Mapping the Level of Evidence of Prenatal, Childhood, and Adolescent Exposure to Volatile Organic Compounds and Health Outcomes: Protocol for a Scoping Review

Abstract

Background: Volatile organic compounds (VOCs) are a diverse group of organic chemicals with widespread presence in daily life. VOCs may have detrimental health effects on humans, particularly during critical periods such as pregnancy, childhood, and adolescence. Although the body of evidence is growing, significant gaps remain in the current understanding of the associations of VOCs on health across these developmental stages. Moreover, existing reviews focused on specific VOCs or individual health conditions, highlighting the need for a comprehensive summary of the current literature to stimulate further research.

Objective: This ongoing scoping review aims to map the current evidence concerning exposure to VOCs and their associations with pregnancy outcomes and health during pregnancy, childhood, and adolescence.

Methods: This review will consider studies investigating potential health effects related to exposures to either total VOCs or any of the following 6 specific VOCs: benzene, toluene, ethylbenzene, xylene, trichloroethylene, and tetrachloroethylene or perchloroethylene during critical windows from pregnancy through adolescence. Original articles published in English from January 1, 2000, through the end of the scoping review period, will be included. We will follow the Joanna Briggs Institute methodology for scoping reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The literature search will use the Ovid MEDLINE, Embase, and Web of Science databases to identify relevant citations. The following steps of the review will be managed through the Covidence platform. A total of 2 reviewers will independently conduct a rapid screening of paper titles, before evaluating the abstracts and full texts to determine which articles will proceed to the data extraction stage. In case of discrepancies during these steps, the reviewers will discuss to reach a consensus, and a third reviewer may intervene if needed. Reviewers will provide commentaries on their findings from the included studies and suggest areas of interest for future studies.

Results: The literature search yielded a total of 7332 citations published during the period January 1, 2000, to July 25, 2024. After the title screening and reading the abstract and full text, 274 papers were selected for the data extraction phase, which is currently underway. Upon completion of the library's updated literature search, covering July 26, 2024, to the present, we will proceed with data analysis and manuscript writing for submission to a peer-reviewed journal.

Conclusions: The results are expected to summarize the current state of knowledge on the association of VOCs with health at critical life stages (pregnancy, childhood, and adolescence). We anticipate identifying gaps in the literature as well that could guide future research priorities.

Trial registration: OSF Registries 10.17605/OSF.IO/EP73G; https://osf.io/ep73g.

International registered report identifier (irrid): DERR1-10.2196/71587.

Keywords: BTEX; PCE; TVOCs; VOCs; benzene; child health; environmental health; ethylbenzene; human (0 to 18 years); perchloroethylene; pregnancy outcomes; tetrachloroethylene; toluene; trichloroethylene; xylene.