## 1 Introduction  
### Literature Review  
Odorants are chemical compounds that stimulate the human olfactory system and, as a consequence, cause odour nuisance, thus affecting the comfort of life [1], the quality of work, and the health of workers [2] as well as the health of those exposed [3]. The emission of odorants is significant for people living near municipal, industrial, and agricultural facilities, which are potential sources of odorant emissions [4, 5]. Odour nuisance is one of the leading causes of environmental complaints [6, 7, 8, 9]. It generally does not threaten health and life. Still, it can be unpleasant and annoying, which is very important from the viewpoint of environmental and social indicators of the circular economy concept [10, 11, 12, 13]. People exposed to long-term odorants may experience headaches, nausea, difficulty concentrating, loss of appetite, stress, insomnia, and discomfort [14, 15, 16, 17]. Some chemical compounds, in addition to unpleasant odours, can cause adverse symptoms, diseases, and even death in human bodies. One of these compounds that make up BTEX (abbreviation for the aromatic compounds benzene, toluene, ethylbenzene, and xylene) is benzene, which is present in the environment, mainly in the air, because of emissions from traffic, the petrochemical industry, and combustion processes. The total metabolism of benzene lasts for many hours from the moment it is introduced into the body by the respiratory tract, and benzene remains in the body for a long time [18]. Benzene is one of the most used chemicals in many countries, including China [19]. Chinese medical literature is full of reports of benzene overexposure and benzene poisoning [20]. Factories, such as refineries and petrochemicals, that are part of some urban agglomerations constitute extensive industrial facilities [21]. Their functioning is associated with the emission of various types of volatile organic compounds into the atmosphere, mainly from production processes, tanks for storing products and intermediate products, and waste storage areas [22]. In the petrochemical industry, most organic compounds come from petroleum fractions, specifically from several basic hydrocarbons, such as methane, ethane, propane, benzene, toluene, and xylene [23]. The process of refining crude oil involves the physical, thermal, and chemical separation of crude oil into major distillation fractions. The primary industrial products, according to the EPA [24], are divided into three main categories:  
* Fuels (motor gasoline, diesel and distillates, liquefied petroleum gas, jet fuel, fuel oil residues, naphtha, and coke);
* Finished non-fuel products (solvents, lubricating oils, greases, kerosene wax, jelly, asphalt, and coke);
* Chemical raw materials (diesel, ethane, propane, butane, ethylene, propylene, butylene, butadiene, butadiene, toluene, xylene). The sources of emissions at refineries are leakage, combustion of fuels in process heaters, and all other refinery processes [24]. In addition to VOC emissions, oil refineries are also a source of emissions of such compounds as sulphur dioxide, reduced sulphur compounds, hydrogen sulphide, thiols, carbon monoxide and nitrogen oxides, as well as particulate matter [25]. In their work, [PERSON] et al. [26] proposed and developed a modelling system based on multi-source detection of air pollution in a transport agglomeration and its heterogeneous features, which can be used to monitor air condition. Research on odour nuisance shows that people's adverse reactions to odours in their surroundings are a very complex problem. This is related to factors such as residents' current state of health, environmental commitment, and social activity [27; 28; 29]. To mitigate the negative impact of potential odour nuisances on the urban environment, it is necessary to reliably assess odour emissions and determine their size and long-term effects [30]. Despite advances in assessment techniques [31; 32; 33] and studies on strategies to minimise odour emissions [34; 35], this issue remains unresolved.