The relationship between greenness and birthweight may differ by ethnicity and socioeconomic statusDadvand and colleagues examined data from 10,780 births in the United Kingdom between 2007-2010 to assess if a relationship exists between neighborhood greenness or proximity to green space and birth weight. The study examined greenness in concentric circles (buffer zones) around mothers' homes at the time of birth from satellite images (the Normalized Difference Vegetation Index). Proximity to green space was defined as living within 300m of a green space of at least 5000m in size. Birth weights were gathered from medical records and other data was collected from questionnaires the mothers had completed previously. Overall the study found that increased greenness around a mother’s home at the time she gives birth is associated with increased birth weight. However, distance from green spaces did not seem to affect birth weight. These results are consistent with those from other recent studies.
The authors also found that ethnicity and socioeconomic status (SES) might modify the relationship between greenness and birth weight. When the data was analyzed by ethnicity the association was true for White British participants but not for those of Pakistani origin. While other ethnicities were represented in the study there were not enough participants of each of the other ethnic groups (Indian, Asian, White-other, black African, mixed, other) to determine if an effect exists for each of those groups. However, the data from this study suggests the effect may vary by ethnicity and that further research is needed. The authors suggest a possible explanation for the ethnicity findings - ethnic minorities have been shown to make less use of green spaces. The authors also found a possible stronger effect for participants of lower education level and those living in more deprived neighborhoods for the larger buffer zones but not the smaller buffer sizes.
The authors suggest that these results could be used to support policy changes regarding urban green space development. Based on evidence from other studies, they suggest that individuals with lower SES tend to have worse health outcomes and give birth to children with lower birth weights while living in areas with more environmental problems and less green space. Therefore, targeted interventions that seek to increase green space might be most effective in increasing birth weight in disadvantaged neighborhoods. The authors of this study conclude that their results, while not conclusive, should be considered in future policies regarding urban green space and interventions to increase birth weight. In addition, the results could be used to help target interventions to increase birth weight by ethnicity and SES.
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