more than two parts can be used at the same time.²¹

To improve the general acoustical quality in sports facilities, the construction of the floor (e.g. floating floor) as well as the flooring material applied, have been considered.^84,85 Masoumi et al.⁸⁴ conducted a set of drop weight tests to investigate the acoustical performance of different floors. They found that the heavy concrete floor was better performing at low frequencies, but the damped lightweight floor performed the best in general. However, the selection of flooring materials also depends on the function of the facilities. For example, for a basketball hall, hardwood is the most used flooring material, while for fitness or aerobic rooms, a resilient flooring material, such as rubber or PVC (polyvinyl chloride), is more common.⁸⁵

Lighting quality in sports facilities

The lighting system in sports facilities should be able to provide a good visual quality for sports practitioners, referees and spectators. Appropriate visual conditions, which include proper illuminance levels and uniformly distributed light through the playing area, can improve both spectators’ experience and players’ performance.⁸⁶ According to the related guidelines,^17,87 requirements for lighting in sports facilities are relatively stricter than for other public buildings, because the high speed of action requires superior visual quality to locate a moving object precisely.⁸⁸ Recently, Shi et al.⁸⁹ defined several new luminance parameter thresholds for users’ visual comfort in a gymnasium by considering subjective responses.

Lighting conditions in sports facilities can also have non-visual (such as psychological and physiological) effects on occupants,^90,91 and might induce violent reactions from spectators. According to Amorim et al.,⁶³ a dynamic LED (light-emitting diode) illumination is a good way to decrease violence among spectators. They suggested changing the illumination levels and colour temperature of the LED illuminance in spectators’ areas at different time periods (before, during and after the match), so that spectators can better enjoy the match.

More importantly, light has been found to be an effective microbiocidal agent since the 19^th century. More than 100 years ago, Downes and Blunt⁹² observed that light is inimical to bacteria reproduction and development, and direct insolation could destroy the germs in solutions. Since the outbreak of COVID-19, many light-based technologies have been studied and suggested to be used to inactivate SARS-CoV-2.⁹³ For example, Kumar et al.⁹⁴ proposed a design with a Xenon lamp source and aluminium high reflecting surface to disinfect the virus attached to the surfaces of phones, keys, clothes, etc. Fischer et al.⁹⁵ compared several decontamination methods (including UV (ultraviolet) radiation, 70°C dry heat, 70% ethanol and vaporized hydrogen peroxide) and found that UV light could rapidly inactive SARS-CoV-2 from the steel surface. Sabino et al.⁹³ reviewed several light-based strategies (such as ultraviolet germicidal irradiation (UVGI), antimicrobial blue light and ultrafast laser irradiation at low irradiance), and summarized advantages and disadvantages of their possible applications. UVGI was claimed to be an effective method that can be used in both air and water disinfection.

Most UV-C systems make use of UV-C with a wavelength of 254 nm, which is harmful to skin and eyes and therefore, should not be used in the vicinity of people. UV-C with a wavelength of 222 nm, on the other hand, is not harmful to people, and has shown to be effective in inactivating, for example, SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome),^96,97 but is as far as is known not yet available on the market. What is important to note, is that UV-lights can only deactivate the pathogens that they can ‘see’.

UV-C cleaning is used in ‘in-duct’ applications, combined with the air conditioning system, for example, for operating theatres where recirculation is a must.⁹⁸ Upper-room ultraviolet light applications, in which lamps are placed in the upper part of the room, either on the walls or mounted on the ceiling, directing the UV-C light into the upper zone with louvres and limiting UV-exposure in the occupied space, have been considered for use in crowded, poorly ventilated environments.⁹⁹ Also, small devices and robots are available to disinfect products and even surfaces of entire spaces with UV-C light.

Apart from the effect on occupants, lighting systems can also play an important role in energy consumption. Suresh et al.¹⁰⁰ and Salis et al.⁸⁶ conducted an on-site investigation on lighting quality and energy consumption in a table tennis court and a squash court, respectively, and found that the lighting system in neither of these two sports courts was energy efficient. Therefore, they proposed a new lighting design by using less but uniformly placed energy-efficient LED luminaires. Nowadays, the usage of LED light is very common in the Netherlands because of the ‘transition to LED lighting’ measure advocated by the Dutch governments,^101,102 however, the high costs are still a problem. Therefore, several Dutch scientists proposed a new technology that combines LED lighting with a Direct Current (DC) power system to improve both performance and costs of LED lights.¹⁰³

Interactions between the IEQ factors

Interactions can occur between the different IEQ factors (air quality, thermal quality, acoustical quality and visual quality). Table 6 presents a list of possible interactions between the different IEQ factors. Unfortunately, few studies including interactions have been undertaken in sports facilities.

Table 6.

Interactions between the different IEQ factors.

Factor	Action	Factor	Interaction
Thermal quality	Increase of temperature	Indoor air	Increase emissions
Thermal quality	Use of solar screens to prevent overheating	Lighting	Reduction of daylight entrance
Visual quality	Use of internal glass walls	Acoustical	Possible sound reflections
Visual quality	Increase glass surface area	Thermal	Possible overheating
Acoustical quality	Sound adsorption material in air supply ducts	Indoor air	Possible decrease supply air quality
Acoustical quality	Closing windows	Indoor air	Decrease outdoor air
Indoor air quality	Increase ventilation rate/opening windows	Thermal Acoustical	Possible draught Possible noise pollution
	Increase rel. humidity	Thermal	Influence on mould growth
	Removal fleecy materials	Acoustical	Reduction sound absorption

Most studies on interactions have been undertaken in schools or offices, and between IAQ and thermal quality.^104–106 For example, Chatzidiakou et al.¹⁰⁷ developed a model to demonstrate the relationship between indoor air temperature and CO₂ concentration. They found that a high CO₂ concentration (e.g. above 1500 ppm) in a normal classroom with 30 occupants might be a sign of overheating (e.g. above 25°C). In naturally ventilated spaces, opening windows is the only way to guarantee enough ventilation and keep a good IAQ, but at the same time this behaviour might influence occupants’ thermal sensations or even threaten their thermal comfort, especially during wintertime.¹⁰⁸ In mechanically ventilated spaces, increasing the ventilation rate is the common way to improve IAQ, however, this can cause draughts and influence occupants’ thermal sensations.¹⁰⁹

