Pregnant women who live in city neighborhoods with more grass and trees were exposed to lower levels of particulate air pollution than pregnant women with little vegetation around their homes, according to a study from Barcelona, Spain. Exposures were lower even when the women spent more time outside. The conclusions are important because exposure to traffic-related air pollution during pregnancy can affect fetal development and health at birth. These can include low birth weight, heart deformities, and infant mortality.
To investigate the connection between green space and exposure, researchers compared vegetation surrounding the homes of 54 pregnant women with their personal exposure to two traffic-related air pollutants. Satellite images were used to calculate the amount of surrounding vegetation, including grass, bushes, and trees.
For up to a week, the women wore small devices that measured nitric oxides and particulate matter less than 2.5 micrometers in diameter (PM2.5). The two pollutants were also measured in specific locations inside and outside the homes. Participants recorded their location and activities in a diary.
As green space surrounding the home increased, exposure to PM2.5 pollution decreased. Lower exposure levels could be due to the lower home indoor PM2.5 levels in greener areas, considering that participants spent an average of 73 percent of their time at home. Additionally, women with more green space nearby spent more time outside — an average of twelve minutes more per day — where the pollution levels were lower than indoors. Nitric oxides showed similar but weaker results.
The use of personal monitors to measure air pollution was a strength of this study. But the method for identifying green space did not distinguish among types of vegetation — for example, trees versus grasses. Trees are known to reduce air pollutants more than grasses or small plants.
Overall, the results suggest having green space around homes can cut exposures to air pollution and provide benefits to residents' health.
This post was originally published by EnvironmentalHealthNews.org