Effects of Prenatal Polycyclic Aromatic Hydrocarbon Exposure on Neonatal Outcomes—MLR and BKMR Models

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental pollutants that pose a potentially serious threat to maternal and infant health, yet there are few studies on low-dose maternal and infant health. Therefore, this study investigated 2566 mother–infant pairs in Zunyi rural area, southwest China, and used multiple linear regression (MLR) and Bayesian kernel machine regression (BKMR) to reveal the relationship between pre-pregnancy PAHs exposures and neonatal birth outcomes. The results showed that more than 75% of the PAHs metabolite concentrations were above the limit of detection, and the main exposure was to 2-OHNAP (2. 9379 µg/L).The results of the MLR showed that, in both the original and adjusted models, 9-OHFLU and 4-OHPH were associated with lower birth weight, corresponding to β (95% CI) of − 36.684 (− 7.580, − 65.788), − 76.931 (− 22.524, − 131. 338), − 33.254 (− 4.628, − 61.879) and − 65.490 (− 12.073, − 118.906) (95%). 9-OHFLU was associated with loss of birth length, corresponding to β (95% CI) of − 0.094 (− 0.013, − 0.176) and − 0.084 (− 0.003, − 0.164). 9-OHFLU and 4-OHPH were associated with decreased neonatal BMI, corresponding to β (95%) CI) of − 0.104 (− 0.006, − 0.202) and − 0.323 (− 0.139, − 0.507), respectively. The results of the BKMR model showed that in the original model, 1-OHNAP, 1-OHPYR and total PAHs were negatively correlated with birth weight, with the corresponding PIP value of 0.0008, and that, after adjusting the model, total PAHs and 2-0HPH were negatively correlated with birth weight and birth BMI, corresponding to PIP values of 0.0232 and 0.0316, and total PAHs levels were negatively correlated with birth length. In conclusion, exposure of pregnant women to PAHs during pregnancy can have a negative impact on the birth outcomes of their newborns. Therefore, it is recommended that pregnant women with potentially adverse pregnancy outcomes, especially those suffering from gestational malnutrition, pre-eclampsia, or who are substance abusers, should reduce or avoid exposure to PAHs.