Another example of interactions is the use of mobile HEPA (high-efficiency particulate air) filter systems, which have been shown to clean the air of particles around the size of SARS-CoV-2. Tests with a mobile HEPA filter system in a semi-laboratory environment showed that the HEPA filter’s cleaning performance depends on the setting of the system and the position in a room.¹¹⁰ Moreover, the system can result in unacceptable noise levels and draught effects, and more than one system is needed in one classroom, resulting in even higher noise and draught effects. In Germany, requirements for mobile air purifiers to reduce airborne transmission of infectious diseases have been developed, including also aspects such as noise generation and comfort aspects.¹¹¹

In terms of the interaction between IAQ and acoustical quality, in most cases, they appear to be irreconcilable. In mechanical ventilated spaces, a positive correlation between ventilation rate and the noise level was found by Khaleghi et al.¹¹²: the higher the ventilation rate, the higher the noise level caused by the HVAC system. In another study,¹¹³ for naturally ventilated spaces was observed, that when the windows are closed, acoustical quality was acceptable but the IAQ was not because of high particle concentrations and low ventilation rates. When the windows were open, IAQ improved but the noise level exceeded the required level. Additionally, some acoustical treatments, such as acoustical ceilings or carpets, might also cause interaction effects between acoustical quality and air quality, because these materials can emit VOCs (volatile organic compounds) and shed fibres.¹¹⁴ Although acoustical treatment can improve acoustical quality by reducing the RT, a lower IAQ could be induced.¹¹²

Discussion

Main indicators to assess IEQ in sports facilities

Indoor air quality

The main indicators used to assess IAQ in sports facilities are dose-related indicators, which can vary per type of facility. Sports halls, specifically larger halls where different team activities and disciplines can take place (from volleyball to rock climbing, etc.) are the most studied type of sports facility, and hence a wider range of pollutants has been investigated. The main pollutants investigated in sports halls are NO_x, magnesia alba, acetone, formaldehyde, PM₁₀ and VOCs. Fitness centres, defined in this study as smaller spaces in which smaller groups of workouts and fitness routines can be exercised, tend to be investigated less than sports halls, and the main pollutants investigated were PM₁₀, VOCs, fungi and yeasts, and bacteria on surfaces and in air. Finally, swimming pools, because of the special cleaning treatment required and the high humidity present, these have been investigated with a different scope of pollutants, with the most common ones being PM_2.5, VOCs, fungi and yeasts, and different compounds resulting from bleaching processes.

While in France, Belgium and Germany national schemes for emissions of construction products have been introduced, the indoor air quality guidelines of the WHO¹³ as well as the different available labelling schemes for building materials are not used in the Netherlands.²⁰ In the Netherlands, instead of pollutant concentrations, the main focus of IAQ assessment is on ventilation performance. As shown in Table 4, the minimum ventilation rates are different in different sports facilities or different areas; and these values are different for different seasons.³⁶ In some guidelines, two different values with different units (l/s/p or l/s/m²) are given and can be selected based on the pollutant sources present. In most sports facilities, occupants are the main air pollutant sources, therefore l/s/p has been suggested to be used.

Ventilation and CO₂

Current guidelines for air quality indoors are mainly based on the CO₂ concentration in air that is allowed.^16,21 CO₂ is used as an indicator for the presence of people. With every breath we take, we exhale CO₂. The amount of air ventilated, in the case of mechanical ventilation, is usually assessed by air velocity sensors in the supply duct and/or exhaust duct.

Whether CO₂ is a good indicator for exhaled ‘infectious’ aerosols, is not known yet. CO₂ is a gas, and exhaled aerosols and droplets are no gasses, and most likely do not all behave as gasses. The CO₂ levels set are based on ‘comfort’, not on health. Moreover, in a study at secondary schools, the CO₂ concentration in a classroom was found to differ per location depending on the ventilation regime, the dimensions of the room and occupancy.¹¹⁵ Also, the outdoor CO₂ concentration can differ during the day and per location.

To cope with the risk of airborne transmission, the most used model has been the Wells-Riley model.¹¹⁶ Based on this model, it is theoretically possible to calculate the infection risk for a certain ventilation rate and the number of persons present, assuming one infected person. Unfortunately, this model or equation has a number of limitations: (a) it does not account for differences between persons; (b) a mixing situation is assumed (the concentration of infectious aerosols is homogeneous in indoor spaces); and (c) this uniform concentration is assumed over time to be constant, and therefore the ongoing inhalation of the concentration is constant over time.⁷

Other IEQ factors

For the other IEQ factors (thermal, acoustical and lighting quality), the indicators used in standards and guidelines are mainly dose-related indicators. For some of the parameters, such as air velocity and horizontal illuminance, the requirements are specific and clear, while for others, such as relative humidity and reverberation time, the requirements are either not mentioned or not consistent in different standards, which makes it difficult to assess the performance of these indicators in various sports facilities.

For those parameters that have clear requirements and can be easily measured (such as air temperature), even if the measured results meet the requirements, it does not mean that all occupants in the sports facilities are comfortable. Kosonen et al.¹¹⁷ found that occupants’ perceived IEQ was, in many cases, lower than the prescribed standards level. For sports facilities, the following reasons might cause this mismatching between occupants’ perceived IEQ and the physically measured IEQ. First, people in different areas of the sports facilities (e.g. audience area and activity area) have different requirements⁷⁰; second, athletes or players in the same area might also have different IEQ perceptions because of different exercise intensity, body mass index (BMI), age or gender¹¹⁸; third, all the IEQ factors might interact with each other, so even if the parameters themselves meet the requirements, the interactions between them might cause discomfort of occupants.¹¹⁹

Building-related and occupant-related indicators

Dose-response related threshold levels or ranges of levels are usually set for an average person, not accounting for differences between people, situations and interactions between the different indicators, both at human and environmental levels. Both occupant-related and building-related indicators are important to account for.¹²⁰

Building-related indicators

With regards to building-related indicators, White et al.¹²¹ observed extensive mould and dampness (which could deteriorate IAQ) in two prefabricated buildings in Australia and their investigation indicated that these problems were caused by flaws in building design and construction. Kim and De Dear¹²² found that building layout and the amount of space (which are easily ignored in previous IEQ research) also could influence occupants’ overall satisfaction with IEQ. Similarly, Wang and Zamri¹²³ also identified space layout as one of the important factors that have significant relationships with occupants’ IEQ satisfaction. Although these correlations between building layout/construction materials and IEQ in sports facilities have been rarely studied before, the principle behind these relationships should be the same. Therefore, floor area, layout and covering materials in sports facilities can also affect the IEQ in these buildings.

