Exposure to air pollution and precocious puberty: a systematic review

<strong>Objectives: </strong>The worldwide incidence of precocious puberty is increasing, associated with negative health outcomes. Several studies have suggested that environmental factors contribute to the development of precocious puberty alongside genetic factors. Some epidemiological studies provide limited evidence suggesting an association between exposure to air pollution and changes in pubertal development. This systematic review aimed the association between air pollution exposure and precocious puberty. <strong>Methods: </strong>Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, we searched two databases, including PubMed, and Web of Science until August 2023. Included studies assessed the association between air pollutant exposure and the risk of precocious puberty, early menarche, or pubertal development. Two authors independently performed the study selection and data extraction. Meta-analysis and analysis of the risk of bias were infeasible due to limited number of studies and the heterogeneity among them. <strong>Results: </strong>The literature search resulted in 184 studies, and we included 6 studies with sample sizes ranging from 437 to 4,074 participants. The outcomes of the studies were heterogeneous. Four studies showed that increased exposure to air pollution was related to earlier pubertal onset. One study was inconclusive, and another suggested air pollutant exposure delays the onset of thelarche.  <strong>Conclusion: </strong>Majority of the studies suggest that exposure to air pollutants accelerates pubertal development; however, the results from the available studies are inconsistent. More extensive and well-designed longitudinal studies are required for a comprehensive understanding of the association between air pollution and precocious puberty.