# Air Quality as a Key Factor in the Aromatisation of Stores: A Systematic Literature Review
## 3 Results and Discussion
### Indoor Air Health Risk Substances in Stores

Table 1: Chemical compounds in the air in buildings, their sources and their potential health effects [2]. o-xylene, 1,1,1-trichloroethane, p-dichlorobenzene, 1,2,4-trimethylbenzene and p-xylene, undecane, 1,3,5-trimethylbenzene, dichloroethane and trichloroethane [2, 5, 6, 8, 11, 40, 41]. In 2010, the World Health Federation published WHO guidelines for indoor air quality selected pollutants in which the individual substances are discussed in more detail. The substances considered in this review, i.e., benzene, carbon monoxide, formaldehyde, naphthalene, nitrogen dioxide, polycyclic aromatic hydrocarbons (especially benzo[a]pyrene), radon, trichloroethylene and tetrachloroethylene, have indoor sources, are known for their hazardous to health and are often found indoors in concentrations large enough for health concerns [41]. Fifteen years after the publication of [PERSON]'s work, another review was published by [PERSON] et al., who focused on the effect of ventilation on the air quality in retail stores [42]. The authors first described the methodology and databases they used for the review. They went through databases such as the ISI Web of science, Compendex and Science Direct and, also, government reports and Google Scholar. They chose the most-known pollutants as keywords and words like retail, mall, shopping, supermarkets, stores and so on. The authors went through more than 110 papers and chose 28 with the most important information connected to measurements in retail spaces. They also discussed some ANSI/ASHRAE Standards, which are the recognised standards for ventilation system design and acceptable indoor air quality (IAQ). The standards specify the minimum ventilation rates and other measures in order to minimise adverse health effects in the occupants. One part of the study was devoted to individual substances (see Table 2). In the second part, they compared the health impact from exposure to VOCs and discussed the individual concentrations found in the works. In another, they discussed substances such as ozone, radon, fungi and bacteria. In the discussion and conclusion of the paper, they summarised their findings: half of the stores exceeded the recommended standards for acrolein, formaldehyde, acetaldehyde, benzene and trichloroethylene. They pointed to acrolein and PM2.5 as potential risks [42]. Over the past two decades, numerous field studies on indoor air quality and Sick Building Syndrome (SBS) have been conducted. The symptoms of SBS are usually nonspecific and are often somewhat particular to the building being occupied by the workers. In their work, the Chinese authors looked at the link between the temperatures in shops in selected large cities in the west of China in relation to the concentrations of carbon dioxide, formaldehyde and total volatile organic compounds (TVOC). They also did a survey of the employees who worked at the stores to see if there were links between the air quality and SBS. This syndrome has been associated with headaches, tearing and other medical conditions. It turns out that, in large stores such as shopping malls, these symptoms can occur and accumulate. In the summer, the values for some substances are higher and vary between shopping malls. [43]. [PERSON] et al. [44] studied the air in Hong Kong, which is said to be one of the most attractive shopping paradises in the world. Good indoor air quality is, therefore, very essential to shoppers. In order to characterise the indoor air quality in shopping malls, nine shopping