The conclusion drawn from previous studies is that building-related indicators are needed in addition to dose-related indicators prescribed in most standards and guidelines. Some requirements for building-related indicators have been set (see Table 2), but those are in general (except for the colours reflection factor of floor, walls and ceiling materials) not meant to improve the IEQ. In Table 7 a list of building-related indicators is presented that would be worthy to include and have been suggested in previous studies.^124,125 More research is required to better define the criteria/requirements for these indicators for different sports facilities, occupants, activities and spaces. In particular is the minimum required height of the space, such as a sports hall, with regards to the ventilation regime, the location of the air supplies and exhausts, the direction, temperature and velocity of the flows (determining the distribution) and resulting ventilation efficiency, local and overall.

Table 7.

Suggested building-related indicators for sports facilities.

Component/topic	Building-related indicator
Ventilation regime	Ventilation type (local)ventilation efficiencyairflow pattern
Natural ventilation	Windows location and dimensionspassive grills
Mechanical ventilation	Location of air supply and exhaustsgrilles direction flowmaintenance schedule
Air cleaning	Type of air filterair cleaning devices
Floor	Type of wall materialmission labelcolour reflection factorhard/fleecy material
Walls	Type of ceiling materialemission labelcolour reflection factor
Ceiling	Type of ceiling materialemission labelheightcolour reflection factor
Cleaning	Cleaning scheduleCleaning products
Windows	Window frame colour versus wall coloursingle/double/triple glazing
Lighting	Type of lightingnatural or artificialreflection on the surface
Sound absorption material	Presence of sound absorption materiallocation of sound absorption material
Heating and cooling system	Type of heating systemlocation of radiators (if there are)type of cooling system

Occupant-related indicators

Several air pollutants are known to cause a variety of detrimental health effects, depending on the exposure time and concentrations of pollutants. However, in the case of halls and fitness centres, due to the increased physical activity of occupants exercising, and hence, due to their increased respiration rate, these persons might be at a greater risk than spectators or personnel. This discrepancy with different occupants is also true for other IEQ factors in sports facilities, for example, sportspeople in the playing area have more strict requirements on thermal quality since it can influence their performance, while for the audience area, wide ranges of requirements are applied, as long as the thermal comfort of the audience is met.^73,126 Indeed, IEQ standards and guidelines for various sports facilities have not been customized, and do not take into account the fact that different humans, depending on their physiology, activity or unique reactions, can have different health effects even when exposed to the same indoor environment.

In Table 8, a list of occupant-related indicators is presented that would be worthy to include and have been suggested in previous studies.^127,128

Table 8.

Suggested occupant-related indicators for sports facilities.

Component/topic	Occupant-related indicator
Personal characteristics	Number of occupants
	age range
	sex
	duration of stay
	activity level
IEQ and health	Needs to deal with diseases and disorders, such as: allergies, asthma, diabetes, etc.
IEQ and comfort	Preferences for IEQ to perform well, such as preferences for light (brighter/darker), background noise (non/a lot), temperature (warm/cold), draft/still air, etc.

Ventilation and SARS-COV-2

To decrease the risk of far-range airborne transmission of SARS-CoV-2, the use of ‘proper’ ventilation measures has been recommended.^4,129–132 ‘Proper’ ventilation means to provide sufficient, and effective ventilation that ensures the supply of ‘clean’ air and exhausts polluted (‘infected’) air from the breathing zones of each individual person, without passing through the breathing zones of other persons, and preferably without recirculation of air. Air cleaning or/and disinfection devices can be added, if general ventilation seems not enough or recirculation (re-use of air) cannot be avoided.¹³³

To remove pollutants, several types of ventilation systems are applied in sports facilities: (a) natural ventilation, established by just opening a window, or (b) mechanical ventilation varying from just an exhaust vent to very advanced air conditioning systems that supply and exhaust the air.¹³⁴ While natural ventilation is an uncontrolled form, mechanical ventilation gives the possibility to control the amount of air that is supplied, exhausted and/or re-used. Natural ventilation depends on several environmental aspects such as the wind and temperature outdoors, but also on the dimensions of the space and the possibility of having openings in the façade. In addition to the ventilation type, also different ventilation principles can be selected such as mixing ventilation, displacement ventilation, cross ventilation and personal ventilation. The most commonly applied mechanical ventilation principle in sports facilities is mixing ventilation, in which air is supplied up (near or via the ceiling) with an air velocity high enough to realize mixing in the space, and therefore the number of ‘infectious’ aerosols in the air is reduced, but not all of them are removed. Displacement and cross ventilation move the air horizontally or vertically through a space, ideally replacing polluted air with ‘fresh’ air. With displacement ventilation air is supplied low nearby or via the floor with a low velocity and exhausted up in the space. Personal ventilation supplies and/or exhausts air in the breathing zone of each individual person.

It is clear that ventilating a space reduces the concentration of possible ‘infectious’ aerosols. How those ‘infectious’ aerosols distribute and possibly meet a healthy person on the way who can inhale them, is difficult to predict with ventilation at room level. To really reduce the risk of transmission to nearly zero, the possible ‘infectious’ aerosols should be extracted as close as possible to the source. Personal ventilation is a possibility when the directions of airflows are considered. Most available personal ventilation systems are focused on the supply of fresh air into the breathing zone, not on the exhaust.¹³⁵ This type of personal ventilation is, for example, used in fitness centres’ treadmills, but may not be functional in a sports hall. Moreover, the consideration should not only be about how much fresh air is supplied but also about where it is ventilated and distributed through the space, in relation to the activities taking place and the occupancy over time.⁷

Conclusions and recommendations

The outcome of this literature study makes several contributions to the current literature.

