The impact of interaction between particulate matter and sunlight duration on neonatal hyperbilirubinemia

• The interactive effect of PMs and sunlight exposure on NHB were first revealed. • Personal daily exposure of PMs was better evaluated by satellite-based model. • NHB risk was linked to PM 2.5-10 and PM 10 during late pregnancy, but not to PM 2.5 . • NHB risk was associated with reduced sunlight exposure during late pregnancy. • PMs interact with reduced sunlight exposure during 3 rd trimester on NHB occurrence. While the associations among particulate matters (PMs) exposure and neonatal hyperbilirubinemia (NHB) have been studied, the potential protective effect role of perinatal sunlight exposure and its interaction with PMs on NHB remains unclear. Thus, we designed this study to investigate the impact of maternal PMs exposure and sunlight duration on NHB. We included 155,970 pregnant women and their singleton newborns (without ABO hemolytic disease) from two major obstetric hospitals in Shanghai (2013–2020). Generalized linear models were used to evaluate the effects of PM 2.5 , PM 10 , and PM 2.5-10 , daily sunlight duration, and their interactive effects on NHB during different periods throughout the pregnancy. Our findings reveal that the risk of NHB was associated with increased exposure levels of PM 2.5-10 (aOR: 1.081; 95%CI: 1.022, 1.144) and PM 10 (aOR: 1.046; 95%CI: 1.018, 1.074) and decreased sunlight duration (aOR: 0.900; 95%CI: 0.870, 0.932) during the 3 rd trimester. While NHB was not directly linked to PM 2.5 exposure alone (aOR: 1.025, 95%CI: 0.988, 1.063), we identified a significant interaction between reduced sunlight duration and increased PM 2.5 exposure during the 3 rd trimester (P for interaction