_applied sciences_  
_Article_  
Variability of Air Pollutants in the Indoor Air of a General Store  
[PERSON] 1, [PERSON] 2\({}^{\copyright}\), [PERSON] 3, [PERSON] 2\({}^{\copyright}\), [PERSON] 1,2,  
[PERSON] 1\({}^{\copyright}\) and [PERSON] 1\({}^{\copyright,2,*}\)\({}^{\copyright}\)  
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Footnote 23: [[https://www.mdpi.com/journals/applsci](https://www.mdpi.com/journals/applsci)]([https://www.mdpi.com/journals/applsci](https://www.mdpi.com/journals/applsci))  
Footnote 24: [[https://www.mdpi.com/journals](https://www.mdpi.com/journals)]([https://www.mdpi.com/journals](https://www.mdpi.com/journals))spend so much time inside, indoor air quality (IAQ) significantly impacts human health and has received a great deal of attention in recent decades [7; 8; 9; 10; 11; 12; 13]. Indoor environments expose individuals to a range of air pollutants, including various size fractions of particulate matter (PM1, PM2.5, PM10) and gaseous pollutants such as carbon monoxide (CO), carbon dioxide (CO\({}_{2}\)), nitrogen dioxide (NO\({}_{2}\)), ozone (O\({}_{3}\)), sulfur dioxide (SO\({}_{2}\)), and volatile organic compounds (VOCs). The origins of these pollutants can be diverse, stemming from sources like smoking, cooking, building materials, furnishings, space heaters, pesticides, personal care products, office equipment, cleaning products, and paints. Additionally, outdoor pollutants can infiltrate indoor spaces through ventilation [14; 15; 16]. Formaldehyde is emitted by carpets, pressed wood products, building materials, and consumer items. It is produced as a byproduct of indoor secondary chemical processes, and larger quantities have been discovered in offices and retail establishments at a level of 28.5 ug/m\({}^{3}\)[17]. The levels of formaldehyde in indoor air are contingent on factors such as the ratio of product surface to air volume, the product's nature, temperature, product age, relative humidity, and emission rates [18; 19]. Formaldehyde air levels found in homes ranged from 9.7 to 47.7 ug/m\({}^{3}\), while outside, the concentrations ranged from 0.96 to 3.37 ug/m\({}^{3}\)[20]. Formaldehyde levels inside newly renovated homes in China averaged 153 g/m\({}^{3}\) from 2011 to 2015 [21]. Formaldehyde can irritate the eyes, sinuses, and mouth, even at low concentrations [22; 23]. Formaldehyde can affect respiratory function and produce skin rashes at higher concentrations [24]. Elevated concentrations of 2-butoxyethanol, D-limonene, and toluene were likewise identified in general stores across the United States, corresponding to sources like cleaning, polishing, and waxing agents, as well as adhesives, paints, and compounds containing solvents [17]. The quantities of volatile organic compounds (VOCs) within retail establishments are significantly higher than those in typical microenvironments such as homes, workplaces, and even cars [25; 26]. An investigation of total volatile organic compounds (TVOCs) concentrations in 32 different retail stores in the Greater Memphis Area, Tennessee, U.S.A. showed that store-level TVOC concentrations ranged from 30 to 869 ug/m\({}^{3}\)[25]. Evidence of cross-contamination between adjacent establishments and a noticeable variation in BTEX concentrations were detected in Chinese and New Jersey retail malls [27; 28]. VOC concentrations can differ by three orders of magnitude between retailers, according to measurements taken in fourteen outlets in Texas and Pennsylvania [29]. Long-term exposure to some VOCs is believed to cause health issues for people, including the chance of cancer, whereas short-term exposure to low VOC concentrations often does not affect most individuals [30; 31]. Particulate matter in indoor air refers to tiny particles that are suspended in the air and can be inhaled by people indoors. These particles can come from various sources, including dust, pet dander, pollen, smoke, and fumes from cooking or burning fuel.