First, it shows that current standards and guidelines for IEQ in sports facilities are mainly focused on the dose-related indicators such as concentration of air pollutants, temperature level, relative humidity and ventilation rate in sports facilities. Occupant-related indicators (such as age, diseases and disorders, preferences and needs, and activity level), and building-related factors (such as certain measures or characteristics of a building and its components) can also play an important role in occupants’ health and comfort, and should therefore be considered. The study recommends the identification of preferences and needs (profiles) of different occupants for different sports facilities and activities, as well as building-related indicators to realize the required environmental conditions (dose-related indicators) for each profile.¹³⁶

Second, in the studies presented in this review little consideration is given to the fact that ventilation may play an important role in the air quality of the location. Further studies and the design of buildings should consider those different ventilation strategies that may be more appropriate for specific types of locations within sports facilities, based on the activities taking place or building and furnishing materials used. It is recommended to consider both occupant and building-related indicators in future standards and studies on IEQ in sports facilities.

Third, few investigations have been performed on the transmission of SARS-CoV-2 in sports facilities. From studies in other settings (e.g. educational settings, restaurants and care homes) with a high density of people, clearly, the question should not only be about which ventilation rates are required to protect against infection transmission, but also how the space should be ventilated for a specific situation. The recommendation is to apply ventilation that not only focuses on the ventilation of a space but also provides a range of ventilation options that fulfil the demands of the occupants over time, whether related to health or comfort.⁷ The applied ventilation strategies should not just focus on the amount of ventilation required for a space, but also on the how (where), and when the ventilation is needed.

Finally, most previous studies, standards and guidelines only focus on one IEQ factor, especially on IAQ. However, much uncertainty still exists about the relationship between IEQ factors. Measures to improve IAQ could have an effect on other factors and consequently affect the health and comfort of the occupants. Therefore, cross-modal effects between the IEQ factors are suggested to be considered for future standards development.

Footnotes

Author contributions

All authors contributed equally in the preparation of this manuscript.

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research,authorship,and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research,authorship,and/or publication of this article: This literature review is part of the project ‘Performance criteria for air quality in sport facilities’,sponsored by the Knowledge Centre for Sport & Physical Activity Netherlands (Kenniscentrum Sport & Bewegen),the NOC*NSF (sportbonden),POS (ondernemende sportaanbieders) and VSG (Gemeenten) in the Netherlands.

ORCID iDs

Dadi Zhang

Philomena M Bluyssen

References

BBC News . Covid map: coronavirus cases, deaths, vaccinations by country, 2020. Available at: https://www.bbc.co.uk/news/amp/world-51235105 (assessed 28 April 2022).

Yong

. Long COVID or post-COVID-19 syndrome: putative pathophysiology, risk factors, and treatments. Infect Diseases 2021; 53(10): 737–754.

World Health Organization . Avoid the three Cs, 2022. Available at: https://www.who.int/brunei/news/infographics–-English (assessed 28 April 2022).

Morawska

Tang

Bahnfleth

Bluyssen

Boerstra

Buonanno

Cao

Dancer

Floto

Franchimon

Haworth

Hogeling

Isaxon

Jimenez

Kurnitski

Loomans

Marks

Marr

Mazzarella

Melikov

Miller

Milton

Nazaroff

Nielsen

Noakes

Peccia

Querol

Sekhar

Seppänen

Tanabe

Tellier

Tham

Wargocki

Wierzbicka

Yao

. How can airborne transmission of COVID-19 indoors be minimised? Environ International 2020; 142: 105832.

World Health Organization . Coronavirus disease (COVID-19): How is it transmitted? Geneva: WHO, 2021.

Morawska

Allen

Bahnfleth

Bluyssen

P. M.

Boerstra

Buonanno

Cao

Dancer

S. J.

Floto

Franchimon

Greenhalgh

Haworth

Hogeling

Isaxon

Jimenez

J. L.

Kurnitski

Loomans

Marks

Marr

L. C.

Mazzarella

Melikov

A. K.

Miller

Milton

D. K.

Nazaroff

Nielsen

P. V.

Noakes

Peccia

Prather

Querol

Sekhar

Seppänen

Tanabe

S.-i.

Tang

J. W.

Tellier

Tham

K. W.

Wargocki

Wierzbicka

Yao

A paradigm shift to combat indoor respiratory infection. Science 2021; 372(6543): 689–691.

Bluyssen

. How airborne transmission of SARS-CoV-2 confirmed the need for new ways of proper ventilation. In: Routledge handbook of resilient thermal comfort. London: Routledge, 2022, pp. 531–550.

Torresin

Pernigotto

Cappelletti

Gasparella

. Combined effects of environmental factors on human perception and objective performance: A review of experimental laboratory works. Indoor Air 2018; 28(4): 525–538.

Toftum

. Human response to combined indoor environment exposures. Energy and Buildings 2002; 34(6): 601–606.

10.

Bluyssen

. Towards new methods and ways to create healthy and comfortable buildings. Building Environ 2010; 45(4): 808–818.

11.

Bodet . Sport facilities. Available at: https://www.bodet-sport.com/sport-facilities.html (cited 18 December 2021).

12.

Fit Athletic . Difference between a gym, fitness center or a health club. Available at: https://fitathletic.com/health-clubs-san-diego/ (cited 11 Nov 2021).

13.

WHO . WHO guidelines for indoor air quality: selected pollutants. WHO Regional Office for Europe. Copenhagen: World Health Organization, 2010.

14.

JGJ 31-2003 . Ministry of Construction, Design code for sports building. Beijing: China, 2003.

15.

Ministry of the Environment Government of Japan . Environmental quality standards in Japan. Tokyo, Japan: The Japan Standards Association.

16.

EN15251: 2007 . Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics, CEN. Paris: France, 2007.

17.

NEN-EN 12193: 2018 . Light and lighting - sports lighting. Delft: NEN, 2018.

18.

EN 12464–1 . Light and lighting-Lighting of work places - Part 1: indoor work places. Brussels: European Committee for Standardization (CEN), 2021.

19.

EN 16798 . Energy performance of buildings - ventilation for buildings - Part 1: indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics. Brussels: European Committee for StandardizationBelgium, 2019.

20.

ISO 16000–11: 2006 . Indoor air, in Part 11: determination of the emission of volatile organic compounds from building products and furnishings–Sampling, storage of samples and preparation of test specimens. Geneva: ISO, 2016 (reviewed and confirmed.

