Effects of Ambient Air Pollution on Precocious Puberty: A Case-Crossover Analysis in Nanjing, China.

Background: Ambient air pollution is closely related to a variety of health outcomes. Few studies have focused on the correlations between air pollution exposure and children's sexual development. In this study, we investigated the potential effects of exposure to air pollution on precocious puberty among children using real-world evidence.

Methods: We conducted a case-crossover study (n = 2201) to investigate the effect of ambient air pollution exposure on precocious puberty from January 2016 to December 2021. Average exposure levels of PM, PM, SO, NO, CO, and O before diagnosis were calculated by using the inverse distance weighting (IDW) method. Distributed lag nonlinear model (DLNM) was used to assess the effect of air pollutants exposure on precocious puberty.

Results: The mean age of the children who were diagnosed with precocious puberty was 7.47 ± 1.24 years. The average concentration of PM and PM were 38.81 ± 26.36 μg/m and 69.77 ± 41.07 μg/m, respectively. We found that exposure to high concentrations of PM and PM might increase the risk of precocious puberty using the DLNM model adjusted for the age, SO, NO, CO, and O levels. The strongest effects of the PM and PM on precocious puberty were observed in lag 27 (OR = 1.72, 95% CI: 1.01-2.92) and lag 16 (OR = 1.95, 95% CI: 1.33-2.85), respectively.

Conclusion: Our findings supported that short-term exposure to air pollution was the risk factor for precocious puberty. Every effort should be made to protect children from air pollution.