HealthDay News — Women exposed to air pollution deliver babies with lower birth weights; however, women living in greener areas give birth to larger babies, which may help counteract the negative effects of air pollution on birth weight, according to a study presented at the European Respiratory Society International Congress 2023, held from Sept. 9 to 13 in Milan. The researchers found that higher levels of air pollution were linked to lower birth weights. Specifically, particulate matter (PM 2.5 and PM 10 ), nitrogen dioxide, and black carbon were associated with average reductions in birth weight of 56, 46, 48, and 48 g, respectively. However, when accounting for greenness, the effect of air pollution on birth weight was reduced. Compared with mothers living in less green areas, women who lived in greener areas had babies with slightly higher birth weights (27 g heavier on average).