21.

Handbook housing physical education (in Dutch) . Zeist, the Netherlands: KVLO, 2019.

22.

NEN-EN 15288–1: 2019 . Swimming pools: safety requirements for design. Delft, the Netherlands: NEN, 2019.

23.

Ministerie van Binnenlandse Zaken en Koninkrijksrelaties . Building decree 2012. Available at: https://rijksoverheid.bouwbesluit.com/Inhoud/docs/wet/bb2012 (assessed 28 April 2022).

24.

Pool Water Treatment Advisory Group . Code of Practice - the management and treatment of swimming pool water. Loughborough, UK, 2021. Available at: https://www.pwtag.org/code-of-practice/(

25.

Légifrance . Public Health Code (Code de la sante publique) in Chapitre II: Piscines et baignades (Chapter II: swimming pools and swimming). Paris: Ministère des Solidarités et de la SantéFrance, 2022.

26.

Energy Diversification and Saving . Regulation of thermal installations in buildings (RITE-2007). Instituto para la Diversificación y ahorro de la Energía. Madrid: Spain, 2007.

27.

Spanish ministry of culture and sport . Halls and pavilions (Salas y Pabellones). Ministerio de educación, cultura y deporte. Madrid: Spain, 2021.

28.

CONI standards for sports facilities . CONI, Italian National Olympic Committee. Rome: Italy, 2008.

29.

DIN 19643: 2012 . Treatment of water of swimming pools and baths. Berlin, Germany: DIN, 2012.

30.

VDI 2089 Blatt 1: 2010 . Building services in swimming baths - indoor pools. VDI, Berlin: Germany, 2010.

31.

Government of Canada . Residential indoor air quality guidelines, 2021. Available at: https://www.canada.ca/en/health-canada/services/air-quality/residential-indoor-air-quality-guidelines.html (assessed 28 April 2022).

32.

ASHRAE Standard 62.1–2022 . Ventilation and acceptable indoor air quality. Atlanta, GA: ASHRAE, 2022.

33.

ASHRAE . Handbook—HVAC applications, in chapter 6 –indoor swimming pools. Atlanta, GA: ASHRAE, 2019.

34.

ASHRAE Standard 55–2020 . Thermal environmental conditions for human occupancy. Atlanta, GA: ASHRAE, 2020.

35.

NOCNSF-US1-RU.1 . Dimensions, finish, heating and ventilation (in Dutch). NOC*NSF. Arnhem, the Netherlands, 2012.

36.

NL-Actief . Handbook development, realization, or renovation of fitness facilities (Concept in Dutch). 2022. Arnhem, the Netherlands: NL-Actief, 2020.

37.

AgBB . Evaluation procedure for VOC emissions from building products, 2021. Available at: https://www.umweltbundesamt.de/sites/default/files/medien/4031/dokumente/agbb_evaluation_scheme_2021.pdf (assessed 29 April 2022).

38.

RTS . M1 for low-emission building materials. Available at: https://cer.rts.fi/en/m1-emission-class-for-building-material/(assessed 29 April 2022).

39.

Alves

Calvo

Castro

Fraile

Evtyugina

Bate-Epey

. Indoor air quality in two university sports facilities. Aerosol Air Quality Res 2013; 13(6): 1723–1730.

40.

Stathopoulou

Assimakopoulos

Flocas

Helmis

. An experimental study of air quality inside large athletic halls. Building Environ 2008; 43(5): 834–848.

41.

Castro

Calvo

Alves

Alonso-Blanco

Coz

Marques

Nunes

Fernández-Guisuraga

Fraile

. Indoor aerosol size distributions in a gymnasium. Sci Total Environ 2015; 524–525: 178–186.

42.

Weinbruch

Dirsch

Ebert

Hofmann

Kandler

. Dust exposure in indoor climbing halls. J Environ Monit 2008; 10(5): 648–654.

43.

Andrade

Dominski

Pereira

de Liz

Buonanno

. Infection risk in gyms during physical exercise. Environ Sci Pollut Res 2018; 25(20): 19675–19686.

44.

Braniš

Šafránek

. Characterization of coarse particulate matter in school gyms. Environ Res 2011; 111(4): 485–491.

45.

Žitnik

Bučar

Hiti

Barba Ž

Založnik

Žitnik

Rodrìguez

Mihevc

Žibert

. Exercise-induced effects on a gym atmosphere. Indoor Air 2016; 26(3): 468–477.

46.

Onchang

Panyakapo

. The physical environments and microbiological contamination in three different fitness centres and the participants' expectations: Measurement and analysis. Indoor Built Environ 2016; 25(1): 213–228.

47.

Tolis

Panaras

Bartzis

. A comprehensive air quality investigation at an aquatic centre: Indoor/outdoor comparisons. Environ Sci Pollut Res 2018; 25(17): 16710–16719.

48.

Ramos

Wolterbeek

Almeida

. Exposure to indoor air pollutants during physical activity in fitness centers. Building Environ 2014; 82: 349–360.

49.

Slezakova

Peixoto

Pereira

Morais

. Indoor air quality in health clubs: Impact of occupancy and type of performed activities on exposure levels. J Hazard Mater 2018; 359: 56–66.

50.

Afifi

Blatchley

III . Seasonal dynamics of water and air chemistry in an indoor chlorinated swimming pool. Water Res 2015; 68: 771–783.

51.

Brandi

Sisti

Paparini

Gianfranceschi

Schiavano

De Santi

Santoni

Magini

Romano-Spica

. Swimming pools and fungi: an environmental epidemiology survey in Italian indoor swimming facilities. Int J Environ Health Res 2007; 17(3): 197–206.

52.

Ramos

Viegas

Verde

Wolterbeek

Almeida

. Characterizing the fungal and bacterial microflora and concentrations in fitness centres. Indoor Built Environ 2016; 25(6): 872–882.

53.

Lévesque

Vézina

Gauvin

Leroux

. Investigation of air quality problems in an indoor swimming pool: a case study. Ann Occup Hyg 2015; 59(8): 1085–1089.

54.

Westerlund

Bryngelsson

I-L

Löfstedt

Eriksson

Westberg

Graff

Occupational exposure to trichloramine and trihalomethanes: adverse health effects among personnel in habilitation and rehabilitation swimming pools. J Occup Environ Hygiene 2019; 16(1): 78–88.

