Today, in our environmental science lecture, we'll discuss the impact of urban green spaces on air quality. A recent study in Melbourne measured pollutant levels in parks versus busy streets. The results showed that trees can reduce particulate matter by up to 30% within a 50-meter radius. However, the effect depends on tree species; broadleaf trees are more effective than conifers because they have larger surface areas for capturing particles. The study also found that wind direction plays a crucial role. When wind blows from industrial areas, the benefit decreases significantly. Therefore, city planners should consider wind patterns when designing green corridors.