Exposure to BTEX concentrations in different indoor microenvironments: Emphasis on different times of the year.

Climatic variations in indoor environments may change concentration patterns. This systematic review and meta-analysis study aimed to investigate exposure to benzene, toluene, ethylbenzene, and xylene (s) (BTEX) concentrations in different indoor microenvironments with emphasis on different times of the year. A systematic review in five bibliographic databases (Scopus, PubMed, Web of Science, Embase, and Medline) was conducted. Adhering to PRISMA guidelines, the search utilized four groups of keywords. The pooled indoor exposure to BTEX under different climatic conditions were estimated using a random-effects model. Among 64 selected articles, the greatest percentage of studies with the highest indoor exposure for BTEX in vehicles and transportation areas was in summer. The highest percentage of these studies at home was in winter. The highest percentage of these studies in educational and sport centers was in winter and summer. In the vehicles and transportation areas, the pooled concentration (µg/m3) of benzene, toluene, ethylbenzene, and xylene(s) were calculated as 29.12, 102.33, 19.24, and 22.73 in summer, respectively. In the homes and sites, the pooled concentration (µg/m3) of benzene, toluene, ethylbenzene, and xylene(s) were measured as 6.39, 22.06, 6.21, and 11.33 in winter, respectively. In the educational and sport centers, the pooled concentration (µg/m3) of benzene, toluene, ethylbenzene, and xylene(s) were calculated as 3.15, 11.09, 5.55, and 5.63 in summer and 2.97, 8.09, 4.16, and 5.49 in winter, respectively. The results of this study introduce the seasons with the greatest concentrations of BTEX in different indoor environments.