55.

Parrat

Donzé

Iseli

Perret

Tomicic

Schenk

. Assessment of occupational and public exposure to trichloramine in Swiss indoor swimming pools: a proposal for an occupational exposure limit. Ann Occupational Hygiene 2012; 56(3): 264–277.

56.

Salonen

Salthammer

Morawska

. Human exposure to air contaminants in sports environments. Indoor Air 2020; 30(6): 1109–1129.

57.

Dyck

Sadiq

Rodriguez

Simard

Tardif

. Trihalomethane exposures in indoor swimming pools: a level III fugacity model. Water Res 2011; 45(16): 5084–5098.

58.

Brown

Moshe

Blackwell

Barclay

. Inactivation of SARS-CoV-2 in chlorinated swimming pool water. Water Res 2021; 205: 117718.

59.

Helsingen

Løberg

Refsum

Gjøstein

Wieszczy

Olsvik

Juul

Barua

Jodal

Herfindal

Mori

Jore

Lund-Johansen

Fretheim

Bretthauer

Kalager

. Covid-19 transmission in fitness centers in Norway - a randomized trial. BMC Public Health 2021; 21(1): 2103–2109.

60.

NEN-EN 15288–2:2018 . Swimming pools: Safety requirements for management. Delft: NEN, 2018.

61.

Özgünen

Kurdak

Maughan

Zeren

Korkmaz

Yazιcι

Ersöz

Shirreffs

Binnet

Dvorak

Effect of hot environmental conditions on physical activity patterns and temperature response of football players. Scand J Med Sci Sports 2010; 20: 140–147.

62.

Carvalho

Barreira

. Sound and noise in high schools gymnasiums. The J Acoust Soc America 2014; 135: 2315–2315.

63.

Amorim

Molina-Moreno

Peña-García

AJS

. Proposal for sustainable dynamic lighting in sport facilities to decrease violence among spectators. Sustainability 2016; 8(12): 1298.

64.

Alam

Nutakom

Chowdhury

. Effect of porosity of badminton shuttlecock on aerodynamic drag. Proced Eng 2015; 112: 430–435.

65.

Xie

Yang

Zhang

. Indoor air quality investigation of a badminton hall in humid season through objective and subjective approaches. Sci Total Environ 2021; 771: 145390.

66.

Wang

Chen

Sheng

. Analysis of Table Tennis Competition Affected by Wind Speed. J Tangshan Teach Coll 2012; 34(5): 84–86.

67.

Dear de

Brager

. Developing an adaptive model of thermal comfort and preference. ASHRAE Trans 1998; 104(1): 73–81.

68.

ISO 7730: 2006 . Ergonomics of the thermal environment - analytical determination and interpretation of thermal comfort using calculation of the PMV and PPD indices and local thermal comfort criteria. Geneva: ISO, 2015 ((reviewed and confirmed).

69.

Nijs

Schuur

. Expressing legal demands in acoustical quantities; is the reverberation time a good predictor for the speech intelligibility in a sports hall? Res Building Phys. London: CRC Press, 2020, pp. 879–887.

70.

Shao

. Challenges and countermeasures for thermal environment and indoor air quality in sports buildings. In: 2011 International Conference on Future Computer Science and Education, Xi'an, 20–21, August 2011, vol. 1. IEEE, pp. 83–86.

71.

Rajagopalan

Luther

. Thermal and ventilation performance of a naturally ventilated sports hall within an aquatic centre. Energy and Buildings 2013; 58(1): 111–122.

72.

Rajagopalan

Jamei

. Thermal comfort of multiple user groups in indoor aquatic centres. Energy and Buildings 2015; 105(Oct.): 129–138.

73.

Huang

Que

Liu

Zhang

. On the gym air temperature supporting exercise and comfort. Building Environ 2021; 206: 108313.

74.

Mazon

. The influence of thermal discomfort on the attention index of teenagers: an experimental evaluation. Int J Biometeorology 2014; 58(5): 717–724.

75.

Zhao

Li X

. Calculated Attendance and its Influences on the Air Conditioning system in Gymnasiums. Heat Ventilating &Air Conditioning 2001; 31(6): 47–50.

76.

Zhao

Yan

. The Difficulty and solution of indoor airflow pattern designing for gymnasium. Refrigeration and Air Conditioning 2002; 2(2): 10–14.

77.

Theodoridou

. Indoor training and thermal comfort: improving thermal comfort of human subjects training indoors by a configuration of parameters, specifically airflows. In: Master of science thesis, department of building engineering. Delft, the Netherlands: Delft University of Technology, 2016. file:///C:/Users/zhang/Downloads/MSc%20Thesis%20report_Elli%20Theodoridou.pdf (assessed at November 23, 2022).

78.

Uğursal

Culp

. The effect of temperature, metabolic rate and dynamic localized airflow on thermal comfort. Appl Energy 2013; 111: 64–73.

79.

Mecenas

Bastos

Vallinoto

Normando

. Effects of temperature and humidity on the spread of COVID-19: A systematic review. PLoS One 2020; 15(9): e0238339.

80.

Jing

Liu

Yuan

Wang

Liu

. Effects of temperature and humidity on the daily new cases and new deaths of COVID-19 in 166 countries. Sci Total Environ 2020; 729: 139051.

81.

Wang

Tang

Feng

Lin

Weifeng

Chen

Wang

. Impact of temperature and relative humidity on the transmission of COVID-19: a modelling study in China and the United States. BMJ Open 2021; 11(2): e043863.

82.

Oliveiros

Caramelo

Ferreira

Caramelo

. Role of temperature and humidity in the modulation of the doubling time of COVID-19 cases. Sci Total Environ 2020; 724: 138226.

83.

Morris

Yinda

Gamble

Rossine

Huang

Bushmaker

Fischer

Matson

Van Doremalen

Vikesland

Marr

Munster

Lloyd-Smith

. Mechanistic theory predicts the effects of temperature and humidity on inactivation of SARS-CoV-2 and other enveloped viruses. Elife 2021; 10: e65902.

84.

