Since the dawn of industrialization, the presence of air pollutants – due to natural and anthropogenic activities – in the biosphere has been regarded as a crucial concern (Besharatlou et al., 2021; Tajer et al., 2021; Aghaei et al., 2022; Zahed et al., 2022; Salehi et al., 2023). These pollutants are distributed and transported into the atmosphere and surface of the Earth via wind, rain, snow, to name but three, leading to irreversible, adverse effects on both environment and human beings. Air pollutants include particulate matter, gases, ultra-fine particles, and heavy metals, with some of the most common compounds being CO2, SO2, CO, NO, NO2, O3, and volatile organic compounds (Lerner et al., 2014; Waked et al., 2016; Kumar et al., 2017; Salehi and Anbia, 2017; Salehi et al., 2020; Salehi and Hosseinifard, 2021). One of the notorious groups of toxic VOCs – known as “BTEX” – is made up of four members: Benzene, Toluene, Ethyl-Benzene, and different isomers of Xylene as shown in Fig. 1 (Du et al., 2014; Masih et al., 2016; Garg and Gupta, 2019; Sjöström et al., 2019; Kuppusamy et al., 2020b; Yu et al., 2022). These hydrocarbons have high vapor pressure and are enormously found in the air as well as the soil and the water. BTEX impose carcinogenic and non-carcinogenic damages on human being along with their harmful effects on global warming and tropospheric ozone formation (Kashyap et al., 2019; Cruz et al., 2020; Turner et al., 2020; Wickliffe et al., 2020; Barul and Parent, 2021; Hanif et al., 2021). The most abundant sources of BTEX are as follows: gasoline, vehicular exhaust, anthropogenic activities, and biogenic resources endangering inhabitants of urban areas as well as workers in these industries (Alenezi and Aldaihan, 2019; Fontes et al., 2019; Dimitriou and Kassomenos, 2020; Hsieh et al., 2020; Ojimelukwe et al., 2021; Wang et al., 2021). Different petrochemical procedures and accidents happening in gas and oil extraction - such as pipeline explosions, oil spills, and crude oil deposits contribute to the BTEX release into the air, soil, and water (Tang et al., 2013; Wollin et al., 2020; Jang et al., 2021; Chen et al., 2022; Stewart et al., 2022). In addition, the solvents and chemicals – for example, Naphta – being used in petrochemical industries contain a range of different VOCs such as BTEX which evaporate easily into the air and cause pollution (Yuan et al., 2020). When the present BTEX concentration in the atmosphere raises above the limit announced by US EPA and EU, they are considered toxic and hazardous. This critical threshold for BTEX is 5 μg / m3 (Charbotel et al., 2014; Kuranchie et al., 2019). US EPA has classified these contaminants into 3 groups according to the extent of damage they impose on human life; Benzene, as a group 1 member, is a human carcinogen chemical; Ethylbenzene, as a member of group 2B, is an animal carcinogenic chemical, and Toluene as well as Xylene, as group 3 members, show non-carcinogenic negative effects. As BTEX members are small molecules showing lipophilic features which contribute to their penetration into the human body, exposure to these air pollutants happens via three principal pathways: 1. Inhalation, 2. Ingestion, and 3. Dermal penetration. Among the aforementioned pathways, inhalation is regarded as the main route. Accordingly, during the recent decade, several studies have been conducted to maintain beneficial information about BTEX level and their potential damage to the environment as well as human health. Additionally, by doing so, risk assessments in HSE systems will be more precise and efficient leading to safer and more protected workplaces.

This review article collects and summarizes relevant, existing knowledge from a wide range of interdisciplinary sources and different fields. One of the main goals of this article is to synthesize and summarize the accessible knowledge on BTEX risk assessment to obtain an overview of this topic. Moreover, by bringing together diverse sources of information, this review paper can provide valuable insights and enhance the general understanding of this topic.

The innovative aspect of this review is providing a comprehensive evaluation of BTEX levels in the biosphere, their detrimental effects on human health, and proposed strategies for managing and mitigating their impact.