Satellite-derived air pollution exposure during pregnancy and preterm birth in South-West Oltenia

Background

Air pollution monitoring remains limited in many regions due to the uneven distribution of ground-based stations. Satellite data from the Copernicus Sentinel-5P mission provide continuous measurements of atmospheric pollutants and allow improved population-level exposure assessment. This study aimed to evaluate the association between satellite-derived air pollution exposure during pregnancy and preterm birth in South-West Oltenia.

Methods

We built a regional dataset of atmospheric pollutants (2019–2023) at administrative unit level. Daily satellite data were processed and summary statistics (minimum, maximum, mean) for each pollutant were computed. For this analysis, NO₂ and O₃ were used. Exposure was defined as the number of months within the 9 months preceding birth in which concentrations exceeded the area-specific mean (>2 to > 6 months), for both mean and maximum values. Birth data from a regional tertiary hospital included 11,945 live births, of which 995 were preterm. Proportions were compared across exposure categories and odds ratios (OR) were estimated.

Results

Preterm births consistently showed higher exposure to months with pollutant levels above local baseline values. For mean NO₂ values above the local average for >2 months, 51% of preterm births were exposed versus 46% of all births (OR = 1.19). For maximum values, the association was stronger (59% vs. 54%; OR = 1.25). Stronger associations were observed for O₃, where 75% of preterm births were exposed compared to 66% of all births (OR≈1.55).

Conclusions

Satellite-derived data provide a practical way to assess cumulative exposure to air pollution during pregnancy. Higher exposure was consistently associated with preterm birth, with stronger signals for O₃, suggesting the value of multi-pollutant approaches in future studies. This findings support the integration of satellite-based monitoring into environmental health surveillance in regions with limited ground infrastructure.

Key messages

• Satellite data can support exposure assessment during pregnancy in regions with limited monitoring.

• Higher air pollution exposure, particularly NO2 and O₃, was associated with preterm birth.