Masoumi

Pinto

Carels

. Improvements in acoustical performance of lightweight floating floors for gym/sports applications. In: Proceeding of Euro Noise 2018, Crete, Greece, 27-31 May 2018, pp. 1683–1689.

85.

Paley

. The impact of flooring on acoustics in athletic facilities. Ecore International, p. 12. Available at: https://www.ecoreintl.com/sites/default/files/documents/EA_WhitePaper_FlooringonAcousticsAthletics.pdf (assessed 28 April 2022).

86.

Salis

Suresh

Shailesh

. Lighting Design of An Indoor Sports Facility-A Case Study. 2019 Second Int Conf Adv Comput Commun Paradigms (Icaccp). In: Second International Conference on Advanced Computational and Communication Paradigms (ICACCP), Gangkok, India, 25–28 February 2018. Institute of Electrical and Electronics Engineers Inc, 2019, pp. 1–5. DOI: 10.1109/ICACCP.2019.8882940.

87.

NPR 13201+A1 . Public lighting-quality criteria. Delft, the Netherlands: NEN, 2018.

88.

Fantozzi

Leccese

Salvadori

Rocca

Garofalo

. LED Lighting for Indoor Sports Facilities: Can Its Use Be Considered as Sustainable Solution from a Techno-Economic Standpoint? Sustainability 2016; 8(7): 618.

89.

Shi

Zhang

Wang

Cheng

Yan

. Luminance parameter thresholds for user visual comfort under daylight conditions from subjective responses and physiological measurements in a gymnasium. Building Environ 2021; 205(4): 108187.

90.

Chellappa

Steiner

Blattner

Oelhafen

Götz

Cajochen

. Non-visual effects of light on melatonin, alertness and cognitive performance: can blue-enriched light keep us alert? PloS One 2011; 6(1): e16429.

91.

Vandewalle

Schwartz

Grandjean

Wuillaume

Balteau

Degueldre

Schabus

Phillips

Luxen

Dijk

D-J

Maquet

Spectral quality of light modulates emotional brain responses in humans. Proc Natl Acad Sci 2010; 107(45): 19549–19554.

92.

Downes

Blunt

. The Influence of Light upon the Development of Bacteria 1. Nature 1877; 16(402): 218–218.

93.

Sabino

Ball

Baptista

Dai

Hamblin

Ribeiro

Santos

Sellera

Tegos

Wainwright

. Light-based technologies for management of COVID-19 pandemic crisis. J Photochem Photobiol B: Biol 2020; 212: 111999.

94.

Kumar

Sagdeo

. Possibility of using ultraviolet radiation for disinfecting the novel COVID-19. Photodiagnosis Photodynamic Ther 2021; 34: 102234.

95.

Fisher

. Technological interdependence, labor production functions, and control systems. Account Organizations Soc 1994; 19(6): 493–505.

96.

Buonanno

Stabile

Morawska

. Estimation of airborne viral emission: Quanta emission rate of SARS-CoV-2 for infection risk assessment. Environ Int 2020; 141: 105794.

97.

Heßling

Hönes

Vatter

Lingenfelder

. Ultraviolet irradiation doses for coronavirus inactivation–review and analysis of coronavirus photoinactivation studies. GMS Hygiene and Infection Control 2020; 15: Doc08. DOI: 10.3205/dgkh000343.

98.

Kujundzic

Matalkah

Howard

Hernandez

Miller

. UV Air Cleaners and Upper-Room Air Ultraviolet Germicidal Irradiation for Controlling Airborne Bacteria and Fungal Spores. J Occup Environ Hyg 2006; 3(10): 536–546.

99.

Kujundzic

Peccia

Schafer

Moss

Hernandez

Miller

. Impact of environmental factors on efficacy of upper-room air ultraviolet germicidal irradiation for inactivating airborne mycobacteria. Environ Sci Technology 2005; 39(24): 9656–9664.

100.

Suresh

Salis

Shailesh

. Lighting Optimization to save energy in an Indoor Sports Facility. In: 2019 Second International Conference on Advanced Computational and Communication Paradigms (ICACCP), Gangkok, India, 25–28 February 2018. published by Institute of Electrical and Electronics Engineers Inc, 2019, pp. 1–5. DOI: 10.1109/ICACCP.2019.8883019.

101.

IGOV . LED in public lighting (in Dutch). Available at: https://www.igov.nl/index.php?option=com_content&view=article&id=883&Itemid=144 (assessed 23 February 2022, 2012].

102.

Deerns . New legislation requests LED lighting (in Dutch). https://static.deerns.nl/publicationsweb/183980/Nieuwe%20wetgeving%20vraagt%20om%20LED%20verlichting.pdf (assessed 26 February 2022).

103.

Hulsebosch

Willigenburg

Woudstra

Groenewald

. Direct current in public lighting for improvement in LED performance and costs. In: 2014 International Conference on the Eleventh industrial and Commercial Use of Energy, Cape Town, South Africa, 19–20 August 2014. IEEE, pp. 1–9.

104.

Jia

L-R

Han

Chen

Q-Y

Lee

C-C

Fung

Y-H

. Interaction between Thermal Comfort, Indoor Air Quality and Ventilation Energy Consumption of Educational Buildings: A Comprehensive Review. Buildings 2021; 11(12): 591.

105.

Wargocki

Wyon

. The effects of moderately raised classroom temperatures and classroom ventilation rate on the performance of schoolwork by children (RP-1257). HVAC&R Res 2007; 13(2): 193–220.

106.

Yüksel

Arıcı

Krajčík

Civan

Karabay

. A review on thermal comfort, indoor air quality and energy consumption in temples. J Building Eng 2020; 2020: 102013.

107.

Chatzidiakou

Mumovic

Summerfield

. Is CO₂ a good proxy for indoor air quality in classrooms? Part 1: The interrelationships between thermal conditions, CO₂ levels, ventilation rates and selected indoor pollutants. Building Serv Eng Res Technology 2015; 36(2): 129–161.

108.

Stazi

Naspi

Ulpiani

Di Perna

. Indoor air quality and thermal comfort optimization in classrooms developing an automatic system for windows opening and closing. Energy and Buildings 2017; 139: 732–746.

109.

Cheng

Lin

Fong

. Effects of temperature and supply airflow rate on thermal comfort in a stratum-ventilated room. Building Environ 2015; 92: 269–277.

110.

