Prenatal exposure to ozone and bone mineral density in early childhood: Susceptible window identification

Area of Science:

• Environmental Epidemiology
• Pediatric Health
• Bone Metabolism

Background:

• The impact of prenatal exposure to air pollutants like ozone on early childhood bone mineral density (BMD) is not well understood.
• Investigating this relationship is crucial for understanding environmental influences on pediatric bone development.

Purpose of the Study:

• To examine the association between prenatal ozone exposure and bone mineral density (BMD) in early childhood.
• To identify specific sensitive windows during pregnancy for ozone exposure effects on BMD.

Main Methods:

• Utilized data from the Fujian Birth Cohort Study, including 1345 mother-offspring pairs.
• Calculated mean ozone exposure for the entire pregnancy, trimesters, and gestational weeks.
• Assessed BMD using quantitative ultrasonography (QUS) and defined low BMD as a z-score less than -1.
• Employed linear, logistic regression, and distributed lag models (DLMs) to analyze exposure-outcome relationships and identify sensitive windows.

Main Results:

• Prenatal ozone exposure was inversely associated with childhood BMD z-scores across different exposure durations.
• An interquartile range (IQR) increase in ozone exposure was linked to decreased BMD z-scores.
• Second-trimester ozone exposure showed a significant association with an increased odds of low BMD (OR=1.47).
• The most sensitive windows for negative effects on BMD z-scores and low BMD were identified in early to mid-pregnancy (gestational weeks 9-16 and 15-17, respectively).

Conclusions:

• Prenatal ozone exposure negatively impacts bone mineral density (BMD) in early childhood.
• Early to mid-pregnancy (first and second trimesters) represents a susceptible period for ozone exposure effects on fetal bone development.
• Findings highlight the importance of air quality during pregnancy for long-term bone health in offspring.