Background Exposome research aims to describe and understand the extent to which all the exposures in human environments may affect our health over the lifetime. However, the way in which humans interact with their environment is socially patterned. Therefore, including social factors in research exploring the exposome is fundamental and may contribute to understand health inequalities. The objective of the present work is to describe the extent to which social factors appear in the exposome literature, the manner in which they are used in empirical analyses and statistical modelling and the way in which they are considered in the overall scientific approach.

Methods We conducted a scoping review of the literature using three databases (PubMed, Embase and Web of Science) up to June 2021. We grouped studies based on the way in which the social variables were used in the analyses and quantified the type and frequency of social variables mentioned in the articles. We also qualitatively described the scientific approach used by authors to integrate social variables.

Results We screened 882 records and 63 studies were included in the analysis. Around 75% used social variables as exposures and/or confounders and a wide array of social variables were represented in the articles. Individual-level social variables were more often found, especially education and race/ethnicity, as well as neighbourhood-level deprivation indices. Half of the studies used a hypothesis-free approach and the other half, a hypothesis-driven approach. However, in the latter group, out of thirty-one studies, only six studies reported and discussed at least one possible social mechanism underlying the relationship observed between the social variable and the outcome.

Discussion The present scoping review established the small but growing role of social variables in recent exposome science. However, the role of these social variables is not always made explicit, and their use is often not placed within the context of an appropriate body of literature on the social determinants of health. Social factors in exposome research should be considered in a more systematic way considering their role in structuring other exposures.