Bluyssen

Ortiz

Zhang

. The effect of a mobile HEPA filter system on 'infectious' aerosols, sound and air velocity in the SenseLab. Building Environ 2021; 188: 107475.

111.

VDI-EE 4300 Blatt 14 . Measurement of indoor pollution - requirements for mobile air purifiers to reduce aerosol-borne transmission of infectious diseases. Germany: VDI, 2021.

112.

Khaleghi

Bartlett

Hodgson

. Factors Affecting Ventilation, Indoor-air Quality and Acoustical Quality in ‘Green' and Non-'Green' Buildings: a Pilot Study. J Green Building 2011; 6(3): 168–180.

113.

Khaleghi

Bartlett

Hodgson

. Relationship between ventilation, air quality, and acoustics in ''green'' and ''brown'' buildings. J Acoust Soc America 2006; 120(5): 3185–3185.

114.

Katsoyiannis

Leva

Kotzias

. VOC and carbonyl emissions from carpets: A comparative study using four types of environmental chambers. J Hazard Mater 2008; 152(2): 669–676.

115.

Zhang

Ding

Bluyssen

. Guidance to assess ventilation performance of a classroom based on CO₂ monitoring. Indoor Built Environ 2022; 31(4): 1107–1126.

116.

Noakes

Sleigh

. Mathematical models for assessing the role of airflow on the risk of airborne infection in hospital wards. J R Soc Interf 2009; 6(suppl.6): S791–S800.

117.

Kosonen

Ahola

Villberg

Takki

. Perceived IEQ conditions: Why the actual percentage of dissatisfied persons is higher than standards indicate? In: Sick building syndrome. London: Springer, 2011, pp. 75–88.

118.

Frontczak

Wargocki

. Literature survey on how different factors influence human comfort in indoor environments. Building Environ 2011; 46(4): 922–937.

119.

Bourikas

Gauthier

Khor Song En

NKS

Xiong

. Effect of thermal, acoustic and air quality perception interactions on the comfort and satisfaction of people in office buildings. Energies 2021; 14(2): 333.

120.

Bluyssen

. Towards an integrated analysis of the indoor environmental factors and its effects on occupants. Intell Buildings Int 2020; 12(3): 199–207.

121.

White

Campbell

Cheong

. Impact of poor building design and materials in overseas and off-site constructed modular buildings–A case study of an IEQ investigation into the assembly of pre-fabricated buildings in a hot and humid climate. In: AIOH 33rd Annual Conference & Exhibition, Western Australia, 2015, pp. 179–184.

122.

Kim

de Dear

. Nonlinear relationships between individual IEQ factors and overall workspace satisfaction. Building Environ 2012; 49: 33–40.

123.

Wang

Zamri

. Effect of IEQ on occupant satisfaction and study/work performance in a green educational building: a case study. In: ICCREM 2013: Construction and Operation in the Context of Sustainability, Karlsruhe, Germany, 10–11 October 2013. Published by the American Society of Civil Engineers, pp. 234–246.

124.

Bluyssen

Roda

Mandin

Fossati

Carrer

de Kluizenaar

Mihucz

V. G.

de Oliveira Fernandes

Bartzis

Self-reported health and comfort in 'modern' office buildings: first results from the European OFFICAIR study. Indoor Air 2016; 26(2): 298–317.

125.

Bluyssen

Zhang

Kurvers

Overtoom

Ortiz-Sanchez

. Self-reported health and comfort of school children in 54 classrooms of 21 Dutch school buildings. Building Environ 2018; 138: 106–123.

126.

Jian

Cao

. A new national design code for indoor air environment of sports buildings. Facilities 2006; 24(11/12): 458–464.

127.

Zhang

Ortiz

Bluyssen

. Clustering of Dutch school children based on their preferences and needs of the IEQ in classrooms. Building Environ 2019; 147: 258–266.

128.

Ortiz

Bluyssen

. Profiling office workers based on their self-reported preferences of indoor environmental quality and psychosocial comfort at their workplace during COVID-19. Building Environ 2022; 211: 108742.

129.

ASHRAE . Position document on infectious aerosols. Atlanta, GA: ASHRAE, 2020.

130.

REHVA . COVID-19 guidance document. Brussels, Belgium: REHVA, 2021.

131.

Wang

Feng

Cao

. Optimization of ventilation performance of side air supply for large indoor spaces using deflectors and slot air outlets. Indoor and Built Environment. Sage 2022; 14: 8587. DOI: 10.1177/1420326X221108587.

132.

Lin

Liu

Zhang

. Systematic summary and analysis of Chinese HVAC guidelines coping with COVID-19. Indoor Built Environ 2022; 31(5): 1176–1192.

133.

Ding

Cao

. HVAC systems for environmental control to minimize the COVID-19 infection. Indoor Built Environ 2020; 29(9): 1195–1201.

134.

Bluyssen

. All you need to know about indoor air: a simple guide for educating yourself to improve your indoor environment. Delft: Delft Academic Press, 2015.

135.

Ding

Zhang

Bluyssen

. Ventilation regimes of school classrooms against airborne transmission of infectious respiratory droplets: A review. Building Environ 2022; 207: 108484.

136.

Bluyssen

. Patterns and profiles for understanding the indoor environment and its occupants, CLIMA 2022. In: REHVA 14th world congress, Rotterdam, the Netherlands, 22–25 May 2022, paper 1504.

A review on indoor environmental quality in sports facilities: Indoor air quality and ventilation during a pandemic

Abstract

Keywords

Introduction

Methods

Results

Current standards and guidelines on IEQ in sports facilities

IAQ in sports facilities

IAQ in sports halls (schools/public)

IAQ in swimming pools

IAQ in fitness centres

Other IEQ factors in sports facilities

Thermal quality in sports facilities

Acoustical quality in sports facilities

Lighting quality in sports facilities

Interactions between the IEQ factors

Discussion

Main indicators to assess IEQ in sports facilities

Indoor air quality

Ventilation and CO2

Other IEQ factors

Building-related and occupant-related indicators

Building-related indicators

Occupant-related indicators

Ventilation and SARS-COV-2

Conclusions and recommendations

Footnotes

Author contributions

Declaration of conflicting interests

Funding

ORCID iDs

References

Ventilation and CO₂